Spinal cord disorders can lead to motor, sensory, or sphincter disturbances, or to some combination of these deficits. Depending on whether it is unilateral or bilateral, a lesion above C5 may cause an ipsilateral hemiparesis or quadriparesis. With lesions lower in the cervical spinal cord, involvement of the upper limbs is partial, and a lesion below T1 affects only the lower limbs on one or both sides. Disturbances of sensation are considered in detail in Chapter 10, Sensory Disorders, but unilateral involvement of the posterior columns of the cord leads to ipsilateral loss of position and vibration sense. Involvement of the spinothalamic tracts in the anterolateral columns impairs contralateral pain and temperature appreciation below the level of the lesion.
Spasticity is a common accompaniment of upper motor neuron lesions and may be especially troublesome below the level of a myelopathy. When the legs are weak, the increased tone of spasticity may help to support the patient in the upright position. Marked spasticity, however, may lead to deformity, interfere with toilet functions, and cause painful flexor or extensor spasms. Pharmacologic management includes treatment with diazepam, baclofen, dantrolene, or tizanidine, as discussed later under Traumatic Myelopathy, but reduction in tone may increase disability from underlying leg weakness.
Although spinal cord damage may result from whiplash (recoil) injury, severe injury to the cord usually relates to fracture-dislocation in the cervical, lower thoracic, or upper lumbar region, which is commonly associated with local pain. Concomitant cerebral and systemic injuries may complicate evaluation. The most common site for traumatic spinal cord injury is in the cervical region.
Total transection results in immediate permanent paralysis and loss of sensation below the level of the lesion. Reflex activity is lost for a variable period, but then increases.
In the acute stage (“spinal shock”), there is flaccid paralysis with loss of tendon and other reflexes, accompanied by sensory loss and by urinary and fecal retention.
Over the following weeks, as reflex function returns, a spastic paraplegia or quadriplegia emerges, with brisk tendon reflexes and extensor plantar responses; however, a flaccid, atrophic (lower motor neuron) paralysis may affect muscles innervated by spinal cord segments at the level of the lesion, where anterior horn cells are damaged. Sensation is reduced at that level and lost below it. The bladder and bowel regain some reflex function, so that urine and feces are expelled at intervals.
Flexor or extensor spasms of the legs may become increasingly troublesome and are ultimately elicited by even the slightest cutaneous stimulus, especially in the presence of bedsores or a urinary tract infection. Eventually, the patient assumes a posture with the legs in flexion or extension, the former being especially likely with cervical or complete cord lesions.
With lesser injury, the neurologic deficit is less severe, but patients may be left with a mild paraparesis or quadriparesis and/or a distal sensory disturbance. Sphincter function may also be impaired—urinary urgency and urgency incontinence are especially common. Hyperextension injuries of the neck can lead to focal cord ischemia that causes bibrachial paresis (weakness of both arms) with sparing of the legs and variable sensory signs.
Plain radiographs will reveal misalignments, fractures, and soft tissue swelling, but CT scanning is more sensitive for detecting spinal fractures, especially in the cervical region, and also allows evaluation of the spinal cord. It is therefore preferred in the acute setting. Spinal MRI provides complementary information about the extent and nature of any spinal cord injury and the presence of an epidural hematoma, which is important for treatment and prognosis.
Immobilization, Decompression, & Stabilization
Initial treatment consists of immobilization until the nature and extent of the injury are determined. Injury of the spinal cord should be assumed in patients with head injuries until excluded by imaging studies. If there is cord compression, urgent decompressive surgery will be necessary. An unstable spine may require surgical fixation, and vertebral dislocation may necessitate spinal traction.
A clear airway must be ensured and the circulation, blood pressure, and ventilation maintained. Tracheostomy may be required. Respiratory complications such as pneumonia, atelectasis, and pulmonary embolism must be treated vigorously. Prophylaxis for deep venous thrombosis with low-molecular-weight heparin is important.
It is doubtful whether corticosteroids (eg, methylprednisolone 30 mg/kg by intravenous bolus followed by intravenous infusion at 5.4 mg/kg/h for 24 hours), once thought to improve function at 6 months when begun within 8 hours of traumatic spinal cord injury, have any significant beneficial effects.
Treatment of Painful Spasms
Painful flexor or extensor spasms can be treated with drugs that enhance spinal inhibitory mechanisms (baclofen, diazepam) or uncouple muscle excitation from contraction (dantrolene). Baclofen is started with 5 mg orally twice daily, increasing up to 30 mg four times daily; diazepam, 2 mg orally twice daily up to as high as 20 mg three times daily; and dantrolene, 25 mg/d orally to 100 mg four times daily. Tizanidine, a central α2-adrenergic receptor agonist, may also be helpful by increasing presynaptic inhibition and reducing alpha motoneuron excitability. The daily dose is built up gradually, usually to 8 mg three times daily. Side effects include dryness of the mouth, somnolence, and hypotension, but the drug is usually well tolerated. Patients who fail to benefit from or who cannot tolerate sufficient doses of oral medications may respond to intrathecal infusion of baclofen.
All these drugs may increase functional disability by reducing tone. Dantrolene may also increase weakness and should be avoided in patients with severely compromised respiratory function.
Skin care is important; continued pressure on any single area must be avoided.
Bladder & Bowel Disorders
Depending on the severity of injury, catheterization may be necessary initially. Subsequently, the urgency and frequency of the spastic bladder may respond to a parasympatholytic drug such as oxybutynin, 5 mg three times daily. Suppositories and enemas will help maintain regular bowel movements and may prevent or control fecal incontinence.
Experimental work has focused recently on enhancing axonal regeneration in the damaged section of the spinal cord through such approaches as neutralization of neurite regrowth inhibitors, use of neurotrophic or growth factors, implantation of synthetic axonal guidance channels, and cellular therapies. Translational application to patients with spinal cord injuries is possible in the near future.
There is a significant mortality after spinal cord injury, and this is highest in those with cervical injuries, associated head injury, cardiovascular or respiratory inadequacy, and coexisting disorders. The greatest improvement is seen in those with incomplete injury, with most recovery occurring in the first few months.
PM. Traumatic myelopathy: current concepts in imaging. Semin Musculoskelet Radiol. 2014;18:318–331.
MG. Emerging therapies for acute traumatic spinal cord injury. CMAJ. 2013;185: 485–492.
Multiple sclerosis is one of the most common neurologic disorders, affecting approximately 300,000 patients in the United States, and its highest incidence is in young adults. It is defined clinically by the involvement of different parts of the central nervous system at different times—provided that other disorders causing multifocal central dysfunction have been excluded. Initial symptoms generally commence before the age of 55 years, with a peak incidence between ages 20 and 40 years; women are affected nearly twice as often as men.
Epidemiologic studies show that the prevalence of the disease rises with increasing distance from the equator, and no population with a high risk for the disease exists between latitudes 40°N and 40°S. Vitamin D level may also play a role as may exposure to Epstein-Barr virus. A genetic predisposition is suggested by twin studies, the occasional familial occurrence, and the strong association between the disease and specific HLA alleles. Alleles of IL2RA (interleukin-2 receptor α gene) and IL7RA (interleukin-7 receptor α gene) have also been proposed as heritable risk factors. Present evidence suggests that the disease has an autoimmune basis.
The disorder is characterized pathologically by the development of focal—often perivenular—scattered areas of demyelination, together with reactive gliosis, axonal damage, and neuronal degeneration. These lesions occur in both white and gray matter of the brain and spinal cord and in the optic (II) nerve.
The cause of multiple sclerosis is unknown, but tissue damage and neurologic symptoms are thought to be triggered by an immune mechanism directed against myelin antigens. Viral infection or other inciting factors may promote the entry of T cells and antibodies into the central nervous system by disrupting the blood–brain barrier. This leads to increased expression of cell-adhesion molecules, matrix metalloproteinases, and proinflammatory cytokines. These molecules work in concert to attract additional immune cells, break down the extracellular matrix to aid their migration, and activate autoimmune responses against several antigens (eg, myelin basic protein, myelin-associated glycoprotein, myelin oligodendrocyte glycoprotein, proteolipid protein, α B-crystallin, phosphodiesterases, and S-100). Binding of these target antigens by antigen-presenting cells triggers an autoimmune response that may involve cytokines, macrophages, and complement. Immune attack on myelin denudes axons, which slows nerve conduction. Together with loss of axons and nerve cell bodies, this leads to progressive neurologic symptoms.
Initial or presenting symptoms—Patients can present with any of a variety of symptoms (Table 9-8). Common initial complaints are focal weakness, numbness, tingling, or unsteadiness in a limb; sudden loss or blurring of vision in one eye (optic neuritis); diplopia; disequilibrium; or a bladder-function disturbance (urinary urgency or hesitancy). Symptoms are often transient, disappearing after a few days or weeks, even though some residual deficit may be found on neurologic examination. Other patients present with an acute or gradually progressive spastic paraparesis and sensory deficit; this should raise concern about the possibility of an underlying structural lesion unless there is evidence on clinical examination of more widespread disease.
Subsequent course—Months or years may elapse after the initial episode before further symptoms appear. Then, either new symptoms develop or the original ones recur and progress. Relapses may be triggered by infection and, in women, are more likely in the 3 months or so after childbirth (but are reduced during the pregnancy itself). A rise in body temperature can cause transient deterioration in patients with a fixed and stable deficit (Uhthoff phenomenon). With time—and after a number of relapses and usually incomplete remissions—the patient may become increasingly disabled by weakness, stiffness, sensory disturbances, unsteadiness of the limbs, impaired vision, and urinary incontinence.
Table 9-8.Symptoms and Signs of Multiple Sclerosis. |Favorite Table|Download (.pdf) Table 9-8. Symptoms and Signs of Multiple Sclerosis.
| ||Percentage of Patients |
|Symptoms (at presentation) || |
|Paresthesia ||37 |
|Gait disorder ||35 |
|Lower extremity weakness or incoordination ||17 |
|Visual loss ||15 |
|Upper extremity weakness or incoordination ||10 |
|Diplopia ||10 |
|Signs || |
|Absent abdominal reflexes ||81 |
|Hyperreflexia ||76 |
|Lower extremity ataxia ||57 |
|Extensor plantar responses ||54 |
|Impaired rapid alternating movements ||49 |
|Impaired vibratory sense ||47 |
|Optic neuropathy ||38 |
|Nystagmus ||35 |
|Impaired joint position sense ||33 |
|Intention tremor ||32 |
|Spasticity ||31 |
|Impaired pain or temperature sense ||22 |
|Dysarthria ||19 |
|Paraparesis ||17 |
|Internuclear ophthalmoplegia ||11 |
Based on its course, the disease is divided into a relapsing-remitting form (85% of cases), in which progression does not occur between attacks; a secondary progressive form (80% of cases after 25 years) characterized by a gradually progressive course after an initial relapsing-remitting pattern; and a primary progressive form (10% of cases) with gradual progression of disability from clinical onset. A progressive-relapsing form occurs rarely, with acute relapses being superimposed on a primary progressive course.
Examination in advanced cases commonly reveals optic atrophy, nystagmus, dysarthria, and upper motor neuron, sensory, or cerebellar deficits in some or all of the limbs (see Table 9-8). The diagnosis cannot be based on any single symptom or sign but only on a total clinical picture that indicates involvement of different parts of the central nervous system at different times.
These may support the clinical diagnosis and exclude other disorders but do not themselves justify a definitive diagnosis of multiple sclerosis.
The cerebrospinal fluid (CSF) is commonly abnormal, with mild lymphocytosis or a slightly increased protein concentration, especially if examined soon after an acute relapse. CSF protein electrophoresis shows the presence of discrete bands in the immunoglobulin G (IgG) region (oligoclonal bands) in 90% of patients. The antigens responsible for these antibodies are not known.
If clinical evidence of a lesion exists at only one site in the central nervous system, a diagnosis of multiple sclerosis cannot properly be made unless other regions are affected subclinically. Such subclinical involvement may be detected by the electrocerebral responses evoked by monocular visual stimulation with a checkerboard pattern (visual evoked potentials), monaural stimulation with repetitive clicks (brainstem auditory evoked potentials), or electrical stimulation of a peripheral nerve (somatosensory evoked potentials).
MRI may also detect subclinical lesions and has become nearly indispensable in confirming the diagnosis (Figure 9-4). T1-weighted images may reveal hypointense “black holes” that probably represent areas of permanent axonal damage; hyperintense lesions are also found. Gadolinium-enhanced T1-weighted images may highlight areas of inflammation with breakdown of the blood–brain barrier. T2-weighed images provide information about disease burden or lesion load (ie, total number of lesions), which typically appear as areas of high signal intensity. Other MRI techniques, including measures of cerebral atrophy, magnetization transfer imaging, magnetic resonance spectroscopy, and diffusion tensor imaging, will likely provide yet more relevant information. The MRI of healthy subjects sometimes shows “unidentified bright objects” that resemble the lesions of multiple sclerosis but are without clinical correlates or significance; the imaging findings must therefore be interpreted in the clinical context in which they were obtained.
(A) A mid-sagittal T2-weighted MRI of the cervical spinal cord in a young woman with multiple sclerosis. An abnormal region of high signal intensity (arrow) is seen. (Used with permission from RA Heyman.) (B) Axial T2-weighted MR brain image of a patient with multiple sclerosis showing multiple, primarily punctate, white matter plaques (arrows); note the typical location in the periventricular region (arrowheads). (Used with permission from RA. Heyman.)
Spinal MRI or CT myelography may be necessary to exclude a single congenital or acquired surgically treatable lesion in patients with spinal involvement and no evidence of disseminated disease. The region of the foramen magnum must be visualized to exclude the possibility of a lesion such as Arnold-Chiari malformation, in which part of the cerebellum and the lower brainstem are displaced into the cervical canal, producing mixed pyramidal and cerebellar deficits in the limbs.
The diagnosis of multiple sclerosis requires evidence that at least two different regions of the central white matter have been affected at different times. Multiple sclerosis can be diagnosed straightaway in patients with at least two typical attacks and two MRI lesions. In a patient with only one lesion, a further attack involving a different site suffices to show dissemination in space; otherwise, repeat imaging in a few months should demonstrate at least one T2 lesion in at least two of four typical sites (periventricular, juxtacortical, infratentorial, or spinal). To show dissemination in time in a patient with only one attack, the simultaneous presence on MRI of asymptomatic gadolinium-enhancing and non-enhancing lesions at any time is sufficient; alternatively, it is necessary to await development of a new T2 or gadolinium-enhancing lesion on follow-up MRI or a second clinical attack. Diagnosis of primary progressive disease requires at least one year of progressive disease plus two of the following: (1) at least one typical T2 brain lesion, (2) at least two spinal T2 lesions, and (3) positive CSF oligoclonal bands, increased IgG index, or both.
In patients with only a single clinical event and who do not satisfy criteria for multiple sclerosis, a clinically isolated syndrome (CIS) is diagnosed. These patients are at increased risk for developing multiple sclerosis and are sometimes offered treatment as if they had the disease in the hope of delaying progression to clinically definite disease. Follow-up MRI should be considered 6 to 12 months later to determine whether any new lesions have occurred.
The treatment approach is summarized in Table 9-9.
Table 9-9.Treatment of Multiple Sclerosis or Clinically Isolated Demyelinating Events Suggestive of Multiple Sclerosis. |Favorite Table|Download (.pdf) Table 9-9. Treatment of Multiple Sclerosis or Clinically Isolated Demyelinating Events Suggestive of Multiple Sclerosis.
Acute episode, including relapse1
Relapse prevention, first-line treatment2
β-1a (Rebif), 44 μg SC 3 times per week
β-1a (Avonex), 30 μg IM once per week
β-1b (Betaseron, Extavia), 0.25 mg SC on alternate days
Glatiramer acetate (Copaxone), 20 mg SC daily
Fingolimod (Gilenya), 0.5 mg PO daily3
Teriflunomide (Aubagio), 14 mg PO daily4
Dimethyl fumarate (Techfidera), 240 mg PO twice daily
Relapse prevention for disease activity despite use of first- line treatment
Natalizumab (Tysabri), 300 mg IV monthly5
Fingolimod, 0.5 mg PO daily
Teriflunomide (Aubagio), 14 mg PO daily4
Dimethyl fumarate (Techfidera), 240 mg PO twice daily
Mitoxantrone, 12 mg/m2 IV every 3 months; maximum lifetime dose, 140 mg/m2
High disease activity (typically with multiple gadolinium-enhancing lesions on MRI)
Relapsing-remitting disease—Treatment on an indefinite basis with interferon β-1a (30 μg intramuscularly once weekly, or 44 μg subcutaneously three times per week) or interferon β-1b (0.25 mg subcutaneously every other day) reduces the relapse rate. Glatiramer acetate (a mixture of random polymers simulating the amino acid composition of myelin basic protein) given by subcutaneous injection (20 mg daily) appears to be equally effective. In addition to their effect on relapses, interferon β-1a and glatiramer acetate may also delay the onset of significant disability in patients with relapsing disease. Natalizumab, an α4 integrin antibody, reduces the relapse rate when given intravenously once each month, but rarely has been associated with progressive multifocal leukoencephalopathy. It is given without other immune-modulating therapies to patients with relapsing-remitting disease poorly responsive to other therapies or with an aggressive initial course. However, if JC virus antibody testing is negative, the risk is low. Alemtuzumab, a lymphocyte inhibitor that also increases the risk of opportunistic infection, is approved in Europe but not the United States; its role in treatment remains undefined. Plasmapheresis is sometimes helpful when patients have severe relapses that are unresponsive to corticosteroids.
Interferons may cause a flu-like syndrome and (in the case of interferon β-1b) injection site reactions. Glatiramer acetate is generally tolerated well but may produce erythema at injection sites, and approximately 15% of patients experience transient episodes of flushing, dyspnea, chest tightness, palpitations, and anxiety after injections. All three of these agents are approved for use in relapsing-remitting multiple sclerosis. They are expensive, but their cost must be balanced against the reduced need for medical care and reduced time lost from work that follows their use.
Oral therapies are now available and are preferred by some, although their long-term safety profile is less clear. There are no trials comparing the efficacy of these newer agents. Fingolimod (0.5 mg daily) reduces relapses and disease progression; it also reduces MRI lesion activity and loss of brain volume in relapsing-remitting disease. Its mechanism of action is unknown but probably involves prevention of lymphocytes from migrating into the central nervous system. It is generally safe and well tolerated, but is contraindicated after recent myocardial infarction or with certain other cardiac disturbances. Adverse effects include headache, fatigue, back pain, diarrhea, respiratory tract infections, elevation of liver enzymes, blood pressure effects, macular edema, and—on initiation of therapy—transient bradycardia and slowed atrioventricular conduction. Therefore, heart rate should be monitored for 6 hours after the first dose, or if fingolimod is restarted after its use was interrupted for 2 weeks or more. Skin and certain other cancers have also been reported. At least until further experience has accumulated, use of fingolimod is probably best restricted to patients with active relapsing-remitting disease who are intolerant of β interferons and glatiramer acetate; it is also prescribed for newly diagnosed patients with active relapsing disease who prefer treatment with oral rather than parenteral medications, provided they understand the associated risks. Another oral agent, dimethyl fumarate (120 mg twice daily for 1 week, then 240 mg twice daily), also reduces relapse rate. Side effects include flushing, gastrointestinal complaints (eg, diarrhea, nausea, abdominal pain), and a reduced peripheral lymphocyte count. Relapse rate and disease progression is reduced also by teriflunomide, an immunomodulatory drug (taken orally in a daily dose of 7 or 14 mg). It has risks of hepatotoxicity and teratogenicity; side effects include alopecia, nausea, diarrhea, paresthesias, flu-like symptoms, elevated serum transaminases, and peripheral neuropathy. Corticosteroids may hasten recovery from acute relapses, but the extent of the recovery itself is unchanged. Treatment is therefore generally reserved for attacks that lead to acute change in functional ability, such as by causing visual or gait dysfunction. Long-term corticosteroid administration does not prevent relapses and should not be used because of unacceptable side effects. There is no standard schedule of treatment with corticosteroids, but the regimen most commonly used is intravenous methylprednisolone (1 g daily) for 5 days, followed by an oral prednisone taper (1 mg/kg/d for 1 week, with rapid reduction over the ensuing 1-2 weeks).
Primary or secondary progressive multiple sclerosis—Optimal treatment in these forms of the disease is less clear. There is no established treatment for primary progressive multiple sclerosis. Interferon β-1b (and probably interferon β-1a) are effective in reducing the progression rate as determined clinically and by MRI in secondary progressive disease, but there is only limited experience with glatiramer acetate in this setting. Mitoxantrone probably reduces the clinical attack rate and may help to reduce disease progression in patients whose clinical condition is worsening. Treatment with cyclophosphamide, azathioprine, or methotrexate, may help to arrest the course of secondary progressive disease, but studies are inconclusive. Pulse therapy with high-dose intravenous methylprednisolone (1 g/d once a month) is also sometimes effective and may carry a lower risk of long-term complications than the cytotoxic drugs. A recent phase 2 study suggests that simvastatin may have a role in treating secondary progressive disease.
General health and symptomatic treatment—Exercise and physical therapy are important, but excessive exertion must be avoided, particularly during periods of acute relapse. Fatigue is a serious problem for many patients and sometimes responds to amantadine or one of the selective serotonin reuptake inhibitor antidepressants. Treatment for spasticity (discussed earlier) is often needed, as is aggressive bladder and bowel management. Treatment for other aspects of advanced multiple sclerosis such as cognitive deficits, pain, tremor, and ataxia is generally less successful.
At least partial recovery from an acute episode can be anticipated, but it is impossible to predict when the next relapse will occur. Features that tend to imply a more favorable prognosis include female sex, onset before 40 years of age, and presentation with visual or somatosensory, rather than pyramidal or cerebellar, dysfunction. Although some degree of disability is likely to result eventually, approximately one-half of patients are only mildly or moderately disabled 10 years after the onset of symptoms.
DS, ed. Multiple Sclerosis and Related Disorders. Handbook of Clinical Neurology. Vol 122. Amsterdam: Elsevier; 2014.
This relapsing disorder (formerly known as Devic disease and once considered a variant of multiple sclerosis) is associated with a specific antibody marker, NMO-IgG, that targets the water channel aquaporin-4. The disorder is characterized by optic neuritis and acute myelitis associated with MRI changes that extend over at least three segments of the spinal cord. Some patients with isolated myelitis or optic neuritis are also antibody positive. Seropositivity suggests a poor visual outcome. Unlike multiple sclerosis, the MRI typically does not show widespread white matter involvement, although such changes do not exclude the diagnosis.
Acute attacks are treated with intravenous methylprednisolone (1 g daily) for 5 days, followed by an oral prednisone taper (1 mg/kg/d for 1 week, with rapid reduction over the ensuing 1-2 weeks). If the response is poor, plasmapheresis is undertaken. Treatment with intravenous immunoglobulins is generally unhelpful. Treatment is otherwise with long-term immunosuppressive therapy. Mycophenolate mofetil (unlabeled use; 1 g twice daily by mouth) may reduce the frequency of attacks and stabilize the disorder. If not, rituximab (unlabeled use) may also reduce the relapse rate and is undergoing clinical trials; a common regimen is 1,000 mg for each of two intravenous infusions 2 weeks apart, but there is no agreement about re-treatment regimens.
ACUTE DISSEMINATED ENCEPHALOMYELITIS
Neurologic symptoms and signs develop over a few days in association with a nonspecific viral infection, after immunization, or without obvious antecedents, when it then may represent the initial manifestation of multiple sclerosis. Pathologically, perivascular areas of demyelination are scattered throughout the brain and spinal cord, with an associated inflammatory reaction. Lesions are all of similar age, and the brain appears swollen.
The disorder has its highest incidence in childhood. It is usually monophasic but relapses occur in rare instances. Initial symptoms often consist of headache, fever, and confusion; examination reveals meningeal irritation. Multifocal neurologic deficits are common. The patient is typically encephalopathic, with disturbances of consciousness that range from somnolence to coma; seizures may occur. Flaccid weakness and sensory disturbance of the legs, extensor plantar responses, and urinary retention are common manifestations of spinal cord involvement. Other neurologic signs may indicate involvement of the optic nerves or cranial nerves, cerebral hemispheres, brainstem, or cerebellum; cerebellar ataxia is often conspicuous (especially when associated with varicella) but optic neuritis, hemiparesis and other long-tract signs, aphasia, and even movement disorders may also occur.
The neurologic deficit resolves spontaneously, at least in part, over a few weeks or months. Many patients make a virtually complete recovery, but some are left with severe residual deficits. Measles-associated disease is often especially severe.
The CSF is occasionally normal but in many cases shows an increased mononuclear cell count; protein concentration may be increased, but glucose concentration is normal. Oligoclonal bands, a nonspecific finding, are sometimes present. CT scans are often normal but MRI is helpful: T2-weighted images show asymmetric high-signal lesions particularly in the hemispheric white matter, optic nerves, basal ganglia, thalamus, cerebellum, brainstem, or spinal cord. There may be mass effect and edema. On T1-weighted images, low-signal lesions are found in the white matter and—depending on their age—may enhance uniformly with gadolinium (Figure 9-5). Gray matter abnormalities may also be present.
Gadolinium-enhanced T1 axial MRI in a patient with acute disseminated encephalomyelitis, showing evolution of the lesions. The MRI in B was obtained 7 days after that in A. (Used with permission from A. DiBernardo.)
The diagnosis is based on the clinical and neuroimaging features. Infective meningitis, encephalitis, and other inflammatory disorders (eg, multiple sclerosis) must be excluded. Long-term follow-up helps to confirm the diagnosis; relapses suggest alternative possibilities, such as multiple sclerosis.
Broad-spectrum antibiotics and acyclovir are often administered until bacterial infections and herpes simplex virus encephalitis are excluded by diagnostic studies. High-dose intravenous methylprednisolone (30 mg/kg/d, up to a maximum dose of 1 g daily, for 5 days) is then usually given. Treatment with intravenous immunoglobulins or plasmapheresis is sometimes helpful in patients with an inadequate response to methylprednisolone. Treatment is otherwise symptomatic.
BG. Acute disseminated encephalomyelitis, transverse myelitis, and neuromyelitis optica. Continuum (Minneap Minn). 2013;19:944–967.
OTHER INFECTIVE OR INFLAMMATORY MYELOPATHIES
Epidural abscess—that is, located within the spinal canal but outside the dura mater—may occur as a sequel to skin infection, septicemia, vertebral osteomyelitis, intravenous drug abuse, spinal trauma or surgery, epidural anesthesia, or lumbar puncture. Predisposing factors include acquired immunodeficiency syndrome (AIDS) and iatrogenic immunosuppression.
The most common causative organisms are Staphylococcus aureus, streptococci, gram-negative bacilli, and anaerobes. Neurologic complications result from compression of the spinal cord or its blood supply, obstructed venous drainage, inflammatory reactions, and vasculitis.
Fever, backache and tenderness, pain in the distribution of a spinal nerve root, headache, and malaise are early symptoms, followed by rapidly progressive paraparesis, sensory disturbances in the legs, and urinary and fecal retention. Spinal epidural abscess is a neurologic emergency that requires prompt diagnosis and treatment.
MRI with gadolinium enhancement is the imaging study of choice and should be sufficient to determine the extent of the abscess. A block may be found at CT myelography. Laboratory investigations reveal a peripheral leukocytosis and increased erythrocyte sedimentation rate. Spinal tap should not be performed at the site of a suspected abscess, as it may disseminate the infection from the epidural to subarachnoid space. The CSF typically shows a mild pleocytosis with increased protein but normal glucose concentration. Blood cultures and cultures of the excised abscess or its aspirate help to identify the causal organism.
Treatment involves surgery and antibiotics. With the advent of MRI, spinal epidural abscess is being diagnosed with increasing frequency before it has compressed the spinal cord and at a time when treatment with intravenous antibiotics alone is successful. Nafcillin or vancomycin is administered to cover staphylococcal or streptococcal infection, and a third- or fourth-generation cephalosporin such as ceftazidime or cefepime, respectively, to cover gram-negative infections; other agents are added or substituted based on the clinical context and results of Gram stain of excised material. The results of culture of the necrotic material that makes up the abscess may subsequently alter the antibiotic regimen. The antibiotic dosages are those used to treat bacterial meningitis, as given in Chapter 4, Confusional States. Intravenous antibiotics are usually continued for 3 to 4 weeks, but treatment for 6 to 8 weeks is required in the presence of vertebral osteomyelitis.
Delayed diagnosis or treatment and suboptimal management may lead to irreversible paraparesis or paraplegia, which occurs in up to 20% cases, depending on the series. The most important prognostic indicator is the patient’s clinical status before decompressive surgery; the more severe the preoperative deficit, the less recovery is to be expected.
RO. Spinal epidural abscess. N Engl J Med. 2006;355: 2012–2020.
ACUTE TRANSVERSE MYELITIS
This syndrome results from a variety of infectious (bacterial, viral, fungal, parasitic) and noninfectious inflammatory disorders (multiple sclerosis, neuromyelitis optica, acute disseminated encephalomyelitis, systemic autoimmune diseases, idiopathic) that produce anatomic and functional disruption of the spinal cord. Children and young adults are affected most often. Clinical findings include bilateral sensory, motor, and autonomic deficits in the limbs and trunk; a discrete sensory level corresponding to the site of inflammation in the spinal cord; a course of hours to days; an inflammatory CSF profile (pleocytosis; an accompanying low CSF glucose suggests an infective cause); and an MRI showing an intrinsic spinal cord lesion that usually enhances with gadolinium administration. Compressive lesions of the spinal cord, such as spinal epidural abscess, must be excluded as they require specific treatment.
Treatment is with corticosteroids, typically methylprednisolone (1 g intravenously daily for 3-5 days), although their benefit has not been rigorously established. Plasma exchange, intravenous immunoglobulins, or cyclophosphamide may be useful in steroid-unresponsive patients, but their utility remains to be established. Patients tend to improve over several months, but may have residual deficits, and mortality rates in excess of 30% have been reported.
DM. Transverse myelitis. N Engl J Med. 2010;363: 564–572.
Syphilis can produce meningovasculitis resulting in spinal cord infarction. Vascular myelopathies are discussed later in this chapter.
Tuberculosis may lead to vertebral disease (Pott disease) with secondary compression of the spinal cord, meningitis with secondary arteritis and cord infarction, or cord compression by a tuberculoma. Such complications assume great importance in certain parts of the world, especially Asia and Africa, and among such groups as the homeless and intravenous drug users, who are at increased risk for contracting tuberculosis. Tuberculous meningitis is considered in more detail in Chapter 4, Confusional States.
A disorder of the spinal cord, vacuolar myelopathy, is found at autopsy in about 30% of patients with AIDS, in most of whom it was asymptomatic. Vacuolation of white matter in the spinal cord is most pronounced in the thoracic lateral and posterior columns. Although attributed to direct involvement by human immunodeficiency virus-1 (HIV-1), the correlation between the presence and extent of HIV-1 infection and spinal pathology is poor. A metabolic basis therefore has been suggested. Myelopathy in patients with AIDS also may be caused by lymphoma, cryptococcal infection, or herpesviruses.
Most patients with vacuolar myelopathy have coexisting HIV-associated dementia. Symptoms progress over weeks to months and include leg weakness, ataxia, incontinence, erectile dysfunction, and paresthesias. There is typically no back pain. Examination shows paraparesis, lower extremity monoparesis, or quadriparesis; spasticity; increased or decreased tendon reflexes; Babinski signs; and diminished vibration and position sense. Sensation over the trunk is usually normal, and a sensory level is difficult to define. MRI of the spinal cord is usually normal. Treatment is with combination antiretroviral therapy (cART), but whether this helps to arrest the myelopathy is not clear. Spasticity and incontinence require symptomatic measures.
Tropical Spastic Paraparesis
A retrovirus, human T-lymphotropic virus type I (HTLV-I), appears to be the cause of tropical spastic paraparesis, a disorder found especially in the Caribbean, off the Pacific coast of Colombia, and in the Seychelles. Transmission of the virus occurs in breast milk, during sexual intercourse, and by exposure to contaminated blood products. Clinical features include spastic paraparesis, impaired vibration and joint position sense, and bowel and bladder dysfunction. A clinically similar myelopathy may also follow infection with human T-lymphotropic virus type II (HTLV-II). The precise pathogenesis is uncertain, specific therapy is lacking, and treatment is symptomatic (primarily for spasticity and a spastic bladder). Preventive therapy is also important; patients should avoid sharing needles or syringes and breast-feeding, use condoms to prevent sexual transmission, and not donate blood, sperm, or other tissues.
Herpesviruses can also produce myelopathy, which commonly affects spinal nerve roots as well as the cord (radiculomyelopathy), especially in immunocompromised patients, such as those with AIDS. Cytomegalovirus causes a myelopathy characterized by demyelination of the posterior columns of the spinal cord and by cytomegalic cells that contain Cowdry type A inclusion bodies. MRI may show increased T2 signal with enhancement. The CSF usually contains a lymphocytosis and increased protein concentration, but is sometimes normal. Viral identification may be possible by polymerase chain reaction in CSF and by antibody studies. The value of treatment with antiviral drugs such as ganciclovir and foscarnet is still uncertain. Herpes zoster and herpes simplex types 1 and 2 may respond to treatment with acyclovir (see Chapter 4, Confusional States).
Tetanus is a disorder of neurotransmission associated with infection by Clostridium tetani. The organism typically becomes established in a wound, where it elaborates a toxin that is transported retrogradely along motor nerves into the spinal cord or, with wounds to the face or head, the brainstem. The toxin is also disseminated through the bloodstream to skeletal muscle, where it gains access to additional motor nerves. In the spinal cord and brainstem, tetanus toxin interferes with release of the inhibitory neurotransmitters glycine and GABA, resulting in motor nerve hyperactivity. Autonomic nerves are also disinhibited.
After an incubation period of up to 3 weeks, tetanus usually presents with trismus (lockjaw), difficulty in swallowing, or spasm of the facial muscles that resembles a contorted smile (risus sardonicus). Painful muscle spasms and rigidity progress to involve both axial and limb musculature and may cause apneic episodes and hyperextended posturing (opisthotonos). Laryngospasm and autonomic instability are potential life-threatening complications.
Although the diagnosis is usually made clinically, the presence of continuous motor unit activity or absence of the normal silent period in the masseter muscle after elicitation of the jaw-jerk reflex is a helpful electromyographic finding. The serum CK may be elevated, and myoglobinuria may occur. The organisms can be cultured from a wound in only a minority of cases.
Immunization—Tetanus is preventable through immunization with tetanus toxoid. Tetanus toxoid is usually administered routinely to infants and children in the United States, in combination with pertussis vaccine and diphtheria toxoids. In children under age 7 years, three doses of tetanus toxoid are administered at intervals of at least 1 month, followed by a booster dose 1 year later. For older children and adults, the third dose is delayed for at least 6 months after the second, and no fourth dose is required. Immunization lasts for 5 to 10 years.
Wound care—Debridement of wounds is important to remove necrotic tissue and spores. Patients with open wounds should receive an additional dose of tetanus toxoid if they have not received a booster dose within 10 years—or if the last booster dose was more than 5 years ago and the risk of infection with C tetani is moderate or high. A moderate likelihood of infection is associated with wounds that penetrate muscle, those sustained on wood or pavement, human bites, and nonabdominal bullet wounds. High-risk wounds include those acquired in barnyards or near sewers or other sources of waste material, and abdominal bullet wounds. Patients with moderate- or high-risk wounds should also be given tetanus immune globulin (3,000-6,000 units intramuscularly).
The treatment of tetanus includes hospitalization in an intensive care unit to monitor respiratory and circulatory function, tetanus immune globulin to neutralize the toxin, and penicillin or metronidazole for 7 to 10 days for the infection itself. Diazepam, 10 to 30 mg intravenously or intramuscularly every 4 to 6 hours, is useful for treating painful spasms and rigidity, as also is intravenous infusion of propofol. Intrathecal baclofen has also been used. Neuromuscular blockade with vecuronium or pancuronium, with mechanical ventilation, may be required when these measures fail.
Autonomic hyperactivity can be treated with intravenous administration of the mixed α- and β-adrenergic receptor antagonist labetalol (up to 1 mg/min) or with morphine sulfate (0.5-1 mg/kg/h). Magnesium sulfate, which also blocks neurotransmitter release at the neuromuscular junction, can also be used and helps to control muscle spasms as well.
Fatality rates of 10% to 60% are reported. Lower fatality rates are most likely to be achieved by early diagnosis, prompt institution of appropriate treatment before the onset of spasms, and possibly by using intrathecal—in addition to intramuscular—tetanus immune globulin. Among patients who recover, approximately 95% do so without long-term sequelae.
CHRONIC ADHESIVE ARACHNOIDITIS
This inflammatory disorder is usually idiopathic but can follow subarachnoid hemorrhage; meningitis; intrathecal administration of penicillin, radiologic contrast materials, and certain forms of spinal anesthetic; trauma; and surgery.
The usual initial complaint is of constant radicular pain, but in other cases paresthesias or lower motor neuron weakness occur. Eventually, a spastic ataxic paraparesis develops, with sphincter involvement and sexual dysfunction.
CSF protein is elevated, and the cell count may be increased. MRI shows thickened and clumped nerve roots. Treatment with corticosteroids or nonsteroidal anti-inflammatory analgesics may be helpful. Surgery may be indicated in cases with localized spinal cord involvement.
This rare event most commonly involves the anterior spinal artery (Figure 9-6). This artery, which supplies the anterior two-thirds of the cord, is itself supplied by only a limited number of feeding vessels, whereas the paired posterior spinal arteries receive numerous feeders at many different levels. Thus anterior spinal artery syndrome usually results from interrupted flow in a single feeder. Other patterns of involvement include central and posterior spinal artery syndromes and a transverse syndrome. Causes include trauma, dissecting aortic aneurysm, aortography, polyarteritis nodosa, and hypotensive crisis. Because the anterior spinal artery is particularly well supplied in the cervical region, infarcts almost always occur more caudally.
Blood supply to the cervical spinal cord (shown in transverse section). Left: Major territories supplied by the anterior spinal artery (dark shading) and the posterior spinal artery (light shading). Right: Pattern of supply by intramedullary arteries. From the pial vessels (around the circumference of the cord), radially oriented branches supply much of the white matter and the posterior horns of the gray matter. The remaining gray matter and the innermost portion of the white matter are supplied by the central artery (located in the anterior median fissure), which arises from the anterior spinal artery. The descending corticospinal tract is supplied by both the anterior and posterior spinal arteries.
The acute onset of a flaccid, areflexic paraparesis is followed, as spinal shock wears off after a few days or weeks, by a spastic paraparesis with brisk tendon reflexes and extensor plantar responses. In addition, there is dissociated sensory impairment—pain and temperature appreciation are lost, but vibration and position sense are spared because the posterior columns are supplied by the posterior spinal arteries. Treatment is symptomatic. Mortality relates to the underlying cause. Survivors may show some improvement; most remain chair-bound, however, and only a minority regain the ability to walk unaided.
A subacute, asymmetric myelopathy sometimes develops as a consequence of a vasculitic process; the cerebrospinal fluid shows a pleocytosis, and clinical benefit may follow corticosteroid therapy. An even more insidious, asymmetric ischemic myelopathy may result from compression of the anterior spinal artery or its major feeder, as by degenerative disease of the spine. The resulting disorder may simulate amyotrophic lateral sclerosis when there is a combined upper and lower motor neuron deficit, without sensory changes.
J. Spinal cord ischemia: clinical and imaging patterns, pathogenesis, and outcomes in 27 patients. Arch Neurol[Archives of Neurology Full Text]
Hemorrhage into the spinal cord is rare; it is caused by trauma, a vascular anomaly, a bleeding disorder, or anticoagulant therapy. A severe cord syndrome develops acutely and is usually associated with blood in the CSF. The prognosis depends on the extent of the hemorrhage and the rapidity with which it occurs.
SPINAL EPIDURAL OR SUBDURAL HEMORRHAGE
Spinal epidural or subdural hemorrhage may occur spontaneously or in relation to trauma or tumor and as a complication of anticoagulation, aspirin therapy, thrombocytopenia, coagulopathy, epidural catheters, or lumbar puncture. Hemorrhage after lumbar puncture—usually epidural in location—is more likely when a disorder of coagulation is present. Therefore, the platelet count, prothrombin time, and partial thromboplastin time should be determined before lumbar puncture, and if anticoagulant therapy is to be instituted, it should be delayed for at least 1 hour after the procedure. Patients with fewer than 20,000 platelets/μL or those with rapidly falling counts to less than 50,000/μL should undergo platelet transfusion before lumbar puncture. Spinal epidural hemorrhage usually presents with back pain that may radiate in the distribution of one or more spinal nerve roots; it is occasionally painless. Paraparesis or quadriparesis, sensory disturbances in the lower limbs, and bowel and bladder dysfunction may develop rapidly, necessitating urgent CT scan or MRI and surgical evacuation of the hematoma.
ARTERIOVENOUS MALFORMATION (AVM) OR FISTULA
This may present with spinal subarachnoid hemorrhage or with myelopathy. Most of these lesions involve the lower spinal cord. Symptoms include motor and sensory disturbances in the legs and disorders of sphincter function. Leg or back pain is often conspicuous.
On examination, there may be an upper or lower motor neuron, or mixed deficit in the legs, and sensory deficits are usually extensive but occasionally radicular; the signs indicate an extensive lesion in the longitudinal axis of the cord. In patients with cervical lesions, symptoms and signs may also be present in the arms. A bruit is sometimes audible over the spine, and there may be a cutaneous angioma.
Spinal MRI shows multiple flow voids (Figure 9-7), but can rarely be normal; myelography reveals serpiginous filling defects caused by enlarged vessels. The diagnosis is confirmed by selective spinal arteriography. Most lesions are extramedullary (dural), posterior to the spinal cord, and can be treated by embolization or by ligation of feeding vessels and excision of the anomalous arteriovenous nidus of the malformation. Left untreated, the patient is likely to become increasingly disabled until chair-bound or bed-bound.
Spinal MRI, sagittal view, T2-weighted image, demonstrating multiple flow voids (within circle) in the posterior subarachnoid space in a patient with an arteriovenous fistula. (Used with permission from A. DiBernardo.)
AA. Vascular diseases of the spinal cord. Neurol Clin. 2013;31:153–181.
Subacute combined degeneration of the cord as a result of vitamin B12 deficiency is characterized by an upper motor neuron deficit in the limbs that is usually preceded by sensory symptoms and signs caused by posterior column involvement (see Chapter 10, Sensory Disorders). In addition to the myelopathy, there may be optic atrophy, mental changes, or peripheral neuropathy. Nitrous oxide toxicity can produce a similar syndrome, as can copper deficiency.
Cervical spondylosis is characterized by any or all of the following:
Pain and stiffness in the neck
Pain in the arms, with or without a segmental motor or sensory deficit
Upper motor neuron deficit in the legs
Cervical spondylosis results from chronic cervical disk degeneration, with herniation of disk material, secondary calcification, and associated osteophytic outgrowths. It can lead to impingement on one or more nerve roots on either or both sides and to myelopathy related to compression, vascular insufficiency, or recurrent minor trauma to the cord.
Patients often present with neck pain and limitation of head movement or with occipital headache. In some cases, radicular pain and other sensory disturbances occur in the arms, and there may be weakness of the arms or legs. Examination commonly reveals restricted lateral flexion and rotation of the neck. There may be a segmental pattern of weakness or dermatomal sensory loss in one or both arms, along with depression of those tendon reflexes mediated by the affected root(s). Cervical spondylosis tends to affect particularly the C5 and C6 nerve roots, so there is commonly weakness of muscles (eg, deltoid, supra- and infraspinatus, biceps, brachioradialis) supplied from these segments, pain or sensory loss about the shoulder and outer border of the arm and forearm, and depressed biceps and brachioradialis reflexes. If there is an associated myelopathy, upper motor neuron weakness develops in one or both legs, with concomitant changes in tone and reflexes. There may also be posterior column or spinothalamic sensory deficits.
Plain x-rays show osteophyte formation, narrowing of disk spaces, and encroachment on the intervertebral foramina. Spinal MRI, CT scanning, or CT myelography may be necessary to confirm the diagnosis and exclude other structural causes of myelopathy. The CSF obtained at the time of myelography is usually normal, but the protein concentration may be increased, especially if there is a block in the subarachnoid space. Needle electromyography is helpful in identifying a radiculopathy and determining whether degenerative anatomic abnormalities of the cervical spine are clinically significant.
Spondylotic myelopathy may resemble myelopathy caused by such disorders as multiple sclerosis, motor neuron disease, subacute combined degeneration, cord tumor, syringomyelia, or hereditary spastic paraplegia. Moreover, degenerative changes in the spine are common in the middle-aged and elderly and may coincide with one of these other disorders.
A cervical collar to restrict neck movements may relieve severe pain. Pain may also respond to simple analgesics, nonsteroidal anti-inflammatory drugs, muscle relaxants, tricyclic antidepressants (taken at night), or anticonvulsants. Provocative activities must be avoided. Physical therapy may help once pain is less severe and increasing mobilization is desirable. Patients with cervical radiculopathy and severe pain are sometimes helped by epidural steroid injections, but complications include spinal cord or cerebral infarction.
Operative treatment may prevent progression of neurologic deficits; it may also be required if radicular pain is severe, persistent, and unresponsive to conservative measures and imaging reveals root compression. Operative treatment is indicated for progressive spinal cord compression, and should be undertaken early if there is sphincter disturbance.
N. Cervical spondylosis: an update on pathophysiology, clinical manifestation, and management strategies. Dis Mon. 2011;57:583–591
CONGENITAL SPINAL ANOMALIES
A combination of corticospinal and cerebellar signs may occur in the limbs of patients with congenital skeletal abnormalities such as platybasia (flattening of the base of the skull) or basilar invagination (an upward bulging of the margins of the foramen magnum). Syringomyelia (cavitation of the cord), which can be congenital or acquired, may lead to a lower motor neuron deficit, a dissociated sensory loss in the arms, and upper motor neuron signs in the legs. Because the sensory findings are so characteristic, this disorder, which is frequently associated with Arnold-Chiari malformation, is discussed in detail in Chapter 10, Sensory Disorders.
Tumors can be divided into two groups: intramedullary (10%) and extramedullary (90%). Ependymomas are the most common type of intramedullary tumor; the various types of gliomas make up the remainder. Extramedullary tumors can be either extradural or intradural in location. Among the primary extramedullary tumors, neurofibromas and meningiomas are relatively common and are benign; they can be intra- or extradural. Carcinomatous metastases (especially from bronchus, breast, or prostate), lymphomatous or leukemic deposits, and myeloma are usually extradural.
PATHOGENESIS OF MYELOPATHY
Myelopathy may occur in patients with malignant neoplasms because of spinal cord compression or direct involvement by the primary tumor or by metastases, ischemic or hemorrhagic complications of the neoplasm or its treatment, complications of radiation or chemotherapy, secondary infection (especially in immunocompromised patients), or a paraneoplastic disorder.
Immunocompromised patients are at particular risk of infection, often with unusual agents that may cause a myelopathy, such as varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, or herpes simplex virus. Treatment of infective myelopathies was discussed earlier in this chapter.
In paraneoplastic necrotizing myelopathy, the most common antibody is anti-Hu; other antibodies may also be found, but sometimes no antibody can be identified. The underlying tumor is commonly a cancer of the lung or breast, lymphoma, or leukemia. Patients present with a rapidly ascending flaccid paraplegia. The myelopathy is often accompanied by an encephalopathy and neuropathy (paraneoplastic encephalomyelitis). The MRI findings are usually nonspecific or normal, but may show swelling of the spinal cord. The CSF may contain inflammatory cells. Treatment is of the underlying malignancy, but improvement of the myelopathy is uncommon. Immunosuppressive therapies are often prescribed, with limited benefit.
Common causes of cord compression are disk protrusion, trauma, and tumors; in certain parts of the world, tuberculous disease of the spine is also a frequent cause. Rare but important causes of cord compression include epidural abscess and hematoma. The present section will be restricted to a consideration of tumors, as other causes are considered elsewhere in this chapter.
Irrespective of its nature, a spinal tumor can lead to cord dysfunction and a neurologic deficit by direct compression, ischemia secondary to arterial or venous obstruction, or, in the case of intramedullary lesions, by invasive infiltration.
Symptoms may develop insidiously and progress gradually or—as with spinal cord compression from metastatic carcinoma—exhibit a rapid course.
Pain is conspicuous—and usually the initial abnormality—in many patients with extradural lesions; it can be radicular, localized to the back, or experienced diffusely in an extremity and is characteristically aggravated by coughing or straining (Table 9-10).
Table 9-10.Clinical Features of Spinal Cord Compression by Extradural Metastasis. |Favorite Table|Download (.pdf) Table 9-10. Clinical Features of Spinal Cord Compression by Extradural Metastasis.
|Sign or Symptom ||Initial Feature (%) ||Present at Diagnosis (%) |
|Pain ||96 ||96 |
|Weakness ||2 ||76 |
|Sensory disturbance ||0 ||51 |
|Sphincter dysfunction ||0 ||57 |
Motor symptoms (heaviness, weakness, stiffness, or focal wasting of one or more limbs) may develop, or there may be paresthesias or numbness, especially in the legs. When sphincter disturbances occur, they usually are particularly disabling.
Localized spinal tenderness to percussion is sometimes present. Involvement of anterior roots leads to an appropriate lower motor neuron deficit, and of posterior roots leads to dermatomal sensory changes at the level of the lesion. Dysfunction of pathways traversing the cord may cause an upper motor neuron deficit below the level of the lesion and a sensory deficit with an upper level on the trunk. The distribution of signs varies with lesion level and may take the form of Brown-Séquard or central cord syndrome (see Figures 10-5 and 10-7).
The CSF is often xanthochromic, due to a greatly increased protein concentration rather than hemorrhage, with normal or elevated white blood cell count and normal or depressed glucose concentration. MRI or CT myelography delineates and localizes the lesion.
Extradural metastases must be treated urgently. Depending on the primary neoplasm, they are best managed by analgesics, corticosteroids, radiotherapy, and hormonal treatment; decompressive laminectomy is often unnecessary. Intradural (but extramedullary) lesions are best removed if possible. Intramedullary tumors are treated by decompression and surgical excision when feasible and by radiotherapy.
The prognosis depends on the cause and severity of the cord compression before it is relieved. Cord compression by extradural metastasis is usually manifested first by pain and may progress rapidly to impair motor, sensory, and sphincter function. Therefore, any patient with cancer and spinal or radicular pain must be investigated immediately. Reliance on motor, sensory, or sphincter disturbances to make the diagnosis will delay treatment and worsen the outcome.
K. Spinal cord tumors: new views and future directions. Neurol Clin. 2013;31:241–268.