For further information, see CMDT Part 24-18: Head Injury
Cognitive impairment tends to affect frontal and temporal lobe function, causing deficits in
Behavioral dysregulation, depression, and disinhibition can impair social functioning
Anosmia, presumably due to shearing of fibers from the nasal epithelium, is common
Severity ranges from concussion to severe traumatic brain injury (TBI)
Concussion is broadly defined as an alteration in mental status caused by trauma with or without loss of consciousness
The term "concussion" is often used synonymously with mild TBI
Grades of TBI are traditionally defined by the Glasgow Coma Scale (GCS) score measured 30 minutes after injury (Table 24–7)
Head trauma may cause cerebral injury through a variety of mechanisms (Table 24–8)
There appears to be an association between head trauma and the later development of neurodegenerative disease, such as
Chronic traumatic encephalopathy
Defined as repetitive, mild head injury (often seen in athletes or military personnel)
Distinct pathologic entity associated with mood and cognitive changes
Characterized by the abnormal aggregation of tau or other proteins either focally or globally in the cerebral cortex
Table 24–7.Glasgow Coma Scale.1 ||Download (.pdf) Table 24–7. Glasgow Coma Scale.1
|Vocal but not verbal
|Verbal but not conversational
|Conversational but disoriented
|Withdraws from pain
Table 24–8.Acute cerebral sequelae of head injury (listed in alphabetical order). ||Download (.pdf) Table 24–8. Acute cerebral sequelae of head injury (listed in alphabetical order).
|Acute epidural hemorrhage
|Headache, confusion, somnolence, seizures, and focal deficits occur several hours after injury (lucid interval) and lead to coma, respiratory depression, and death unless treated by surgical evacuation.
|Tear in meningeal artery, vein, or dural sinus, leading to hematoma visible on CT scan.
|Acute subdural hemorrhage
|Similar to epidural hemorrhage, but interval before onset of symptoms is longer. Neurosurgical consultation for consideration of evacuation.
|Hematoma from tear in veins from cortex to superior sagittal sinus or from cerebral laceration, visible on CT scan.
|Cerebral contusion or laceration
|Loss of consciousness longer than with concussion. Focal neurologic deficits are often present. May lead to death or severe residual neurologic deficit.
Bruising on side of impact (coup injury) or contralaterally (contrecoup injury).
Vasogenic edema, multiple petechial hemorrhages, and mass effect. May ...