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This chapter addresses the following Geriatric Fellowship Curriculum Milestone: #60
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Learning Objectives
Learn the epidemiology, pathobiology, clinical manifestations, and genetics of Parkinson disease (PD).
Understand the latest terminology and major clinical differences between parkinsonism and Parkinson disease.
Learn the common presenting features of diseases, such as progressive supranuclear palsy, corticobasal degeneration (CBD), and multiple system atrophy that mimic and require differentiation from Parkinson disease.
Acquire new knowledge about the latest tests to diagnose Parkinson disease and indications and adverse effects of cutting-edge therapies, including dopaminergic and nondopaminergic agents and surgical treatments for Parkinson disease.
Understand the significance of exercise, physical activity, and supportive care for management of patients with Parkinson disease.
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Key Clinical Points
Parkinsonism includes a constellation of motor and nonmotor symptoms, and Parkinson disease is the most common cause of parkinsonism. Other causes include medications, structural lesions of the brain, and diseases that present with extrapyramidal manifestations
The gold standard of making a diagnosis of Parkinson disease remains autopsy that shows Lewy bodies in substantia nigra.
Parkinson disease affects more than 1 out of every 100 individuals over the age of 60, and is more common in men.
Patients with Parkinson disease almost always respond to dopaminergic medications, while those with parkinsonism generally do not. The symptoms most responsive to treatment include bradykinesia and rigidity.
Besides symptoms, dopamine transporter single-photon emission computed tomography (SPECT) imaging helps to diagnose Parkinson disease and differentiate it from essential tremor.
Amantadine improves symptoms in approximately two-thirds of patients and is the only effective treatment for dyskinesia.
Deep brain stimulation (DBS) surgery is typically indicated for patients with difficult motor complications and medication-refractory tremors.
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DEFINITION AND TERMINOLOGY
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Parkinsonism is the unifying term that describes a constellation of motor and nonmotor neurologic features. Parkinsonism can be defined as a variable combination of six specific, independent motor features: bradykinesia (slowness of movement), tremor at rest, rigidity, loss of postural reflexes, flexed posture, and freezing of gait (where the feet are transiently “glued” to the ground). Of these features, bradykinesia—either affecting the arms or legs (“appendicular bradykinesia”) or midline structures including the trunk, head and neck, oropharynx, or eyes (“axial bradykinesia”)—is the most central element of parkinsonism and is caused by loss of dopaminergic neurons in a midbrain structure called the substantia nigra pars compacta (SNpc) responsible for innervating a group of critical motor nuclei within the deep portions of the brain collectively labeled the basal ganglia.
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There are multiple causes of parkinsonism. The most common and extensively studied is idiopathic Parkinson disease (PD), which is estimated to affect approximately 1% to 2% of people over the age of 60. PD is a complex disorder with a wide variety of clinical presentations whose exact pathogenesis is incompletely understood. The eponymous name “Parkinson disease” was coined following the publication of “An Essay on the Shaking Palsy” by the British surgeon ...