American Board of Internal Medicine (ABIM) Certification Practice Exam

What syndrome involves a combination of parkinsonism and prominent dysautonomia?

1. Shy-Drager syndrome

2. Alzheimer's disease

3. Normal pressure hydrocephalus

4. Vascular dementia

The correct answer is: Shy-Drager syndrome

Shy-Drager syndrome, now often included under the umbrella term multiple system atrophy (MSA), is characterized by the combination of parkinsonism and significant dysautonomia. Patients typically present with symptoms such as rigidity, bradykinesia, and postural instability, typical of Parkinson's disease. However, what distinguishes Shy-Drager syndrome is the severe autonomic dysfunction that may manifest as orthostatic hypotension, urinary incontinence, and abnormal sweating. This dysautonomia is a hallmark of the condition, leading to complications not commonly seen in primary Parkinson's disease. The other conditions listed do not exhibit this specific combination of symptoms. Alzheimer's disease primarily affects cognition and does not present with parkinsonism and dysautonomia. Normal pressure hydrocephalus can lead to gait abnormalities and cognitive decline but is not characterized by dysautonomia and parkinsonism occurring together. Similarly, vascular dementia can cause cognitive impairment and sometimes gait issues but lacks the extent of autonomic dysfunction seen in Shy-Drager syndrome. Therefore, the defining features of parkinsonism and pronounced dysautonomia prominently link it to Shy-Drager syndrome.