USMLE · Question #592
A 40-year-old male comes to his physician due to progressive muscle weakness and paralysis. Over the next few years, his condition progresses to complete paralysis of all voluntary muscles and he…
The correct answer is D. spinal cord. Amyotrophic lateral sclerosis (ALS) commonly known as Lou Gehrig disease is a devastating disease characterized by the degeneration of both upper and lower motor neurons. Depending on the stage of the disease, patients may primarily experience either upper motor symptoms…
Question
A 40-year-old male comes to his physician due to progressive muscle weakness and paralysis. Over the next few years, his condition progresses to complete paralysis of all voluntary muscles and he eventually dies of respiratory failure. Microscopic examination of tissue obtained at autopsy shows that both upper and lower motor neurons are degenerated. Of the listed options, the location which would likely reveal the most marked neuronal loss is the
Options
- Acaudate nucleus
- Bcerebellum
- Cglobus pallidus
- Dspinal cord
- Esubstantia nigra
How the community answered
(59 responses)- A5% (3)
- B2% (1)
- C10% (6)
- D81% (48)
- E2% (1)
Explanation
Amyotrophic lateral sclerosis (ALS) commonly known as Lou Gehrig disease is a devastating disease characterized by the degeneration of both upper and lower motor neurons. Depending on the stage of the disease, patients may primarily experience either upper motor symptoms (hyperreflexia, spasticity, Babinski reflex) or lower motor symptoms (weakness, muscular atrophy, fasciculations) usually both. Upper motor neurons are located in the motor area of the cerebral cortex and lower motor neurons are located in the anterior horn of the spinal cord. ALS may be caused be a defect in superoxidase dismutase 1. There is no effective therapy although riluzole may be used to manage symptoms.
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