CSD 482: N EUROSCIENCE FOR C OMMUNICATION D ISORDERS Case 3 Chief Complaint A 53
ID: 3516255 • Letter: C
Question
CSD 482: NEUROSCIENCE FOR COMMUNICATION DISORDERS Case 3
Chief Complaint
A 53-year-old right-handed man was referred for a second opinion regarding progressive bradykinesia, tremor, rigidity, and unsteady gait.
History
The patient was well until 10 years previous, when, while working as a fireman, he had noticed some slowness and difficulty using his right arm. This symptom gradually progressed, and 2 years later he had to change jobs and began working for the phone company. In the interim, he developed occasional shaking of the right arm and right leg. He saw a neurologist, who diagnosed him with Parkinson’s disease. Treatment with levodopa plus carbidopa (Sinemet) provided significant benefit. Bromocriptine (a dopaminergic agonist) was also helpful. He was later enrolled in an experimental trial of deprenyl (selegiline) plus vitamin E, but his symptoms gradually continued to worsen. The tremor spread to involve his whole body, and he became progressively slower and stiffer, complaining that he often had difficulty initiating movements. He had no family history of Parkinson’s disease, and no history of use of dopaminergic antagonist medications, toxin exposure, strokes, or encephalitis. CT and MRI scans were normal, and blood tests for Wilson’s disease were negative.
Neurological Exam
Mental Status: Alert and oriented. Normal language. Recalled 3/3 words after 5 minutes. Spelled “world” forward and backward correctly. Copied shapes correctly. In writing a sentence, exhibited micrographia.
Cranial Nerves: Normal, except for mask-like decreased facial expression and slightly hypophonic voice.
Motor: 4 Hz tremor of the head and all extremities, worse on the right side and worse at rest. Cogwheel rigidity, especially of the right arm. Finger tapping and rapid alternating movements slow bilaterally. No pronator drift. Good strength.
Reflexes: No extinction of the glabellar reflex (positive Myerson’s sign).
Coordination: Slow but not ataxic on finger-to-nose and heel-to-shin testing.
Gait: Unable to rise from a chair without assistance. Slow, stiff gait, with stooped posture, short steps, and decreased arm swing. Turned slowly without twisting body. Exhibited retropulsion of two steps when pulled gently backward.
Sensory: Intact light touch, pinprick, vibration, and joint position sense.
Localization and Differential Diagnosis
1) On the basis of the symptoms and signs above, is this patient more likely to have typical idiopathic Parkinson’s disease or atypical parkinsonism?
2) Degeneration of neurons in which structure is primarily responsible for this patient’s type of Parkinson’s disease? What is the main neurotransmitter associated with this structure? How does loss of these neurons result in a hypokinetic movement disorder?
Explanation / Answer
1. Typical Parkinson's
2. Degeneration of Dopaminergic neuron (specially in substantia nigra area of brain).
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