Neuroscience Clerkship

Neuroscience Clerkship Teaching Vignettes

Case 1: A 22-year-old, right-handed man complained of fatigue. For the past three months, he had noted increasing difficulty when rising from chairs, climbing stairs and brushing his teeth. Symptoms were less pronounced in the morning and after periods of rest. More recently, he developed intermittent double vision. Sensory symptoms were absent. Exam demonstrated bilateral ptosis and the inability to fully squeeze the eyes shut. He was unable to whistle. Sensory exam was normal. There was mild fatigability of the shoulder and hip girdle muscles. Muscle bulk was normal. Reflexes and coordination were normal.

1. What is the likely diagnosis in this case?

2. What further studies might be performed?

3. After the diagnosis is secured, what therapies might be indicated?

4. What medicines or other conditions might exacerbate this patient’s symptoms?

Case 2: A 45-year-old, left-handed bartender developed tingling in his feet four days prior to admission. He had been well other than a mild upper respiratory tract infection two weeks earlier. By the next day, he was stumbling and complaining of tingling in the fingers as well. Subsequently, his weakness progressed so that he could not stand alone, and could not lift his arms over his head. On exam, temperature was 98.6 deg. F., pulse 115, blood pressure was 170/90, respirations were 24 and vital capacity was 2.2 liters. He had mild bifacial weakness, absent reflexes and weakness in all limbs, proximal and distal. Position, vibration, temperature and pin sensations were diminished in all four extremities.

1. At what site in the neuraxis is the disease located in this case?

2. What is the differential diagnosis in this 35-year-old man?

3. What laboratory studies should be obtained?

4. What management should be initiated?

Case 3: A 63-year-old, right-handed man comes to clinic after abruptly suffering the onset of left knee extension weakness, and numbness and pain over the left anterior thigh one week earlier. The condition has been stable since. He indicates that two weeks before he had awakened in bed with a right wrist drop and numbness over the back of his hand, accompanied by pain in the right upper arm. He was prescribed a cock-up splint from his internist. He has had a low grade fever over the last month and has lost ten pounds of weight. Examination demonstrates weakness in the areas mentioned. Numbness is present over the left anterior thigh and medial calf, as well as over the dorsum of the right hand between the thumb and index finger. Reflexes are unobtainable in the left knee and right triceps.

1. What is the difference between a mononeuritis multiplex and a polyneuropathy?

2. What nerves are involved in this patient?

3. What is the differential diagnosis of this condition?

4. What laboratory investigations are indicated?

5. What treatments should be considered?

Case 4: A 42 year-old woman developed progressive weakness over the past three months. She noted increasing difficulty when rising from chairs, climbing stairs and combing her hair. She also developed mild difficultly with swallowing, especially solid food. There was no pain, no sensory symptoms and no rash. On examination, cranial nerve testing was normal. There was mild weakness of neck flexors.

Moderate weakness of shoulder and hip girdle muscles was present. Muscle bulk was normal. Reflexes were normal. Sensory examination was normal to all modalities.

1. What is the pattern of weakness?

2. What is the differential diagnosis of this patient?

3. Would knowing the patient’s list of medicines be helpful? Why?

4. What laboratory testing would be useful?

Extra Case if Time Permits
 

Case 5: A 47-year-old, right-handed man had been suffering for six months from slowly progressive numbness of both feet. Recently, his fingertips had begun to become numb. He described an unpleasant burning sensation. Weakness was denied. On exam, cranial nerves were normal. Position and vibration sense was grossly diminished in the feet. Cool stimuli and pin were perceived, but there was a subjective stocking distribution of numbness to the mid-calf bilaterally. Reflexes were absent at the ankles and diminished elsewhere. Atrophy of the intrinsic foot muscles was present bilaterally. Strength was close to normal in the arms, but intrinsic hand strength was rated 4/5. He could not heel or toe walk.

1. Is there evidence for a neuropathy, radiculopathy or myelopathy in this case?

2. What are some of the more common causes of a slowly progressive neuropathy?

3. What investigations should be initiated?