Lec 14: Approach to Patients with Neuromuscular Disorders

Question 1

The following are features of UMN lesions EXCEPT:
A. spasticity
B. decreased muscle tone
C. increased reflexes
D. minimal atrophy
E. absent fasciculations

Answer 1

B. muscle tone should be increased

Question 2

The following are features of UMN lesions EXCEPT:
A. normal/decreased reflexes 
B. decreased muscle tone
C. flaccid muscle weakness
D. profound muscle atrophy
E. absent fasciculations

Answer 2

E. fasciculations are usually present

Question 3

clinical hallmark of myasthenia gravis

Answer 3

fatiguable muscle weakness

Question 4

muscle fibers are replaced by fat and connective tissue resulting in muscle weakness

Answer 4

calf-muscle pseudohypertrophy

Question 5

deformity caused by peroneal muscle atrophy

Answer 5

stork leg deformity (characteristic finding in Charcot Marie Tooth disease)

Question 6

patients with pelvic girdle weakness stand up from a sitting position by protruding their hips and straighten their legs

Answer 6

Gower’s sign

Question 7

average grip strength in males

Answer 7

48-52kg

Question 8

average grip strength in females

Answer 8

26-30kg

Question 9

most important blood examination to determine a muscle lesion

Answer 9

CK test

Question 10

autoantibody test for myasthenia gravis

Answer 10

Anti-AChR antibody

Question 11

nerve conduction findings seen in axonal abnormalities

Answer 11

reduction in compund motor action potentials

Question 12

nerve conduction findings in demyelinating injuries

Answer 12

prolonged latency, decreased nerve conduction velocities

Question 13

a peripheral nerve is stimulated repetitively at rates of 2-5Hz

Answer 13

Repetitive nerve stimulation

Question 14

EMG finding in myopathies

Answer 14

small motor unit action potentials with low amplitude

Question 15

EMG finding in neuropathies

Answer 15

prolonged MUAP and increase in amplitude

Question 16

EMG finding for myasthenia gravis

Answer 16

jitters on single fiber EMG

Question 17

Most sensitive test for MG

Answer 17

single fiber EMG

Question 18

CT scan finding for Distal Myopathy with Rimmed Vacuoles

Answer 18

marked hypodensity of tibialis anterior muscles

Question 19

CT scan finding for Miyoshi Myopathy

Answer 19

affected gastrocnemius and soleus muscles

Question 20

pharmacologic test used for the diagnosis of myasthenia gravis

Answer 20

edrophonium chloride/tensilon test

Question 21

specimens for muscle biopsy are usually taken from where?

Answer 21

biceps beacuse they have equal ratio of type 1, 2A, 2B

Question 22

histological features of segmental demyelination

Answer 22

onion bulb formation

Question 23

histological feature of wallerian/axonal degeneration

Answer 23

myelin ovoids