Motor Neuron/Peripheral Nerve Disorders

Question 1

Abnormality of an individual nerve

Answer 1

Mononeuropathy

Question 2

Progressive motor weakness, usually symmetrical, in more than one limb, usually involving bulbar/facial weakness

Answer 2

Guillain-Barre syndrome

Question 3

Presents with both upper motor neuron and lower motor neuron findings

Answer 3

ALS (pathology at level of motor neuron in Anterior Horn Cell –> LMN signs)

Question 4

muscle atrophy, fasciculations

Answer 4

LMN signs

Question 5

Increased DTR is d/t

Answer 5

Upper motor neuron lesion

Question 6

These nerves may be involved in Guillain-Barre syndrome

Answer 6

Autonomic nerves: Heart rate variability, blood pressure lability, bowel-bladder dysfunction

Question 7

Decreased DTR is d/t

Answer 7

Lower motor neuron lesion

Question 8

hyper-reflexia, spasticity, Babinskis

Answer 8

UMN signs

Question 9

Dementia in ALS

Answer 9

Frontotemporal dementia

Question 10

Elbow mononeuropathy

Answer 10

Ulnar groove

Question 11

Common infections preceding Guillain-Barre syndrome

Answer 11

campylobacter
CMV
EBV

Question 12

Usual cause of death in ALS

Answer 12

Respiratory failure

Question 13

Acute foot drop/numbness

Answer 13

Fibrillar head/perineal nerve mononeuropathy

Question 14

Presents as length-dependent weakness (first in toes), stocking-glove distribution sensory loss
–> affects small unmyelinated fibers (impaired pain/temp) and large myelinated (impaired prop/vibratory sense)

Answer 14

Diabetic Axonal Sensorimotor Polyneuropathy

Question 15

Most common form of Guillain-Barre syndrome

Answer 15

Acute inflammatory demyelinating polyradiculoneuropathy

Question 16

atrophied tongue with fasciculations

Answer 16

ALS hallmark

Question 17

Spontaneous discharge of one or more sensory axons

Answer 17

Paresthesias

Question 18

Painless asymmetric weakness in absence of sensory abnormalities

Answer 18

Limb-onset ALS

Question 19

Pathogenesis for ALS

Answer 19

UNKNOWN

problem with glutamate intake/tox? 
oxidative stress?
neuroinflammation?
protein folding defects?
mitochondrial dysfunction?

Question 20

Visible muscle twitching

Answer 20

Fasciculations

Question 21

Responsible for UMN signs in ALS

Answer 21

motor cortex

Question 22

Dysarthria, dysphagia, dyspnea, worse prognosis

Answer 22

Bulbar-onset ALS