M1.4 — 4 mononeuropathies

Question 1

sign of injury to the axillary nerve?

Answer 1

• weakness of arm abduction
• deltoid muscle atrophy
• sensory loss lateral upper arm

Question 2

sign of injury to long thoracic nerve?

Answer 2

winging of scapula d/t innervation of serratus anterior

• compression from milwaukee brace

Question 3

sign of injury to musculocutaneous nerve?

Answer 3

weakness in arm flexion and sensory loss to lateral forearm d/t innervation of biceps brachii, brachialis and coracobrachialis

Question 4

sign of injury to suprascapular nerve?

Answer 4

weak shoulder abduction and external rotation d/t innervation of supraspinatus and infraspinatus

Question 5

the sciatic nerve supplies sensation to where? and motor?

Answer 5

sensation = skin of foot, posterior lower leg
motor = hamstrings, distal adductor magnus, intrinsic muscles of foot, anterior/posterior compartments of leg

Question 6

signs of sciatic neuropathy?

Answer 6

weakness of dorsiflexion (progressive foot drop), weakness of plantar flexion, weak inversion, weak knee flexion, decreased sensation entire foot, achilles reflex affected

Question 7

signs of peroneal nerve injury?

Answer 7

weakness and foot drop, pain and paresthesia over dorsomedial of foot

Question 8

What does the femoral nerve innervate?

Answer 8

iliopsoas, quadriceps femoris

Question 9

what are pyogenic, specific and traumatic causes of discitis?

Answer 9

pyogenic = staph aureus (90%)
specific = TB, Brucella (unpasteurized goat cheese)
traumatic = injection of button batteries, direct trauma

• vertebral discs more vascularized in children until 7 years

Question 10

what are signs of discitis in 1-5 yo?

Answer 10

• may complain of LBP
• behavior demonstrating LBP
• refusal to walk, sit or stand
• sudden onset of limping
• low-grade fever sometimes
• refuse to flex legs
• rarely neurological signs

may see asymmetrical muscle stretch reflexes or positive SLR

Question 11

what are signs of discitis in school aged children?

Answer 11

• acute severe LBP
• malaise
• fever
• lumbar sine affects gait
• cervical spine causes torticollis, dysphagia

Question 12

how is discitis diagnosed? why is it hard to diagnose?

Answer 12

• Xray may not be positive for up to 6 weeks
• blood tests may not be reliable
• MRI imaging of choice

Question 13

what are signs of AS? who tends to get it?

Answer 13

• early morning stiffness
• positive HLA B27
• adolescent boys

Question 14

what is Wallerian Degeneration?

Answer 14

distal axon degenerates within a few days of injury, proximal axon regenerates

Question 15

What is axonal degeneration? signs?

Answer 15

“dying back” neuropathy - distal portions of axons first affected

• distal muscle wasting
• stocking glove sensory loss

Question 16

what is segmental demyelination?

Answer 16

primary damage to the myelin sheath with intact axon - proximal and distal parts affected

• seen in Guillain-Barre syndrome and Charcot-Marie-Tooth

Question 17

what is neuronopathies?

Answer 17

primary destruction of the nerve cell body

Question 18

what does neuronopathy in the anterior horn cell cause?

Answer 18

spinal muscular atrophy

Question 19

what does neuronopathy of the dorsal root ganglion cause?

Answer 19

distal degeneration of sensory axons, gross proprioceptive disturbance and ataxia

Question 20

what is Charcot-Marie-Tooth

Answer 20

hereditary neuropathy causing peroneal muscle atrophy

Question 21

What is Chronic Inflammatory Demyelinating Polyradiculoneuropathy?

Answer 21

chronic childhood neuropathy that’s potentially treatable. Subacute onset, progressive within 4 weeks, relapsing and remitting autoimmune disease

Question 22

What are clinical symptoms of Chronic Inflammatory Demyelinating Polyradiculoneuropathy?

Answer 22

• gait difficulty
• clumsy, frequent falls, inability to run, difficulty getting up from floor
• widespread areflexia and hyporeflexia