Session 12: nerve injuries in l/ limb and gait abnormalities

Question 1

common l/limb examples of nerve compression

Answer 1

meralgia paraesthesia - compression of lateral cutaneous nerve of theigh in inguinal region

tarsal tunnel syndrome - compression of posterior tibial nerve at the ankle

Question 2

classification of nerve injuries according to Herbert J Seddon

Answer 2

Neuropraxia: transient interruption, recovery, no Wallerian degeneration, caused by eg biochem. lesion from concussion/compression/blunt blows/shock-like injuries, temporary loss of function -> reversible w/in hours - months, greater involvement of motor than sensory (autonomic is retained)

Axonotmesis: severe crush/contusion > neuropraxia, loss of continuity of myelin sheath and axon, epi and perineureum are retained, Wallerian degeneration, equal loss in both motor and sensory, element of retrograde/proximal degeneration of axon, axonal regen. occurs down intact neural tubes, 1-3mm per day

Neurotmesis: severe contusion/stretch/lacerations, epi and perineureum damaged, no gross loss instead there is internal disruption, loss of motor, sensory and autonomic, axonal regen. causes a neuroma to form

Question 3

neuropraxia

Answer 3

transient interruption, recovery, no Wallerian degeneration, caused by eg biochem. lesion from concussion/compression/blunt blows/shock-like injuries, temporary loss of function -> reversible w/in hours - months, greater involvement of motor than sensory (autonomic is retained)

Question 4

axonotmesis

Answer 4

severe crush/contusion > neuropraxia, loss of continuity of myelin sheath and axon, epi and perineureum are retained, Wallerian degeneration, equal loss in both motor and sensory, element of retrograde/proximal degeneration of axon, axonal regen. occurs down intact neural tubes, 1-3mm per day

Question 5

neurotmesis

Answer 5

severe contusion/stretch/lacerations, epi and perineureum damaged, no gross loss instead there is internal disruption, loss of motor, sensory and autonomic, axonal regen. causes a neuroma to form

Question 6

what stages do these represent?

Answer 6

1 normal

2 Neuropraxia: transient interruption, recovery, no Wallerian degeneration, caused by eg biochem. lesion from concussion/compression/blunt blows/shock-like injuries, temporary loss of function -> reversible w/in hours - months, greater involvement of motor than sensory (autonomic is retained)

3 Axonotmesis: severe crush/contusion > neuropraxia, loss of continuity of myelin sheath and axon, epi and perineureum are retained, Wallerian degeneration, equal loss in both motor and sensory, element of retrograde/proximal degeneration of axon, axonal regen. occurs down intact neural tubes, 1-3mm per day

4 Neurotmesis: severe contusion/stretch/lacerations, epi and perineureum damaged, no gross loss instead there is internal disruption, loss of motor, sensory and autonomic, axonal regen. causes a neuroma to form

5 5th degree lesion

Question 7

sunderland system

Answer 7

1st degree/Seddon’s neuropraxia: transient interruption, recovery, no Wallerian degeneration, caused by eg biochem. lesion from concussion/compression/blunt blows/shock-like injuries, temporary loss of function -> reversible w/in hours - months, greater involvement of motor than sensory (autonomic is retained)

2nd degree/Seddon’s axonotmesis: severe crush/contusion > neuropraxia, loss of continuity of myelin sheath and axon, epi and perineureum are retained, Wallerian degeneration, equal loss in both motor and sensory, element of retrograde/proximal degeneration of axon, axonal regen. occurs down intact neural tubes, 1-3mm per day

3rd degree: endoneureum disrupted, epi and perineureum intact, recovery can range from poor -> complete, depends on degree of intrafascicular fibrosis, nerve may not appear seriously on gross inspection

4th degree/Seddon’s neurotmesis: severe contusion/stretch/lacerations, epi and perineureum damaged, no gross loss instead there is internal disruption, loss of motor, sensory and autonomic, axonal regen. causes a neuroma to form

5th degree: complete transection w/ loss of continuity

Question 8

what is lesion of common peroneal nerve associated w/?

Answer 8

foot drop -> high steppage gait

loss of sensation of lateral leg and dorsum of foot

Question 9

what may stiffness/poor mobility/pain in a joint result in?

Answer 9

antalgic gait: walk in a manner that reduces the painful sensations

Question 10

what are the clinical presentations of nerve injuries?

Answer 10

bruising/crushing/entrapment -> compression (eg piriformis syndrome, meralgia parasthetica, below knee POP- Paris of plaster, prolapsed/herniated IV disc)

stretching/traction (dislocated hip, THR surgery- total hip replacement, leg lengthening)

anoxia- complete loss of oxygen, ie extreme hypoxia (dead leg, saturday night palsy, compartment syndrome)

division/transection (penetrating wounds, laceration by bone fragments, surgery)

Question 11

deep peroneal nerve damage results

Answer 11

motor loss of tibialis posterior, EDL, EHL, fibialis tertius

Question 12

piriformis syndrome

Answer 12

bruising/entrapment/crushing and conpression

piriformis muscle irritates sciatic nerve

pain in the buttocks

referring pain along course of sciatic nerve