Peripheral Neuropathies

Question 1

What is peripheral neuropathies?

Answer 1

Nerve pathologies outside the CNS of peripheral nerve

Question 2

What are the causes of peripheral neuropathies

Answer 2

Demyelination is often secondary to an infectious, an ischemic, a metabolic, or a hereditary disorder or to a toxin (eg, alcohol, ethambutol).
Primary causes are sually autoimmune(GBS)

Question 3

|What are the mechanism by which peripheral neuropathy can be caused>

Answer 3

demylination
axon damage
nerve compression
vacular compromise-infarction

Question 4

What are the differennt type of peripheral neuropathies?

Answer 4

Mononeuropathies : Affect single nerve
mononueritis multiplex: affects several individual nerves
Polyneuropathy - diffuse nerve involvemnet - often symmetrical pathologies

Question 5

Name 4 types of mononeuropathies?

Answer 5

Carpal Tunnel syndrome
Radial Nerve palse
Ulnar nerve pasly
Sciatica

Question 6

What is carpal tunnel syndrome?

Answer 6

Carpal tunnel syndrome is caused by nerve compression of the medial nerve passing originating from C6-T1

Question 7

What are the RF/CAUSES of carpal tunnel sydrome

Answer 7

Female>Males
>30
Obesity
Hypothyroidism, Acromegaly, preganancy, RA

Question 8

How would carpal tunnel sydrome present?

Answer 8

Gradual onset and intermittent
Numbness and parathesia of hand
Weakened grip
Aching forearm and hand
Night time worsening (relieved by hand hanging overside bed); wake and shake

Question 9

How to diagnose carpal tunnel syndrome?

Answer 9

Phalen test: flex wrist>1min = pain and aprathesia
Tinel test - Tapping of wrist causes tingling

Question 10

Treating carpal tunnel syndrome

Answer 10

Wrist splint to wear at night
Steroid injection if painful

Last resort - Surgical decompression

Question 11

What is radial nerve palsy?

Answer 11

Typically caused by injury to the radial nerve (originating from C5-T1) classically presenting wrist drop.

Radial nerve innervates extension arm muscles

tx- analgesia+ wrist splint

Question 12

What is ulnar nerve palsy

Answer 12

Typically caused by injury to the ulnar nerve (originating from C8-T1) classically presenting with claw hand.

TX - Wrist splint and simple analgesia

Question 13

What is sciatica

Answer 13

L5/S1 lesion due to:
Spinal disc hernation / prolapse
non-spinal: Piriformis syndrome (piriformis msucle compress spinal tracts), tumour

Question 14

How would sciatica present?

Answer 14

Pain from buttock down lateral leg to toes
Absent Ankle jerke

Question 15

Diagnosing sciatica?

Answer 15

Clinical examination: cant raise a straight leg without pain
MRI Spinal cord to confirm

Question 16

Sciatica tx

Answer 16

Analgesia
Physiotherapy
Neurosurgery

Question 17

What are the causes of mononeurities multiplex?

Answer 17

Think vasculities and
Wards PLC
Wegners
Amyloidosis
RA
DMT2
Sarcoidosis
polyarteritis boidisa
Leprosy
Carcinomas

Question 18

What are the causes of polyneuropathies

Answer 18

Diabetic neuropathy - Mostly sensory neuropathy
Guillian barr syndrome - Motor neuropathy

Other: vasculities, malignancy , b12 def, RA

‘Glove and stocking disrubution (numbness, weakness, or pain in the hands and feet)

Question 19

What is charcot mary tooth

Answer 19

Inherited sensory and motor PNS poly neuropathy.
Autosomal dominant inheritance pattern PUP22 gene ~ Chr7
Diagnosed via nerve biopsy

Question 20

How does charcot mary tooth present

Answer 20

Foot drop
Stork legs ( calves are skinny)
Hammer toes (Toes always curled up)
Feet : flat/high arched

Question 21

What is foot drop

Answer 21

Front of the patients foot drags on the ground as they walk, most commonly caused by peroneal nerve compression

Question 22

What causes foot drop?

Answer 22

Causes:
→ Nerve injury - e.g knee injury can cause compression of the peroneal nerve, can also be injured during hip or knee replacement surgery
→ Muscle or nerve disorders that cause progressive muscle weakness - e.g Charcot-Marie-Tooth disease
→ Brain and spinal cord disorders - Stroke/MS/ALS
→ tumour/cyst/bone lesions pressing on peroneal nerve

Question 23

Signs of foot drop

Answer 23

Difficulty lifting the front part of the foot, foot drag on the floor when pt walks
→ steppage gait - pt raises thigh more than usual when walking as though climbing stairs
→ numbness of the top of foot and toes can occur
→ can affect one or both feet

Question 24

Foot Drop DX and TX

Answer 24

Investigations and diagnosis
→ Imaging - X-rays/ultrasound/CT/MRI
→ nerve conduction studies

TX -Treatment
→ Braces or splints
→ physical therapy
→ nerve stimulation
→ Surgery