1. Symptom Scenario: Tingling
Tom Gamble and Jo Swallow
20/11/13

2. Common Mononeuropathies
Describe the presentation and causes of the following:
Median nerve (carpal tunnel syndrome)
Ulnar nerve
Radial nerve
Sciatic nerve
Lateral cutaneous nerve
Common peroneal nerve
Tibial nerve
Bell’s Palsy
Ramsay Hunt

3. Split into pairs and discuss/research a mononeuropathy

4. Radial nerve
The radial nerve may be damaged anywhere in its course. It is most commonly affected in the upper arm where it winds round the humerus
Finger and wrist drop are common, their severity depending upon the site of the lesion.
sensory loss on the dorsum of hand and forearm appropriate to the cutaneous distribution - see radial nerve anatomy

5. Common peroneal nerve
terminal of the sciatic nerve, providing motor supply to the muscles of the anterior and lateral leg.
most commonly damaged nerve in the lower limb and traverses the lateral aspect of the head of the fibula.
foot drop
weakness of dorsiflexion and eversion of the foot
weakness of extensor hallucis longus
inversion and plantar flexion are normal
anaesthesia over the lower lateral part of the leg and dorsum of the foot; often with little or no sensory loss
all reflexes are intact - the ankle jerk is lost in a sciatic nerve lesion

6. entrapment of the lateral cutaneous nerve of the thigh is named meralgia paraesthetica
Damage to the tibial nerve is uncommon. Most usually, there is paralysis of gastrocnemius which is easily tested by asking the patient to stand on tiptoe

7. Ramsay hunt
The Ramsay Hunt Syndrome is characterised by sensorineural deafness, vertigo and facial paralysis following Herpes Zoster infection. The patient is usually elderly. ?Treatment
otalgia - pain in the ear and the mastoid region - often with few signs on examination
a vesicular eruption involving the external ear
facial paralysis, deafness and vertigo
ipsilateral loss of taste in the anterior two-thirds of tongue

8. Mononeuritis multiplex is a condition which is characterised by multiple individual nerve palsies, for example an ulnar nerve palsy in one arm, a radial nerve palsy in the other arm, and an asymmetrical foot drop due to a lateral popliteal nerve lesion.

9. Causes of polyneuropathy:
Metabolic: Diabetes; renal failure; hypothyroidism; hypoglycaemia; mitochondrial disorders
Inflammatory: Guilain Barre; sarcoid
Vasculitis: PAN; Rheumatoid arthritis; Wegener’s
Malignancy
Infection: Lyme disease; HIV; syphilis; leprosy
Vitamin deficiency (Vit B1,6,12 – alcoholism)
Drugs: alcohol; isoniazid; nitrofurantoin; phenytoin
Inherited porphyria; Charcot Marie Tooth

10. Blood Tests for Polyneuropathy
Glucose; FBC; U&E; B12, TFTs +/- LFTs, autoimmune profile,syphilis serology

11. Polyneuropathy ?Motor – eg guillain – barre ?sensory
Painful – eg diabetic, alcoholic, B12 defic
Other, demyelenation, axonal

12. Guillain-Barre
Guillain-Barre syndrome is an acute, inflammatory, postinfectious polyneuropathy.
A prodromal malaise with vomiting, headache, fever and limb pains is rapidly surmounted by a progressive and ascending paralysis. This can lead to respiratory dysfunction, and as such, the acute presentation can be a neurological emergency.
The incidence is 2 per per year.
Usually within 3 wks of a viral illness
Muscle weakness evolves over 3-21 days. It may be generalised, proximal in distribution, or commence distally and ascend

13. Treatment for Guillain-Barre syndrome is supportive
Treatment for Guillain-Barre syndrome is supportive. Early tracheostomy is indicated if there is progressive bulbar and respiratory weakness
Specific treatment for Guillain-Barre syndrome consists of high-dose intravenous immunoglobulin (IvIg) or plasma exchange

14. Myasthenia Gravis
Myasthenia gravis is an acquired autoimmune disorder characterised by weakness, typically of the periocular, facial, bulbar, and girdle muscles.
serum IgG antibodies to acetylcholine receptors in the postsynaptic membrane of the neuromuscular junction. Classically, the muscles are easily fatigued.
It affects 5 people in every
external ocular muscles - affected in over 90% of cases, and are the muscles first affected in 65% of cases; diplopia or ptosis, often asymmetrical, are typical
lower limbs are rarely affected

15. Management of myasthenia gravis
oral anticholinesterase medication, e.g. pyridostigmine or neostigmine
thymectomy - required if there is a thymoma because of the risk of local infiltration
immunosuppression with corticosteroids +/- cytotoxic agents is also highly effective in inducing remission of disease