Peripheral Neuropathy.mansfans.com

PERIPHERAL NEUROPATHY

Prof.Dr/ Ahmed Gamal Azab

Definition  It

is inflammation or degeneration of the peripheral or cranial nerves resulting in impairment of conduction along these nerves leading to motor , sensory and/or autonomic manifestations. www.MansFans.com

Classification 1- Mononeuropathy : affection of a single nerve trunk in one limb. 2- Mononeuropathy multiplex : affection of more than one nerve trunk in the same limb. 3- Polyneuropathy : affection of more than one nerve trunk in more than one limb. www.MansFans.com

Causes of mononeuropathy & mononeuropathy multiplex 1- Traumatic : - Compression by a bony fragment or callous formation. - Dislocation. - Wrong injection into a nerve . - Crossed leg palsy & Saturday night paralysis. 2- Infective : - Leprosy – Herpes zoster. 3- Vascular : Polyarteritis nodosa . 4- Metabolic : Diabetes mellitus.

Causes of Polyneuropathy A- Heridofamilial : - Peroneal muscle atrophy . - Hypertrophic interstitial polyneuropathy. - Refsum disease. B- Acquired : 1- Infective : - Viral : mumps , measles. - Bacterial : Typhus , Typhoid , Tetanus. - Mycobacterial : Leprosy.

Acquired Polyneuropathy ( cont.. ) 2- Toxic : - Inorganic : lead, copper, arsenic, antimony, gold…. ( all heavy metals ). Organic : alcohol, insecticides. 3- Metabolic & Endocrinal : Diabetes mellitus, uremia, amyloidosis, acromegaly, myxoedema. 4- Nutritional : Pellagra, Beri-beri, subacute combined degeneration. 5- Iatrogenic : INH, sulphonamides, phenytoin, vincristine. 6- Autoimmune : Guillain Barre syndrome , collagen vascular disorders. 7- Paraneoplastic : bronchogenic carcinoma , lymphoma.

Pathology 1- Axonal neuropathy : in which the nerve cell body & axon are primarily affected. - It shows mild reduction in the nerve conduction velocity but regeneration is slow. - It occurs in traumatic, ischemic, nutritional and toxic causes.

Pathology ( cont.. ) 2- Demyelinating neuropathy : - In which Schwann cell is affected w/out involvement of the axon. - It shows marked reduction of the conduction velocity, but with rapid regeneration. - occurs in infective & metabolic causes.

Clinical Picture of Polyneuropathy  Regardless

of the cause, It is one of various combinations of motor, sensory and/or autonomic manifestations .  The manifestations are usually bilateral, symmetrical, distal more than proximal, involving the lower limbs earlier than the upper limbs.

Clinical Picture ( cont…) A- Sensory manifestations : 1- Subjective : pain, parasthesia ( numbness, tingling ) at the limbs periphery. 2- Objective : glove & stocking hyposthesia + distal deep sensory loss > sensory ataxia.

Clinical Picture ( cont…) B- Motor manifestations :LMNL ( wasting, weakness, hypotonia, hyporeflexia ). C- autonomic manifestations : - Vasomotor : coldness , cyanosis . - Trophic : loss of hair, brittle nails , trophic ulcers (in severe cases).

Investigations 1- EMG & NCS : reduced nerve conduction velocity. 2- Nerve biopsy : usually the sural nerve. 3- To detect the cause: Bl.sugar, tests for collagen vascular disorders, s.creatinine.

Diabetic Neuropathy 1- Diabetic sensorimotor polyneuropathy : -Common in insulin-dependent diabetics. -Sensory > motor . -Burning pain, stock, glove hyposthesia, impaired deep sensation. -Lost ankle reflex. -Autonomic neuropathy may occur. -In long standing cases > distal wasting, weakness may occur. Pathogenesis (still controversial) : -in elderly patients it may be an ischemic neuropathy. -in young patients > it may be due to a metabolic factor (hyperglycemia > sorbitol accumulation > decreased myoinositol uptake by nerve fibres > impaired impulse conduction) .

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Diabetic neuropathy( cont…) 2- Diabetic autonomic neuropathy: -Sweating, diarrhea, postural hypotension, impotence . 3- Diabetic proximal neuropathy : -Common in non-insulin dependent . -Start by pain front of the thigh followed by proximal leg weakness, lost knee reflex.

Diabetic neuropathy( cont..) 4- Diabetic mononeuropathy: - Affects peripheral or cranial nerves. - Nerves vulnerable to compression are the commonest ,such as : Median, ulnar , radial, common peroneal and lateral cutaneous nerve of the thigh. - Ocular nerves are commonly affected(improve in 3-6 months). 5- Diabetic truncal neuropathy : -Recurrent attacks of truncal pain w/sensory deficit in the distribution of a single thoracic root. -Spontaneous recovery occurs in few months.

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Treatment of diabetic neuropathy 1- Proper control of diabetes. 2- Pancreatic transplantation : minor recovery occurs 3.5 years post transplant. 3- Carbamazepine or Gabapentin for burning pain & Amitriptylline for aching pain. 4- Vitamins B1,B6,B12 ( help regeneration ). 5- Vasodilators. 6- Physiotherapy for motor weakness.

Peroneal Muscle Atrophy ( HMSN ) = ( Charcot-Marie-Tooth disease ) Type l : the commonest type, autosomal dominant, occurs in the first decade . - Starts by distal leg weakness & wasting w/ inverted champagne-bottle appearance ( as it involves the muscles transversely, does not extend above the junction between lower and middle third of the thigh). - Later on, there is hand weakness. - Stocking, glove hyposthesia, pes cavus, - There may be associated tremors.

HMSN ( cont…) Type ll : less common, autosomal dominant , onset in the second decade. - Pes cavus, hand weakness and sensory loss are less frequent. Type lll: uncommon, autosomal recessive, starts in infancy > delayed walking.skeletal deformities. Treatment : - Physiotherapy. - Ankle splints for foot drop.

Diphtheritic Neuropathy. Clinical picture : 1-Starts by true bulbar palsy (within few days) followed by > 2- Paralysis of eye accomodation ( ciliary muscle paralysis ) > blurred near vision. 3-Generalized sensorimotor polyneuropathy. 4-Diaphragmatic paralysis. Prognosis : - Good if the child survives. - Bulbar & accomodation weakness improve within 6 weeks. - Polyneuropathy recovery takes months.

Diphtheritic neuropathy ( cont…) Treatment : - Penicillin G : 600,000 u/12 hours for 14 days. - Diphtheritic antitoxin : should be given early as 100,000 u IM. - Assisted ventillation if need .

Leprotic Neuropathy - Organism : Mycobacterium leprae . - Long Incubation period ( about 3.5 years ). - Insidious onset. Types : 1- Lepromatous : nodules over the face > leonine facies. 2- Tuberculoid : maculo-anaesthetic skin patches, trophic ulcers. - It may be a mono or polyneuropathic affection. - Commonly affacts the facial, sensory 5th, great auricular, ulnar and common peroneal nerves. - Thickened affected nerves. - Sensory > motor affection. Treatment : - Dapsone 100mg/day + Rifampicin 600 mg/day ( for 1-2 years ). - Nerve grafting : for severe mononeuropathy with trophic ulcers.

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Guillain-Barre syndrome ( acute postinfective polyradiculoneuropathy ) Aetiology (theories) : 1- Post infection : 50% of cases have preceding respiratory or GIT viral infection. 2- Post vaccination : following vaccination against Swine influenza virus. 3- Lymphoma (Hodgkin disease). 4- Autoimmune theory. www.MansFans.com

Guillain-Barre ( cont…) Clinical picture : - Initial febrile illness. - Usually starts in LLs, then ascends to ULs. - Proximal > distal, bilateral symmetrical affection. - Bilateral LMNL 7th paralysis. - Bulbar weakness, followed by respiratory muscle paralysis. - Glove , stocking hyposthesia - Papilloedema (due to increased CSF proteins > diminished absorption.). www.MansFans.com

Guillain-Barre ( cont…) Prognosis : - Recovery in 3-6 months. - May be with mild residue in 40% of cases. - Survival for 8 weeks > good prognosis. Investigations : - CSF proteins > 2 g/L with normal cell count.

Guillain-Barre (cont…) Treatment: 1- Nasogastric tube feeding for bulbar palsy. 2- S.C heparin to guard against DVT. 3- Assisted ventillation. 4- Plasmapheresis ( must be done in the first 2 weeks). 5- IVIG : 0.4 g/Kg /day for 5 succesive days. www.MansFans.com