Approach to peripheral neuropathy

for undergraduate students

1. Approach to peripheral neuropathy By Mohamed A. Tarek Assistant lecturer of Neurology Master of Neuropsychiatry Sohag university By Mohamed A. Tarek Assistant lecturer of Neurology Master of Neuropsychiatry Sohag university

2. Agenda: 1-Definition 2-classification 3-causes 4-c.p 5-investigations 6-management 7-Examples

3. Definition: Means inflammation or degenerative diseases affecting peripheral nerves &/or cranial nerves. leading to defective motor and /or sensory and /or autonomic functions of the affected nerves. Peripheral neuropathy may be : -   Mononeuropathy : single affected nerve. -   Mononeuropathy multiplex: multiple mononeuropathy or more than one nerve is affected in one limb. -   Polyneuropathy: affection of peripheral nerves in the four limbs. - Polyradiculoneuropathy: damage to peripheral nerves & roots. - Plexopathy - Radiculopathy

4. Classification: There are 3 types of peripheral nerves : Motor Sensory Autonomic

5. Classification: -   Mononeuropathy : single affected nerve. -   Mononeuropathy multiplex : multiple mononeuropathy or more than one nerve is affected in one limb. -   Polyneuropathy: affection of peripheral nerves in the four limbs. - Polyradiculoneuropathy : damage to peripheral nerves & roots. - Plexopathy - Radiculopathy

6. Classification: Axonal Demyleinating

7. Axonal

8. Demyleinating

9. Classification : inherited : - CMT (Peroneal muscular atrophy): 1,2,3,4,5,6,7 - Refsum dis : Neuropthy , RP , Ataxia , Skeletal deformities, CM , Deafness, Anosmia - P orphyria : p ositive family history , P urely motor , p roximal , P reserved ankle, P ain in Abdomen , P ort wine urine - Metachromatic leukodystrophy : PN ,Fits , Optic atrophy ,MR - Adreno leucodystrophy : PN , Adrenal insufficiency , Ataxia , Fits , Paraparesis. - Mitochondrial diseases

10. Acquired: 1-Acute idiopathic polyneuropathy: eg - Guillian - Barre syndrome. Miller Fisher syndrome. 2- Chronic idiopathic polyneuropathy .eg -Chronic inflammatory demylinating polyneuropathy (CIDP) 3- Polyneuropathy with infections .eg - Leprosy - Diphtheria -CMV HIV infections. - Lyme disease 4- Neuropathy due to systemic disease : -DM -CRF -Hypothyroidism -Acromegaly -SLE -Amyloidosis

11. Acquired : 5- Neoplastic and paraneoplastic : -Myeloma -Lymphoma 6-Drug induced neuropathy. - Dapsone - INH - Colchicine - Lithium -Metronidazole - vincristine -phenytoin. -Amiodarone 8- Metal poisoning (toxic) neuropathy - Lead. - Mercury. - Irradiation - Arsenic - Organophosphorus -Gold 9-Vitamin deficiency: B1. - B6 - B12. - Vit E 10-Vascular : - Systemic vasculitis -PAN - Major arterial occlusion - Collagen diseases

12. 1- Motor: Symptoms : - Weakness: of LMN features" characterized with weakness affecting - Both UL and LL ,more in LL - Bilateral symmetrical -Distal more than proximal usually leading to foot drop and wrist drop. -Extensors are more affected than flexors Signs : Atrophy , Hypotonia, hyporeflexia usually affecting distal limb parts. +/- Neuropathic Tremors C.P:

13. C.P : 2-Sensory: - Postive symptoms : Pain(burning) and parasthesia (tingling and numbness) - Negative symptoms : Impairment of superficial sensations leading to glove and stock hypothesia . - Impairment of deep sensation . Subjectively the patient will complain of - Pain and parathesias in the form of numbness, hotness in the distal limb parts -  Falling of shoes unconsciously.

14. C.P: 3-Cranial nerves : 7 , 3 , 9 , 10

15. C.P : 4-Gait : - High steppage gait due to weakness ( foot drop ). -Stamping gait due to deep sensory loss.

16. C.P : 5-Autonomic: - Postural hypotension -impotence -hyperhidrosis / Anhydrosis -skin changes in LLs : trophic ulcers , brittle nails , thin skin , coldness -Neurogenic bladder.

17. Important clinical Points : Common Causes of Mononeuropathy : 1- trauma : wrong injection into nerve . 2-infective : leprosy , Herpes zoster 3-vascular : PAN 4-metabolic : DM

18. Important clinical Points :   Mainly pure motor Neuropathy as in;  lead neuropathy   Porphyric neuropathy -  dapsone neuropathy - Beri-Beri. - G.B. syndrome. - Organophosphorus Inherited neuropathy is suggested in the presence of the following;  Positive family history of neuropathy or parental consanguinity. -  Often other system affection.

19. Important clinical Points : Mainly pure sensory Neuropathy as in; -  Vitamin E, B12 deficiencies neuropathy. -  Diabetic neuropathy "some types" -  Leprosy. Paraneoplastic Sjogren $ The weakness may be proximal as in; -   Porphyric neuropathy -  Demyelinating neuropathies. -  G.B. syndrome. -  Diabetic neuropathy(some types).

20. Important clinical Points : The autonomic features may be prominent as in; - DM. ( impotence,Neurogenic bladder) Hereditary sensory autonomic neuropathy. Demyelinating neuropathy is suggested in the presence of -  Proximal muscle weakness. -  Relative lack of muscle wasting. -  Lost deep sensations compared to relative preservation of superficial sensation. Causes of focal neuropathy includes; irradiation, compression, leprosy, trauma, D.M., vasculitis, tumors (Local infiltration).

21. Investigations : 1-Nerve conduction studies (NCS) 2-Electromyography (EMG ) 3- Nerve biopsy 4-Lab test 5-Genetic testing 6-other : -CSF. -CT scan

22. Management: According to the cause Drugs for neuropathic pain : Ex: anticonvulsants : Carbamazepine- Gabapentin- Lamotrigine-Pregabalin. Antidepressants : TCA - Duloxetine – venlafaxine.

23. Diabetic polyneuropathy D.M., is one of the most common causes of disabling polyneuropathy world wide . L ength dependant diabetic Polyneuropathy. More than 80% of patients with clinical diabetic neuropathy have the distal symmetrical form of the disorder. Neuropathy may be the 1st symptom of D.M. Patterns of DPN: -Diabetic sensori -motor neuropathy. - Diabetic autonomic neuropathy. - Diabetic proximal neuropathy. - Diabetic mononeuropathy (cranial or peripheral) - Diabetic trunkal neuropathy. The same patient may develop two or more of these types.

24. Diabetic polyneuropathy Management : 1-  Strict control of blood sugar. 2-  Aldose reductase inhibitors " sorbinol " 3-  Vasodilators and tonics. 4-  Carbamazepine, gabapentin, amitriptyline, duloxetine may help in sensory discomfort. 5-  Skin care is very essential.

25. Guillian Barre syndrome Acute inflammatory demylinating polyneuropathy.(AIDP) pathogenesis

26. C.P: -URTI or GIT infections is usually reported days before the disease with backache. - Paraesthia is often the 1st heralding symptom for the disease and LL are more commonly affected. -  Hours or days later, acute or subacute onset and progressive course of weakness or paralysis starting in both LL, usually ascends to involve trunk, respiratory, and both upper limbs muscles. -   Weakness is usually symmetrical, more proximal of LMN features with areflexia, hypotonia, or flaccidity. Progress of weakness takes usually takes1-4 weeks for maximum.

27. C.P:   Sensory affection is mainly subjective, e.g. parathesias , pain in calf muscles, but objective sensory changes as mild glove and stoke hypothesia may be present. The presence of sensory level will cast doubt on the diagnosis. -   No definite or persistant sphincteric disturbance can be detected, except in minority of cases and usually transient, but persistent &definite sphincter disturbance will rule out the diagnosis. -   Cranial nerves affection is common e.g. III, VII, X. -   Involvment of UL and trunk muscles may herald the occurrence of chest infection and respiratory failure and ventilation may be required.   Hyponatremia , papillodema , and autonomic disturbances, may develop . -   Prognosis is usually good, and mortality rate is about 5%.

28. Investigations: 1- CSF analysis : CSF shows cytoalbuminous dissociation ( High CSF proteins & Low WBCs) 2- NCS: show marked slowing in CV, conduction blocks.

29. Management: 1-Plasma exchange is highly needed within the 1st week for 4-5 sessions. 2-  High dose IV immunoglobulin may be superior to plasma exchange 0.4gm/kg for five days. 3- Complete bed rest.&physiotherapy 4-  Care of bed ridden patients as usual. 5-  Care of respiration and bulbar muscles. 6- Prophylactic Anticoagulants for DVT prophylaxis .

30. Chronic inflammatory demyelinating polyneuropathy CIDP -Slowly Progressive (more than 2 months ). Proximal and distal weakness. Fluctuating course. Good response to steroids and immunosuppressive drugs. I.V IG and plasma exchange is an alternative option as well .

31. Charcot Marie tooth Peroneal Muscular Atrophy CMT It is a hereditary motor and sensory neuropathy usually associated with autosomal dominant mode of inheritance. Types : 7 types The age of onset of this type is usually in the 1st or 2nd decades of life. Onset : gradual Course : progressive

32. C.P: Motor : Distal leg muscle wasting and weakness up to the lower third of the thigh giving the leg picture of inverted champagne bottle appearance. -Areflexia especially at the ankles .

33. Inverted champagne bottle appearance

34. C.P: Sensory: All modalities of sensations may be impaired distally. Glove and stock hypothesia Loss of vibration sense (Early) No pain and parasthesia is rare. Skeletal deformities : scoliosis , Pes cavus , thickened nerves

35. Management : No drug ttt Rehabilitation : Splints , Ankle foot brace. Orthopedic surgical intervention. Genetic counseling

36. Vitamin B12 deficiency Subacute Combined degeneration SCD Degeneration of → - Spinal cord leading to paraparesis, spasticity, sensory ataxia with late sphincteric disturbances. - Optic nerves >>bilateral optic atrophy. -Peripheral nerves >> mainly sensory neuropathy with glove stoke hypothesia . - Brain >> leading to dementia, impaired memory, confusion, and psychiatric disorders. + Pernicious Anemia

37. Dermatome vs Myotome

38. Dermatomal map:

39. Common myotomes:

40. Patterns of sensory loss

41. Email : [email protected] Slide share account : Mohamed Ahmed Tarek