This document discusses peripheral neuropathy, including: - The clinical effects of motor, sensory, and autonomic nerve injury, including weakness, loss of sensation, and autonomic dysfunction. - The two main types of peripheral neuropathies - axonopathies which affect nerve fibers, and myelinopathies which affect the myelin sheath. - The many potential causes of peripheral neuropathy both inherited and acquired, such as diabetes, toxins, infections, inflammation and genetic disorders. A thorough history and examination is needed to determine the underlying cause.

1. Peripheral Neuropathy
Dr. Mohammad Tanvir Islam

2. Nervous System
• CNS
• PNS

5. Loss of function
“- symptoms”
Disturbed function
“+ symptoms”
Motor nerves Wasting
Hypotonia
Weakness
Hyporeflexia
Orthopedic deformity
Fasiculations
Cramps
The clinical response to motor nerve injury

6. www.neuro.wustl.edu/neuromuscular/pics/people/patients/Hands/handatrophymnd3.jpg

7. Loss of function
“- symptoms”
Disordered function
“+ symptoms”
Sensory
“Large Fiber”
↓ Vibration
↓ Proprioception
Hyporeflexia
Sensory ataxia
Paresthesias
Sensory
“Small Fiber”
↓ Pain
↓ Temperature
Dysesthesias
Allodynia
The clinical response to sensory nerve injury

8. Loss of function
“- symptoms”
Disturbed function
“+ symptoms”
Autonomic nerves ↓ Sweating
Hypotension
Urinary retention
Impotence
Vascular color changes
↑ Sweating
Hypertension
The clinical response to autonomic nerve injury

9. http://www.neuro.wustl.edu/neuromuscular/nother/skel.html#nosteo

10. The two types of peripheral neuropathies:
axonopathies and myelinopathies

12. Causes
Conditions causing mononeuropathy
• Acute (trauma-related)
• Chronic (nerve entrapment)
Disorders causing mononeuropathy multiplex
Acute
• Diabetes mellitus
• Multifocal motor neuropathy
• Vasculitic syndromes
Chronic
• Acquired immunodeficiency syndrome
• Leprosy
• Sarcoidosis

13. Causes
Conditions causing neuropathy with autonomic features
• Alcoholism
• Amyloidosis
• Chemotherapy-related neuropathy
• Diabetes
• Heavy metal toxicity
• Porphyria
• Vitamin B12 deficiency

14. Causes
Conditions causing painful neuropathy
• Diabetes
• Alcoholism
• Amyloidosis
• Chemotherapy (heavy metal toxicity)
• Idiopathic polyneuropathy
• Porphyria
• Paraneoplastic syndrome

15. Axonal & Demyelinating causes
• Axonal
• Diabetes mellitus
• Alcohol
• Uraemia
• Cirrhosis
• Amyloid
• Myxoedema
• Acromegaly
• Paraneoplastic
• Drugs and toxins
• Deficiency states
• Hereditary
• Infection
• Idiopathic
• Demyelinating
• Chronic inflammatory demyelinating
polyradiculoneuropathy
• Multifocal motor neuropathy
• Paraprotein-associated demyelinating
neuropathy
• Charcot–Marie–Tooth disease type I
and type X

18. In short
Inherited: e.g. Charcot-Marie-Tooth disease (HMSN)
Infectious: e.g. Leprosy
Inflammatory: e.g. Guillain Barre syndrome (AIDP)
Neoplastic: e.g. Monoclonal gammopathy
Metabolic: e.g. Diabetes
Drug: e.g. Vincristine
Toxic: e.g. Ethanol

19. History
• The temporal course of a neuropathy varies, based on the etiology.
• Trauma or ischemic infarction-acute, with the most severe symptoms at onset
• Inflammatory and some metabolic neuropathies have a subacute course
extending over days to weeks.
• A chronic course over weeks to months is the hallmark of most toxic and
metabolic neuropathies

20. History
• A chronic, slowly progressive neuropathy over many years
• Hereditary neuropathies
• Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)
• Neuropathies with a relapsing and remitting course include
• CIDP
• acute porphyria
• Refsum's disease
• hereditary neuropathy with liability to pressure palsies (HNPP)
• familial brachial plexus neuropathy
• repeated episodes of toxin exposure

21. • Ischemic neuropathies often have pain as a prominent feature
• Small-fiber neuropathies often present with burning pain, lightning-
like or lancinating pain, aching, or uncomfortable paresthesias
(dysesthesias).
History

22. • The clinical assessment should include:
• Careful past medical history
• looking for systemic diseases, eg. CTD
History

23. • All patients should be questioned regarding
• HIV risk factors
• diet (nutrition)
• vitamin use (especially B6)
• possibility of a tick bite (Lyme disease)
• Constitutional symtoms (malignancy)
History

24. Investigations: