2. Aims
• Define neuropathy
• Describe different neuropathies and identify common
disease patterns
• List a differential diagnosis for each type of neuropathy
3. What is neuropathy?
Peripheral neuropathy
(PN) is damage or
disease affecting nerves
• may impair sensation,
movement, gland or
organ function, or other
aspects of health,
depending on the type
of nerve affected.
9. Mononeuropathies
• Affects one nerve
• Direct injury to a nerve,
ischemia, or inflammation.
• likely that the cause is a
physical compression, localized
trauma or infection
• e.g. carpal tunnel, cubital tunnel
• "pins-and-needles" sensation of
one's "foot falling asleep"
10.
11. Mononeuritis multiplex
• Simultaneous or sequential involvement of individual noncontiguous nerves,
• either partially or completely,
• evolving over days to years
• asymmetric
• Typically presenting with acute or subacute loss of sensory and motor function of
individual nerves
• May also cause pain
• deep, aching pain
• worse at night
• frequently in the lower back, hip, or leg
• In diabetes typically encountered as acute, unilateral, severe thigh pain followed by
anterior muscle weakness and loss of knee reflex.
18. Polyneuropathy
•Affects many nerve cells
in various parts of the
body
•Symmetrical
•Progresses slowly
•Caused by processes
affecting the whole body
19. Disease Patterns
• D istalaxonopathy e.g. diabetes, impaired glucose tolerance, alcohol
• the cell bodies of neurons remain intact
• axons are affected in proportion to their length.
• symptoms occur first and most severely in the feet.
• Myelinopathy aka Demyelinating disease e.g. Gullain Barre Syndrome
• myelin sheath around axons is damaged
• affects the ability of the axons to conduct electrical impulses
• Neuronopathy affects the cell bodies of neurones directly
• motor neurones (e.g. motor neurone disease)
• sensory neurones (sensory neuronopathy e.g. Herpes Zoster or
dorsal root ganglionopathy).
27. Summary
• Neuropathy has several different
patterns
• Early identification of pattern
helps target diagnosis, which in
turn influences management
• Diabetes may present with many
different disease patterns
• Causes are diverse from
metabolic processes, infection,
nutritional deficits, autoimmune
disease, drugs, toxins and more
Mononeurtitis multiplex
Vasculitis
A sural nerve biopsy from a patient with mononeuritis multiplex and systemic lupus shows the sural nerve (arrow head) on the left and an adjacent arteriole (arrow) with an inflammatory infiltrate and occluded lumen consistent with vasculitis.
The following patterns of nerve injury are shown in the figure: distal symmetrical polyneuropathy (DSP), small-fibre predominant neuropathy, and treatment-induced neuropathy (A); radiculoplexopathy and radiculopathy (B); mononeuropathy and mononeuritis multiplex (C); and autonomic neuropathy and treatment-induced neuropathy (D).
