Neuropathies Flashcards
What are the types of peripheral nerve fibers?
A, B, C
A alpha M motor
A beta M touch, pressure, vibration
A gamma M muscle spindle
A delta somatic pain, temperature, touch
B M autonomic preganglionic
C nonM visceral pain, temperature, autonomic postganglionic
What are the 3 basic pathological processes in peripheral nerves?
Wallerian distal degeneration
Segmental demyelination
Distal axonal degeneration
What is neuropathy?
A pathological process that affects one or more peripheral nerves such as
Segmental Demyelination
Distal axonal degeneration (Wallerian)
What are the patterns of neuropathy?
Mononeuropathy - focal single
Multifocal neuropathy (mononeuritis multiplex) - multiple single
Polyneuropathy - diffuse multiple symmetrical length dependent
“Stocking - and - glove”
What are the symptoms of neuropathy?
Negative phenomena
- loss of JPS, vibration and touch
- loss of pain and temperature
- Charcot joint
Positive phenomena
- paresthesia
- painful (allodynia, hyperesthesia, hyperalgesia, hyperpathia, burning)
Secondary manifestations
Burns, trauma, ulcers, Charcot, trophic change
What are the sensory signs of neuropathy?
Sensory modalities absent
Gait examination
Romberg +
Neuropathic ulcers, burns, Charcot
Trophic changes
- cold blue extremities
- cutaneous hair loss
- brittle nails
- edema
- shiny featureless skin
Axon reflex absent
What are the motor signs of neuropathy?
Muscle wasting
Fasciculations and cramps
Weakness flaccidity
Deep tendon reflexes depressed
What are the autonomic signs of neuropathy?
Postural hypotension
Impotence
Constipation
incontinence
Diarrhea
Diaphoresis
Vision blurring
Pupillary dysfunction
What are the causes of neuropathy?
VASCULITIS polyarteritis nodosa Wegener’s granulomatosis Rheumatoid arthritis SLE
INFLAMMATORY
GBS
chronic inflammatory demyelinating polyradiculoneuropathy
Multifocal motor neuropathy with conduction block
NUTRITIONAL
Vitamin B 12 deficiency
NEOPLASTIC MALIGNANCY Bronchus Breast Ovarian Uterine
INFECTION
HIV
Leprosy
TRAUMA
crush. Section. Avulsion
TOXINS DRUGS
alcohol
Isoniazid
Lead
ENDOCRINE/ METABOLIC
diabetes
Renal disease
Porphyria
What are the investigations for neuropathy?
BLOOD TESTS
ESR CRP FBS FBC RFT LFT RF ANCA B12
NCS EMG
Nerve Bx
CSF for protein
What are the examples for mononeuropathy?
Carpal tunnel syndrome
Ulnar nerve compression
Radical nerve compression (Saturday night palsy)
Common perineal nerve palsy
Lateral femoral cutaneous nerve (meralgia paresthetica)
What are the examples for mononeuritis multiplex?
Diabetes mellitus
CTD small vessel vasculitis
Sarcoidosis
Amyloidosis
Neurofibromatosis
HIV
Leprosy
What are the causes for polyneuropathy?
RESULT OF SYSTEMIC DISEASE Diabetic neuropathy Renal disease Paraneoplastic polyneuropathy CTD vasculitis Porphyria Amyloidosis
RESULT OF DRUGS AND TOXINS chloramphenicol Phenytoin Isoniazid Amphotericin Dapsone Cisplatin Lead Arsenic Alcohol
INFLAMMATORY DEMYELINATING
Acute - GBS
Chronic - CIDP
What is GBS?
Acute ascending inflammatory demyelinating polyradiculoneuropathy
Few weeks after a respiratory or diarrheal infection, vaccination
Lasting only 6-8 weeks
Ascending classic symptoms Distal paresthesia Little sensory loss Proximal weakness or generalized Facial weakness Ophthalmo paresis Bulbar weakness
Risk of respiratory failure
Autonomic dysfunction
Arrhythmia
Incontinence
Constipation
