27: Neuropathies - Mahoney Flashcards
6 most common causes of acute peripheral neuropathy
PAT PAT
Proximal diabetic neuroapthy (diabetic amyotrophy)
Arterial (vasculitis)
Trauma
Paraneoplastic syndrome
Acute inflammatory demyelinating polyradiculoneuropathy AIDP (GB)
Toxins (thallium, arsenic, mercury, pesticides)
chronic neuropathy possible causes (3)
- hereditary neuropathies
- chronic inflammatory demyelinating polyradiculoneuropathy CIDP
- diabetic polyneuropathy
neuropathies that come and go
- GB
- CIDP
- HIV
- Toxins
- Porphyria
- MS*
excessive rxn to sensation
hyperesthesia
decreased vibration sensation suggests –>
diminished pinprick and light touch suggest –>
lg. fiber involvement and dying back phenomenon
small fibers (unmyelinated)
inability to stand on heels suggests –>
inability to stand on tiptoes suggests –>
peripheral neuropathy (longest nerves affected first)
CNS problem (spinal cord tumor or lesion)
most statistically relevant combination of signs that increase the likelihood of distal symmetrical polyneuropathy
- decreased or absent ankle reflexes
- decreased distal sensation (symmetric polyneuropathy)
metabolic causes neuropathy
A DUMB
amyloidosis diabetes uremia myxedema (hypothyroidism) B12, B6, B1 Thiamine deficiencies
toxic causes neuropathy
MedICAL
Medications (
Metal (heavy) exposure
Insecticides
Alcohol
what medications can cause neuropathy?
cancer: vincristine, taxol, interferon, cisplatin
arthritic: colchicine, chloroquine, gold
psychotropic: lithium, amitriptyline, phenytoin
antibiotics/antivirals: metronidazole, retrovirals, dapsone, nitrofurantoin, isoniazid
cardiac: hydralazine, amiodarone
malignant causes of neuropathy
BL(mO)G
Bronchogenic carcinoma
Lymphoma
mOnoclonal paraproteinemias
Gastric carcinoma
hereditary cause of neuropathy
to CHARt
charcot-marie tooth
infectious causes of neuropathy
Infections (5)
HIV Lyme Borreliosis Leprosy Hepatitis
only truly informative blood tests for neuropathy
Fasting blood glucose and A1C
Creatinine
TSH
B12
consider plasma electrophoresis in older men to rule out multiple myeloma
distinguishes nerve from muscular disease
EMG
NCV- distinguishes axonal from demyelinating disease
these are good for lg. fiber neuropahties (not small)
use sural n. biopsy if…
vasculitis, amyloid, sarcoid or malignancy are suspected
what is the use for intra-epidermal nerve fiber density biopsy?
useful only for diagnosing small fiber neuropathy
we __________ the sole use of monofilament testing to diagnose peripheral neuropathy
do not recommend
25% of diabetics have positive SWM test even if they dont have neuropathy
MGUS =
monoclonal gammopathy due to clonal proliferation of B cells
IgM most common when neuropathy is found
nerve tissue damaged by deposition of antibodies specific for a myelin or axonal component
**_____ of diabetics have neruologic deficit attributable to non-diabetic causes
10%
diabetic sensory distalpolyneuropathy should only be diagnosed when..
retinopathy or nephropathy can also be demonstrated
