27: Neuropathies - Mahoney

Question 1

6 most common causes of acute peripheral neuropathy

Answer 1

PAT PAT

Proximal diabetic neuroapthy (diabetic amyotrophy)
Arterial (vasculitis)
Trauma

Paraneoplastic syndrome
Acute inflammatory demyelinating polyradiculoneuropathy AIDP (GB)
Toxins (thallium, arsenic, mercury, pesticides)

Question 2

chronic neuropathy possible causes (3)

Answer 2

• hereditary neuropathies
• chronic inflammatory demyelinating polyradiculoneuropathy CIDP
• diabetic polyneuropathy

Question 3

neuropathies that come and go

Answer 3

• GB
• CIDP
• HIV
• Toxins
• Porphyria
• MS*

Question 4

excessive rxn to sensation

Answer 4

hyperesthesia

Question 5

decreased vibration sensation suggests –>

diminished pinprick and light touch suggest –>

Answer 5

lg. fiber involvement and dying back phenomenon

small fibers (unmyelinated)

Question 6

inability to stand on heels suggests –>

inability to stand on tiptoes suggests –>

Answer 6

peripheral neuropathy (longest nerves affected first)

CNS problem (spinal cord tumor or lesion)

Question 7

most statistically relevant combination of signs that increase the likelihood of distal symmetrical polyneuropathy

Answer 7

• decreased or absent ankle reflexes

- decreased distal sensation (symmetric polyneuropathy)

Question 8

metabolic causes neuropathy

Answer 8

A DUMB

amyloidosis
diabetes
uremia
myxedema (hypothyroidism) 
B12, B6, B1 Thiamine deficiencies

Question 9

toxic causes neuropathy

Answer 9

MedICAL

Medications (
Metal (heavy) exposure
Insecticides
Alcohol

Question 10

what medications can cause neuropathy?

Answer 10

cancer: vincristine, taxol, interferon, cisplatin
arthritic: colchicine, chloroquine, gold
psychotropic: lithium, amitriptyline, phenytoin

antibiotics/antivirals: metronidazole, retrovirals, dapsone, nitrofurantoin, isoniazid

cardiac: hydralazine, amiodarone

Question 11

malignant causes of neuropathy

Answer 11

BL(mO)G

Bronchogenic carcinoma
Lymphoma
mOnoclonal paraproteinemias
Gastric carcinoma

Question 12

hereditary cause of neuropathy

Answer 12

to CHARt

charcot-marie tooth

Question 13

infectious causes of neuropathy

Answer 13

Infections (5)

HIV
Lyme
Borreliosis
Leprosy
Hepatitis

Question 14

only truly informative blood tests for neuropathy

Answer 14

Fasting blood glucose and A1C
Creatinine
TSH
B12

consider plasma electrophoresis in older men to rule out multiple myeloma

Question 15

distinguishes nerve from muscular disease

Answer 15

EMG

NCV- distinguishes axonal from demyelinating disease

these are good for lg. fiber neuropahties (not small)

Question 16

use sural n. biopsy if…

Answer 16

vasculitis, amyloid, sarcoid or malignancy are suspected

Question 17

what is the use for intra-epidermal nerve fiber density biopsy?

Answer 17

useful only for diagnosing small fiber neuropathy

Question 18

we __________ the sole use of monofilament testing to diagnose peripheral neuropathy

Answer 18

do not recommend

25% of diabetics have positive SWM test even if they dont have neuropathy

Question 19

MGUS =

Answer 19

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

Question 20

**_____ of diabetics have neruologic deficit attributable to non-diabetic causes

Answer 20

10%

Question 21

diabetic sensory distalpolyneuropathy should only be diagnosed when..

Answer 21

retinopathy or nephropathy can also be demonstrated