Neuropathy-vitamin related

 

Thiamine Deficiency-Vitamin B1

 

  • Beriberi-      “I can’t, I can’t” in Singhalese-Dutch East Indies, now Sri Lanka
  • 1st nutritional disorder recognized-17 century, although thiamine etiology recognized in 20th century
  • Presently rare in developed countries-due to restrictive diet, alcoholism, weight reduction surgery, recurrent vomiting
  • B1 is water soluble vitamin-present in most plant/animal tissue-greatest source is cereal grains, wheat germ, yeast, soybean flour, pork.
  • Recommended daily allowance-1-1.5 mg daily-no toxicity from over ingestion.
  • Deficiency symptoms-develop gradually over weeks to months, but on occasion rapidly.
    • Fatigue, irritability, muscle cramps
    • Prolonged deficiency- burning dysesthesia toes/feet and/or mild  sensory loss
    • Pain may be predominate feature.

 

 

 

Vitamin B6 Deficiency- Pyridoxine

 

  • Neuropathy from both deficiency and toxicity
  • Commonly seen due to side effect from TB and HTN meds
  • Also seen in malnutrition from alcoholism or pts receiving chronic peritoneal dialysis.
  • Peripheral neuropathy- axonal sensorimotor type
  • Toxicity
    • Striking clinical symptom of ataxic sensory neuropathy-numbness/tingling with ataxic gait
    • May occur in doses as low as 200 mg per day.  Daily intake greater than 100 mg is probably best avoided

 

 

 

Vitamin B12 Deficiency- Cobalamin deficiency

 

  • Pernicious anemia and other conditions of malabsorption are the most common cause
  • Pathology occurs in the posterior columns and lateral spinal cord tract, producing vibratory and position sense deficit, along with paraparesis and plantar responses.
    • Peripheral nerve pathology without in absence of myelopathy controversial.
  • Rarely due to inadequate dietary intake.
  • B12 only present in animal products
    • Vegans need to ingest some form as supplement; vegetarians can consume egg or dairy products

 

 

 

Vitamin E Deficiency

 

  • Present in animal fat, vegetable oils, and various grains-deficiency usually due to factors other than insufficient intake
  • Deficiency usually due to lipid malabsorption.
  • Pathology-swelling and degeneration of axons in the posterior column (vibratory/position sense deficit) and Spinocerebellar tracts-resembles Friedreich’s ataxia.  May present as isolated peripheral neuropathy-but this is rare.
  • NCS-sensory neuropathy.
  • Treatment with high doses vitamin E

 

 

 

Niacin Deficiency-Pellagra

 

  • Mostly underdeveloped countries where corn is main source of carbohydrate
  • Most Western countries have niacin enriched bread.
  • peripheral neuropathy mild, resembles beriberi; axonal degeneration
  • Treatment with niacin supplement-40-250 mg per day may not resolve neuropathy.

 

 

 

Gastric Surgery

 

  • Peripheral neuropathy may follow gastric surgery for ulcer, cancer, or weight reduction.
  • peripheral neuropathy-non specific axonal  sensory/motor loss
  • Usually occurs in the context of rapid, significant weight loss and recurrent protracted vomiting.
  • Treatment-vitamin supplement to include niacin

 

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