Disorders of Nervous System Caused Deficiencies

Question 1

Key features of B12 (cobalamine) deficiency 1

Answer 1

Genelde hayvansal gıdalarda bulunur
B12 azalırsa Homocysteine artar, bu da stroke ve heart attack riskini arttırır. Methylcobalamine de artar.
Neurologic symptoms: Sensory and motor deficits (Pyramidal + posterior column) dementia. Post column involvement varsa rhomberg +, corticospinalde de babinski +
Strawberry tongue!
Megaloblastic anemia
Pernicious anemia

Question 2

Key features of B12 (cobalamine) deficiency 2

Answer 2

Mental slowing, subacute combined degeneration of the spinal cord, Posterior columns of upper thoracic and cervical cord, Peripheral nerve axonal degeneration, May involve cerebral white matter and optic nerve

Question 2

Key features of B9 deficiency

Answer 2

Same signs as B12 deficiency except no neurological
signs
■ Also should be checked for B12 deficiency
■ B12 deficiency appear within years (stored in liver)
■ Folate deficiency are seen within 4‒6 weeks.

Co-exists with
– Alcoholism or malnutrition
– Pregnancy
– Phenitoin, methotrexate, trimethoprim, azathioprine
– Crohn or ulcerative colitis

Question 2

Thiamine deficiency (B1) key features 1

Answer 2

Sarı serum = B1 + glikoz
Thiamine involves carbohydrate metabolism
– pyruvic acid and alpha ketoglutaric acid decarboxylation
■ Thiamine requirement increases during high caloric intake,
high metabolic rate
■ Therefore, thiamine can be needed when IV glucose infusion is given.
■ Result: Peripheral neuropathy, subacute start after strenous athletic training in summers

Neuronal necrosis

Question 3

What is thiamine deficiency’s (B1) peripheral nervous system involvement?

Answer 3

Beriberi: extreme weakness (Peripheral nervous system)
– affecting heart and peripheral nerves
– resulting in congestive cardiomyopathy, sensory-motor
polyneuropathy
■ Paresthesia, weakness of lower extremities, muscle tenderness,
tachycardia, weakness in extensors of wrist or finger
■ Cranial nerve palsies, hoarseness of voice (laryngeal nerve)
■ Lab: serum levels of thiamine, EMG, ECG, chest Xray: cardiac enlargement
*Hyperemesis gravidarum

Question 3

What is thiamine deficiency’s (B1) central nervous system involvement?

Answer 3

WERNICKE-KORSAKOFF’s syndrome
Wernicke encephalopathy: an acute syndrome with
– Mental confusion,
– ophthalmoplegia,
– gait ataxia
■ Hemorrhages in periventricular gray matter near aquaduct, 3rd-4th ventricles, mamillary bodies
■ In malnourished patients (may be related to alcoholism)
■ IV glucose administration or carbohydrate loading in pts with poor nutritional state
– Hypothermia, postural hypotension (hypothalamic involvement)
– Same biochemistry pathway as seen in beriberi
– Mortality is high (even with thiamine replacement) %10-20

■ Chronic condition after Wernicke’s encephalopathy with
– Memory problems (antero and retrograde amnesia)
– Confabulation
– Despite treatment, improvement in memory is incomplete
– Anatomical basis:
■ involvement of diencephalon and temporal lobes

Question 3

Nicotinic acid or niacin (b3) deficiency key features?

Answer 3

PELLEGRA (pelle agra: rough skin)
Coenzyme in carbohydrate metabolism
■ Seen in alcoholism or corn-dependent diet (corn does not contain niacin)
■ Adding animal proteins or legumes can cure pellagra
■ 3 D’s: diarrhea, dermatitis, dementia
– Erythema, reddish-Brown hyperkeratotic rash
– İrritability, apathy, depression
– Spasticity, startle myoclonus
■ In unresponsive pts with Wernicke Korsakoff syndrome, Niacin def should be sought

Spasticity, gegenhalten, babinski sign, startle myoclonus

Question 3

VITAMIN B6 (Pyridoxine) deficiency key features?

Answer 3

Causes peripheral neuropathy and seizures
Only vitamin that can cause seizures
Excess is also harmful
Should be thought if an infant with seizures are unresponsive to antiepileptics

Question 4

Vitamin C (ascorbate) key features?

Answer 4

Brains antioxidant
Neuromodulator of glutaminergic, dopaminergic, cholinergic and GABAergic transmission
Has therapeutic effect in neurodegenerative disorders

Question 4

Vitamin A key features?

Answer 4

Vitamin A’s aldehyde form (retinal) bind with the protein opsin to form rhodopsin
■ Deficiency can be seen in fat-malabsorbtion, biliary atresia, cystic fibrosis
■ Reduced ability to see in dim light
■ Symptoms also include
– White foamlike spots in cornea
– Xerosis, keratinosis of conjunctiva-cornea
■ On the other hand,
– Toxicity of Vitamin A may result in intracranial pressure
increase and might cause vision loss

Question 5

Vitamin D deficiency key features?

Answer 5

Pain and myopathy (proximal weakness) in pelvic girdle (after supplement, the pain disappears)
■ Multiple bone fractures
■ Caused by
– Hyperparathyroidism
– Hypophosphatemia
– Anticonvulsant use
– Malabsorbtion
– Dietary deficiency
■ Pain disappears quickly after D vitamin replacement

Question 6

Key features of vitamin e deficiency

Answer 6

Vitamin E
■ A fat-soluble vitamin that gives syptoms after a depletion occurring in 15 yrs
■ Sx: Weakness, unsteadiness
■ Neuro-exam: spinocerebellar degeneration + peripheral neuropathy or nystagmus, ptosis, external ophthalmoplegia
■ Lab: Low serum Vit E level
■ Symptoms ocur in patients with fat malabsorbtion

Question 7

Which vitamins’ deficiencies cause dementia and encephalopathy?

Answer 7

Vitamine B12, nicotinic acid, thiamine (B1), folate (B9)

Question 8

Which vitamins’ deficiencies cause seizures?

Answer 8

Pyridoxine (B6)

Question 9

Which vitamins’ deficiencies cause myelopathy?

Answer 9

Vitamin B12, vitamine E, folate, copper

Question 10

Which vitamins’ deficiencies cause Myopathy?

Answer 10

Vitamin E and D

Question 11

Which vitamins’ deficiencies cause peripheral neuropathy?

Answer 11

Thiamine, B12

Question 12

which vitamins’ deficiencies cause optic neuropathy?

Answer 12

Thiamine, B12