Neuropathology Review Questions

11/2/2012

Match the metal with the toxicity or description

• Arsenic• Lead• Mercury• Manganese

1. Mees’ transverse white lines on fingernails

2. Psychological dysfunction 3. Parkinson’s symptoms4. Red blood cell basophilic

stippling5. Brain levels increased by

dimercaprol (BAL)6. Symptoms improve with L-dopa7. Increased urine coproporphyrin8. Penicillamine and BAL are used

in treatment

ArsenicMercury

Mercury

Manganese

Manganese

Lead

Lead

Lead

Arsenic• Acute intoxication

– Encephalopathy– Peripheral neuropathy– Abdominal pain– Nausea/vomiting– Diarrhea– Shock

• Chronic intoxication– Malaise– Mees lines– Increased pigment & hyperkeratosis

• From insecticides• Detect in hair & urine• Treat with (BAL)

Lead• Kids

– Encephalopathy• Adults

– Motor demyelinating peripheral neuropathy (wrist drop)– Anemia– Gingival lead line

• Diagnosis– Erythrocyte basophilic stippling– Long bone metaphyseal lead lines– Serum lead level– Increased urine proporhyrin & delta-aminolevulinic acid

• Treatment– EDTA– BAL– Penicillamine

Mercury

• Symptoms– Psychologic dysfunction– Tremor, movement disorder, cerebellar signs– Peripheral neuropathy– GI dysfunction– Rental tubular necrosis

• From contaminated fish & felt hat dyes• Treatment– Penicillamine– BAL increases brain levels

Manganese

• Miners• Symptoms– Parkinsonianism– Psychologic disorders– Headache

• Neuronal loss & gliosis in pallidum & striatum• Treatment– L-Dopa– Chelators do not help

Match the vitamin with is deficiency or toxicity

1. Wernicke’s encephalopathy2. Korsakoff’s psychosis3. Pellegra4. Beriberi5. Seen in rice eaters6. Seen in corn eaters7. Rickets8. Pernicious Anemia9. Subacute combined

degeneration10. Pseudotumor

•Thiamine•Niacin•Vitamin B12

•Vitamin A•Vitamin D

Thiamine

Thiamine

ThiamineThiamine

Niacin

NiacinVitamin D

Vitamin B12Vitamin B12

Vitamin A

Thiamine

• Deficiencies– Alcoholics– GI tumors– Dialysis– TPN– Gastric Plication– Europeans

• Involved in carbohydrate metabolism (transketolase)• High transketolase activity in mamillary bodies

Wernicke Encephalopathy• Signs

– Conjugate gaze & lateral rectus palsy– Nystagmus– Gait ataxia– Confusion

• Affected areas– Mammilary bodies– Mediodorsal nucleus of thalamus– Periaqueductal gray– Floor of 4th ventricle (dorsal motor nuclei of X, vestibular nuclei)– Superior cerebellar vermis

• Path findings– Brown-gray discoloration– Edema– Hemorrhage– Loss of purkinje cells– Reactive astrocytosis

• Lab findings– Increased pyruvate & thymidine triphosphate– Decreased transketolase

Korsakoff Psychosis & Beriberi

• Korsakoff– Chronic disorder– Deterioration in memory– Lesions in dorsomedial thalamus

• Beriberi– Common in rice eaters (refined)– Peripheral neuropathy– Autonomic dysfunction– Heart disease

Niacin

• Common in corn eaters (tryptophan deficiency)

• Deficiency causes pellagra– Dermatitis– Dementia– Diarrhea

• Similar syndrome caused by carcinoid tumors

Vitamin B12

• Deficiency causes– Pernicious anemia– Tumors– Infection– Parasites– Nitrous Oxide

• Signs & Symptoms– Megaloblastic anemia– Glossitis– Anorexia– Diarrhea– Impaired vibration sense, proprioception, paraplegia

• Spinal Cord Involvement– Subacute combined degeneration– Lower C-Spine/Upper T-Spine posterior & lateral columns– Spongiform demyelination

• Diagnosis– Hypersegmented PMNs– B12 assay– Increased methylmalonic acid & homocysteine

Others

• Vitamin A– Deficiency: decreased vision– Toxicity: pseudotumor & increased ICP

• Vitamin B6

– Deficiency: lower limb paresthesia, pain & weakness• Vitamin D– Deficiency: Rickets, decreased bone strength

• Vitamin E– Deficiency: thick dystrophic axons in posterior columns,

polyneuropathy.