Demyelinating/Degenerative/Genetic/Toxic diseases- PART 2 (Martin)

Question 1

What enzyme is deficient in Tay-Sachs?

This causes accumulation of?

What is the diagnostic hallmark?

Answer 1

1) Hexosaminidase A
2) GM2 Gangliosides
3) Cherry red spot in maculae

Question 2

What is the most prevalent mutation in Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS)?

Answer 2

tRNAs

Question 3

What symptoms are seen with Myoclonic epilepsy and ragged red fibers (MERRF)?

Answer 3

1) Myoclonus
2) Seizure disorder
3) Myopathy
4) Ataxia

Question 4

Where are the ragged red fibers found in MERRF?

Answer 4

Muscle

Question 5

What symptoms are seen with Kearn-Sayre syndrome?

Answer 5

1) Ataxia
2) Pigmentary retinopathy
3) Cardiac conduction defects
4) Progressive external ophthalmoplegia (unable to move eyes and eyebrows)

Question 6

Lactic academia, arrest of psychomotor development, feeding problems, seizures, extraocular palsies, and weakness with hypotonia are symptoms seen in infants with?

Answer 6

Leigh syndrome

Question 7

Brain MRI of a patient with Leigh syndrome will show multifocal abnormalities with loss of tissue in what regions of the midbrain, pons, thalamus, and hypothalamus?

Answer 7

Periventricular regions

Question 8

What effect does vitamin B12 deficiency have on the spinal cord?

Answer 8

Subacute combined degeneration of the spinal cord

Question 9

Is thiamine (vitamin B1) deficiency AKA Wernicke encephalopathy reversible?

Answer 9

Yes if treated early, but if left untreated can lead to Korsakoff syndrome

Question 10

With Wernicke encephalopathy, there are foci of hemorrhage and necrosis in?

Answer 10

The mammillary bodies and the walls of the 3rd and 4th ventricles

Question 11

When do we see selective injury to large pyramidal neurons of the cerebral cortex that can lead to pseudolaminar necrosis?

Answer 11

Hypoglycemia

Question 12

What is commonly due to uncontrolled diabetes mellitus and is associated with ketoacidosis or hyperosmolar coma?

Answer 12

Hyperglycemia

Question 13

Why must fluid repletion be gradually corrected in hyperglycemic patients?

Answer 13

To avoid severe cerebral edema

Question 14

What cells are found in the cerebral cortex and the basal ganglia with hepatic encephalopathy?

Answer 14

Alzheimer type II cells

Question 15

What areas of the brain are injured due to carbon monoxide poisoning?

Answer 15

1) Layers III and V of cerebral cortex
2) Sommer’s sector
3) Purkinjie cells

Question 16

Bilateral necrosis of what area of the brain may be seen with carbon monoxide poisoning?

Answer 16

Globus pallidus

Question 17

How can methanol cause blindness?

Where might there also be bilateral necrosis in the brain?

Answer 17

1) Degeneration of retinal ganglion cells

2) Putamen

Question 18

Due to ethanol abuse, 1% of chronic alcoholics have atrophy and loss of granule cells predominately in?

How do they present?

Answer 18

1) Anterior vermis of cerebellum

2) Truncal ataxia, unsteady gait, and nystagmus