Metaboic Disorders - Krafts

Question 1

A “cherry red” spot in the retina is diagnostic of what disease?

Answer 1

Tay Sachs

Question 2

What enzyme is deficient in Krabbe disease?

Answer 2

Galactosylceramidase

When absent, galactocerebroside accumulates, gets converted to galactosylsphingosine (toxic to oligodendrocytes)

Question 3

What things are diagnostic of Krabbe disease?

Answer 3

Usually early onset, rapidly progressive muscle stiffness
Globoid Cells (fat macrophages)

Question 4

Two B vitamins critical to brain function?

Answer 4

B1 (Thiamine) and B12 (cobalamine)

Question 5

Most people eat enough thiamine, so how else can you get a B1 deficiency?

Answer 5

Chronic alcoholism

Question 6

What metabolic brain disorders are caused by B1 deficiency?

Answer 6

Wernicke encephalopathy
confusion, ophthalmoplegia, ataxia
hemorrhage and necrosis in mammillary bodies, walls of third and fourth ventricles
acute, reversible

Then progresses to:

Korsakoff syndrome
memory disturbances, confabulation
cystic spaces, hemosiderin-laden macrophages in mammillary bodies, ventricle walls
thalamic lesions too
prolonged, mostly irreversible

Question 7

What structures in the brain should you remember are affected by Wernicke’s Encephalopathy and Korsakoff Syndrome?

Answer 7

Wernicke’s Enceph: Mammillary bodies

Korsakoff: Mamillary Bodies, thalamus

Question 8

How does abnormal blood sugar affect neurons?

Answer 8

Hypoglycemia and Hyperglycemia are bad

Hypoglycemia
Most vulnerable: large pyramidal neurons of cortex (“pseudolaminar necrosis”) (sheet of destruction)
Also vulnerable: hippocampus and cerebellum

Hyperglycemia
Most commonly seen in diabetes mellitus
Can be associated with either ketoacidosis or hyperosmolar coma
Dehydration, confusion, stupor, coma

Question 9

How does CO poisioning hurt the brain? What areas are vulnerable?

Answer 9

Injury is due to hypoxia

Turns brain pink…

Particularly vulnerable areas:
cortex (layers III and V)
hippocampus
Purkinje cells

Question 10

An alcoholic drinks methanol, thinking it is ethanol. You are in the ER treating the individual. What are your biggest concerns?

Answer 10

MethanolPreferentially affects retina
Degeneration of ganglion cells
May cause blindness

Can be deadly

Question 11

How does ethanol affect the brain?

Answer 11

Acute effects are reversible; chronic effects are not

Preferentially affects cerebellum

Truncal ataxia, unsteady gait, nystagmus

Cerebellar atrophy, loss of granule cells, loss of Purkinje cells, Bergmann gliosis

Question 12

What is Bergmann Gliosis?

Answer 12

Astrocytic proliferation, between the granular and molecular layers of the cerebellum

Occurs in alcoholism

Question 13

In heriditary neuronal storage diseases, what do typical diseased neurons look like?

Answer 13

They have ballooned out because they are so filled with whatever irregular storage they have going on

Question 14

What do children born with Tay-Sachs disease lack?

Answer 14

They lack hexoaminidase A - which causes accumulation of ganglioside in all tissues

Paralysis and loss of neuro function folllows