CNS QandA Rubin's

Question 1

Polymicrogyria is a

Answer 1

congenital disorder where surface of the brain exhibits excessive number of small, irregularly sized, randomly distributed gyral folds (think MENTAL RETARDATION)

Question 2

Lissencephaly

Answer 2

is a congenital disorder in which the cortical surface of cerebral hemispheres is smooth or has imperfectly formed gyri

Question 3

Pachygyria

Answer 3

is a condition in which the gyri are reduced in number and usually broad

Question 4

Congenital defects of the CNS are often associated with

Answer 4

chromosomal abnormalities, which are best exemplified by trisomies of chromosome 13-15 (holoprosencephaly) and chromosome 21 (Down Syndrome); in holoprosencephaly, you have horseshoe-shaped cerebral hemispheres with fused frontal poles

Question 5

Tabes dorsalis is a feature of

Answer 5

tertiary syphilis, with chronic fibrosing meningitis, which constricts the posterior root of the spinal cord with its sensory nerves

Question 6

Alzheimer’s is characterized by

Answer 6

loss of memory, cognitive impairment, difficulty with language, and eventual dementia; BRONCHOPNEUMONIA is usually the lethal outcome of Alzheimer’s!

Question 7

Hydrocephalus ex vacuo refers to

Answer 7

enlargement of the ventricular system as a compensatory response to severe brain atrophy and is unrelated to obstructive lesions (think Alzheimer’s!!!)

Question 8

End-stage lesions of MS feature

Answer 8

1. astrogliosis!!!
2. thick-walled blood vessels
3. moderate perivascular inflammation
4. secondary loss of axons;
   think additional DEMYELINATED PLAQUES!!

Question 9

Thiamine leads to ____, characterized by

Answer 9

Wernicke syndrome;

1. thermal regulation
2. altered consciousness
3. ophthalmoplegia
4. nystagmus
5. ataxia

Question 10

Rabies is a(n) _____ caused by what virus? Transmission? How does virus do its work? Symptoms? Histo features?

Answer 10

encephalitis, rabies virus;
dogs, wolves, foxes, skunks, bats BITE!!;
viral replication begins at site of bite and transports to CNS through viral entry into peripheral nerves;
get painful spasms of the throat, difficulty swallowing, tendency to aspirate fluids (hydrophobia);
perivascular cuffing by lymphocytes, neuronophagia, microglial nodules, NEGRI BODIES that are eosinophilic, cytoplasmic inclusions in infected nerve cells

Question 11

Cerebral veins empty into

Answer 11

large venous sinuses, most prominent of which is sagittal sinus (with DEHYDRATION, worry about venous obstruction and abrupt thrombosis!!)

Question 12

Transtentorial herniation is a

Answer 12

fatal event when the medial temporal lob on the side of a hematoma formed is compressed against the midbrain to displace it through the opening created by the tentorium!! Think third nerve palsy (pupil fixed and dilated!!) think hypoxia with venous stagnation in midbrain and herniated hippocampal uncus compresses midbrain vasculature (DURET hemorrhages, going here from upper midbrain to midpons!!)

Question 13

Consciousness is a ___ neurologic activity that depends on function of

Answer 13

specific neurons, especially the brainstem reticular formation ones (with a blow leading to head up and posterior, think of torque on brainstem and functional paralysis of neurons of reticular formation)

Question 14

Astrocytosis is demonstrated by imunostaining with what? Result is what?

Answer 14

GFAP; glial scar!!

Question 15

Someone who had a subdural hematoma is at risk of

Answer 15

rebleeding of the previous hematoma

Question 16

Tay-Sachs is a

Answer 16

autosomal recessive disorder with inborn deficiency of hexosaminidase A, permitting accumulation of ganglioside GM1 in CNS neurons (macular transparency and cherry-red spot); think lipid droplets in cytoplasm of nerve cells of CNS and PNS

Question 17

Herpes simplex targets the; poliovirus goes for

Answer 17

temporal lobes;

brainstem nuclei

Question 18

CMV is one of the ____ agents; these particles are demonstrated as

Answer 18

TORCH syndrome;

intranuclear and intracytoplasmic inclusions in neurons and astrocytes

Question 19

If _____ is mixed with India ink, this organism shows

Answer 19

contaminated CSF; cryptococcus neoformas;

a CLEAR HALO about the encapsulated organism

Question 20

Hypertensive intracerebral hemorrhage occurs preferentially

Answer 20

at basal ganglia-thalamus!!

Question 21

TB meningitis has a predilection for _____; if not treated well, results in

Answer 21

base of brain, with infarcts in striate arteries;
meningeal fibrosis, communicating hydrocephalus, arteritis (last leads to infarcts!!!)
CAM Newton got a TouchBack!!

Question 22

Inadequate perfusion of the brain resulting from generalized blood flow or occlusive cerebrovascular disease can affect in particular _____ due to a lack of ______

Answer 22

Purkinje cells of the cerebellum and the pyramidal neurons of Sommer’s sector in the HIPPOCAMPUS; lack of O2 affects these neurons!!

Question 23

With someone suffering trauma and developing _____ in the brain, think

Answer 23

petechiae; fat emboli (go downstream through cerebral vessles until they lodge and block blood flow)

Question 24

Major complication of atherosclerotic aneurysms is

Answer 24

THROMBOSIS!!

Question 25

Watershed infarct can occur due to

Answer 25

prolonged hypotension (diminished perfusion)

Question 26

Diffuse axonal injury can occur because of

Answer 26

lateral aspects of cerebrum being able to move more freely, so this allows for generation of shearing forces between different brain regions and sheearing injuries, especially in VEHICULAR ACCIDENTS!!
Axons can lose myelin

Question 27

Hepatic encephalopathy can manifest as; what changes histologically and what substance is higher than usual?

Answer 27

delirium, seizures, coma;
altered astroglia (Alzheimer type II astrocytes);
AMMONIA!!

Question 28

VHL syndrome is a ______ disorder in which

Answer 28

cerebellar hemangioblastomas are associated with retinal angiomas and other tumors (renal cell carcinoma) due to mutations in VHL tumor suppressor gene

Question 29

In end-stage Alzheimer’s, what predominates and what makes these up?

Answer 29

Neuritic plaques;

have Abeta at core and periphery and plaques are positive for Cogo red!!