CNS pathology-1

Question 1

What is the most common location of a hypertensive bleed?

Answer 1

The Basal Ganglia- Thalamus (75%)

Question 2

What causes a Berry Aneurysm?

Answer 2

• Congenital arterial defects that occur when the bifurcation of an artery creates a “Y-shape”, creating a point of weakness
• Continuous pressure on the point of bifurcation causes membrane to degenerate and fragment
• A saccular aneurys evolves, walls are only adventitia

Question 3

Where are most Berry aneurysms?

Answer 3

over 90% occur at branching points in the Circle of Willis

Question 4

Berry aneurysms are distributed equally at the unions of…

Answer 4

1. Anterior cerebral artery and anterior communicating artery
2. Complex of the internal carotid artery- posterior communicating artery-anterior cerebral artery
3. The trifurcation of the middle cerebral artery

20% have multiple berrys

Question 6

What does a ruptured Berry Aneurysm result in?

Answer 6

• life threatening subarachnoid hemorrhage
• Initial hemorrhage= 35-50% mortality

Question 7

Berry aneurysms- what do large aneurysms of the internal carotid complex produce?

Answer 7

1. Palsies of the 3rd, 4th and 6th cranial nerves
2. Seizures from compression of temporal lobe

Question 9

Clinical presentation of Berry Aneurysms

Answer 9

• many asymptomatic (only found at autopsy)
• Sudden severe HA due to SAH and can be followed by coma
• If pt survives 3-4 days: progressive decline in consciousness (from arterial spasm leading to cerebral ischemia and infarction)

Question 10

What happens in 1/3 of patients with a ruptured Berry Aneurysm?

Answer 10

Rupture can either cause an intracerebral or intraventricular hemorrhage

Question 11

What are the two most common organisms that cause neonatal meningitis?

Answer 11

1. Group B Strept
2. E.coli

Question 12

What is the most common organism causing bacterial meningitis in infants (3 months-3 years)?

Answer 12

H. influenza

Question 13

What is the most common origanism that causes bacterial meningitis in adults not in crowded conditions?

Answer 13

Strep pneumo

Question 14

What is the most common organism that causes bacterial meningitis in people in crowded conditions (military barracks)?

Answer 14

N. meningitidis

Question 15

How is Parkinson Disease characterized pathologically?

Answer 15

A neurologic disorder characterized pathologically by the loss of neurons in the Substantia Nigra

Question 16

How is Parkinson Disease characterized clinically?

Answer 16

1. Tremors at rest
2. Muscular rigidity (Cog wheel rigidity) throughout entire ROM
3. Expressionless face (“mask”)–> expression fixed, eyes unblinking and staring, mouth open
4. emotional lability
5. slowness of all voluntary movements
6. Course tremor of distal extremities (“pill-rolling”)- present at rest, disappears w/ voluntary movement
7. Drooling
8. spontaneous movement diminished (akinesia)
9. Posture is stooped

Question 17

When does Parkinson Disease typically appear?

Answer 17

In the 6th decade to 8th decades of life

Question 18

What neurotransmitters are deficient in Parkinson Disease?

Answer 18

Dopamine!

Parkinsons= Accelerated loss of neurons in the Substantia Nigra and reduction in the dopamine content of that region

Note: Substantia Nigra relays info to basal ganglia through dopaminergic synapses

Question 19

What group of brain tumors is the most common type of brain tumor?

Answer 19

Gliomas (tumors of neuroectodermal origins)

=60% of primary intracranial neuoplasms

Question 20

What does gross examination of a brain with Parkinson disease reveal?

Answer 20

A loss of pigmentation in the Substantia Nigra and Locus Ceruleus

Question 21

What area of the brain is Parkinson disease

Answer 21

Substantia Nigra (in the midbrain) and Locus Ceruleus (a nucleus in the pons of the brainstem)

Question 22

What is there an increased incidence of in people with Parkinson disease?

Answer 22

Depression

Dementia

Question 23

What brain tumor accounts for 75-80% of adult primary brain tumors?

Answer 23

Astrocytomas

Question 24

What is alzheimers disease?

Answer 24

an insidious and progressive neurological disorder characterized by loss of memory, cognitive impairment and eventual dementia

Question 25

Gross features seen in Alzheimers

Answer 25

1. narrow gyri
2. Sulci widen
3. Bilateral cortical atrophy

–>All 3 are apparent in the frontal, temporal, parietal and hippocampal cortices (spares the occipital lobes)

Question 26

Microscopic features seen in Alzheimers

Answer 26

1. Senile (neuritic) plaques- found predominantly in hippocampus, amygdala and cortex
2. Neurofibrillary Tangles (Flame cells seen on histology)- found in cortex, hipocampus and amygdala
3. Amyloid angiopathy (within cerebral blood vessels)

Question 28

What are the most common tumors that metastasize to the brain?

Answer 28

Disseminated Melanoma (50% of metastasis)

Breast and lung (35%)

Kidney and colon (5%)

**Prostate, liver and sarcomas rarely spread

Question 29

How do metastatic tumors reach the brain

Answer 29

through the bloodstream

Question 30

What brain tumor accounts for 20% of brain tumors in children?

Ex: Neuroblastoma, Retinoblastoma, etc

Answer 30

Medulloblastoma

Question 31

Where are Medulloblastomas located?

Answer 31

infiltrates the vermis of the Cerebellum

frequently disseminates through the CSF

Question 32

What is the most common genetic alteration associated with Medulloblastoma?

Answer 32

loss of material from short arm of chromosome 17

Question 33

Medulloblastoma- radiosensitivity

Answer 33

Tumor is highly malignant but also extremely radiosensitive if diagnosed early enough

With total excision and radiation- 10 yr survival rate is 50%