2. Neurophysiology Flashcards Preview

Neurosurgery Rounds > 2. Neurophysiology > Flashcards

Flashcards in 2. Neurophysiology Deck (102)
Loading flashcards...
1

How does Mg prevent excitotoxicity in brain?

Blocks Ca and NMDA channels

2

Most abundant excitatory neurotransmitter in the brain?

Glutamate

3

Cellular elements of BBB

Endothelial cells
Astrocyte endfeet
Pericyte

Capillary endotheilal cells connected by tight junctions

4

Platelet function after SAH?

Enhanced leading to increased platelet aggregation in cerebral microcirculation

5

Cerebral blood flow immediately after SAH?

Decreases

6

What is GPIIb/IIIa?

Platelet surface integrin - mediator of platelet aggregation

7

Dense granules of platelets?

5HT, ATP, PDGF

8

Disturbed balance of which peptide contributes to vasospasm?

Endothelin 1 (vasoconstriction) and nitric oxide (vasodilation)

9

Superoxide and hydrogen peroxide generates highly reactive hydroxyl radical - name?

Haber-Weiss reaction

10

Mechanism of steroid treatment in blunt spinal cord injury?

Local blood flow, inhibition of immunologic injury, and free radical-mediated lipid peroxidation and neuronal damage

11

What is S100B?

Calcium binding protein abundant in astrocytes - may be neuroprotective/neurotrophic

12

What is Windkessel phenomenon?

Cerebral vasculature expand and ability of CSF/venous blood to translocate to accomodate arterial pulsations and provide smooth capillary flow in the brain

13

Ischemic penumbra?

Region where cerebral blood flow reduction has passed threshold that leads to failure of electrical but not membrane function - structurally intact, but functionally disturbed

14

Role of infiltration with local anesthetic at beginning of a case?

Prevents activation of nociceptors during surgery and lessens need for analgesics

15

Structural unit of gap junction

Connexon allows direct electrical communication between cells

16

Functions of TGF beta?

Development/progression of brain tumors

17

What enzyme is inhibited by acetazolamide?

Carbonic anhydrase

18

Difference between bioactive Guglielmi detachable coil (GDC) and platinum GDC?

Bioactive coil accelerates clot and promotes development of mature connective tissue

19

Mutation in Crouzon syndrome

Fibroblast growth factor receptor 2 - absence of ligand binding - premature fusion of cranial sutures leading to abnormal cranium shape, restricted growth and increased ICP

20

Baclofen mechanism?

GABA agonist

21

Hyparrhythmia

Chaotic, high amplitude EEG (Infantile spasm)

22

Subsidence?

Loss of vertebral column heigh with aging

23

Genetic defect in Gorlin syndrome?

autosomal dominant
Mutation of PTCH gene that predisposes to neoplasias and widespread congenital malformations

24

Water channel proteins of the brain?

Aquaporins

25

Most common agent for pharmacologic dilatation of vasospastic cerebral vessels?

Papaverine hydrochloride - endothelium-independent smooth muscle relaxant

26

How do intervertebral disks receive nutrition?

Passive diffusion from capillary beds in subchondral endplate region of vertebral body

27

Composition of PEEK cage

Polyetheretherketone (PEEK) spacers - strong polymer that withstand compressive load of vertebral column

28

Common areas of leptomeningeal dissemination for tumors

Basilar cisterns, sylvian fissure, cauda equina (gravity and slower rate of CSF)

29

Resting membrane potential in myelinated pheripheral nerves? in soma?

~ 90 mV and ~ 65 mV
Determined by K+ (100x more permeable than Na+)

30

Botulinum toxin mechanism

Inhibit release of ACh from presynaptic terminal