Neurosurgery, stroke, neurophysiology and TLOC [04/11/20]]

Question 1

What seperates the cerebral hemispheres?

Answer 1

Falx cerebri [dura mater]

Question 2

Embryologically, what is the cerebrum derived from?

Answer 2

The prosencaphalon

Question 3

Compare the grey and white matter function

Answer 3

Grey - surface each hemisphere, and is associated with processing and cognition

White - consists of glial cells and myelinated axons, connecting various areas

Question 4

What are the main sulci in the brain?

Answer 4

Central sulcus [frontal and parietal lobes], lateral sulcus [frontal and parietal from the temporal lobes], lunate sulcus [occipital cortex]

Question 5

What are the main sulci in the brain?

Answer 5

Precentral gyrus, postcentral gyrus, superior temporal gyri [inferior to the lateral sulcus, responsible for reception and processing sound]

Question 6

Function of frontal lobe

Answer 6

Higher intellect, personality, mood, social conduct, language [dominant hemispehre only]

Question 7

Function of parietal lobe

Answer 7

language and calculation dominant side, visuospatial functions [e.g. 2-point discrimination] on the non-dominant side

Question 8

Function of the temporal lobe

Answer 8

memory and language [including where the auditory cortex lies]

Question 9

What does the inferior part of the occipital cortex lie on?

Answer 9

Tentorium cerebelli, seperates the cerebrum from the cerebellum.

Question 10

Vasculature of the brain

Answer 10

ACA supplying the anteromedial aspect, MCA [continuation internal carotids] supplying the lateral parts, PCA [branches of the basilar arteries] supplying both the medial and lateral sides of the cerebrum posteriorly

Question 11

Describe how a CVA would present in the frontal lobe?

Answer 11

personality, behavioural, problem solving disability

Question 12

CVA in the parietal lobe

Answer 12

attention deficits, contralateral neglect syndrome

Question 13

CVA in the temporal lobe

Answer 13

Recognition dericits [e.g. auditory or prosopagnosia], occipital [contralateral hemaniopia or quadrantanopia], global deficits [severe cognitive deficits like dementia]

Question 14

What are the two major functions of the meninges?

Answer 14

Provide supportive framework for the cerebral and cranial vasculature, act with CSF to protect the CNS from mechanical damage

Question 15

Which pathways do each of these tests evoke: somatosensory EP, visual EP, TMS

Answer 15

SEP - sensory pathways
VEP
TMS - motor

Question 16

What is a nerve?

Answer 16

a bundle of axons

Question 17

Which neurotransmitter is at the NMJ that NCS tests?

Answer 17

ACh

Question 18

In NCS, response is small then what, is slow then what?

Answer 18

Small = axonal loss
Slow = myelin loss

Question 19

What is the most common cause of axonal loss in the UK?

Answer 19

Alcohol and DM

Question 20

Example of a treatable demyelinating condition?

Answer 20

GBS

Question 21

When are EMGs used?

Answer 21

When myopathy and problem with muscle [not nerve problem]

Question 22

How is neurotransmission dodgy in MG?

Answer 22

Time between contractions vary therefore this can cause a jitter

Question 23

how sensitive is EMG for MG?

Answer 23

More sensitive than antibody tests

Question 24

When are EEGs primarily done?

Answer 24

Primarily done for seizures

Question 25

When are intra-cranial EEGs done?

Answer 25

Pts with focal epilepsy where medication doesn;t work

also helps ascertain where seizures come from

Question 26

How are focal seizures often Dx?

Answer 26

Often simple observations all that is needed.

Question 27

Sx of temporal vs Sx of frontal lobe seizures

Answer 27

Temporal = aura, behavioural arrest, automatisms
Frontal = sleep dep., brief, hypermotor

Question 28

What are the main uses of somatosensory evoked potentials?

Answer 28

MS: demyelination shows response recorded from scalp is delayed
Inappropraite monitoring e.g. spinal cord durgery; if cord compromised response gets smaller, then is lost. Aim to warn surgeon before too late.

Question 29

When is TMS used?

Answer 29

Record contralateral muscle; can selectively look at central motor pathqway. Used for MND, MS.
Therapuetic in depression.