Neurosurgery notes

Question 1

Difference white and grey matter?

Answer 1

• Grey matter surface each hemisphere and associated processing and cognition.
• White matter forms bulk deeper parts brain and consists glial cells and myelinated axons

Question 2

Describe the appearance of the external layer of the brain

Answer 2

Cerebrum is highly convoluted, consisting of sulci [grooves/depressions] and gyri [ridges/elevations]

Question 3

What are the hemispheres of the brain divided by?

Answer 3

The longitudinal fissure

Question 4

List the main sulci and what they separate

Answer 4

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

Question 5

List the main gyri, their location, and what their function is

Answer 5

Precentral gyrus [anterior anterior central suclus, location primary motor cortex], postcentral gyurs [posterior to central sulcus, primary somatosensory cortex], superior temporal gyrus [inferior to lateral sulcus, responsible for reception and processing sound]

Question 6

What do the names of the lobes correspond to?

Answer 6

Name of the cranial bone that overlies each part

Question 7

What is the cortical association of the frontal lobe?

Answer 7

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

Question 8

What is the cortical association of the parietal lobe?

Answer 8

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

Question 9

What is the cortical association of the temporal lobe?

Answer 9

Memory and language [including hearing as this is where the primary auditory cortex lies]

Question 10

What is the cortical association of the occipital lobe?

Answer 10

Primary visual cortex

Question 11

What does the inferior aspect of the occipital lobe lie on?

Answer 11

The tentorium cerebelli, which separates the cerebrum from the cerebellum.

Question 12

Describe the large vessel vasculature of the brain

Answer 12

Anterior cerebral artery supplies the anteromedial aspect of the brain, middle cerebral artery supplies the lateral parts, the posterior cerebral arteries supply the medial and lateral sides of the cerebrum posteriorly

Question 13

What is the MCA a continuation of?

Answer 13

The internal carotid arteries

Question 14

What is the PCA a branch from?

Answer 14

The basilar arteries

Question 15

Compare how a cerebrovascular accident would clinically present in each of the four lobes

Answer 15

Frontal:
- personality, behaviouiral, problem solving ability

Parietal:
- attentioonal deficits, contralateral neglect syndrome

Temporal
- recognition deficits e.g. auditory or prosopagnosia

Occipital
- contralateral hemaniopia or quadrantanopia

Question 16

When might global deficits of brain vasculature occur?

Answer 16

In severe cognitive deficits like dementia

Question 17

What are the two major functions of the meninges?

Answer 17

a) provide supportive framework for the cerebral and cranial vasculature
b) act with CSF to protect the CNS from mechanical damage

Question 18

Two instances when the meninges are involved in cerebral pathology

Answer 18

Common site of infection [meningitis]

Intracranial bleeds

Question 19

What are the two layers of the dura called?

Answer 19

Periosteal layer [lines cranium], and the meningeal layer [deep to the periosteal later inside cranial cavity].

Question 20

Which dural layer also exists in the spinal column?

Answer 20

Meningeal layer

Question 21

What lies between the two dural layers?

Answer 21

The dural venous sinuses

Question 22

Function of the dural venous sinuses? Where do they drain to?

Answer 22

Responsible for the venous vasculature of the cranium.

Drain into the internal jugular veins.

Question 23

In which parts of the brain does the dural layer of the meninges fold into the brain? Which part of the dura does this?

Answer 23

Meningeal layer does this.

Tentorium cerebelli divides brain into the supratentorial and infratentorial compartments.

Question 24

Does the dura mater get a blood supply? And if, then where?

Answer 24

Yes, it gets its own vasculature from the middle meningeal artery and middle meningeal vein.

Question 25

How is the dura mater innervated?

Answer 25

By the trigeminal nerve [V1, V2, V3].

Question 26

What is an extradural haemorrhage?

Answer 26

Arterial blood collecting between the skull and periosteal layer of the dura.

Question 27

What is the common causative vessel of an extra-dural haemorrhage?

Answer 27

Usually the MMA, tearing as a consequence of brain trauma.