Neurosurgery notes Flashcards
Difference white and grey matter?
- Grey matter surface each hemisphere and associated processing and cognition.
- White matter forms bulk deeper parts brain and consists glial cells and myelinated axons
Describe the appearance of the external layer of the brain
Cerebrum is highly convoluted, consisting of sulci [grooves/depressions] and gyri [ridges/elevations]
What are the hemispheres of the brain divided by?
The longitudinal fissure
List the main sulci and what they separate
Central sulcus [frontal and parietal lobes], lateral sulcus [frontal and parietal from the temporal], lunate sulcus [occipital]
List the main gyri, their location, and what their function is
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]
What do the names of the lobes correspond to?
Name of the cranial bone that overlies each part
What is the cortical association of the frontal lobe?
Higher intellect, personality, mood, social conduct, language [dominant hemisphere only]
What is the cortical association of the parietal lobe?
Language and calculation on the dominant side, visuospatial functions [e.g. 2-point discrimination] on the non-dominant side
What is the cortical association of the temporal lobe?
Memory and language [including hearing as this is where the primary auditory cortex lies]
What is the cortical association of the occipital lobe?
Primary visual cortex
What does the inferior aspect of the occipital lobe lie on?
The tentorium cerebelli, which separates the cerebrum from the cerebellum.
Describe the large vessel vasculature of the brain
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
What is the MCA a continuation of?
The internal carotid arteries
What is the PCA a branch from?
The basilar arteries
Compare how a cerebrovascular accident would clinically present in each of the four lobes
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
When might global deficits of brain vasculature occur?
In severe cognitive deficits like dementia
What are the two major functions of the meninges?
a) provide supportive framework for the cerebral and cranial vasculature
b) act with CSF to protect the CNS from mechanical damage
Two instances when the meninges are involved in cerebral pathology
Common site of infection [meningitis]
Intracranial bleeds
What are the two layers of the dura called?
Periosteal layer [lines cranium], and the meningeal layer [deep to the periosteal later inside cranial cavity].
Which dural layer also exists in the spinal column?
Meningeal layer
What lies between the two dural layers?
The dural venous sinuses
Function of the dural venous sinuses? Where do they drain to?
Responsible for the venous vasculature of the cranium.
Drain into the internal jugular veins.
In which parts of the brain does the dural layer of the meninges fold into the brain? Which part of the dura does this?
Meningeal layer does this.
Tentorium cerebelli divides brain into the supratentorial and infratentorial compartments.
Does the dura mater get a blood supply? And if, then where?
Yes, it gets its own vasculature from the middle meningeal artery and middle meningeal vein.
How is the dura mater innervated?
By the trigeminal nerve [V1, V2, V3].
What is an extradural haemorrhage?
Arterial blood collecting between the skull and periosteal layer of the dura.
What is the common causative vessel of an extra-dural haemorrhage?
Usually the MMA, tearing as a consequence of brain trauma.
