Neurology Flashcards
What does white matter contain?
Myelinated neuronal axons which bundle together to form tracts
What is grey matter contain?
Neuronal cell bodies and glial cells (e.g. astrocytes, oligodendrocytes, and microglial cells)
What divides the frontal and parietal lobe?
Central sulcus
What divides the parietal and occipital lobe?
Parieto-occipital sulcus
What divides the temporal lobe from the frontal and parietal?
Lateral fissure
What are the types of cerebral cortices?
Primary and secondary/association
What motor areas are in the frontal lobe?
Primary motor cortex, supplementary motor area and premotor area.
What are the functions of the prefrontal cortex?
- Attention
- Adjusting social behaviour
- Planning
- Personality
5, Decision making
What can frontal lobe lesions cause?
- Personality changes
- Impaired restraint/inappropriate behaviour
- Inability to plan actions
- Repetition of same behaviour
What are the key regions in the temporal lobe?
- Temporal association cortex
- Primary auditory cortex
- Auditory association cortex
What does the temporal association cortex do?
Recognition and identification of stimuli, particularly those that are relatively complex
What does the primary auditory cortex do?
Processes auditory stimuli
What does the auditory association cortex do?
Gives meaning and interpretation of auditory input
What can damage to either temporal lobe cause?
Agnosia
What is agnosia?
Difficulty recognizing, identifying, and naming different categories of objects
What is prosopagnosia?
Inability to identify familiar individuals by their facial characteristics, and in some cases cannot recognise a face at all (inability to learn new faces)
What can damage to the inferior temporal cortex (fusiform gyrus) cause?
Prosopagnosia
What can a lesion of the right temporal cortex cause?
Agnosia for faces and objects
What can a lesion of the corresponding regions of the left temporal cortex?
Difficulties with language-related material
What is anterograde amnesia?
Inability to form new memories
What is retrograde amnesia?
Difficulty retrieving memories established prior to the neuropathology
What can lead to anterograde amnesia?
Damage to or resection of (e.g. to cure epilepsy) anterior medial temporal lobe structures (particularly the hippocampus)
What can damage to or resection of (e.g. to cure epilepsy) anterior medial temporal lobe structures (particularly the hippocampus) cause?
Anterograde amnesia
What key areas are within the occipital lobe?
- Primary visual cortex
2. Visual association cortex
What does the primary visual cortex do?
Processes visualstimuli
What does the visual association cortex do?
Gives meaning and interpretation of visual input?
What does Broca’s area do?
Production of language
What does Wernicke’s area do?
Understanding of language
Where is Broca’s area located?
Frontal association cortex of the left cerebral hemisphere
Where is Wernicke’s area located?
Temporal association cortex of the left cerebral hemisphere
What is colour agnosia?
Inability to recognise colours
What is inability to recognise colours?
Colour agnosia
What can a lesion to Broca’s or Wernicke’s area cause?
Aphasia
What is aphasia?
Inability to comprehend and/or to produce language
What can a lesion to Broca’s area cause?
Expressive aphasia
What is expressive aphasia?
Poor production of speech, comprehension intact
What can a lesion to Wernicke’s area cause?
Receptive aphasia
What is receptive aphasia?
Poor comprehension of speech, production is fine
What does the limbic lobe include?
- Amygdala
- Hippocampus
- Mamillary body
- Cingulate gyrus
What is the function of the limbic lobe?
- Learning
- Memory
- Emotion
- Motivation
- Reward
Where do you find the insular cortex?
Lies deep within lateral fissure
What is the function of the insular cortex?
- Visceral sensations
- Autonomic control
- Interoception
- Auditory processing
- Visual-vestibular integration
What do association fibres connect?
Connect areas within the same hemisphere
What are the two types of association fibres?
Short and long fibres
What are the four long fibres?
- Superior Longitudinal Fasciculus
- Arcuate Fasciculus
- Inferior Longitudinal Fasciculus
- Uncinate Fasciculus
What does the Superior Longitudinal Fasciculus connect?
Frontal and occipital lobes
What does the Arcuate Fasciculus connect?
Frontal and temporal lobes
What does the Inferior Longitudinal Fasciculus connect?
Temporal and occipital lobes
What does the Uncinate Fasciculus connect?
Anterior frontal and temporal lobes
What do commissural fibres connect?
Homologous structures in left and right hemispheres
What do projection fibres connect?
Cortex with lower brain structures (e.g. thalamus, brain stem and spinal cord)
What are two main sources of blood supply to the brain?
Vertebral arteries (posteriorly) Internal carotid arteries (anteriorly)
What are the types of intracranial haemorrhage?
- Extradural
- Subdural
- Subarachnoid
- Intracerebral
Why are extradural haemorrhages more rapid onset than subdural haemorrhages?
Extradural haemorrhages are caused by rupture of a meningeal ARTERY (high pressure) whereas subdural haemorrhages are caused by rupture of veins in the skull.
Which of extradural and subdural haemorrhages are more rapid onset?
Extradural
Define stroke
Rapidly developing focal disturbance of brain function of presumed vascular origin and of >24 hours duration
Define Transient Ischaemic Attack (TIA)
Rapidly developing focal disturbance of brain function of presumed vascular origin that resolves completely within 24 hours
Define infarction
Degenerative changes which occur in tissue following occlusion of an artery
Define cerebral ischaemia
Lack of sufficient blood supply to nervous tissue resulting in permanent damage if blood flow is not restored quickly
State two causes of vessel occlusion
- Thrombosis
2. Embolism
What is thrombosis?
Formation of a blood clot (thrombus)
What is embolism?
Plugging of small vessel by material carried from larger vessel e.g. thrombi from the heart or atherosclerotic debris from the internal carotid
What are the first factors for a stroke?
- Age
- Hypertension
- High cholesterol
- Cardiac disease
- Smoking
- Atrial fibrillation
- Diabetes mellitus
