Week 17 - Nervous System Flashcards
What are the 2 main types of stroke?
Ischaemic
Haemorrhagic
What are some common symptoms of a stroke?
Typically asymmetrical
- limb weakness
- facial weakness
- dysphagia
- visual field defects
- sensory loss
- ataxia
- vertigo
What defines a TIA?
Temporary neurological dysfunction (<24hrs)
Caused by ischaemia but without infarction
What are crescendo TIAs?
2 or more TIAs within a week
What can be the causes of ischaemia in a stroke?
Embolism
Thrombosis
Systemic hypoperfusion
Cerebral venous sinus thrombosis
What is the classification system of Ischaemic stroke? What are the types?
Bamford classification
- total anterior circulation stroke
- partial anterior circulation stroke
- posterior circulation syndrome
- lacunae stroke
What is the criteria for a total anterior circulation stroke?
All 3 of the following must be present:
• Unilateral weakness (and/or sensory deficit) of the face, arm and leg
• Homonymous hemianopia
• Higher cerebral dysfunction (dysphasia, visuospatial disorder)
What is the criteria for a partial anterior circulation stroke?
2 of the following need to be present:
• Unilateral weakness (and/or sensory deficit) of the face, arm and leg
• Homonymous hemianopia
• Higher cerebral dysfunction (dysphasia, visuospatial disorder)*
What is the criteria for posterior circulation syndrome?
1 of the following needs to be present:
• Cranial nerve palsy and a contralateral motor/sensory deficit
• Bilateral motor/sensory deficit
• Conjugate eye movement disorder (e.g. horizontal gaze palsy)
• Cerebellar dysfunction (e.g. vertigo, nystagmus, ataxia)
• Isolated homonymous hemianopia
What is the criteria for a lacunae stroke?
1 of the following needs to be present:
• Pure sensory stroke
• Pure motor stroke
• Sensori-motor stroke
• Ataxic hemiparesis
What is a total anterior circulation stroke?
Large cortical stroke affecting the areas of the brain supplied by both the middle and anterior cerebral arteries
What is a partial anterior circulation stroke?
Less severe form of TACS
Only part of the anterior circulation has been compromised
What is posterior circulation syndrome?
Involves damage to the area of the brain supplied by the posterior circulation e.g. Cerebellum and brainstem
What is a lacunar stroke?
Subcortical stroke
Occurs secondary to small vessel disease
No loss of higher cerebral function
What are the 2 subtypes of haemorrhagic stroke?
Intracerebral haemorrhage
Subarachnoid haemorrhage
What is the most common cause of a subarachnoid haemorrhage?
Berry aneurysm in the circle of Willis
Where do posterior cerebral arteries supply?
Mixture of medial and lateral areas of the posterior cerebrum
Where do the middle cerebral arteries supply?
Majority of the lateral cerebellum
Where do the anterior cerebral arteries supply?
Ateromedial area of the cerebrum
What symptoms are seen in a blockage of the anterior cerebral artery?
Weakness of contralateral leg
Behaviour changes
Typically present with weakness and sensory loss in the lower leg and foot opposite the lesion, incontinence and behaviour changes
What symptoms are seen in a blockage of the middle cerebral artery?
Weakness of contralateral face and arm
Speech disturbance
Visual field defect
Intattention to stimuli
Sensory defecits
Typically present with symptoms most associated with stroke
What symptoms are seen in the blockage of the posterior cerebral artery?
Visual field defects
Sensory defecits
What symptoms are seen with a lesion in the vertebrobasilar system?
Dizziness
Ataxia
Impaired balance
Pupil and eye movement abnormalities
Changes in voice and swallowing
Weakness and sensory changes
Decreased level of consciousness
What is found in grey matter?
Cell bodies
Cerebral cortex
What is found in the white matter?
Glial cells and myelinated axons
What are the 4 lobes of the brain?
Frontal
Parietal
Temporal
Occipital
What is the function of the frontal lobe?
Higher intellect
Personality
Mood
Social conduct and language
Where is the broca region located?
Frontal lobe