14) Stroke Flashcards
Define stroke
Damaging or killing of brain cells due to a lack of oxygen as the blood supply is cut off to that area of the brain. Signs and symptoms last for more than 24 hours
Define Transient Ischaemic Attack (TIA)
A stroke which recovers within 24 hours
What types of strokes are there ?
> Ischaemic - Most common > Haemorrhagic > Dissection > Venous sinus Thrombosis > Hypoxic brain injury
What does the Anterior Cerebral Artery supply.
It supplies the medial parietal and frontal lobes as well as the corpus callosum
How is a patient presented in a ACA territory infarct ?
Medial homunculus damaged:
> Contralateral Motor and Sensory loss to the lower limb and genitals
> LMN signs and then UMN
Frontal Lobe damage:
> Apraxia - Inability to complete motor planning
> Dysarthria / Aphasia
If paracentral lobules affected => Incontinence
Corpus Callosum affected => Split Brain Syndrome
- 2 halves of the brain cannot communicate with each others
What the does Middle Cerebral Artery Supply ?
> Consider its branches as well.
Supplies the Lateral parietal and frontal lobes
> Also supplies Macular Cortex and Basal Ganglia
> Lenticulostriate Arteries branch of proximally supplying internal capsule
How is a patient presented with MCA territory infarct ?
> 3 points of obstruction
Proximal:
> Contralateral Hemiparesis (Face, Arm, Leg)
> Contralateral sensory loss
> Visual field Defects => Optic radiations affected depending on how many is affected = Hemianopia or Quadranaopia
> Dominant Hemisphere affected => Aphasia b/c Broca and Wernicke’s area affected
> Non - Dominant Hemisphere => Contralateral Neglect ; Tactile Extinction ; Visual Extinction
Lenticulostriate Arteries:
> otherwise referred to as Lacunar Strokes
> Distinguishing feature compared to a proximal infarct is that their is no cortical features only motor function loss.
> IF Thalamoperforator Artery affected => Purely sensory loss
Distal: MCA splits into Superior and Inferior Divisions.
> Superior supplies the Lateral Frontal Lobe
- Contra lateral Motor weakness and expressive aphasia
> Inferior supplies the Lateral Parietal Lobe
- Contra lateral Sensory Changes and Visual field defect without Macular Sparing
What does the PCA Supply
Occipital and Frontal Lobes and Thalamus
How may a patient present with PCA obstruction ?
> Homonymous Hemianopia with Macular Sparing
> Contra lateral sensory loss
What does the Cerebellar Arteries Supply
> Cerebellum
> Mid brain en passant
How may a patient present with a Cerebellar Artery Obstruction
> DANISH (Ipsilateral) > Brainstem damage - Ipsilateral Oculomotor Damage - Contra lateral Motor function damage - Ipsilateral Horner Syndrome
How may a patient present with Basilar Artery Obstruction ?
Bilateral symptoms
Distal => Occipital lobe ; Thalamic and Mid brain Infarct
Proximal => Locked in syndrome b/c Pontine arteries affected
What clinical tool is used to quickly diagnose strokes ?
Bamford Stroke Classification
What imaging is used to diagnose strokes ?
CT b/c Faster and cheaper
But MRI is clearer
