Stroke 2 Flashcards
What happens in a Stroke on a cellular level?
- Hypoperfusion in the endothelial lumen which eventually results in depletion of available ATP and impairment of energy dependant cell processes
- The lack of ATP means there is a drop in the Action Potentials which leads to an absence of neuronal transmission
What are the features of a typical stroke syndrome event?
- Evolves Suddenly ( reflecting the phase transition of AP cessation
- Focal (only neurovascular units in the concerned vascular territory are affected)
- Predominately negative ( reflecting the loss of function that attends AP cessation)
- Fits into a Vascular territory
What features are NOT seen in a stroke syndrome event?
- Isolated presentation
- Migration (especially slow of symptoms)
- Stereotyping ( defined as episodic recurrence of neurological disturbance in an identical fashion with complete resolution in between)
When there is evidence of stereotyping what stroke mimics is the event likely to be?
- Migranous Aura
- Focal Seizures
- Functional Neurological Episodes
What stroke syndromes can present with something similar to stereotyping?
- Capsular Warning Syndrome ( not true stereotyping but fluctuation of symptoms, with episodes usually recurrent over minutes to hours)
- Intracranial Stenosis ( focal symptoms usually coincide with other evidence of generalised hypoperfusion - dizziness)
What is it called when the causes of stroke remains unclear after assessment?
- Cryptogenic Stroke
What is the typical cause of a PACS presentation?
- Embolisation
- Cardiac Emboli determined if the patient has atrial fibrillation, cardiomegaly, valvular heart disease, heart failure, endocarditis or following an acute MI
What are some of the sources of a Large Embolic Source?
- Carotid bruits
- Peripheral Vascular disease
What would you suspect in a patient who is hypertensive or diabetic with a LACS presentation?
- Fribrinolytic necrosis
What would you suspect in an elderly lady with a few months of headache, weight loss, lethargy, pallor, temporal arteritis and past medical history of SLE (systemic lupus erythematosus) ?
- Vasculitis
What would you suspect in a pregnant stroke patients/ patient with previous VTE, miscarriages or active cancer?
- Thrombophillia
What would you suspect in historical evidence of recent local neck trauma?
- Dissection
What are some of the common post- stroke complications?
- Recurrent Stoke and Extension of Stroke ( Extension of stroke - loss of ischaemic penumbra)
- Raised ICP ( haematoma expansion, malignant oedema, haemorrhagic transformation or hydrocephalus)
- Infections (common chest infections - aspiration, UTIs - incomplete bladder emptying, constipation - supine/ bed bound posture)
- Complications of immobility ( VTE, constipation and bed sores)
- Mood and Cognitive dysfunction
- Post stroke pain and fatigue (joint dislocation, central/neuropathic pain, poor sleep - result of brain cell damage)
- Spasticity, Contractures and Secondary Epilepsy
What is important in the “Stroke Bundle” for patients?
- Admission to the stroke unit
- Revascularisation therapy
- Optimising Physiology (surveillance, prevention and early intervention of complications) and nutritional support
- Secondary Prevention
- Rehabilitation and Reablement
What determines the recovery of the patient and how well the patient will do?
- The recovery trajectory as this reflects the neuroplasticity at the site of neuronal damage
What are the three types of recovery trajectories?
- Early, high functioning plateau ( TIA/ minor stroke)
- Early, low functioning plateau ( TACS - no meaningful improvement in function as time passes)
- Delayed and medium functioning plateau ( most people after a stroke, patients will benefit from a chance at sustained rehabilitation efforts until a functional plateau is achieved)
What is the definition of a Stroke?
- A cerebrovascular accident is a serious life threatening condition that occurs when the blood supply to part of the brain is cut off
- The symptoms and signs persist for more than 24 hours
What is a TIA?
- A Transient ischaemic attack known as a mini stroke, it has similar clinical features of a stroke but completely resolve within 24 hours
What are the types of Stroke?
- Ischaemic (thromboembolic)
- Haemorrhagic (intracerebral, subarachnoid)
- Other (dissection, venous sinus thrombosis, hypoxic brain injury)
What are the symptoms of ACA infarct (Anterior Cerebral Artery)?
- Contralateral weakness in lower limb (Lower limb affected much worse than upper limb and face)
- Contralateral sensory changes in same pattern as motor deficits
- Urinary Incontinence due to paracentral lobules being affected ( paracentral lobules - essentially the most medial part of the motor/ sensory cortices and supply the perineal area)
- Apraxia ( damage to the left frontal lobe, Inability to complete motor planning - difficulty dressing oneself even when the power is normal)
- Dysarthria/ Aphasia ( unusual sign)
- Split brain syndrome/ Alien hand syndrome - involvement of the corpus callosum, normally supplied by the ACA
What are the symptoms of a complete MCA infarct?
- Contralateral full hemiparesis ( face, arm and leg affected due to the involvement of the internal capsule)
- Contralateral sensory loss
- Visual Field Defects ( Contralateral homonymous hemianopia without macular sparing - due to destruction of both superior and inferior optic radiations running through the temporal and parietal lobes)
- Aphasia (usually left hemisphere)
- Contralateral neglect ( can not acknowledge one side of the body. Features include: Tactile extinction (touch isn’t felt on one side), Visual extinction ( half clock face), Anosognosia ( does not acknowledge that they have had a stroke)
What are the features of Lenticulostriate Arteries Occluded?
- Pure motor
- Pure sensory
- Sensorimotor
What are the features of a distal superior MCA branch?
- Lateral frontal lobe
- Primary motor cortex + Broca’s area = Contralateral face and arm weakness and expressive aphasia
What are the features of a distal inferior MCA branch?
- Lateral parietal lobe and superior temporal lobe
- Primary sensory cortex + Wernicke’s area + both optic radiations
- Contralateral sensory change
- Receptive aphasia
- Contralateral visual field defects without macular sparing
What are the features of a PCA (posterior cerebral artery) Stroke?
- Contralateral homonymous hemianopia (macular sparing due to collateral supply of MCA)
- Contralateral sensory loss due to damage to the thalamus