Strokes, raised ICP and CSF Flashcards
Consequences of left anterior cerebral artery occlusion
R sided lower limb flaccid paralysis followed by spasticity
R sided lower limb sensory loss of all modalities
Loss of voluntary control of micturation (if affects paracentral lobules)
Split brain, alien hand syndrome due to corpus collosum damage
Consequences of PROXIMAL left middle cerebral artery occlusion
Malignant MCA - large infarction causes large cerebral oedema leading to death or coma
Total right sided flaccid paralysis followed by spasticity due to damage to internal capsule
Right sided facial and upper limb sensory loss in all modalities
Right homonymous hemianopia (not macular sparing)
Global aphasia (Broca’s and Wernicke’s) if left is dominant hemisphere
Neglect if left is non-dominant hemisphere
Consequences of DISTAL left middle cerebral artery occlusion
Right sided facial and upper limb flaccid paralysis followed by spasticity
Right sided facial and upper limb sensory loss in all modalities
Right homonymous quadrantanopia (not macular sparing)
Wernicke’s aphasia if left is dominant hemisphere
Neglect if left is non-dominant hemisphere
Consequences of left posterior cerebral artery occlusion
Right homonymous hemianopia which is macular sparing
Consequences of PROXIMAL left cerebellar artery occlusion
Left sided DANISH signs
Right sided ascending and descending tract damage
Left sided cranial nerve nuclei damage
Consequences of DISTAL left cerebellar artery occlusion
Left sided DANISH signs
Consequences of PROXIMAL basilar artery occlusion
Locked in syndrome
CN1-4 intact (eye movements)
Sensation and consciousness intact
Consequences of DISTAL basilar artery occlusion
Cortical blindness due to bilateral occipital damage
Impaired sensation and consciousness due to bilateral thalamus damage
CNIII damage due to midbrain
Describe pure motor lacunar stroke syndrome
Lenticulostriate artery occlusion
Damage to internal capsule so contralateral paralysis
Describe pure sensory lacunar stroke syndromes
Thalamoperforator artery occlusion
Damage to thalamus so contralateral sensory loss of all modalities
Function of thalamus in sensation
Relays sensory information to postcentral gyrus
What is used to investigate strokes
CT because:
Quick
Determines wether haemorrhage or infarction
What mimics a stroke
Hypoglycaemia
Epilepsy
Migraine
Intracranial tumours/infection
Stroke management
Rule out haemorrhage Thrombolysis within 4.5hrs Stroke unit Swallowing assessment PT/OT Aspirin for 14 days Statin Investigate cause
What contributes to intracranial pressure
Brain
Blood
CSF
How can you measure ICP
LP
IC catheter
How is ICP regulated within normal range
Autoregulation
Vasodilation if pH decreases
When does raised ICP become symptomatic
When lost maximum blood and CSF because compression of brain
What is Cushing’s reflex
Triad of symptoms:
Bradycardia
Decreased RR
Increased BP
Due to herniation of brainstem through foramen magnum
Symptoms of raised ICP
Generalised headache worse in morning and with coughing/sneezing/bending over
N+V to eventual projectile vomiting as activation of vomiting centre
Decreased consciousness
Visual disturbances
Why is headache with raised ICP worse in morning
Hypoventilation during sleep leads to vasodilation so increased blood in cerebral circulation
Lying down increases ICP
Why does raised ICP impair consciousness
Compression of reticular formation
What visual disturbances may someone experience with raised ICP
Transient blindness when coughing/sneezing/bending over - optic nerve compression
Papilloedema in chronic
CNVI palsy
Stages of worsening papilloedema on fundoscopy
1-2: grey halo around optic disc
3-5: compressed blood vessels
4 broad causes of raised ICP
Increased cerebral blood flow - venous sinus thrombosis
Increased CSF - hydrocephalus, idiopathic intracranial hypertension
SOL - haemorrhage, tumour, abscess
Cerebral oedema - meningitis, encephalitis, diffuse HI or infarction
Management for increased CSF as cause of raised ICP
Diuretics
CSF drainage
VP shunt
Describe idiopathic intracranial haemorrhage
Mostly affects young obese women
First line management is weight loss
Acute management of raised ICP
No LP, nil by mouth, put patient at 45 degrees
ABCDE - give O2, shock?, rule out hypoglycaemia
If not in shock, give hypertonic saline
Call anaesthetist to intubate as low GCS=hypoventilation
CT when stable
Treatment for cerebral oedema
Treat underlying cause
Hypertonic saline
Describe production and absorption of CSF
Choroid plexus cells filter arterial blood to produce CSF
CSF drains back into circulation:
Subarachnoid space-> Meninges-> Arachnoid villus-> Saggital venous sinus
What layers of the meninges does CSF go through
Only arachnoid mater as the arachnoid Vikki pierce through the dura mater
Describe CSF flow within the ventricular system
Lateral ventricles Interventricular foramina 3rd ventricle Cerebral aqueduct 4th ventricle Median and lateral apertures Venous circulation
Definition of hydrocephalus
Imbalance between production and absorption of CSF with subsequent ventricular enlargement
Categories of causes of hydrocephalus
Non-communicating: CSF obstructed within ventricles or between ventricles and subarachnoid space
Communicating: decreased absorption or increased production with no obstruction
Examples of communicating hydrocephalus causes
Post meningitis
SAH
Choroid plexus papilloma
Examples of non-communicating hydrocephalus causes
Cerebral aqueduct stenosis, atresia compression
Common brain tumours in each demographic
Children: astrocytomas or medulloblastomas (most near midline so surgery difficult)
Adults: most are metastases but also gliomas and meningiomas
Definition of a stroke
Sudden onset, focal neurological deficit specific to a vascular territory
Definition of papilloedema
BILATERAL optic disc swelling
Triad of normal pressure hydrocephalus
Apraxic gait
Urine incontinence - S2-4 damage
Confusion - periventricular tissue damage
Cause of NPH
Decreased CSF absorption
Management of NPH
VP shunt
Acetazolamide
Regular LP to remove CSF
