stroke Flashcards
what factors are involved I maintaining cerebral perfusion pressure
pH and O2 drop and CO2 raise = vasodilation; opposite vasoconstriction in high CPP
define CPP
net pressure gradient causing cerebral blood flow to the brain i.e. mean arterial p - intracranial pressure
define stroke
clinical syndrome of abrupt loss of focal brain function lasting over 24 hours (or causing death) that is due to either spontaneous haemorrhage into brain substance or inadequate blood supply to a part of the brain.
what are the differences between to types of stroke
ischaemic (occlusion, more common), haemorrhagic (raptured cerebral blood vessels)
what are possible causes for haemorrhaging stroke
primary: no structural lesions, secondary: structural lesions i.e. tumour; hypertension, malformations, aneurisms
define TIA
Sudden onset, focal disturbance of brain function (occasionally global)
What are the characteristics of TACS
ICA/MCA occlusion => contralateral hemiparesis and hemiopia, higher cerebral disfunction => high mortality
What are the characteristics of PACS
MCA=> 2/3 of TACS and restricted motor deficit i.e. face or leg or arm only Or isolated cortical signs => high recurrence
What are the characteristics of LACS (lacunar)
single perforating artery affected with symptoms related to tissue death => underdiagnosed and silent
What are the characteristics of POCS
brainstem, cerebellar or occipital involvement=> with complex presentation
what does fast stands for
F=>face weakness, A=>arm weakness; S=> slurred speech, Time => rapid treatment required
What are the symptoms of stroke
“o Suggesting bleeding – Headache, Seizure
o Suggesting raised ICP – Heading, vomiting, drowsiness
o Suggesting aetiology – Cardiac symptoms
-ve symptoms”
what are the risk factors for stroke
smoking, family history, personal history, diabetes, hypertension AF, hypercholesteraemia, heavy drinking and poor diet
What are common differentials for stroke
hypoglycaemia, TIA, epilepsy, space occupying lesion, MS
how effective is CT in diagnosis of stroke
good for haemorrhagic , may no show early ischaemic changes or only settle once
how effective is MRI in stroke detection
changes seen much earlier on than CT but may not be available i.e. not routinely used
what is normal intracranial pressure what does it raise to with coughing
0-10 and 20 mmHg …60 may prevent blood flow to the brain
what are common causes of RICP
tumour, haemorrhage, meningitis, cerebral infarct, space occupying lesion
what are the 3 areas scriptable to compression with RICP
“o The Cingulate Gyrus
o The Uncus
o The Cerebellar Tonsils
“
What are the symptoms of RICP why do they change over time
early morning headache and nausea=> compensated
what are the steps of herniation
hemispheres squeezed through tentorium => brainstem compression=> bottom cerebellum squeezed into foramen magnum=> further compression of brainstem => suppressed blood supply to the brainstem and its death
what are the signs of RICP
local signs => reduced consciousness=> coma=> death
what is a possible complication of temporal bone infection, what are the symptoms
“temporal cerebral abscess.
“
what are the symptoms of meningitis
a severe headache, neck stiffness, aversion to bright lights, non-blanching
what tissue is inflamed in meningitis
pia and arachnoid
what is a common cause in neonates, 2-5 and 5-30
neonates => E.coli or L. monocytogenes; 2-5=> H. Influenza B; 5-39 N. Meningitidis and S pneumoniae
What are the characteristics of chronic meningitis
granulomatis inflammation of meningeal fibres leading to entrapment of cranial nerves. Cause by M. Tuberculosis or cryptococcal meningitis
what are common complication of meningitis
death, cerebral infarction, cerebral abscess, subdural empyema
What is encephalitis
infection of brain tissue usually viral
what are common viruses that cause encephalitis and where in the CNS
polio=> spinal cord, Harpies simplex => temporal lobe, rubella=> brain stem;
what are the actions of cytomegalovirus and toxoplasmosis on nerves
takes over cell body machinery and eventually leads to cell death
what type of organism is toxoplasmosis
protozoa
what is the pathological process sin Alzheimer’s and what are the macroscopical changes
beta-amyloid deposition leads to neuronal death and shrinkage of the cortex
What are the common changes in Alzheimer’s disease
memory impairment, language impairment agnosia
what are the risk factors for Alzheimer’s
family history, some anti-inflammatory drugs, down’s
What type of dementia is PD what is the pathology
Lewy body dementia => accumulation of alpha-synuclein
what are the changes in subfalcine herniations
subflacine=> compression of blood flow through ACA=> disturbances of frontal, parietal and corpus callosum and cingulate gyrus pushed under the falx cerebri
what are the changes in uncial herniations
CN3 damage, secondary haemorrhage into the brainstem, occlusion of PCA (common death in tumour)
what are the changes in tonsillar herniations
cerebellar tonsils push into jugular foramen and compress the rasp centre of the brainstem
what are the two types of damage seen with head injury
focal bruising=> coup and contrecoup and diffused axonal injury due to tearing of axons
what is the location of subarachnoid haemorrhage
between arachnoid and pia
what is the location of subdural haemorrhage
between dura and arachnoid
what is the location of extradural haemorrhage
between dura and bone
what are the different bleeding vessels in intracranial haemorrhage
extradural => middle meningeal a; subdural=> bridging veins,
what is the appearance of extradural haemorrhage on CT and why
lens shape pilling of the dura
who is more susceptible to subdural haemorrhage
elderly and alcoholics due to brain shrinkage
what is Berry aneurism and why does it occur
aneurism at the junctions of circle of wellies; often due to congenitale defects of blood vessels or cystic kidney disease
What are the symptoms of subarachnoid haemorrhage
Sudden, severe Thunderclap headache
