Neuro histopath Flashcards
Name 4 main stroke syndromes
ACA
MCA
PCA
lacunar
What are the RFs for stroke and which is the main one
ATHEROSCLEROSIS (esp. cerebral atherosclerosis is the commonest cause, can also be embolism form intra/extracranial plaques)
smoking
HTN
DM
high cholesterol
excessive alcohol
past TIA
OCP
hyperviscosity e.g. PV or SCD
FH
PVD (?)
What are the similarities and differences between stroke and TIA
similar: rapid onset focal neurological sx
differences: stroke >24h, TIA <24h (usually lasting 1-5 minutes)
What is the risk of having a stroke following a TIA?
1/3 of people following TIA go on to have a stroke after 5 years if left untreated.
15% of first strokes are preceded by TIA
What is the incidence of strokes in the UK?
100 000 new strokes every year in the UK
What is the incidence of TIA in the UK
4/1000 in a year
What is the commonest territory to be affected by stroke?
MCA
What is the immediate management in stroke?
if ischaemic:
aspirin +/- dipyridamole (antiplatelet medication)
thrombolytics if <3h from event
+/- carotid endartectomy
What is the long term management in stroke/TIA?
treat HTN
lower lipids
anticoagulation
What is the immediate management in TIA?
aspirin +/- dipyridamole
+/- carotid endartectomy
What are the investigations for stroke/TIA?
stroke: CT/MRI
TIA: carotid USS
both: BP, FBC, ESR, U&E, glucose, lipids, CXR, ECG, carotid doppler
What features are seen in ACA syndrome
contralateral leg paresis
contralateral sensory loss in leg
urinary incontinence
cognitive deficits (apathy, confusion, poor judgement)
What features are seen in MCA syndrome?
proximal occlusion:
- contralateral weakness and sensory loss of face and arm
- contralateral hemisensory loss
- may have contralateral homonymous hemianopia or quadrantanopia
- if dominant (usually left hemisphere): aphasia
- if non-dominant (usually right) hemisphere: neglect
- eye deviation towards the side of the lesion and away from the weak side
What is the problematic result in cerebral oedema?
raised ICP
What is cerebral oedema?
excess accumulation of fluid in the brain parenchyma
Name mechanisms of CNS damage
oedema
hydrocephalus
raised ICP
stroke (haemorrhage and infarction)
Traumatic brain injury
What causes communicating and non-communicating hydrocephalus?
non-communicating is due to obstruction of flow of CSF (most commonly the aqueduct is affected)
communicating: problems with reabsorption of CSF into venous sinuses
What are causes of raised ICP?
SOL (tumour, abscess)
oedema
or both
What is normal ICP
7-15 mmHg (in a supine adult)
What conditions does the diagnosis of a stroke include and exclude?
Includes:
- cerebral infarcion
- primary intracerebral haemorrhage
- most cases of SAH
- intraventricular haemorrhage
excludes:
- subdural haemorrhage
- epidural haemorrhage
- intracerebral haemorrhage
- infarction caused by infection or a tumour
What is an important predictor of a future stroke?
TIA
Is there permanent injury to the brain following a TIA?
no (usually)
unlike in a stroke
What are AVMs? where can they occur?
arteriovenous malformations
can occur anywhere in the CNS
When and how to AVMs present?
present with haemorrhage, seizures, headache and focal neurological deficits
high pressure can cause massive bleeding
present between the 2nd and 5th decade of life
Mx of AVMs
surgery
embolisation
radiosurgery
Cavernous angioma
well defined malformative lesion composed of closely packed vessles with no parenchyma interposed between vascular spaces.
When do cavernous angiomas become symptomatic?
after age 50
Mx of cavernous angiomas
surgery
How do cavernous angiomas present
headache
seizures
focal deficits
haemorrhage
you get low pressure recurrent bleeds
Rare causes of non-traumatic cranial haemorrhages
AVMs
cavernous angiomas
capillary telangiectasias
connective tissue d/o e.g. Ehler Danlos syndrome
What is a key difference between AVMs and cavernous angiomas
AVM: high pressure - massive bleeds
Cavernous angioma: low pressure - low pressure recurrent bleeds
How common are berry aneurysms?
1% of gen pop affected
presentation of SAH
sudden onset severe headache
vomiting
LOC
What is the commonest site for a berry aneurysm
80% internal carotid artery bifurcation
20% occur within the vertebro-basilar circulation
Focal vs global cerebral ischaemia
focal: defined vascular territory
global: systemic circulation fails
Focal vs global cerebral ischaemia
focal: defined vascular territory
global: systemic circulation fails
What is the single largest cause of death in people under 45?
trauma
pervalence of truamatic head injury
9 in 100 000
What are the types of head trauma
non-missile (acceleration/deceleration; rotation)
missile
RTA, falls and assaults
focal or diffuse
What is diffuse axonal injury
occurs at the moment of injury
shear and tear forces affecting axons
commonest cause of coma (when no bleed)
midline structures are particularily affected e.g. corpus callosum, rostral brainstem and septum pellucidum
MCA - full words
middle cerebral artery
Sx of PCA syndrome
- contalateral hemianopia/quadrantanopia with macular sparing
- thalamic findings: contralateral sensory loss, amnesia, decreased level of conciousness
- midbrain findings (CN III and IV palsy/pupillary changes, hemiparesis)
- if bilateral: cortical blindness and prospagnosia (inability to recognise faces)
lacunar infarcts
non-cortical infarcts characterised by the absence of cortical signs (no aphasia, hemianopsia, agnosia, apraxia)
most commonly due to chronic HTN-ive vasculopathy
What is the main RF for lacunar infarcts
HTN
skull fractures - types
cranial vault fractures
basilar skull fractures
Signs seen in skull fractures
Liquorrhoea
Battle sign
Raccoon eyes
otorrhoea
signs of TBI
lacerations
haematoma
contusions
palpable deformities
mobile bone fragments
-> risk of infection!!
What is battle sign
bruising over the mastoid process
What are contusions?
brain in collision with the skull
coup and countercoup meaning
coup = where the impact occurs
countercoup = opposite region of the impact
straw coloured fluid buzzword
indicates leakage of CSF -> skull fracture
Which areas of the brain are affected by contusions?
lateral surfaces of the hemispheres
inferior surfaces of frontal and temporal lobes
What is the commonest cause of intraparenchymal haemorrhage?
50% due to HTN
What site is most commonly affected by intraparenchymal haemorrhages
basal ganglia
What is a concussion
minor traumatic brain injury
transient LoC and paralysis - recovery within hours or days
typically associated with no changes on standard neuroimaging (CT/MRI)
What are the types of brain haemorrhages
non-traumatic
- SAH
- intraparenhchymal haemorrhage
- rare (AVMs, capillary telangiectasia, cavernous angiomas, Ehler Danlos syndrome)
traumatic
- subdural haemorrhage
- extradural haemorrhage
- traumatic parenchymal injury (skull #, concussion, contusion, diffuse axonal injury)
imaging buzzword for SAH
hyperattenuation around circle of willis
What conditions are associated with SAH
APKD
Ehler danlos
aortic coarctation
hyperattenuation around circle of willis - buzzword for..?
SAH
lemon shape on neuroimaging buzzword for….?
Extradural haemorrhage
presentation of EDH
rapid arterial bleed (most commonly affecting MMA)
lucid interval
then LoC
banana shape on neuroimaging buzzwird
subdural haemorrhage
who is commonly affected by subdural haemorrhages?
elderly
alcoholics
poeple on anticoagulation
buzzwords for subdural haemorrhage
banana shape on neuroimaging
fluctuating consciousness
gradual headache
behavioral change
What vessels are damaged in SDH? is it a slow or rapid bleed>
damaged bridging veins with slow venous bleed
CAUSES OF NON-COMMUNICATING HYDROCEPHALUS?
meningitis -> meninges can become fibrous and this reduces absorption
how does CSF flow from lateral to 3rd ventricle?
interventricular foramen
