Brain Haemorrhage Flashcards
What is a subarachnoid haemorrhage
When an aneurysm bursts and blood fills the subarachnoid space. Space between the dura and Pia matter.
Why are subarachnoid haemorrhages so important to diagnose
The risk of the aneurysm bursting again within the next couple of weeks is high if the aneurysm is not secured or blocked off. Most people can not survive two aneurysm bleeds.
What is an aneurysm
A local dilation of a blood vessel wall. Has a neck, body and fungus.
Neck: where it comes off the blood vessel.
Body: main bulk of the aneurysm
Fundus : dome of the aneurysm where it usually bursts
Why do aneurysms usually burst at the fundus
Because the fundus is only composed of tunica adventitia and intima , No media of internal elastic lamina. thinnest part
Where do aneurysms tend to develop
At the branching of blood vessels
When is an aneurysm considered wide neck
if neck is grater than 4 mm
What are the important findings in a clinical history of subarachnoid haemorrhage
1- Thunderclap headache ( comes on suddenly and hits peak ) 2- vomiting 3- neck stiffness 4- photophobia 5- seizure and loss of consciousness
What tests are done if subarachnoid haemorrhage is suspected and what are the important clinical examination findings
1- GCS : for loss of consciousness
2- Pupils : bilateral fixed dilated pupils means very high ICP / 3rd CN aneurysm
3- Cranial nerves esp fundoscopy to look for papilodema or vitreous bleed in eye
4- Peripheral nervous system incase haemorrhage has caused weakness
What aneurysm can press on cranial nerve 3 and how will it present
Posterior communicating artery aneurysm can press on the 3rd cranial nerve , resulting in a dilated pupil on that side / oculomotor palsy
What are the risk factors for subarachnoid haemorrhages
1- Strong family history ( 2+ relatives, will offer yearly screening )
2- smoking
3- hypertension
4- alcohol excess
What is the first imaging done for a suspected subarachnoid haemorrhaged why is it vital to do it right away
CT Brian. sensitivity of the aneurysm drops every 6 hours of waiting , since blood will be reabsorbed and washed off by the CSF
What is the percentage of sensitivity if patient get’s CT brain for subarachnoid haemorrhage a week after symptoms
Less than 50%
Explain how different things present ( colour wise ) on a CT scan
Bone : White
CSF : black
Blood : whitish
What is the next step if a patient coming in with suspected subarachnoid haemorrhage but CT brain scan is normal and what are it’s requirements
Lumber puncture. More sensitive test than CT.
Have to wait at least 12 hours after headache. CSF then assessed via spectrophotometry.
What does a lumber puncture look for if subarachnoid haemorrhage is suspected
Bilirubin
How is bilirubin found in subarachnoid haemorrhages
1- RBC is borked down and release HB
2- HB is metabolized to oxyHB and bilirubin
How to preform a lumber puncture
1- Patient is positioned on their side , curled up in the fetal position.
2- aiming for interspinal space between L4 & L5 , landmark is iliac crest at L4
3- aim for umbilicus
Why are lumber punctures does between L4& L5
Because there’s no spinal cord there so it is safe
What will happen to CSF lumber puncture sample if it is not spun asap
There will be a big surge in oxyhemoglobin that could mask other findings like the bilirubin shoulder
What are the contraindication to a lumber puncture and why
1- patients with focal neurological defect or abnormal conscious level : if patient has tutor or hematoma LP will draw CSF downwards which will make the brain sink downwards and put pressure eon brainstem
2- Coagulation disorders
3- infection at puncture site
4- it’s been more than 2 weeks since headache
What is the next step if the CT Brian for SAH is positive
Have a CT angiogram and if positive then schedule with neurosurgery
What is the next step if CT brain for SAH is negative but it has been over 2 weeks
Have to discuss with neurosurgery the next step
What is the next step if the LP is positive for SAH
CT angiogram or catheter angiogram if necessary
What are the possible treatment options for a SAH
1- Coiling
2- Clipping
Explain the process of coiling and the risks
Done by : interventional neuroradiologist
How: endovascularly , puncture the radial or femoral artery and pass catheter into the aneurysm which deploys detachable platinum coil.
Risk of defect due to thromboembolism , risk of stroke is less than 5
What is the follow up process with SAH patient having undergone coiling
The could be regrowth due to loose packing of coil , so patients are followed up with serial scans
Explain the process of clipping , it’s difficulties and risks
Done by : neurosurgeons
How: have to open the scalp, performing a craniotomy and putting a clip on the aneurysm
Difficulties : brain is swollen
Risks: Death ( 1-2 ) , Stroke ( 10 ) , bleeding, seizure, infection ( meningitis )
Which SAH treatment option is preferred now
Coiling
The grading for SAH is based on what ( explain each grade )
The Glasgow Coma Score Grade 1 : GSC 15 Grade 2: DSc 14 Grade 3 : GCS 13 Grade 4: GSC 7-12 Grade 5: GSC 3-6
When could coiling not be possible
If coiling the aneurysm would occlude a vessel
Why would a post clipping surgery CT brain show a wide circle figure in ventricles
A drain put in to reduce brain swelling , to make surgery easier
If a patient’s CT brain shows a part of their brain darker than the rest what is assumed
decreased blood flow, stroke
What is a major complication and cause of morbidity in 30% of patients with SAH
Vasospasm that causes stroke / death. more likely if patient had more bleeding due to aneurysm
How are vasospasm prevented
1- Nimodipine reduces risk of stroke : has to be given within 96hrs of SAH
2- Hypervolemia : 125 normal saline to keep blood volume high
What will happen if a SAH patient is dehydrated
They will have a stroke
What are the rescue measures if SAH patient gets a vasospasm
1- Bolus of IV saline
2- Hypertensive therapy to push BP and reduce stroke risk : noradrenaline
3- Chemical angioplasty : nimodipine is injected directly into cranial vessels
What is a decompressive craniotomy
Surgery done to accommodate brain swelling and reduce ICP
Complications of SAH
1- Hydrocephalus
2- Seizures
3- Electrolyte problems : low sodium
4- ECG/cardiac rhythm changes : due to sympathetic discharge cause arrhythmias
5- Pulmonary oedema / pneumonia : sympathetic discharge cause pulmonary vasoconstriction
What is hydrocephalus
build up of fluid in brain
What are the outcomes for SAH
- Fatality : 51%
- survivors : 1/3 are dependant
The risk of aneurysm rupturing increased when
1- If aneurysm is more posteriorly located , in basilar artery / posterior communicating artery
2- bigger the aneurysm
3- previous SAH
4- age
5- Hypertension
6- Geographical location : more common in Japan and Finland
What are intracerebral haemorrhages
Bleeding into the Brian tissue itself. High mortality
What is probably the underlying reason of a patient <45 years getting a ICH
underlying Vascular lesion
List the causes of ICH ( 9 )
1- Hypertension 2- Vascular lesion : aneurysm rupture / arteriovenous malformation 3- tumor 4- coagulation disorders 5- thrombosis 6- Bleeding into Ischaemic stroke 7- vasculitis 8- substance abuse 9- amyloid
What is AVM
Arteriovenous malformation where there Is abnormal connection between blood vessels. Tangled fistulous connecting arteries and veins, so high pressure blood from artery going into vein = weakness in vessel wall = can rupture and bleed
What factors can give poor prognosis for ICH patient
1- hematoma
2- blood in ventricles
3- increasing age
4- poor conscious level
What would give incentive for neurosurgery on ICH patient
Young patent and borderline conscious level
Why are some ICH not operated on
Deep into the brain and have to go through a lot of normal tissue , risky and trial shows that sometimes there isn’t much benefit
What are the possible options for AVM treatment
1- Surgery
2- Embolisation : glue it
3- Stereotactic radio surgery
What is Stereotactic radio surgery
Radiation will damage blood vessel wall and obliterate AVM by occluding vessel lumen
What are the complications of stereotactic radosurgery
1- radiation necrosis
2- bleeding
3- seizure
If patient has lost visual acuity ( CN2 ) and lost eye movements ( CN 3, 4 ,5 ). Where could the problem be
Cavernous sinus , all of these nerves meet
What is a Carotid Cavernous Fistula
Fistula between the internal carotid artery cavernous part and the cavernous sinus or its venous outflow. Increases cavernous sinus pressure. Could be spontaneous or due to trauma
What are the signs of Carotid cavernous fistula
1- orbital bruit 2- exophthalmos , ocular pulsation , chemises 3- pulsatile tinnitus 4- visual loss 5- headache 6- extra ocular muscle palsies
What is the treatment for Carotid cavernous fistulas
Endovascular treatment
What percentage of thunderclap headache patients have SAH
10-25%
What are differential diagnosis for thunderclap headache
1- Bening thunderclap / headache 2- ischaemic stroke /. venous sinus thrombosis 3- pituitary apoplexy 4- carotid/vertebrobasilar dissection 5- sinusitis/meningitis / brain abscess 6- brain tumour/ hydrocephalus
What is the most important diagnosis to exclude form thunderclap headache
SAH
What is the prevalence of ICH
3%
Why should aneurysms be treated quickly
to prevent risk of rebleed
