Lecture 9- Brain Haemorrhage

Question 1

What are the usual cause of subarachnoid haemorrhage?

Answer 1

Saccular aneurysms- localised dilations of vessel wall which have a neck, body and fundus
Fundus composed of adventitia and intima only (no media/ int. elastic lamina)
Occur at branching points, and considered wide if neck > 4mm

Question 2

Clinical indications of SAH

Answer 2

Hx- thunderclap h, vomiting, stiff neck, photophobia, seizures/loss of consciousness
Exam- GCS, Pupils, CNS (esp fundoscopy), PNS
Risk factors- F HX, Smoking, HT, XS alcohol

Question 3

Investigation of SAH

Answer 3

CT brain- 98% when <12hr, 95% bt 12-24hr, <50% by end of W1
If negative, lumbar puncture
>12hrs after stroke/seizure, RBC lysis (HB released and metabolised to oxyHb/Bilirubin)
Bilirubin only formed in vivo and appears after 10 hours (spectrophotometry)

Question 4

How to perform a lumbar puncture

Answer 4

Position patient- foetal position if lying, sitting forward
Landmark- iliac crest at l4
Prep, LA and aim for umbilicus
Send urgently- must be spun within 30 mins, protect from light and immediate exam of CSF to avoid IV lysis of RBC > OHb

Question 5

Contraindications to LP

Answer 5

Focal neurology and abnormal conscious level with no known brain imaging
- e.g post fossa mass/ lateral mass effect on brain imaging causing displacement of midbrain/ cerebral hemispheres
Coagulopathy
Local infection and puncture site

Question 6

Investigation and treatment of SAH

Answer 6

Confirmed? > angiogram, CTA (computed tomography angiography) first then angiogram if necessary. CTA can detect 90-95% aneurysms > 2mm

Question 7

Investigation and treatment of SAH

Answer 7

Confirmed? > angiogram, CTA (computed tomography angiography) first then angiogram if necessary. CTA can detect 90-95% aneurysms > 2mm
Treament:
Coiling ( interventional neuroradiology), thromboembolism and transient deficient in 30%, permanent in <5%, regrowth from loose packing 13-20% esp in 1st 3 months (lower mortality at 1yr than clipping)
Clipping- neurosurgery: risks include death, stroke, bleeding, seizure, infection

Question 8

Vasospasm in SAH and treatment

Answer 8

causes stroke/death in 15% SAH- D7 up to 70% have angiographic vasospasm, clinically in 30%
Pathophysiology poorly understood but inc. risk w/ heavy blood load
Prevention- nimodipine, reducses risk of infarction and risk of poor outcome within 96hrs SAH
Hypervolemia- 125mls/hr normal saline
Rescue measures- bolus iv saline/colloid, HT inotropic therapy, chemical angioplasty w/ nimodipine

Question 9

Other complications of SAH

Answer 9

Hydrocephalus (25%), seizures (5-10%), electrolyte problems (Hyponatremia), ECG changes in 50% (mimic myocardial ischaemia, raised troponin)
Pulmonary oedema/pneumonia (sympathetic burst causes pulmonary VC)

Question 10

ICH- causes

Answer 10

HT, Vascular lesions (aneurysm rupture/ AVM), Neoplastic, coagulation disorders, CVT, haemorrhagoc transformation of ischaemic stroke, vasculitis, substance abuse, amyloid
Prognosis- poor initial GCS, haematoma volume >60ml (30 day mortality 90%)
Intraventricular haemorrhage on CT, increasing age
Collapse, obeying/aphasia/drowsy, hemiplegia and no pmhx

Question 11

Arterio-venous malformation

Answer 11

Tangled fistulous connections between arteries/veins, centred on nest, a vascular mass replacing capillary bed where shunting occurs
Incidence 1/100,000
1% annual rupture rate, 10-20% have associated aneurysms
Hx of seizure, collapse and recovery, homonymous hemianopia

Question 12

AVM treatment

Answer 12

Surgery, embolisation, stereotactic radiosurgery- radiation induced endothelial damage with SM proliferation, occluding vessel lumen
70-80% obliterated after 3yrs
Complications- radiation necrosis, bleeding, seizure

Question 13

Carotid cavernous fistula

Answer 13

Trauma, pain in eye? blurred/double vision/ reduced acuity, whooshing noise in head
Dural AV fistula between cavernous part of ICA and cavernous sinus/ its venous outflow
- can be spontaneous or after trauma: orbital bruit, exopthalmos, ocular pulsation, chemosis, pulsalite tinnitus, visual loss, headache, extrocular muscle palsies
Endovascular treatment

Question 14

Differential diagnosis for SAH

Answer 14

Thunderclap headache (11-25% have SAH)> can be
benign TC headache/migraine/ice pick headache, TGN, Cluster HA, Tension HA
Ischaemic stroke, venous sinus thrombosis, reversible cerebral VC syndrome
Pituitary apoplexy
Cartoid/vertebrobasilar dissection
sinusitis/meningitis (viral/bacterial), encephalitis/brain abcess
Brain tumour/hydrocephalus