subarachnoid haemorrhage

Question 1

what is it?

Answer 1

Subarachnoid haemorrhage (SAH) refers to a bleed between the arachnoid and pia mater (the middle and innermost layers of meninges).
SAH may be traumatic due to head injury, or spontaneous, which is usually because of bleeding from a ruptured cerebral aneurysm.

Question 2

what are RF?

Answer 2

Risk factors for spontaneous SAH include smoking, hypertension and alcohol excess
Patients with berry aneurysms are at risk of these rupturing, causing a spontaneous SAH
The larger an aneurysm is, the higher the risk of rupture with those < 1cm at low risk

Question 3

what is the aetiology?

Answer 3

Trauma
Ruptured cerebral aneurysm (80-90% of which are in the anterior circulation)
Arteriovenous malformation
Arterial dissection
Vasculitis
Cocaine use

Question 4

what are the features?

Answer 4

Headache - typically severe and sudden onset, reaching maximum intensity within seconds (“thunderclap”)
Photophobia
N+V
Neck stiffness
Seizures

Reduced level of consciousness
Focal neurological deficit
Cranial nerve palsies (an isolated oculomotor nerve palsy may be seen in patients with an enlarging aneurysm or SAH)
Kernig’s sign (unable to fully extend the knee when the hip is flexed to 90 degrees)
Brudzinski’s sign (when the neck is flexed, the knees and hips also flex)
Hypertension
Limited or painful neck flexion

Question 5

what re the differentials?

Answer 5

meningitis - systemically unwell
migraine
primary sexual headache
epidural haemorrhage

Question 6

what are the bedside ix?

Answer 6

ECG - t wave inversion, ST elevation or depression , QT prolongation

Question 7

what are the bloods done?

Answer 7

FBC + CRP - may show thrombocytopenia, inflammatory markers

U+Es - baseline renal function + electrolytes, hyponatremia may occur
LFTs
clotting screen
group + save

Question 8

what imaging is done?

Answer 8

non contrast CT ideally within 6hrs symptom onset
CT angio to look for bleeding point

Question 9

what specials tests done?

Answer 9

LP - if a CT head was done longer than 6 hours after symptom onset and shows no evidence of SAH
The lumbar puncture is to look for elevated bilirubin in cerebrospinal fluid (xanthochromia)

Question 10

what is conservative mx?

Answer 10

A to E approach; airway support including intubation may be required for patients with reduced levels of consciousness
Close monitoring with regular neuro-observations
Once the diagnosis is confirmed, urgently refer for transfer to a specialist neurosurgical centre for further management

Question 11

what is the medical mx?

Answer 11

Ensure adequate analgesia is given (including opioid analgesia if required)
Antiemetics should also be given as vomiting may increase bleeding
Nimodipine 60 mg 4 hourly enterally is given to reduce vasospasm and further ischaemic brain injury
Correct electrolyte disturbance with IV fluids if required

Question 12

what is surgical mx?

Answer 12

Treating aneurysms with coiling (an interventional radiology procedure) or surgical clipping
In patients who develop hydrocephalus, external ventricular drain insertion may be required to reduce intracranial pressure

Question 13

what are complications?

Answer 13

hydrocephalus
re-bleeding
cerebral vasospasm
hyponatremia
cardiovascular complications
VTE
cognitive impairments
headaches, fatigue, sleep disturbance
seizures

Question 14

what is hydrocephalus?

Answer 14

Hydrocephalus is a neurological disorder characterized by an excessive accumulation of CSF within the brain’s ventricular system, leading to ventricular enlargement or ventriculomegaly. This increase in CSF results in raised intracranial pressure.

Question 15

what are the types of hydrocephalus?

Answer 15

Obstructive (or non-communicating) hydrocephalus

Communicating hydrocephalus

Question 16

what is obstructive hydrocephalus?

Answer 16

This occurs when the flow of CSF is blocked along one or more of the narrow passages connecting the ventricles. Common sites of obstruction include the foramen of Monro (e.g. due to colloid cysts), cerebral aqueduct (e.g. due to aqueduct stenosis), or fourth ventricle (e.g. due to posterior fossa tumour).

Question 17

what is communication hydrocephalus?

Answer 17

: In this type, CSF can exit the ventricular system, but absorption into the bloodstream is impeded. This is commonly due to problems in the subarachnoid space, often stemming from complications like subarachnoid haemorrhage and infective meningitis which may damage the arachnoid granulations.

Question 18

what are the features of hydrocephalus?

Answer 18

Early morning headaches
Nausea and vomiting
Lethargy
Vision disturbances
Balance problems
Cognitive difficulties

Question 19

what are ix for hydrocephalus?

Answer 19

Computed Tomography (CT) scan: This can reveal ventricular enlargement and is generally the initial imaging modality.
Magnetic Resonance Imaging (MRI): This provides a more detailed view of the brain and can help determine the cause of hydrocephalus.

Question 20

what is the mx for hydrocephalus?

Answer 20

ventriculoperitoneal or ventriculoatrial shunt.
Regular follow-up is required to monitor for complications such as shunt malfunction or infection.