Thunderclap headache

Clinical

• Severe and abrupt headache reaching maximum intensity within 1 min

• Not defined by severity of pain, more by rapidity of onset

• Often described as:

o Explosion in head

o Being hit or struck across the head

• Clinical features suggesting aetiology

Reduced LOC, seizures, focal signs	SAH, ICH, Stroke, CVT
Recurrent over days/weeks	RCVS
Onset with sexual activity	SAH, Benign sex headache
Worse standing, muffled hearing	Intracranial hypotension
Neck pain	Dissection

DDx

Most common causes

RCVS

SAH

Primary/idiopathic thunderclap headache (including benign sex headache)

Less common causes

Cerebral infection

Cerebral venous thrombosis

Cervical artery dissection

Complicated sinusitis

Hypertensive crisis

Intracerebral haemorrhage

Ischaemic stroke

Spontaneous intracranial hypotension

Subdural haematoma

PRES

Uncommon Causes

Aqueductal stenosis

Brain tumour

Cardiac cephalgia

Pituitary apoplexy

Phaeochromocytoma

Retroclival haematoma

Spontaneous spinal epidural haematoma

Third ventricle colloid cyst

Possible causes

Unruptured intracranial aneurysm

Specific causes

Dissection

• In one series thunderclap occurred in 9.2% or vertebral dissection and 3.6% of carotid dissection

• Neck pain in 66% of vertebral dissection and 33% of carotid dissection

• Signs of cerebral ischaemia in 84%-90% of patients with vertebral artery dissection

• Signs of cerebral ischaemia in 70-73% of internal artery dissection

CVT

• Usually presents with subacute/chronic headache

• Up to 5% might present with a thunderclap headache

Intacranial hypotension

• 15% present with thunderrclap

Diagnosis

Examination:

• Blood pressure (HTN encephalopathy, PRES)

• Papilloedema

• Focal neurological signs

• Visual fields

o Bitemporal hemianopia (pituitary apoplexy)

CT Head

• Sensitivity for SAH within 6 hours 92-100%

Lumbar puncture

• Main purpose is to exclude SAH, but also look for infection etc

• Measure RBC acutely and xanthochromia at a delay

• Controversial as to which is most appropriate

• 2-15% of patients with a normal CT will have SAH detected on LP

CT Angiogram

• Aneurysm, dissection, RCVS

• Indication for use will depend on circumstances

Venous imaging

• CTV or MRV

MRI brain

• Consider in most cases if no SAH found

References:

*

Primary thunderclap headache associated with sexual activity

Treatment

• Indomethacin

• Nimodipine has been suggested in case report

• Topiramate – case report

• Triptans

o Used either acutely to shorten headache when it occurs or 30min prior to sexual activity as preventative

o Case report with 2/4 patients responding.