IHS	Diagnosis	ICD-10
6.5.1	Headache or facial or neck pain attributed to arterial dissection [I67.0]	G44.810

Diagnostic criteria:

Comments:

Headache with or without neck pain can be the only manifestation of cervical artery dissection. It is by far the most frequent symptom (55-100% of cases) and it is also the most frequent inaugural symptom (33-86% of cases).

Headache and facial and neck pain are usually unilateral (ipsilateral to the dissected artery), severe and persistent (for a mean of 4 days). However, it has no constant specific pattern and it can sometimes be very misleading, mimicking other headaches such as migraine, cluster headache, primary thunderclap headache and SAH (particularly since intracranial vertebral artery dissection can itself present with SAH). Associated signs are frequent: signs of cerebral or retinal ischaemia and local signs. A painful Horner's syndrome or a painful tinnitus of sudden onset are highly suggestive of carotid dissection.

Headache usually precedes the onset of ischaemic signs and therefore requires early diagnosis and treatment. Diagnosis is based on Duplex scanning, MRI, MRA and/or helical CT and, in doubtful cases, conventional angiography. Several of these investigations are commonly needed since any of them can be normal. There have been no randomised trials of treatment but there is a consensus in favour of heparin followed by warfarin for 3-6 months according to the quality of the arterial recovery.