031 Left internal carotid artery dissection presenting as an isolated left hypoglossal nerve palsy

A 33 year old male with no significant past medical history presented to the emergency department with an acute onset 4 day history of an odd sensation over his tongue and slurring of his speech. He had noted that his tongue deviated to the left when he stuck it out. There was no headache and no taste disturbance.

Clinical examination revealed a left sided hypoglossal nerve palsy. Sensation of the tongue to pin-prick and taste was normal. There was no Horner’s syndrome.

CT Angiogram of aortic arch and carotid vasculature demonstrated marked irregular calibre and increase in wall thickness of the left internal carotid artery (ICA), just adjacent to the external aperture of the hypoglossal canal, in keeping with a localised left ICA dissection. There was no clinical or radiological evidence of infarction. He was treated with high-dose anti-thrombotic treatment.

An acute isolated hypoglossal nerve palsy as a sequelae of a high ICA dissection is a rare but well docu- mented clinical presentation. The hypoglossal nerve is vulnerable to compression as it passes between the internal jugular vein and internal carotid artery at the skull base. It is crucial that neurologists and stroke physicians swiftly recognise this clinico-radiological syndrome to facilitate prompt, appropriate investigation and commencement of appropriate treatment.