Cranial nerve palsies due to internal carotid artery dissection: seven cases.

Cranial nerve palsies are rare complications of internal carotid artery (ICA) dissections. The aim of this study is to evaluate the incidence of cranial nerve palsies in consecutive patients with ICA dissection and to describe clinical and radiological characteristics and their evolution over time. This study was conducted in 52 consecutive patients with dissection of the ICA. We have analyzed clinical data of patients with cranial nerve palsy as complication of ICA dissection. We defined ICA dissection as angiographic evidence of a string sign, double lumen, or internal flaps or visualization on magnetic resonance imaging (MRI) or computed tomographic scans of an enlarged arterial wall due to the hematoma. Of 52 consecutive patients with ICA dissection 7 had cranial nerve palsies: 2 had an involvement of the Vth cranial nerve and 5 had lower cranial nerve palsies. Five patients totally recovered while 2 did not after a 2 to 10-month period. The frequency of cranial nerve palsies associated with ICA dissection is higher in our study than in those of the literature. Many patients presenting with cranial nerve palsies due to ICA dissection without any ischemic event are probably not referred to stroke units. Angiography is less sensitive than cervical MRI to detect such patients. Cranial nerve palsies could either be due to compression by the enlarged ICA wall or an ischemia of the nerve.