NONINVASIVE INVESTIGATION OF PERICAROTID SYNDROME - ROLE OF MR-ANGIOGRAPHY IN THE DIAGNOSIS OF INTERNAL CAROTID DISSECTION

A 52-year-old man presented with unilateral left periorbital and front otemporal pain associated with a partial ipsilateral Horner's syndrome of the postganglionic type and representing a pericarotid syndrome. M RI demonstrated a perivascular subacute hematoma at the level of the c ervical portion of the left internal carotid artery with a markedly re duced flow-void signal. MR angiography confirmed the narrowed lumen of the dissected cervical internal carotid artery. There was also a righ t-sided precavernous carotid aneursym. Three months later the left-sid ed pain had subsided, with complete resolution of the hematoma and inc omplete restoration of the left carotid lumen seen on MR angiography. Dissection of the carotid wall may cause the oculosympathetic paralysi s by producing a lesion of the superior cervical ganglion, the interna l carotid nerve, or the perivascular sympathetic plexus. Whereas in pe ricarotid syndrome the most common cause is cervical carotid dissectio n, Raeder's syndrome additionally involving parasellar cranial nerves, may be caused by any paracavernous/cavernous lesion, including neopla sms and intracranial carotid aneurysms. The clinical distinction is us eful to determine the appropriate diagnostic investigation, in view of the different pathoanatomical localization and different disease spec trum. As demonstrated in the present case, the combination of MRI end MR angiography is a reliable noninvasive tool to investigate the diffe rential diagnosis of pericarotid syndrome, accurately depicting occlus ive, stenotic or aneurysmal lesions of the carotid artery. We suggest that intraarterial angiography is no longer necessary.