role of MRI in the diagnosis of vertebrobasilar dolicoectasia

ABSTRACT

Aging changes especially when it is associated with hypertension and arteriosclerosis may lead to elongation, dilatation and so tortuosity of the involved arteries. The clinical effect of this is either pressure symptoms or ischemic events. This phenomenon is called Dolicoectasia. It is defined as fusiform dilatation and elongation of an artery. The process can involve vertebral, basilar, posterior or anterior inferior cerebellar or labyrinthine arteries, The Vertebrobasilar system is more commonly involved by this process. The clinical presentations are non specific and could be related to wide range of pathological vascular and non vascular causes. The aim of the study was to demonstrate different MRI and MRA patterns of The vertebrobasilar Dolicoectasia as a respectable cause for neurological symptoms and signs including nerve palsies and posterior fossa infarctions. One hundred patient with neurological symptoms related to the portrait of the vertebrobasilar system were evaluated with MRI and MRA. Patients were referred from the outpatient clinics with retrolabyrinthine Hearing deficit, pulsatile tinnitus. facial spasm, trigeminal neuralgia or vertebrobasilar stroke features. The average age was 59 years with a standard deviation of 12 years. The females represent one third of cases while the males were two thirds. The most common presentation was vertebrobasilar insufficiency [VBI] in thirty percent, followed by facial spasm and pulsatile tinnitus in twenty three percent, trigeminal neuralgia in twenty one percent, cerebellar infarctions in seventeen percent and brain stem stroke in nine percent. Basilar and vertebral arteries were more commonly involved, while Labyrinthine artery was the least involved vessel The commonly missed vertebrobasilar Dolicoectasia should be considered as a respectable cause for neurological symptoms and signs including nerve palsies and posterior fossa infarctions. MRI and MRA are the modalities of choice to demonstrate the wide range of vascular changes occurred with Dolicoectasia and also their effect as nerve compression or vascular occlusions by embolization or thrombosis. The most common nerves to be involved is the trigeminal, acoustic and facial ones. If the radiologist does not consider this pathological entity as a cause for cranial nerve compression palsy, false negative results could occur. Vertebrobasilar Dolicoectasia [VBD] is considered uncommon, but this consideration should be changed in searching for causes of posterior fossa neurological symptoms especially in nerve compression or strokes