Agenesis of the Right Internal Carotid Artery and Klippel-Feil Syndrome

Abstract

Case report. To describe the case of a Klippel-Feil anomaly associated with carotid agenesis. Klippel-Feil anomaly is a spinal malformation characterized by fusion of the cervical vertebrae. Four subtypes have been identified for this congenital disorder with different severity of vertebral fusion and different extra-axial anomalies. Most cases are sporadic, although autosomal dominant and autosomal recessive cases are recognized. It can cause neurologic disorders and is associated to vascular abnormalities. However, agenesis of internal carotid and Klippel-Feil syndrome is an unusual association. A 49-year-old woman came to our attention for recurrent transitory ischemic attacks presenting with weakness of left limbs associated with sensory abnormalities. Neurologic examination revealed mild left limb weakness and tactile hypoesthesia. Brain magnetic resonance (MR) and MR angiography demonstrated absence of the right internal carotid and the middle right cerebral artery was filled from the basilar artery. Fusion of vertebral bodies was documented at MR and confirmed at spinal CT scan. The day after the admission the neurologic examination became normal. Ticlopidine was then started. Literature of vascular abnormalities in association with Klippel-Feil syndrome takes the form of anecdotal reports. Aortic coarctation, vertebral artery dissection, aneurysms, persistent trigeminal artery, and abnormal origin of internal carotid are described. An unusual association of carotid internal agenesis and Klippel-Feil syndrome is reported with a literature review.