Straight artery sign in extracranial carotid artery dissection.

BACKGROUND AND PURPOSE: Magnetic resonance imaging (MRI) has become generally accepted as a non-invasive method to provide the definitive diagnosis of cervicocerebral vessel dissection. The finding of an intramural hematoma on axial MR images is the characteristic sign of the disease. However, there has been no previous report of the characteristic magnetic resonance angiographic (MRA) findings. METHOD: The authors retrospectively reviewed MRI and MRA findings of patients with spontaneous extracranial carotid dissection. The most striking finding on MRA was the straightness of the affected artery when compared to the non-affected side of the same patient. For quantitative measurement, "Carotid Straightness Index (CSI)" was developed to measure the straightness of the arteries and compared the indices of both extracranial internal carotid arteries in the same patient. RESULTS: The patients' age range was from 21-55 years (mean 38 years). There were 6 males and 3 females. All patients had the classical "Straight artery sign" on the MRA. The carotid straightness index was significantly higher in the affected artery when compared to the normal side of the same patient. CONCLUSION: The straight artery sign and the carotid straightness index can be very useful for early detection of the extracranial carotid dissection. It can be found in early stage disease or in less severe forms of carotid dissection where significant narrowing is not demonstrated.

Mutation of the Notch 3 gene in a Thai cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy family.

The authors report the first Thai family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) in which the family members had a classical history of progressive vascular dementia. The proband was a 31-year old Thai male who presented with an acute stroke in the subcortical region. His past history revealed mental disturbance, including poor judgement and regressive behavior as well as mood changes for 1 year. He did not have a history of migraine or any other vascular risk factors except for a strong family history of ischemic stroke and progressive dementia. Magnetic resonance imaging demonstrated multiple small infarctions in the subcortical white matter of the bilateral frontal, parietal and occipital lobes with another small lesion in the pons. Genetic study demonstrated a Notch 3 mutation consisting of the substitution of a nucleotide at position 406 in exon 3 leading to the replacement of an Arginine by Cysteine at position 110 in the 2nd EGF motif, which is compatable with CADASIL.