Clinical Manifestation And Imaging Finding Of The Top Of The Basilar Artery Syndrome

Background: Top of the basilar artery syndrome (TOBS) is a special ischemic cerebrovascular disease ,which is due to the disturbance of the circulation of the top of the basilar artery. Its main clinical manifestation is a group of syndromes such as : sudden vertigo , unconsciousness with the dismovment of the eyeballs, the abnormalty of the pupils, the dyskinesia ,partial blindness or cortical blindness and dystrophy. There are five vasculars converge to the top of the basilar artery─two posterior cerebral arteries,two superior cerebellar arteries and the top of the basilar artery itself.These branches are mostly distributed to several cerebral parts, for instance: midbrain, thalamus, upside of the cerebell, inner side of the temporal lobe and the occipital lobe . Brain CT scan shows that the most important pathological festures of TOBS is infarctions in both sides of thalamus, midbrain, cellebellum ,occipital and temporal lobes .The resolution of MRI is higher than CT in some soft tissues,which can also been displayed from all directions.Especially MRI is more sensitive to the lesions of brain stem and cerebellum,so the diagnosis according to MRI is more exact.But the golden standard for the diagnose of TOBS is still the cerebral angiogram,which is able to show directly the infarction of the top of the basilar artery.Because the manifestation of TOBS is different from that of other ischemic cerebrovascular diseases, people realize it after Caplan reported TOBS firstly in 1980.Due to the speciality and low incidence of the TOBS ,there are some limities of undersdanding clinically, affecting the diagnose and treatment. Objective:For the above mentioned reasons , we analyse some cases in our hospital in many aspects such as pathogenesis, pathology, clinical, imaging ,diognosis, treatment and prognosis etc. In oeder to help clinical doctors comprehend the TOBS better, making correct diagnose and prompt treatment .Method: The clinical data of 16 cases in our hospital were analysed retrospectively, These data include its pathogenesis, clinical manifestation, character of imaginology ,diagnosis,therapy and prognosis and so on .In order to make differential diagnosis , we enumerate 2 cases which have similar clinical manifestation but differ in vascular infarction when compared to the cases of TOBS. The differential diagnosis is mostly according to cerebral angiography.Results: Most of the cases were middle or old aged.The etiological and high risk factors included hypertention,diabetes,heart diseases, hypercholesterol and so on . Clinical manifestation comprised of the sudden vertigo or unconsciousness with the dismovement of the eyeballs, the abnormality of the pupils, the dyskinesia,partial blindness or cortical blindness and dystrophy , due to different combination of thalamus and midbrain infarctions.The examination of imagiology reveal that the most characteristic pathological festures of TOBS was infarctions in both sides of thalamus and midbrain (50%) ,and /or various combination of cellebellum ,occipital and temporal lobes . The CT scans may demonstrate the bilateral infarctions thalamus just like a butterfly. (which is on T1-weighted MRI lower signal but higher signal on T2-weighted MRI) . MRI is more sensitive than CT for the diagnosis of TOBS. DSA is the golden standard for the diagnosis of TOBS,and could offer a strong evidence for differential diagnosis.Conclusion:TOBS simultaneously comprise multi-infarctions involving many territories. Correct diagnosis could be made mainly according to clinical manifestation and imaginology.CT and MRI can offer objective data, whill cerebral angiography has most important significance in defecting location of vascular occlusion. Earlier check of MRI or DSA for clinical patient who is suspected have the TOBS could help making correct diagnosis,so the patient can receive treatment promptly. Although this disease has bad prognosis and high mortality rate, through elevating cellular survival rate in ischemic penumbra , ameliorating microcirculation,and alt...