Name : Morteza
Family : Sanei Taheri
Affiliation :Radiology Department,Shohada Tajrish Hospital,SBMU
Academic Degree : Associate Professor of Radiology
Resident : Razmin Aslani
Gender : Male
Age : 70
A 70 y/o man with ataxia,nausea, vomiting
multiple T2w high signal lesions are seen in both hemisphere of cerebellum and medulla.In DW diffusion restriction is noted. severe narrowing in basilar artery and filling of both PCA by P.com arteries is noted in brain MRA.
Multiple ischemic stroke in basilar branches territory.
Discussion (Related Text)
Three arteries provide most of the blood supply to the cerebellum. The posterior inferior cerebellar arteries (PICAs) arise from the intracranial portions of the vertebral arteries. The PICAs supply the posterolateral aspects of the medulla, the cerebellar tonsils, and the inferior and posterior surfaces of the cerebellar hemispheres. Occlusion of the proximal PICA can cause infarction of the lateral medulla and tonsil, whereas a more distal occlusion results in infarction mainly along the inferior cerebellar hemisphere.In a small number of patients, the PICA serves both cerebellar hemispheres. Hence, a bilateral PICA infarction is not necessarily a cardiac embolic problem but can be related to a single PICA.The anterior inferior cerebellar arteries (AICAs) are usually small vessels that provide reciprocal supply of the cerebellum along with the PICAs. The AICAs are occasionally duplicated and may arise together from a common trunk with the PICA. The AICA gives rise to the artery of the internal auditory canal. Therefore, in addition to causing inferior cerebellar infarction, occlusion of the AICA can result in sensorineural hearing loss, nausea, vertigo, and facial paralysis.The superior cerebellar arteries (SCAs) arise from the distal basilar artery and supply the superior portions of the cerebellar hemispheres.(1) They often appear duplicated (or tripled) on angiograms.Infarction of the SCA territory may involve a variable amount of the superior portion of the hemisphere.DW images are highly sensitive to the diffusion restriction that occurs in acute stroke.Regions of acute cerebral ischemia are typically hyperintense on DW images and result in diminished ADC values of up to 40%.It is often assumed that hyperintense signal on DW images represents irreversible ischemia. However, studies of experimental stroke and some depicted on imaging studies represent potentially reversible ischemia.(2)
1-John R.Haaga , CT and MRI of the whole body , fifth edition 2009 , page 209,211,220. 2-Jones SC, Perez-Trepichio AD, Xue M, et al: Magnetic resonance diffusion-weighted imaging: Sensitivity and apparent diffusion constant in stroke. Acta Neurochir Suppl (Wi en) 60:207-210,1994