Posterior reversible encephalopathy syndrome: magnetic resonance imaging and diffusion-weighted imaging in 12 cases.

Posterior reversible encephalopathy syndrome (PRES) is a potentially devastating neurologic syndrome, but timely treatment may lead to complete reversal of the disease course. We reviewed 12 cases of PRES and describe the clinical history and imaging findings, including conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), and calculated apparent diffusion coefficient (ADC) maps, used to establish the diagnosis of PRES. Three male and nine female patients aged between 11 and 70 years (mean, 37 years) with clinical and imaging findings consistent with PRES were enrolled in the study. All patients had undergone conventional MRI and 10 had undergone additional DWI studies. Ten patients had follow-up MRI studies. DWI was performed using a 1.5T system with a single-shot spin-echo echoplanar pulse sequence. Initial and follow-up neuroimaging and clinical history were reviewed. Lesions were almost always present over the posterior circulation, mainly the parieto-occipital region, affecting primarily the white matter. The anterior circulation region, brainstem, cerebellum, deep cerebral white matter, and thalamus were also involved in five cases. Conventional MRI revealed hyperintensity on T2-weighted and fluid-attenuated inversion recovery images. DWI showed isointensity and increased signal intensity on ADC values in all cases, indicating vasogenic edema. Clinical and MRI follow-up showed that the symptoms and radiologic abnormalities could be reversed after appropriate treatment of the causes of PRES in most patients (9 of 10). In one patient, the ADC value was lower on follow-up images, indicating cytotoxic edema with ischemic infarct. DWI was a useful complement to MRI in the diagnosis of PRES.

Stroke registry in Kaohsiung Veterans General Hospital.

BACKGROUND: Stroke ranks as the second major cause of death in Taiwan. For better understanding of stroke characteristics in southern Taiwan and to provide further information to other studies of stroke, we reviewed the clinical data of our in-patients with acute stroke. METHODS: Patients who were admitted to our hospital due to acute stroke between January 1999 and December 1999 were enrolled in our study. We used a stroke registration form to collect clinical data, including laboratory data, stroke subtype, risk factors, neurosonographic result, treatment, related complications, and Rankin Scale. Chi-square test was used to compare clinical parameters among the stroke patients. RESULTS: A total of 578 patients with acute stroke were enrolled in our study. Among 578 patients, 408 (71%) patients were of ischemic stroke and 170 (29%) patients were of hemorrhagic stroke type. In the ischemic stroke group, the prevalence rate of risk factors were hypertension (71%), intracranial arterial stenosis (41%), diabetes mellitus (37%), current smoking (30%), hyperlipidemia (30%), atrial fibrillation (15%) and extracranial carotid stenosis (15%). Hypertension (79%) and diabetes (17%) were also major risk factors in hemorrhagic stroke patients. The in-hospital case-fatality rate for ischemic stroke (8.8%) was less than that for hemorrhagic stroke (20.6%). CONCLUSIONS: The proportion of hemorrhagic stroke in our acute stroke patients was higher in comparison to western countries. Hypertension, diabetes, smoking and hyperlipidemia were major modifiable risk factors in ischemic stroke. Better control of such risk factors is an important issue in either primary or secondary prevention of stroke. In our study, intracranial arterial stenosis (41%) was more common than extracranial carotid stenosis (15%). The result was different from western stroke registration. The cause is worth further study.