HYPERTENSION ILLUSTRATED Hypertensive encephalopathy with predominant brain stem involvement: MRI findings SK Karampekios 1 , E Contopoulou 1 , M Basta 2 , M Tzagournissakis 2 and N Gourtsoyiannis 1 1 Department of Radiology, University Hospital of Heraklion, Crete, Greece; 2 Department of Neurology, University Hospital of Heraklion, Crete, Greece Journal of Human Hypertension (2004) 18, 133–134. doi:10.1038/sj.jhh.1001654 Keywords: hypertensive encephalopathy; brain stem; magnetic resonance imaging Case report A 40-year-old man with a 3 months history of progressive headache presented with nausea, vomit- ing, visual disturbances and an episode of epileptic seizure with loss of consciousness. From his medical history, the patient had been diagnosed as hypertensive and received treatment with beta- blockers in the past, but he discontinued it, 1 year ago. At the time of admission, his blood pressure was elevated to 180/120 mmHg and remained high in several measurements during the first 24 h, despite the prompt start of antihypertensive treat- ment. MRI of the brain was performed on the admission day demonstrating multiple scattered areas of increased signal intensity on T2-weighted and FLAIR images in both occipital and posterior parietal lobes. There were also similar lesions in both hemispheres of the cerebellum (especially the cerebellar white matter on the left) as well as in the medulla oblongata (Figure 1a–c). The lesions were not associated with mass effect and after contrast administration there was no evidence of abnormal enhancement. The patient received combined anti- hypertensive treatment with beta-blockers, convert- ing enzyme inhibitors and calcium channel blockers and the blood pressure was satisfactorily controlled within the next few days. The clinical status was distinctly improved with regression of the headache as well as improvement of the vision and ataxia. A second follow-up brain MRI was performed 10 days later and showed complete resolution of the lesions (Figure 1d–f). Hypertensive encephalopathy is an acute and severe disorder that develops typically in patients with malignant hypertension or eclampsia and has also been reported in patients on immunosuppres- sive drug therapy. There are associated rapidly progressive symptoms from CNS involvement, such as headache, altered mental status, seizures or visual disturbances. 1 Although the clinical findings are nonspecific, the findings on MRI are quite char- acteristic due to the pattern of the lesions which predominantly involve the supratentorial white matter, especially in the occipital lobes, as well as the brain stem and cerebellum. 2 In our case, the MRI findings showed that the parietal and occipital lobes were minimally and moderately involved, respec- tively, while extensive lesions were seen within the cerebellum and medulla oblongata. Two different mechanisms have been proposed to explain the pathophysiology of hypertensive encephalopathy. 3 The first theory suggests that acute hypertension causes cerebral vasculature vasospasm followed by a decrease in blood flow and intravascular thrombo- sis. These two factors seem to cause ischaemia and cytotoxic oedema. The second theory suggests that a sudden elevation of blood pressure produces a breakdown on autoregulation of cerebral vessels causing an extravasation of fluid into the surround- ing brain tissue and inducing a reversible vasogenic oedema. 4,5 References 1 Pavlakis SG, Frank Y, Chusid R. Hypertensive encephalopathy, reversible occipitoparietal encephalo- Received 28 July 2003; revised and accepted 9 August 2003 Correspondence: Dr SK Karampekios, Department of Radiology, University of Heraklion, Heraklion T.K. 71500, Crete, Greece. E-mail: karampek@med.uoc.gr Journal of Human Hypertension (2004) 18, 133–134 & 2004 Nature Publishing Group All rights reserved 0950-9240/04 $25.00 www.nature.com/jhh