MR Imaging Findings of Medulla Oblongata Involvement in Posterior Reversible Encephalopathy Syndrome Secondary to Hypertension

Abstract

SUMMARY:Although the combination of MR imaging findings and clinical evidence of hypertension may suggest the diagnosis of posterior reversible encephalopathy syndrome (PRES), MR imaging findings with only involvement of the medulla oblongata pose a diagnostic dilemma. In the cases presented here, we demonstrated MR imaging findings of a presumed brain stem (medulla oblongata) variant of PRES and emphasized the diagnostic value of diffusion-weighted imaging (DWI). Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, vomiting, altered consciousness, seizure, and cortical blindness associated with imaging findings of predominantly posterior bilateral symmetric subcortical and cortical edema without frank infarction.1 Hyperintense lesions on T2-weighted MR imaging and swelling of the brain stem may be related to many different pathologic processes. PRES rarely presents with predominant involvement of the brain stem, and involvement of only the medulla oblongata is uncommon.2,3 Only 1 patient with PRES was reported to have medulla oblongata, upper cervical spinal cord, and supratentorial involvement. 4 Herein we report 2 cases of a presumed variant of PRES with only medulla oblongata involvement. Case Reports Case 1A 59-year-old man with history of left putaminal hemorrhage 15 years previously had a 1-week history of poor appetite, vomiting, altered consciousness, and seizure-like movements. His history was also significant for hypertension controlled with medications. Initial blood pressure (BP) was 210/108 mm Hg. Serum electrolytes were normal. Brain MR imaging (Signa LX2; GE Healthcare, Milwaukee, Wis) revealed isointensity on T1-weighted images (T1WIs) and diffusionweighted images (DWIs), and hyperintensity on T2-weighted images (T2WIs) of the medulla oblongata and upper cervical spinal cord (Fig 1). Because of clinical signs and history and MR imaging findings of edema (not infarction) in the medulla oblongata and upper cervical spinal cord, the differential diagnosis included a variant of PRES, encephalitis, and encephalomyelitis. Because there was no evidence of infection or fever, and results on CSF examination were unremarkable, a variant of PRES was the likely diagnosis. An angiotensinconverting enzyme inhibitor and a calcium channel blocker were administered for BP control. His clinical condition improved, BP normalized to 140/90 mm Hg, and level of consciousness returned to normal. MR imaging 45 days later (Fig 1) indicated resolution of hyperintensity confirming a variant of PRES secondary to hypertension with involvement of the medulla oblongata. Case 2A 62-year-old man with a history of hypertension and cerebral infarction was seen with a 3-day history of headache, vomiting, involuntary movement, and change in consciousness. BP was 180/100 mm Hg. No signs of infection or a meningeal abnormality were present, and serum electrolyte levels and CSF were normal. Brain MR imaging showed hyperintensity on T2WIs and isointensity on DWIs, which involved the medulla oblongata (Fig ...

Involvement of the cervical cord and medulla in posterior reversible encephalopathy syndrome

“…Patients with ADEM have a history of fever, preceding viral illness, and a more profound neurodeficit. Massive brainstem infarction has a sudden onset and patients are comatose at presentation 4. The involvement of the cervical cord is exceedingly rare, and to our knowledge only two cases have been reported in the literature; one of the patients had cocaine-induced malignant hypertension 512.…”

“…Holo-hemispheric, superior frontal sulcus, and uncommonly, involvement of brainstem, pons, cerebellum, basal ganglia, and splenium have also been described 23. The involvement of the medulla and cervical cord is very rare, with only few cases reported 45. We report a case of PRES with involvement of the cervical cord and medulla, in addition to typical parieto-occipital lesions.…”

“…The involvement of medulla oblongata and especially the cervical cord, however, is very rare 4. The imaging differential in such patients is brainstem infarction or ADEM, which can be distinguished by clinical grounds from PRES.…”

Risk of Subsequent Dementia in Patients with Hypertensive Encephalopathy: A Nationwide Population-Based Study in Taiwan

“…Delay in the treatment of HE may in fact result in death or irreversible neurological sequelae [24]. Second, because there are no specific ICD-9 numbers for RPLS and posterior reversible encephalopathy syndrome and they both have similar clinical presentations and radiological features to HE [25,26,27,28], their ICD-9 number was therefore coded as HE. Third, additional, theoretically relevant confounding variables such as smoking, lifestyle, and drugs could not be included in our analysis because they were not included in our data set.…”

Posterior Reversible Encephalopathy Syndrome and Anti-Angiogenic Agents: A Case Report

“…6,7 Originally described as a subcortical disease of the posterior cerebrum, 2 with symmetrical changes in both parietal and occipital lobes, more recently published series have shown different radiological findings and patterns, such as cortical involvement, as well as frontal, temporal, or, less commonly, cerebellum, brainstem, or basal ganglia lesions. 4,6,16 Although it occurs but rarely, a unilateral pattern of PRES may be found. 7 Brain computed tomographic (CT) imaging may be useful as a first examination, exhibiting hypodense areas in susceptible regions, but the diagnosis is more firmly established using brain magnetic resonance imaging (MRI).…”