Should Posterior Reversible Encephalopathy Syndrome Be Mainly Considered an Epileptic Disorder? Results of a Sequential Neurophysiological Study in a Pediatric Cohort.

Despite a wide number of studies trying to define clinical, physiopathological, and neuroradiological features of posterior reversible encephalopathy syndrome (PRES), the true nature of symptoms is still not fully understood. We studied a standard cohort of 24 pediatric patients, affected by hemato-oncological diseases, with a neuroradiological diagnosis consistent with PRES identified from 2006 to 2013. Ten of them developed PRES after hematopoietic stem cell transplantation. We analyzed the sequence of clinical, radiological, and electrophysiological data. In all the patients who were recorded at the onset of the first symptoms, electroencephalograms showed focal nonconvulsive seizures or status epilepticus (SE). We found a sensitivity of 100% for electroencephalogram (EEG) with a good correlation between clinical signs and the localization of seizures, whereas computed tomography scans showed a sensitivity of 50% only. Following prompt treatment, intensive care unit admission rate was only 8%. PRES is a multifactorial neurologic event with focal nonconvulsive seizures or SE as the main feature in pediatric patients. Clinical manifestations are epileptic in nature, and prompt EEG recording is useful for diagnosis and supports an earlier treatment, potentially preventing the appearance of complications such as generalized seizures or refractory SE.

Spectrum and potential pathogenesis of reversible posterior leukoencephalopathy syndrome.

BACKGROUND: Controversy still exists over the etiology and pathophysiology of reversible posterior leukoencephalopathy syndrome (RPLS). This large single-center case series aims to describe the clinical and imaging features of RPLS in an attempt to deduce the etiology of the disorder and the mechanisms of brain injury. METHODS: A retrospective chart and imaging review was conducted on 59 cases of RPLS in 55 patients. RESULTS: Five RPLS imaging patterns were observed: posterior predominant (n = 40), anterior predominant (n = 7), diffuse lesion (n = 7), basal ganglia predominant (n = 3), and brainstem/cerebellum predominant patterns (n = 2). RPLS resulted in permanent neurologic deficits in 14 patients and death in 4 patients. Hypertension was seen in 57 (97%) cases, and mean arterial blood pressure exceeded 140 mm Hg in 30 (51%) cases. Follow-up magnetic resonance imaging scans revealed a significant worsening of vasogenic edema in 2 cases, both with persistent hypertension. Magnetic resonance imaging scans revealed areas of ischemia in 14 cases, all within or at areas closely adjacent to vasogenic edema. Diffuse vasculopathy was seen in 8 cases. There was a lack of correlation between the presence of vasculopathy and the degree of vasogenic edema (P = .62), but a correlation was suggested between ischemia and vasculopathy (P = .02). CONCLUSIONS: This study strongly suggests that hypertension-induced vasodilation rather than vasoconstriction-mediated hypoxia is likely the major mechanism responsible for the development of vasogenic edema, and that vasoconstriction may contribute to the development of ischemia in RPLS.

[A case of brainstem variant of reversible posterior leukoencephalopathy syndrome].

A rare case of a brainstem variant of reversible posterior leukoencephalopathy syndrome (RPLS) is reported. A 34-year-old man with a past history of untreated chronic renal failure and hypertension was admitted to our hospital complaining of severe nuchal headache lasting for about four days. His neurological examination was normal, however physical examination revealed his blood pressure was 216/120 mmHg. Computed tomography imaging (CT) showed his brain stem with a low attenuation. Magnetic resonance imaging (MRI) revealed extensive hyperintensity and enlargement of the midbrain and pons on T2 weighted and fluid attenuated inversion-recovery (FLAIR) image. However, there was no abnormal lesion seen in either bilateral occipital lobe. Diffusion-weighted image (DWI) was normal at the brainstem, but apparent diffusion coefficient (ADC) values were slightly elevated at the left midbrain. There was no contrast enhancement. His symptom and radiological finding improved soon after his blood pressure was controlled. A repeated MRI taken two weeks later showed complete resolution of the lesion. RPLS associated with predominant involvement of the brainstem and sparing of the supratentorial region is rare, but it should be differentiated from brain stem infarction, pontine glioma, central pontine myelinolysis and infective encephalitis, since the neulological consequences are potentially fully reversible after adequate and prompt treatment.