[Case of posterior reversible encephalopathy syndrome caused by Fisher syndrome]

Posterior reversible encephalopathy syndrome associated with mild COVID-19 infection in a 9-year-old child: A case report and literature review

The neurologic complications associated with the coronavirus disease 2019 (COVID-19) is becoming more prevalent in children after the appearance of the Omicron strain. An association between COVID-19 and posterior reversible encephalopathy (PRES) has been consistently reported in adults, but little information is available in the pediatric age group. There are only few case reports of COVID-19-related PRES in children, and all of these patients were either on some type of immunomodulatory medications or whose general condition was severe. The present case, a 9-year-old Japanese boy, who had no fever but vomited several times from days 1-4 of a COVID-19 infection had an afebrile seizure on the 8th day of his illness. The patient had no history of hypertension, and had not previously been administered any immunosuppressive drugs before or during the period of his COVID-19 infection. On admission, his physical findings were unremarkable, except for a high blood pressure. The results obtained by brain computed tomography and magnetic resonance imaging were consistent with PRES. The patient recovered with no sequelae after treatment with antihypertensive drugs. Further investigations did not suggest any underlying disease that could have caused the transient hypertension. Although PRES is relatively rare in children, pediatricians should keep in mind that this syndrome can be complicated, even in children with mild COVID-19 infections.

Posterior reversible encephalopathy syndrome following Miller-Fisher syndrome

A 71-year-old woman presented to the emergency room with dysphonia, diplopia, dysphagia and generalised weakness since that day. Neurological examination revealed eye adduction limitation, ptosis, hypoactive reflexes and gait ataxia. Blood and cerebrospinal fluid analysis and brain CT were normal. Electromyography revealed a sensory axonal polyneuropathy. She was diagnosed with Miller-Fisher syndrome (MFS) and started on intravenous immunoglobulin. Two days after intravenous immunoglobulin treatment was completed, she developed a sustained hypertensive profile and presented a generalised tonic-clonic seizure. Brain MRI was suggestive of posterior reversible encephalopathy syndrome (PRES) and supportive treatment was implemented with progressive improvement. PRES may be a possible complication of MFS not only due to autonomic and inflammatory dysfunctions, but also as a consequence of its treatment. Patients with MFS should be maintained under close surveillance, especially in the first days and preferably in intermediate care units.