Acute Progressive Supranuclear Palsy Syndrome Secondary to Pontine Myelinolysis: A Case Report (P06.238)

OBJECTIVE: We present a case of a severe parkinsonism, mimicking progressive supranuclear palsy, which was due to centropontine myelinolysis (CPM), with no obvious extrapontine myelinolysis (EPM). The patient had a full recovery within 3 months. We discuss the pathophysiology of this specific case, and discuss the prognosis of CPM and EPM. BACKGROUND: Centropontine and/or extrapontine myelinolysis (CPM and EPM) are considered to have poor prognosis. Extrapyramidal involvement have been described with CPM and EPM, but the pathophysiology is poorly understood, and the prognosis is unpredictable. DESIGN/METHODS: A 63-year-old man with a history of chronic peripheric adrenal insufficieny was admitted to intensive care unit because of confusional state and severe hyponatremia (96 mmol/l). The correction fo hyponatremia was slow, following usual recommandations. Five days after correction of hyponatremia, the patient developed severe and progressive PSP-phenotype parkinsonism with rigidity, akinesia, supranuclear gaze palsy, dysphagia and frontal release signs. Initial brain MRI, lumbar puncture, DAT scan were normal. Brain MRI 2 weeks after onset of symptoms showed discrete lesions of CPM, there was no lesion of basal ganglia. RESULTS: The patient showed almost complete recovery at 3 months follow-up, with a normal brain MRI. CONCLUSIONS: CPM and/or EPM can occur even when the recommandation for hyponatremia correction is followed. CPM with EPM can manifest as severe parkinsonism without pyramidal involvement. The outcome is often good and depends mainly on secondary complications. Clinicians should take the potentially good prognosis into consideration and treat complications intensively. Disclosure: Dr. Andrea has nothing to disclose. Dr. Labeyrie has nothing to disclose. Dr. Laroche has nothing to disclose. Dr. Levy has received personal compensation for activities with Novartis, Esai, and Smith-Kline-Beecham. Dr. Levy has received personal compensation in an editorial capacity for la Revue Neurologique. Dr. Garcin has nothing to disclose.