O3.03 * THE SPECTRUM OF LATE PAROXYSMAL NEUROLOGICAL SYNDROMES AFTER BRAIN IRRADIATION

Abstract

INTRODUCTION: Late delayed multifocal paroxysmal neurological syndromes, known as stroke-like migraine attacks after radiation therapy (SMART), peri-ictal pseudoprogression (PIPG) and acute late-onset encephalopathy after radiotherapy (ALERT), have been recently reported after brain irradiation (RT). These syndromes share clinical and neuro-radiological features and might result from a common radiation-induced damage. Their diagnosis is challenging even for expert neurologists, as they have to be differentiated from a broad spectrum of complications, such as tumor progression, seizures, and toxic/metabolic encephalopathies. METHODS: We conducted a retrospective study in five institutions. Patients' inclusion criteria were 1) a remote history of brain irradiation; 2) the appearance of acute/subacute neurological signs and symptoms not related to tumor progression or epilepsy; 3) the presence of MRI abnormalities. Patients with stroke and transient “stroke-like” focal neurological signs in absence of ischemic/hemorrhagic lesions were included in the study. In all cases a thorough diagnostic workup was performed to exclude all other possible aetiologies. We identified 16 patients matching these criteria, and their clinical records were reviewed. RESULTS: Five patients presented a typical SMART pattern. Clinical presentation was characterized by hemianopia (3/5), confusion (2/5), headache (2/5), aphasia (2/5). Recovery was complete in 3 out of 5 patients after median interval of 8 days after symptom onset. Five patients presented ALERT syndrome. Clinical presentation was characterized by stupor/coma (5/5), headache (3/5), aphasia (3/5) and hemiparesis (3/5). All patients were treated with high dose steroids. Recovery was complete in 3 out of 5 patients after median interval of 9 days. Two patients presented an ischemic lesion within the radiation field, and were put on antiplatelet drugs. Four patients presented transient “stroke-like” events. Clinical presentation was characterized by aphasia (2/4), motor/sensory hemisyndrome (3/4). Two patients received antiplatelet drugs. Recovery was complete within hours or days in 3 out of 4 patients. We did not observe cases of PIPG in this series. In none of the patients tumor relapse occurred within the follow-up period. Three patients died due to pulmonary conditions. CONCLUSIONS: Long-term survivors after brain irradiation may present late paroxysmal neurological syndromes, that can be confused with tumor progression. Clinical presentation may be dramatic and recovery incomplete, resulting in residual severe morbidity. The aim of this report is to strengthen the observation of late delayed paroxysmal neurological syndromes after brain irradiation and to raise the neuro-oncologists' attention to the importance of developing adequate algorithms for the diagnosis and treatment of these conditions.