BACKGROUND: Patients with history of brain radiotherapy can experience acute "stroke-like" syndromes related to the delayed effects of brain radiation, including "Stroke-like Migraine Attacks after Radiation Therapy (SMART)", "Peri-Ictal Pseudoprogression (PIPG)", and "Acute Late-onset Encephalopathy after Radiation Therapy (ALERT)" syndrome. The aim of this study is to collect evidence on the long-term outcome and treatment of these conditions, whose knowledge is undermined by their rarity and fragmented description. METHODS: Cases were collected, both prospectively and retrospectively, among six neuro-oncology departments. Inclusion criteria were: 1) history of brain radiotherapy (completed from at least 6 months); 2) new onset of acute/subacute neurological symptoms; 3) exclusion of all etiologies unrelated to brain irradiation. A review of current literature on "stroke-like" syndromes was performed to corroborate our findings. RESULTS: Thirty-two patients with acute neurological conditions attributed to the delayed effects of radiation were identified, including 26 patients with "stroke-like" syndromes. Patients with "stroke-like" syndromes commonly presented with a mosaic of symptoms, including focal deficits (77%), encephalopathy (50%), seizures (35%) and headache (35%). Seventy-three percent of them had acute consistent MRI alterations. Treatment included high-dose steroids in 65% of cases. Twenty-two patients recovered completely (85%). Sixteen patients (62%) experienced relapses (median follow-up: 3.5 years). Literature review identified 87 additional "stroke-like" cases with similar characteristics. CONCLUSIONS: "Stroke-like" events related to brain irradiation may be associated with permanent sequelae. Steroids are often administered on empirical grounds, as they are thought to accelerate recovery. Relapses are common, highlighting the need to elaborate adequate prevention strategies. This article is protected by copyright. All rights reserved.
- ALERT syndrome
- SMART syndrome
- brain tumor
- focal deficit
- peri-ictal pseudoprogression (PIPG)