Abstracts

Rationale: Epilepsy diagnosis is often difficult to diagnose since it is principally based on anamnestic information from non-medical witnesses. A significant differential diagnosis is PNES (psychogenic non-epileptic seizures), a functional disorder verging on the edge of neurology and psychiatry. Patients diagnosed with PNES have symptoms that bear confusing resemblance to epileptic seizures, but are not related to simultaneous changes in the brain’s electrical activity.Uncertain and delayed diagnostic of epilepsy and PNES has potentially serious consequences for the patient, including risk of trauma, sudden unexpected death in epilepsy (SUDEP), long-lasting pharmacotherapy and side effects, as well as family-related, psychosocial and business-related consequences.In some cases, transient changes in MR-scans (postictal changes) are observed in relation to epileptic seizures, which are believed to be oedema formed on the basis of metabolic processes in the brain tissue during epileptic activity.Due to the lack of certain biomarkers for epileptic seizures, supportive methods of differentiation between epileptic seizures and PNES are being investigated. The purpose of current project is to map the occurrence and nature of postictal changes on MRI in inpatients with epileptic seizure and PNES. It is considered whether better application of early MRI will lead to more safe and faster diagnostics. Methods: A retrospective review of journal information and MRI results in patients admitted to Aalborg University Hospital and diagnosed in 2015 with status epilepticus, singular or recursive seizures and PNES. Exclusion criteria: Patients who received a diagnosis, which could potentially lead to changes in the brain tissue and thus could not be differentiated from postictal changes.In cases where there were acute changes to the MRI that could not be attributed to any known neurological disorders, the location, characteristics and reversibility of the changes were assessed together with the type of seizure and its duration.Moreover, it was investigated whether the changes found in the MRI were later attributed to other pathology. Results: 12/116 (10,3 %) inpatients diagnosed with epileptic seizure had acute MRI changes unrelated to other known brain pathology.8/12 received control MRI scans within 4 and 330 days after the seizure.In 7/8 (87,5 %), the changes on MRI had disappeared on the control scan.2 out of 12 (16.7%) were subsequently given a second diagnosis that could explain the changes to the previous MRI. Among the 9 patients with PNES, there were no changes to the MRI, as expected. Conclusions: 10 out of 116 patients with epileptic seizures were found to have postictal changes in MRI, where there were no other reasons for MRI pathology. However, postictal changes in MRI were not found in patients with PNES. It is possible that an early MRI scan in all patients with seizures may lead to safer and faster diagnosis. The study indicates that further investigations should include a prospective study where all patients will be MRI scanned directly after seizures. Funding: none