041 Cognitive impairment in late onset epilepsy

Objective Late onset, unprovoked epilepsy patients with cognitive impairment can have complex pathophysiology.1 Our objective was to study the characteristics and contributors of cognitive impairment in this group; and how patients with dementia could be differentiated from late onset epilepsy patients. Methods Twenty-six patients with epilepsy, onset after 50 years of age, with new cognitive complaints and 26 patients with clinically diagnosed Alzheimer’s Disease (AD) were recruited. These participants had comprehensive neuropsychological and neuroimaging assessments. A subset of 17 participants from the Epilepsy group underwent longitudinal neuropsychological assessment. Results In the Epilepsy group, the neuropsychological profile of cognitive impairment was consistent with the foci and severity of seizure activity in 46% of participants; subcortical microvascular change in 15%; mood disturbance in 15%; medication in 15%; alcohol in 4% and AD in 4%. Compared with the Epilepsy group, the AD group had a lower Addenbrookes Cognitive Examination III (ACE-III) score (79.3±10.8 versus 87.5±6.5, p=0.01); specifically in the attention, memory and visuospatial subdomains (p=0.004, p=0.002 and p=0.02) but not fluency and language subdomains (p>0.05); and lower scores on additional assessments of naming, visuospatial and executive function (p≤ 0.001). The AD group had more abnormal metabolism in the temporal, parietal and occipital lobes than the Epilepsy group (p=0.02, p=0.006 and p=0.005). Conclusion Patients with late onset epilepsy and cognitive complaints rarely have dementia diagnosed at their first neuropsychological assessment and tend to have milder cognitive impairment than patients with AD. The two groups can be differentiated by their neuropsychological and FDG-PET profiles. Reference Sen A, Capelli V, Husain M. Cognition and dementia in older patients with epilepsy. Brain 2018;141(6):1592–1608.