Co-morbid seizures in frontotemporal dementia: MRI and PET correlations

• Seizures were identified in 10% of patients with frontotemporal dementia. • Temporal lobe hypometabolism was frequent in FTD patients with seizures. • MRI showed comparable atrophy and WMH patterns regardless of seizure status. • Structural brain lesions were infrequent in FTD patients with seizures. • PET imaging may enhance recognition of seizure-prone FTD phenotypes. Seizures are common in frontotemporal dementia (FTD). MRI and PET findings may provide valuable diagnostic insights for FTD patients with seizures, but are understudied. This retrospective, single-center study aimed to investigate these findings. All patients with FTD from 5/1/2011–4/30/2024 were included. Patients with (FTD + SZ) and without (FTD-SZ) comorbid seizures were identified. Data on demographics, PET findings (presence, laterality, and region of hypometabolism), and MRI (presence of cerebral atrophy, white matter hyperintensities (WMH), atrophied regions, stroke, hemorrhage, or tumor) were obtained. FreeSurfer was utilized for segmentation, to attempt image analysis. Data were analyzed using Pearson’s Chi-squared, Fisher’s exact, or t-tests. Of a total of 326 FTD patients, thirty-three (10%) FTD + SZ (55% female, average age at dementia onset = 61.88 ± 10.47 years) and 293 (90%) FTD-SZ (45% female, average age at dementia onset = 64.27 ± 8.91 years) were identified. Overall, 61 patients underwent PET imaging (7[21.21%]FTD + SZ; 54[18.43%]FTD − SZ). Among those who underwent PET, temporal lobe hypometabolism was more frequent in the FTD + SZ (6[85.71%]) compared with FTD − SZ (32[59.26%]). MRI was performed in 264 patients overall (29[87.88%]FTD + SZ; 235[80.2%]FTD − SZ). Among FTD + SZ patients who underwent MRI, 25 (86.21%) demonstrated abnormalities. FTD + SZ predominantly showed a frontotemporal pattern. The presence of atrophy, WMH, mesial temporal sclerosis, and lobar involvement did not differ significantly between groups. Stroke was detected in 6.90% of FTD + SZ. In FTD, temporal hypometabolism was a common correlate of seizures in FTD. Although these differences did not reach statistical significance, our findings contribute to the literature, suggesting structural and functional neuroimaging may offer valuable diagnostic insights in FTD with seizures and should be more widely utilized in clinical practice. Larger, multi-center studies are needed to better define the role of neuroimaging in FTD with seizures.