Pallister-Killian Syndrome: Further MRI and Clinical Findings in a Patient

Background. Patients with Pallister-Killian syndrome have received significant attention due to their phenotypic, genetic, and clinical abnormalities, especially their tendency to develop epilepsy. Neuroimaging studies have revealed major brain abnormalities, particularly polymicrogyria in the perisylvian frontotemporal cortex. Nevertheless, each new patient case can contribute to our understanding of the condition. Case presentation. We present a patient with Pallister-Killian syndrome who underwent long-term clinical, neurological, electroencephalographic, and neuroimaging follow-up. This follow-up allowed us to confirm that the type of seizure is variable. Neuroimaging revealed the presence of the known cortical asymmetric polymicrogyria, which extended beyond the typical affected regions. Additionally, we identified previously unreported developmental brain anomalies, including temporal arachnoid cysts, hippocampal dysmorphisms, and brainstem underdevelopment. Conclusions. This study shows that comprehensive follow-up is always recommended for these patients in order to better recognize all developmental brain anomalies. The study also demonstrates that the syndrome can present with a wider range of clinical and brain structural abnormalities than is typically recognized, confirming its heterogeneity. All brain abnormalities are developmental defects except for focal, mostly peri-paraventricular, signal abnormalities that are lesional.