Brief Communication Hemifacial Seizure of Cerebellar Ganglioglioma Origin: Seizure Control by Tumor Resection *Jong Hee Chae, †Seung-Ki Kim, †Kyu-Chang Wang, *Ki Joong Kim, *Yong-Seung Hwang, and †Byung-Kyu Cho *Department of Pediatrics, Seoul National University Children’s Hospital; and †Division of Pediatric Neurosurgery and Laboratory of Neuro-Oncology in Cancer Research Institute, Seoul National University Children’s Hospital and Neurological Research Institute, SNUMRC, Seoul, Korea Summary: The cerebellum is known to have an inhibitory effect on seizures. Nevertheless, cerebellar dysplastic lesions can be epileptogenic. A 4-month-old infant had paroxysmal facial contractions; tachypnea and nystagmoid eyeball and tremulous movements were occasionally combined. These evolved to stereotypic clinical patterns and frequencies, which increased despite administration of antiepileptic drugs (AEDs). Magnetic resonance imaging (MRI) demonstrated a mass aris- ing from the superior cerebellar peduncle, although video-scalp EEG monitoring revealed no abnormal findings. Positron emis- sion tomography with [ 18 F]fluorodeoxyglucose revealed focal hypermetabolism in the same area identified by MRI. A depth electrode implanted in the mass revealed focal spike-and-wave discharges. The lesion was partly removed; pathologic diagno- sis was ganglioglioma. Because of incomplete seizure control and residual tumor visible on MRI, a second operation was performed. After complete excision of the tumor, the patient became seizure free without AEDs. This case confirms the presence of seizure originating from the cerebellum and em- phasizes the need for the complete removal of an epileptogenic lesion. Key Words: Cerebellar ganglioglioma—Epileptic sei- zure—Infancy. Epileptic seizures are defined as excessive paroxysmal discharges from nerve cells leading to clinical and elec- trical changes, which usually arise from the cerebral cor- tex (1). Subcortical structures are thought to have indirect effects only on cerebral epileptic activity through neurochemical modulation (2,3). However, epi- lepsy of subcortical origin has been demonstrated in ani- mal models (4). More recently, the subcortical origin of epileptic seizures has been well documented in humans with hypothalamic hamartomas (5) and cerebellar dys- plastic lesions (6,7). Depth electrodes placed within hypothalamic hamar- tomas have revealed ictal activity arising from these structures (5). The epileptogenicity of these hamartomas may come from the aberrant connectivity of neuronal structures or from the intrinsic epileptogenicity of dys- plastic neurons (8). Although most of the cerebellar outputs inhibit epilep- tic seizure, Jayakar and Seshia (9) reported the case of a child with a cerebellar astrocytoma with paroxysmal seg- mental rhythmic myoclonus. Marked clinical improve- ment after tumor resection suggested that the cerebellar lesion was primarily responsible for the movement dis- order. Harvey et al. (6) presented the case of a child with hemifacial seizures and cerebellar ganglioglioma and re- viewed six previously reported cases of infants with hemifacial spasm and cerebellar masses. In the single case they presented, single-photon-emission computed tomography (SPECT) and a depth electrode revealed that hemifacial seizures can originate in the cerebellar gan- glioglioma itself. In addition to ganglioglioma, dysplas- tic lesions such as gangliomatous hamartomas were suggested to have epileptic seizure activities in the cer- ebellum (7). We describe the case of an infant with cerebellar gan- glioglioma and episodic paroxymal facial spasms, shown to be of cerebellar origin. Our case provides more evi- dence confirming the existence of epilepsy of cerebellar origin. Revision accepted May 22, 2001. Address correspondence and reprint requests to Dr. B-K. Cho at Division of Pediatric Neurosurgery, Seoul National University Chil- dren’s Hospital, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea. E-mail: bkcho@snu.ac.kr Epilepsia, 42(9):1204–1207, 2001 Blackwell Science, Inc. © International League Against Epilepsy 1204