Seizure Localization in Patients with Multiple Tubers: Presurgical Evaluation in Tuberous Sclerosis
The patient was a 23-year-old male who had a history of epilepsy since 8-year-old. He was transferred to our clinic for the presurgical evaluation. He was bi-handed, college graduate, and unemployed. Physical examination revealed shagreen patch on his lumbar region, no other definite dermatologic abnormalities were seen. Neurological examination revealed no remarkable neurological deficit. He reported seizures consisting of automotor seizure and generalized tonic clonic seizure once in a year, and psychic auras several times per month while on valproate, topiramate, lamotrigine, and clonazepam. He reported infrequent complex partial seizures and secondary generalization. He also complained about the severe disability in concentration following polytherapy. He reported that seizures are provoked by loud music, thus he avoids earphone use or places with loud speakers, which withdraws him from normal social activities. Caregivers also reported the change in the personality and aggressive behavior since high school years. Intellectual assessment revealed IQ score of 108 which is average level.\nDuring the six-day VEEG monitoring the patient experienced approximately five seizures and one aura. Semiology was psychic aura to unresponsive dialeptic seizure which then evolves to left versive seizure and generalized tonic clonic seizure. The video-EEG study revealed frequent interictal epileptiform activity, maximal over the right frontotemporal region with frequency of 3–6 per minute. These seizures all were lateralized to right hemisphere: three started from right frontotemporal area, and one from posterior temporal area (). Ictal discharges of all four seizures had theta range rhythm build up at right frontotemporal area. The brain MRI revealed multiple cortical tubers located at right hippocampus, inferior, and superior frontal gyri, left middle frontal gyrus, left mesial frontal cortex, left parietal cortex, and left occipital cortex. Radiotracer for ictal SPECT was injected at 34 seconds from the onset of 104 second duration habitual seizure. SISCOM revealed hyperperfusion at right temporal cortex (more on mesial) (). Brain PET reveals right temporal lobe hypometabolism, especially involving mesial and basal cortex (). He carried a disease-associated mutation in TSC1 (c.2578delG). His abdominal and thoracic CT scan showed no abnormal findings.