Ganglioglioma and Intractable Epilepsy: Clinical and Neurophysiologic Features and Predictors of Outcome After Surgery

Abstract

Summary: Purpose: To review the clinical, neurophysiologic, and radiological data of patients with ganglioglioma who had undergone evaluation and surgery in our Epilepsy Program.Methods: The medical and neurophysiologic records of 38 patients with intractable epilepsy and ganglioglioma were reviewed. Data underwent statistical analysis.Results: There were 28 temporal and 10 extratemporal resections, with a mean age at seizure onset of 10.5 years and mean age at surgery of 22 years. Five tumor resections performed earlier were recorded. Twenty-nine patients had auras and 20 had secondarily generalized seizures. All 28 patients with temporal tumor had complex partial seizures. Preoperative MRI demonstrated the tumor in 36 of 36 patients: 17 of 29 demonstrated gadolinium enhancement, and 17 of 36 had mass effect. Scalp interictal sharp waves were present in 32 patients, and in 15 they were multiregional. In two patients, scalp EEG seizure onset was from the hemisphere contralateral to the tumor. Postoperatively, 79% of patients (30 of 38) were seizurefree (Engel's class I) at 6 months, 72% at 1 year (26 of 36), and 63% at 2 years (20 of 32). Excellent outcome was associated with a lower age at operation (p = 0.008), shorter duration of epilepsy (p = <0.01), absence of generalized seizures (p = <0.01), and no epileptiform discharges on a postoperative EEG Conclusions: Good surgical outcome is expected in patients with ganglioglioma despite years of medically resistant seizures. Good outcome may be achieved despite EEG findings that may conflict with tumor location, and is more likely when surgery is performed relatively soon after epilepsy onset.

Clinical characteristics and surgical outcome of patients with temporal lobe tumors and epilepsy

“…In accordance with other authors 6,7,21 , 76.2% of the patients have been seizure-free. These surgical results are similar to those that studied mesial temporal sclerosis, that has a well-known good surgical outcome [22][23][24][25] .…”

“…As reported by others [5][6][7] , the TLT related to epilepsy have a benign course explaining the long duration of epilepsy.…”

“…Different surgical approaches have been used varying from simple lesionectomy to total lobectomy including the hyppocampus and amygdala. In some series as ours the inclusion of the mesial temporal structures didn't promote a better prognosis 7,14,15 while in others extensive resections implied in control of the seizures 3,16,17 . Studies have identified incomplete tumor resections or tumor recurrences as a important cause of a poor postoperative seizure control 8,[18][19][20] .…”

“…This tumor accounts for 0.4-9% of primary brain tumors diagnosed at different institutions, and has been described in all parts of central nervous system, but more commonly comes to clinical attention when present in the cerebral hemispheres, particularly in the temporal lobe 7 .…”

“…These studies were also small or contained a heterogeneous group of patients with several types of tumors or lesions. Precocious surgery should be considered in the evaluation of these patients due to cognitive and psychosocial consequences of chronic epilepsy 28,29 and, perhaps, better seizure control 7 . …”