PURPOSE: Focal neocortical seizures can be associated with a number of specific pathologies including supratentorial tumors and cavernous malformations (CMs), both of which are highly epileptogenic. METHODS: To begin to address the question of whether these lesions have different mechanisms of epileptogenesis, we used intracellular recordings from neurons adjacent to intracerebral neoplasms and cerebral CMs. Developmental anomalies were not included in this study. RESULTS: Neurons adjacent to CMs had a greater propensity to show large (>5 mV), complex spontaneous synaptic events than did neurons neighboring neoplastic substrates (50 vs. 4.7% of cells and 75 and 8% of patients, respectively; p < 0.004; p < 0.05). Both spontaneous excitatory and inhibitory events were noted. In contrast, in tissue adjacent to tumors, low-amplitude (<3 mV) spontaneous excitatory activity predominated. Neurons neighboring CMs also exhibited more excitable responses to synaptic stimulation, with multiple action potentials riding on prolonged excitatory postsynaptic potentials (EPSPs) being evoked in 71% of these cells, versus 32% of cells from the tumor group; p < 0.05. In studies using hippocampal tissue, we noted a similar pattern of spontaneous activity in tissue adjacent to CMs. CONCLUSIONS: These data suggest that CMs may induce seizure activity via a different pathophysiologic mechanism(s) than glial tumors.
PURPOSE: Focal neocortical seizures can be associated with a number of specific pathologies including supratentorial tumors and cavernous malformations (CMs), both of which are highly epileptogenic. METHODS: To begin to address the question of whether these lesions have different mechanisms of epileptogenesis, we used intracellular recordings from neurons adjacent to intracerebral neoplasms and cerebral CMs. Developmental anomalies were not included in this study. RESULTS: Neurons adjacent to CMs had a greater propensity to show large (>5 mV), complex spontaneous synaptic events than did neurons neighboring neoplastic substrates (50 vs. 4.7% of cells and 75 and 8% of patients, respectively; p < 0.004; p < 0.05). Both spontaneous excitatory and inhibitory events were noted. In contrast, in tissue adjacent to tumors, low-amplitude (<3 mV) spontaneous excitatory activity predominated. Neurons neighboring CMs also exhibited more excitable responses to synaptic stimulation, with multiple action potentials riding on prolonged excitatory postsynaptic potentials (EPSPs) being evoked in 71% of these cells, versus 32% of cells from the tumor group; p < 0.05. In studies using hippocampal tissue, we noted a similar pattern of spontaneous activity in tissue adjacent to CMs. CONCLUSIONS: These data suggest that CMs may induce seizure activity via a different pathophysiologic mechanism(s) than glial tumors.
Authors: Anna Raabe; Ann Kristin Schmitz; Katharina Pernhorst; Alexander Grote; Christian von der Brelie; Horst Urbach; Alon Friedman; Albert J Becker; Christian E Elger; Pitt Niehusmann Journal: Epilepsia Date: 2012-03 Impact factor: 5.864
Authors: Jamie J Van Gompel; Jesus Rubio; Gregory D Cascino; Gregory A Worrell; Fredric B Meyer Journal: J Neurosurg Date: 2009-06 Impact factor: 5.115