Date of Award
Medical Doctor (MD)
Loss of consciousness is an important morbidity associated with epileptic seizures, and understanding how altered consciousness occurs could have impact on future therapies. Consciousness includes multiple levels of input and output that maintain alertness, attentiveness, and awareness of both self and the environment. Previous work using SPECT imaging and intracranial EEG analysis of temporal lobe seizures has supported the network inhibition hypothesis. This hypothesis states that impaired consciousness in temporal lobe epilepsy involves activation of the temporal lobe leading to abnormal activity in the thalamus and brainstem subcortical arousal systems. These changes lead to the depressed function in the frontal and parietal association cortices and impaired consciousness. Research on the mechanisms of loss of consciousness in frontal lobe epilepsy is not well defined, though loss of consciousness in frontal lobe seizures may be associated with widespread low voltage fast activity. To further investigate this, this study analyzes 26 frontal lobe seizures from 14 patients that had undergone intracranial EEG monitoring. Based on this data analysis, there is an increase of low voltage fast activity associated with frontal lobe seizures exhibiting loss of consciousness. In addition, seizures with impaired consciousness exhibit higher amounts of epileptic activity based on EEG ictal patterns, and more post ictal slowing than seizures with maintained consciousness. These findings suggest a novel mechanism for loss of consciousness during frontal lobe seizures which may differ from temporal lobe seizures, and could guide improved treatments for frontal lobe epilepsy.
Gebre, Rahiwa, "Frontal Lobe Seizures: Intracranial Markers Of Loss Of Consciousness" (2017). Yale Medicine Thesis Digital Library. 2124.