Application of the directed transfer function method to mesial and lateral onset temporal lobe seizures.
Key Words: Directed transfer function, temporal lobe, complex partial seizure, propagation, autoregressive model.
The directed transfer function method is a multichannel analysis based
on an autoregressive model that detects flow of seizure activity. This
report extends the application of the DTF method to compare patterns of
flow of seizures with different sites of origin. Analysis of a seizure
originating from mesial temporal structures is compared with a seizure
originating from lateral temporal neocortex; both complex partial seizures
were recorded with intracranial electrodes that combine subdural grid arrays
and depth electrodes. The DTF method has the potential to determine patterns
of flow of activity, including periods when visual analysis of the intracranial
ictal EEG may not allow for definitive source localization. The extension
of the DTF analyses into integrated DTF (IDTF) formats is also illustrated.
When activity of a relatively discrete frequency can be identified, the
IDTF analysis facilitates display of patterns of flow of this selected
activity.
Brain Topography, 11:13-21,(1998).