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This day was split into three sections: Merritt-Putnam lectures, Engineering special interest group, and a set of lectures on high-frequency EEG recordings.

The morning was dedicated to the Merritt-Putnam lecture series, with this one focusing on traumatic brain injury (TBI) and the resulting possibility of epilepsy. The key theme was that there was a correlation between TBI, such as getting hit with a baseball, and developing epileptic seizures down the road (epileptogenesis). There are some clinical measures which can sort the severity of the TBI into mild, moderate and severe categories, however, the specifics were not presented. Various mechanisms, ranging from molecular to neural network organization, were implicated as potential targets for epileptogenesis, however, the key point that was reiterated by every presenter was that there was concern that troops coming back from Iraq were looking forward to epilepsy in their later years. Part of the reason for this is that explosives play a much larger role in modern warfare, as compared to bullets, which have a higher propensity to generate shock waves and thereby contribute to TBI. According to the statistics presented, there are over 2,000 “official” cases of severe TBI as of October 2007 with an estimated 10,000-20,000 more at risk.

The main focus of the SIG was to demonstrate to try to define what a seizure was. Several groups were presenting data from tiny electrodes embedded in standard electrode arrays to help get better spatial resolution of EEG measurement for seizure focus detection. The most entertaining talk, however, came at the very end and provided an overview of stimulation efficacy for seizures. The point was that in many cases, simply implanting the electrodes was enough to stop seizures. It didn’t statistically matter if the stimulator was turned on or not, providing that the seizure focus was located correctly.

The last session was titled “Broadband EEG”, but the range of talks was very wide. Gyorgy Buzsaki gave the first talk part of which dealt with qualitative energetics. The idea can be explained with this analogy: when people clap at the end of a musical performance, they clap randomly at first, then, a pattern develops and people clap rhythmically. When people clap in unison, they typically clap slower than they did before, expending less energy. The same can be seen on functional MRI (something that measures metabolism) where things like the hippocampus, a popular seizure focus, shows decreased energy usage during seizure activity.

 
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