Hemisphere - as in cerebral hemisphere, is one half of the brain
Hippocampal Sclerosis - Scar tissue in the temporal lobe. It is the most common cause of focal seizures (temporal lobe epilepsy).
Hippocampus - Situated on the inner aspect of the temporal lobe. The hippocampus is important for long term memory storage and is often the focus of many seizures.
Hypoxia - Lack of oxygen (below normal levels) to the tissues and organs, including the brain.