Why is the hippocampus so often where focal seizures start? · Grey Matter

The hippocampus is built to change: densely recurrent excitatory circuits that strengthen quickly with use, which makes it good at storing associations and also prone to runaway synchronous firing.

Why is the hippocampus so often where focal seizures start?

The hippocampus is built to change: densely recurrent excitatory circuits that strengthen quickly with use, which makes it good at storing associations and also prone to runaway synchronous firing. It is vulnerable to the injuries that start epilepsy (prolonged febrile seizures, hypoxia, encephalitis), and the most common lesion found in surgery for drug-resistant temporal lobe epilepsy is hippocampal sclerosis: loss of neurons, scarring and rewiring such as the sprouting of mossy fibres back onto their own cells. Seizures starting there often begin with a rising feeling in the stomach, déjà vu or fear, the signature of the medial temporal lobe.