Subjects will undergo a single stereotactic intracerebral administration of neural cells, called interneurons, that secrete the inhibitory neurotransmitter gamma-aminobutyric acid (GABA).~Subjects will then take medicines to partially suppress their immune system (aimed to prevent the body from rejecting the cells) for 1 year. Safety, tolerability, evidence of neural cell viability and local inflammation (using MRI scans of the brain), and effects on epilepsy disease symptoms will be assessed for 2 years post-transplant. Subjects will be followed for an additional 13 years with quarterly phone contact and annual visits.
This clinical trial is designed to test whether a single stereotactic intracerebral administration of inhibitory nerve cells into subjects with drug-resistant mesial temporal lobe epilepsy is safe (frequency of adverse events) and effective (seizure frequency).