Electrical Stimulation of the Anterior Nucleus of the Thalamus for the Treatment of Intractable Epilepsy
Abstract number :
3.218
Submission category :
Year :
2000
Submission ID :
2483
Source :
www.aesnet.org
Presentation date :
12/2/2000 12:00:00 AM
Published date :
Dec 1, 2000, 06:00 AM
Authors :
John F Kerrigan, Robert S Fisher, David E Blum, Andrew Shetter, Selma Krone, Brian Litt, Jacqueline A French, Marc Dichter, Gordon Baltuch, Mary Ann Brodie, Mark Rise, Nina Graves, Barrow Neurological Institute, Phoenix, AZ; Univ of Pennsylvania, Philadel
RATIONALE: Animal studies and sporadic case reports in human subjects have suggested that intermittent electrical stimulation of the anterior nucleus of the thalamus reduces seizure activity. METHODS: We have undertaken an open-label pilot study of intermittent high-frequency electrical stimulation of the anterior nucleus of the thalamus. Four patients (3 male, 1 female, age range 24-47 years) have been studied, with follow-up between 3-24 months. All patients have intractable partial epilepsy including secondarily generalized seizures. Bilateral programmable electrical stimulation devices (Medtronic ITREL II) were implanted over the chest wall, with stereotactic implantation of stimulation wires into the anterior nuclear group of the thalamus. Electrical stimulation was delivered intermittently for 60 seconds, alternating every five minutes between right and left. Stimulation parameters: 100 cycles per second AC, pulse width 90 microseconds, and voltages ranging between 1.5 V and 10 V. Seizure counts were monitored, and compared to pre-implantation baseline. RESULTS: All four of the patients have shown clinically significant improvement with respect to the severity of their seizures. Two of the patients have had a reduction in secondarily generalized tonic-clonic seizures (by 56% and 8% at 3 months follow-up, and by 62% and 40% at 12 months follow-up, respectively). The third patient has had a 100% reduction in complex partial seizures associated with falls. The fourth patient has had >90% reduction in total seizure frequency, although this reduction began shortly before surgical implantation of the stimulation system (follow-up of 2.5 months). No adverse events could be clearly attributed to stimulation. None of the patients could determine whether the stimulator was on or off at the parameters used in this study. CONCLUSIONS: Electrical stimulation of the anterior nucleus of the thalamus appears to be well-tolerated. Preliminary evaluation suggests clinical improvement in seizure control in this small group of intractable patients. Further controlled study of deep brain stimulation of the anterior nucleus is required.