Depression, Depressionen

Vagus-Nerv-Stimulation (VNS):

VNS Therapy for patients with persistent seizures after epilepsy surgery.

VNS THERAPY NEWS FLASH - ISSUE 23 - SEPTEMBER 2004

Surgical treatment of medically pharmacoresistant epilepsy achieves long-term control in only 50-80% of patients, while the other 20-50% with persistent or recurrent seizures are considered 'surgical failures'. Of the patients who fail epilepsy surgery, only a minority is considered appropriate for repeat craniotomy.

VNS Therapy has already been proven safe and effective for patients with intractable epilepsy who are not candidates for cranial surgery, and several lines of evidence suggest its appropriateness for patients who continue to have seizures after such procedures as well.

This study reports the effectiveness of vagus nerve stimulation (VNS Therapy) among patients who failed cranial surgery for intractable epilepsy. Data were obtained from the VNS Therapy Patient Outcome Registry (an international database, located in the US). The integrity of the systems for collecting and processing registry data was authenticated by an independent auditing agency.

Two nonconsecutive cohorts were compared in this study: patients who had previously undergone cranial surgery

(CS group, n=921) and all other registry patients (non-CS group, n=3822).

The median reduction in seizure frequency for both groups increased over time. For the CS group the median reduction in seizure frequency was 45.7% at 12 months, 60.0% for the non-CS group.

The VNS Therapy System is indicated for treatment of chronic or recurrent depression in patients that are in treatment-resistant or treatment-intolerant major depressive episode.

CS-Group:patients have undergone Cranial Surgery ; Non CS-Group:all other registry patients

These differences between the two groups were statistically significant at 3, 6, 12, and 24 months.

In spite of the limitations inherent in this database, the authors conclude that the effectiveness of VNS Therapy is maintained during prolonged stimulation, and overall seizure control continues to improve with time. Patients who had failed prior cranial surgery did not respond quite as favorably as all other patients receiving VNS Therapy. Nonetheless, many patients improved greatly.

Source: Arun Paul Amar, Michael L.J. Apuzzo, Stereotact Funct Neurosurg 2003; 80:9-13.