Introduction: Introduction: Patients with intractable epilepsy may suffer from co-morbid psychogenic nonepileptic seizures (PNES). The efficacy of vagus nerve stimulation (VNS) for epilepsy is well established, but its impact on PNES is unknown. The goal of this study is to determine whether VNS leads to an improvement in psychogenic episodes in patients with comorbid disease.
Methods: Methods: All patients who underwent VNS at our institution were included. Video EEG results were reviewed and patients who demonstrated both epileptic seizures and PNES were identified. These patients were contacted and queried for data regarding preoperative and post-operative non-epileptic seizure burden. Post-operative quality of life (QoL) was evaluated using the QOLIE-31 questionnaire.
Results: Results: 518 patients underwent VNS for epilepsy in the period from 1998 to 2015. 16 patients were found to carry concomitant diagnoses of epilepsy and PNES. Of this subset, 13 patients completed a survey administered by the research team. The remaining patients could not be contacted or were lost to follow up. 10 of the 13 patients reported a 25-50% improvement in their psychogenic episodes after VNS implantation and 11 of the 13 patients had improved quality of life as measured using the QOLIE questionnaire.
Conclusions: Conclusion: Patients with epilepsy and co-morbid PNES benefit from VNS. It is unclear whether the benefit is conferred strictly from decreased epileptic seizure burden. The possible effect on PNES may be related to the known effect of VNS on depression and mood. Further studies are necessary to elucidate the role of VNS and other forms of neuromodulation in the treatment of psychiatric disease.
Patient Care: Patients with epilepsy commonly have co-morbid psychiatric diseases such as PNES. VNS may represent a treatment modality that addresses both pathologies independently. In the future, there may be a role for VNS (and by extension other forms of neuromodulation) in the treatment of mood disorders and other related psychiatric diseases such as PNES.
Learning Objectives: By the conclusion of this session, patients should be able to:
1. Describe the current indications for VNS in patients with epilepsy.
2. Discuss the possible mechanisms by which VNS may treat PNES and other mood disorders.
3. Discuss in small groups the future of neuromodulation in the treatment of psychiatric disorders.
References: 1. Arain AM, Song Y, Bangalore-Vittal N, Ali S, Jabeen S, Azar NJ. Long term video/EEG prevents unnecessary vagus nerve stimulator implantation in patients with psychogenic nonepileptic seizures. Epilepsy Behav. 2011;21(4):364-366. doi:10.1016/j.yebeh.2011.06.003.
2. Attarian H, Dowling J, Carter J, Gilliam F. Video EEG monitoring prior to vagal nerve stimulator implantation. Neurology. 2003;61(3):402-403. http://www.ncbi.nlm.nih.gov/pubmed/12913209.
3. Benbadis SR, Agrawal V, Tatum WO th. How many patients with psychogenic nonepileptic seizures also have epilepsy? Neurology. 2001;57(5):915-917. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11552032.
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