Onset of Hiccups Following Vagal Nerve Stimulator Implant.
Abstract number :
2.333
Submission category :
Year :
2001
Submission ID :
319
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
S.L. Lannon, RN MA, Neurology, University of North Carolina, Chapel Hill, NC; B.V. Vaughn, MD, Neurology, University of North Carolina, Chapel Hill, NC; E. Bernard, MD, Division of Neurosurgery, University of North Carolina, Chapel Hill, NC
RATIONALE: Use of the vagus nerve stimulator (VNS) system as adjunctive therapy for intractable complex partial seizures was approved in the United States in 1997. In clinical trials, post activation side effects included voice alteration, cough, pain, dyspnea, nausea and vomiting. As with other therapies, wider application has permitted identification of other potential side effects. We report 3 cases of new onset hiccups in 73 VNS patients implanted at our center.
METHODS: Seventy-three patient medical records were reviewed. Information collected included: time from implant to onset of hiccups, generator settings at onset of hiccups, severity of symptoms, need for other therapeutic interventions, and outcome.
RESULTS: We found 3 patients who developed chronic hiccups. No data correlation was found on chart review. The two females and one male ranged in age from 20 to 54 years. Time of hiccup onset ranged from 2 months to 3.5 years post implant. Output current was 0.25 to 2.75 mAmps. Two patients had mild, recurrent hiccuping episodes that resolved spontaneously. The third developed a continuous three-month episode of severe hiccups refractory to either [dsquote]home[dsquote] remedies or chlorpromazine, baclofen or methocarbamol. At the onset of symptoms his generator settings were: output current of 2.75 mAmps, pulse width of 500 microseconds and a signal frequency of 30 Hz. He became significantly sleep deprived and developed complex partial status requiring hospitalization. During hospitalization, his generator was turned off and the hiccups ceased within 30 minutes. Trials of re-programming the generator over the next two weeks resulted in tolerance without hiccups being achieved at an output current of 1.0 mAmp, a pulse width of 250 microseconds, and a signal frequency of 30 Hz.
CONCLUSIONS: Hiccups may be a side effect of VNS therapy. The underlying mechanism is as yet undetermined. However, this side effect appears to be output current and pulse width dependent. When patients report severe symptoms, steps need to be take to intervene before serious problems result.
Disclosure: Honoraria - Cyberonics Inc. (all authors)