Authors :
First Author: Santiago Vidaurri, n/a – Texas A&M University
Presenting Author: Rafael Villalobos, MD – University of Texas Rio Grande Valley
Alejandro Betancourt, Professor – Neurosurgery – University of Texas at Rio Grande Valley; Rafael Villalobos, Medical Doctor – Pediatric Neurology – Pediatric Neurology of South Texas PC; Alfonso Duran, Research assistant – Pediatric Neurology – Pediatric Neurology of South Texas PC; Gilberto Mauricio-Suarez, Research assistant – Pediatric Neurology – Pediatric Neurology of South Texas PC
Rationale:
Vagal Nerve Stimulation is a form of therapy that is used for intractable, non-resective surgery candidates. The side effects and the potential problems related to the procedure are well known. However, little is known when it comes to problems in a patient that tolerated the initial procedure well, and eventually a re-implantation becomes problematic, particularly when it is implanted in a different site within the vagal nerve itself. We report a case where the lead placement was different in the vagal nerve and patient started to develop intractable vomiting.
Methods:
We analyzed the case of a 15-year-old male patient with intractable epilepsy and on several anticonvulsants that was previously on VNS Therapy for more than 6 years. The case is a bilateral frontal abscess before age one secondary to meningitis. The patient eventually showed severe recurrent intractable partial seizures of bilateral origin as well as developmental delay and severe impairment in functioning (non-verbal, non-ambulatory). He had a ventriculo-peritoneal shunt in the early in life and has been on multiple anticonvulsants.
Patient was stable with about one to three seizures per day on current treatment, but due to increased events and the VNS being not functional, a replacement was done. In the past, the VNS was well tolerated until it got replaced and the position of the VNS was moved up 13 to 15 millimeters above the previous incision, as surgical scar tissue and impedance problems were detected in the original lead connection.
Results:
After the procedure, the patient developed severe vomiting that prompted a VP shunt revision (no intracranial increased pressure was found with the operation). The original settings that were always kept were decreased and the vomiting subsided for 24 hours but returned the following day. Eventually patient was found with severe dehydration and the device was turned off that showed dramatic improvement in the symptoms.
Conclusions:
Vagal nerve stimulation has been found to be effective in refractory epilepsy in patients that are not candidates for cortical resection procedures. In this communication, we presented a case of recurrent intractable vomiting after the procedure was repeated in a higher position than the original operation, all despite the fact that the stimulation settings were kept at the same level after the procedure. The severe intractable vomiting was to the point that a shunt revision was made (hydrocephalus history case) with no evidence of increased intracranial pressure. We conclude that stimulation higher on the nerve anatomy is associated with recurrent emesis to the point of dehydration as has been described in isolated communications, and surgical planning is to be taken into consideration especially when the past lead placement cannot be reused for another procedure.
Funding: .