Vagal nerve stimulation for epilepsy

• vagal-nerve stimulation (VNS) has been shown to stop strychnine-induced seizures in dogs and phentylenetratol - induced seizures in rats
• a commercial device is now available for use in human beings - this device is composed of a pulse generator, a bipolar lead to stimulate the nerve, and a programming wand and software with handheld magnets capable of switching the simulator on and off. The device is implanted to stimulate the left vagus nerve rather than the right - this is because stimulation of the left vagus nerve is less likely to result in cardiac effects
• principle and predictable side effects included increased cough, alteration in voice and throat pain or discomfort. VNS has associated with ventricular asystole (1) and it is important to determine whether sudden death might be more frequent with this form of treatment
• trial evidence has shown that VNS has an unequivocal although modest therapeutic effect against partial seizures

NICE state (3):

In adults:

• vagus nerve stimulation is indicated for use as an adjunctive therapy in reducing the frequency of seizures in adults who are refractory to antiepileptic medication but who are not suitable for resective surgery. This includes adults whose epileptic disorder is dominated by partial seizures (with or without secondary generalisation) or generalised seizures

In children:

• vagus nerve stimulation is indicated for use as an adjunctive therapy in reducing the frequency of seizures in children who are refractory to antiepileptic medication but who are not suitable for resective surgery. This includes children whose epileptic disorder is dominated by partial seizures (with or without secondary generalisation) or generalised seizures

Reference:

1. Tattum WO et al . Ventricular asystole during vagus nerve stimulation for epilepsy in humans. Neurology 1999; 52: 1176-80.
2. Lancet 2001; 357 (9270): 1726-7.
3. NICE (October 2004).The epilepsies: the diagnosis and management of the epilepsies in adults and children in primary and secondary care.