Vagus Nerve Stimulation (V.N.S) Training for staff who support people with epilepsy and a vagus nerve implant

Transcription

1 Vagus Nerve Stimulation (V.N.S) Training for staff who support people with epilepsy and a vagus nerve implant

2 Vagus Nerve Stimulation is used in people whose epilepsy has proved difficult to control using anti epileptic drugs (A.E.D s) or are not suitable for surgery It is used around the world by over 43,000 people who have a variety of seizure types and syndromes

3 Following the surgical procedure to implant the VNS, the patient will visit the neurologist at regular intervals to have the device programmed to its optimum operating setting. The pattern of pre-programmed stimulation will vary according to individual needs. During this phase explanations will be given regarding the use of the magnet

4 How does it work? A small generator is implanted into the chest / neck area of an individual This is connected to the Vagus Nerve by a short lead A doctor programmes the generator using an external device called a wand which is connected to a laptop

5 The generator gives a 24/7 programmed dose of stimulation A typical dose could be 30 seconds of stimulation followed by 5 minutes of no stimulation. This occurs automatically When a patient, care giver or family member senses or observes a seizure coming on, they can pass a magnet over the area of the implant.

6 The magnet triggers an extra, on demand stimulation. As the implant is preprogrammed the magnet cannot cause over stimulation. The on demand stimulation can abort seizures or reduce the severity of seizures. Staff will need a care plan / protocol to give detail to the circumstances in which the magnet can be used.

7 Side Effects Temporary hoarseness / changes in voice tone Sore / tickling throat Shortness of breath Coughing

8 These problems usually occur during the on time, usually about 30 seconds every 5 minutes Other discomforts such as breathing difficulties if the generator setting is too high or increased too rapidly. The doctor can re-programme the stimulation settings to help with this. Those who cannot tolerate the VNS can have it removed

9 Anatomy of Vagus Nerve A mixed cranial nerve (80% afferent fibres originating from heart, aorta, lungs and G.I tract) Widespread projections to numerous areas of the forebrain and brainstem. Projections to amygdala and thalamus, which are recognised areas of the brain that are potentially causal in epileptic seizures

10 The left vagal nerve is used for the VNS implant. The right vagal nerve mostly influences heart rate.

11 Theories about how VNS actually affects seizure activity in the brain The VNS stimulation may cause the release of seizure-suppressing neuro- transmitters Possible threshold modulation in structures known to play an important role in epileptogenicity

12 Research is ongoing to find what the specific effects of VNS is within the various brain structures, neuro transmitters and cell membranes

13 Practical use of the VNS in people with learning disabilities Staff / family members have care plans / protocol that gives details regarding the use of the VNS magnet. When the onset of a seizure is observed, the implant is stimulated by a swipe of the magnet. This is achieved by one slow swipe / or more slow swipes as indicated by protocol.

14 The magnet can be used through clothing Be aware that the magnet is powerful (avoid contact with credit cards, watches etc) The magnet causes an on-demand stimulation which should then either abort the seizure, lessen its severity or shorten any seizure activity

15 Following its use, staff should then record usage and outcome

16 REMEMBER THAT IF A CONVULSIVE EPILEPTIC SEIZURE BECOMES PROLONGED (usually 5 minutes or more) THE V.N.S WILL NOT HAVE BEEN EFFECTIVE. IN THIS CIRCUMSTANCE OTHER PROTOCOLS WILL COME INTO EFFECT: ie: Rectal diazepam Buccal midazalam Call 999