During your surgery, a frame will be positioned around your head to help avoid movement during the procedure. Two thin, insulated wires (each with electrodes known as ‘contacts’) are inserted into the brain. Rarely, when the symptoms mainly affect one side of the body, these leads are only inserted on one side of the brain. The lead implanted in the left side of the brain controls symptoms affecting the right side of the body and the lead implanted in the right side of the brain controls symptoms on the left side of the body.
Your surgeon will implant the leads into a specific area of the brain that is suitable for your Parkinson’s – the position will not be the same for everyone. After surgery you might have a detailed scan of your brain (CT scan) to make sure that the leads are in the correct place.
Depending on the technique used, the procedure is either completed during one operation or during two separate operations. This might happen so that the device can be implanted a few days after the leads.
There are several deep brain stimulation devices available that transmit the electrical current needed. These are called pulse generators or neurostimulators. Different manufacturers make different devices and the team at your surgical centre will explain which are available and the advantages of each one.
There are a few differences between each device, but the main difference is that there are rechargeable and non-rechargeable devices.
Non-rechargeable pulse generator
On average, the battery lasts between three and five years depending on the settings required. Some batteries for non-rechargeable devices may last longer than chargeable ones before a replacement is needed.
Rechargeable pulse generator
If you have a rechargeable unit implanted, you will be taught how to use it. The pulse generator will need recharging regularly and you will need to take your recharging unit with you if you are going to be away from home for more than a few days. The battery will last around 15 years before it has to be replaced.
There are precautions that need to be taken with each device but these will vary depending on the manufacturer and model. The team at your surgical centre will be able to give you information specific to your device so make sure you ask them any questions you have.
The deep brain stimulation system is not switched on immediately. A few days or weeks after surgery (depending on your centre), the system is switched on. This allows an electric current to pass into the brain in order to improve mobility symptoms. Your specialist or Parkinson’s nurse will programme the generator using a small portable computer. They will try out various settings to determine which ones work best and which ones cause side effects for you.
Then over a few weeks the settings will slowly be increased, and at the same time medication adjustments can be made as needed. This means it will probably take a few weeks after your surgery before your stimulator setting and medication doses are optimised and you notice the full benefit. Some people find that their symptoms actually get worse before they get better during these weeks. If this happens you may experience issues such as increased dyskinesia and ‘off’ time until your stimulator settings and medication doses are right for you.
You may also be given the option to make some changes to the settings.
It may take several months to fully programme the stimulator and adjust your Parkinson’s medication to get the most benefit from your treatment.
What are the side effects from programming your pulse generator?
You may also experience side effects from the stimulation that targets a specific area of your brain. These side effects can usually be managed by altering the programming of your deep brain stimulation device. They include:
- tingling or a sensation of pins and needles
- changes in speech or language, such as problems articulating words, a soft voice or difficulty finding words
- dizziness or light-headedness
- involuntary muscle contractions (dystonia or dyskinesia)
- problems with balance and falls
- movement problems or reduced co-ordination
- closure of the eyelids (although this is rare)
- jolting or shocking sensations
- problems associated with the pulse generator and leads, including wound breakdown and infection. These can usually be treated with antibiotics but occasionally the whole system needs to be removed.
These side effects can be uncomfortable but are not dangerous. Usually they can be minimised by changing the settings on your device.
You will usually need to stay in hospital for a couple of days after you have had surgery. Before you are discharged, healthcare staff should assess what support you may need when you leave hospital.
If you or your healthcare professionals identify any support needs, these should be recorded in a written care plan. You should not be discharged until the support you need has been put in place.
If you’re concerned about arrangements for going home after your hospital stay, you should speak to a hospital social worker.
If you go into hospital in the future, It’s important to make staff aware that you have had deep brain stimulation surgery. You should also tell any other healthcare professionals you see that you have a deep brain stimulation system implanted. This includes dentists, surgeons and physiotherapists.
- Diathermy (the use of a high frequency electronic current to produce heat, often used for muscle relaxation) should not be used if you have had deep brain stimulation surgery.
- If you require any surgery in the future, the surgeon and anaesthetist should be told you have a deep brain stimulator as there are certain precautions they need to take during surgery.
- MRI scans can only be used under very strict conditions.
Antibiotics have to be prescribed when there is a risk of germs getting in to the blood stream, for example during dental procedures or other surgery. Your specialist or Parkinson’s nurse can advise healthcare professionals on this before antibiotics are prescribed.
Most everyday activities are safe, but there are some that could damage the system. You should talk to your specialist about these.
You can travel by plane, but you should inform airport security and carry a card with you that explains you have had deep brain stimulation. Ask your healthcare professional if they can provide one for you. You should also carry the hand-held programmer with you when travelling, in case the stimulator is accidentally switched off.