If DBS is being considered, a workup is needed to assess whether you are suitable to have this treatment. For example, we need to assess whether your condition will respond to DBS, and if so, which brain target we should implant to best suit your needs. We also need to assess whether you can tolerate going through the process of having surgery and receiving stimulation. The first step is a consultation with A/Prof Thevathasan, the DBS neurologist. Depending on your condition, you may then need to see our neuropsychiatrist to assess mood and intellectual functioning. Patients with Parkinson’s disease will have their movement graded by a specialist nurse or physiotherapist, both off and on their medication. If the assessment suggests that you are suitable for DBS and you wish to proceed, you will then see Mr Kristian Bulluss, the neurosurgeon.
DBS surgery is elective, so it can be deferred until you are ready – although the exact date will also depend on our waiting list. In the weeks before surgery, you will need to have a special MRI brain scan – which we use to plan the operation. If needed, we can give sedation (or even a general anaesthetic) for this scan.
You are usually admitted to hospital the day before surgery. In the private system we perform the entire procedure under general anaesthetic. In the public system, we do not have a CT scanner in theatre, so need to implant the brain electrodes with the patient awake (except for dystonia). If requested, in many patients we can perform the procedure with a minimal hair shave (that is, hair on the head is mostly preserved). On the morning of surgery, any medications for tremor or Parkinson’s disease are withheld.
In theatre, Mr Bulluss (the neurosurgeon) physically performs the procedure and A/Prof Thevathasan (the neurologist) guides the electrodes into the brain target (using brain scans and by assessing brain signals and the effects of stimulation).
Duration: 1 Hour
You meet the team in the anaesthetic bay outside theatre. A ‘frame’ is placed on the head. You then have a CT scan with the frame on and the scans are merged with the preoperative MRI by Dr Thevathasan.
Duration: 1.5 Hours
Mr Bulluss makes a skin and scalp incision. A small hole is drilled through the skull bone. A tiny test wire (‘microelectrode’) is passed into the brain. A/Prof Thevathasan assesses brain signals and the impact of stimulation (e.g. improvement of tremor and any side effects). Based on this information, the microelectrode may be shifted. When the target is identified, the microelectrode is replaced with the permanent electrode under X-Ray guidance. The procedure is then repeated on the other side of the brain. In the private system, we use a CT scanner available in the operating room to assess electrode location and can then make any adjustments there and then if necessary.
Duration: > 1 Hour
The head frame is removed. The battery (usually sited beneath the collar bone) and connecting cables (running between the brain electrode and battery) are implanted under the skin under a general anaesthetic.
In the first weeks postoperatively, control of the underlying condition can fluctuate whilst medication and stimulation are adjusted. In this period, you may need to see the neurologist frequently (e.g. every 1-2 weeks).
Even without stimulation, movement often improves due to ‘stun effect’. ‘Stun effect’ refers to temporary swelling around the freshly implanted electrodes that reduces abnormal brain signals. Stun effect peaks around day 3 then subsides over the following weeks. Because of this, stimulation is often started at a low level then slowly increased. With stun effect and stimulation, medication for Parkinson’s disease can usually be decreased very substantially.
For most patients, the bulk of the stimulation adjustments are over by about 6 weeks. However further adjustments may be needed over time (e.g. around 2-3 times a year).
You are given your own personal DBS controller which allows you to check battery status and turn stimulation off and on. Occasionally, patients are given the capability to adjust their own DBS (within certain limits).
This varies from person to person. Driving can usually resume from 6-8 weeks after surgery. This is also a useful ‘rule of thumb’ for other activities such as return to work and other responsibilities. Like other types of neurosurgery, patients can feel that their intellectual functioning, particularly attention span, is reduced for several weeks postoperatively. We therefore suggest deferring any major decisions and return to work until this recovers back to normal.
There are some long-term precautions when living with DBS systems. For example, avoiding heavy contact sports (e.g. boxing), avoiding routine MRI (MRI is usually possible, but we need to organise it using special precautions) and advising surgeons and dentists of your DBS. Patients with DBS cannot arc weld or scuba dive.
Surgical Consulting and Movement Precinct,
Level 1, Cabrini Medical Centre,
183 Wattletree Rd, Malvern 3144
E: [email protected]
P: 9079 1880