Figure: A guide tube being implanted through a burr hole in the skull during deep brain stimulation surgery at Sir Charles Gairdner Hospital. Constant pressure irrigation is performed during this manouevre to avoid net loss of brain fluid thereby reducing movement of the brain during surgery. Copyright Neurofinity 2009

The Neurofinity Surgical NeuroDiscovery Group is introducing brain stimulation surgery for individuals with particular severe unrelenting pain for whom common treatments have failed to relieve their suffering. Referrals can be made to Professor Christopher Lind by medical practitioners. Prof. Lind will review the individual as quickly as possible in his personal clinic. If surgery is feasible then multidisciplinary collaborators will be asked to review some or all of the following dimensions: previous and ongoing chronic pain management and neuropsychiatric status. We will then discuss whether brain stimulation surgery is an option.

Once surgery is planned we will perform detailed quantitative baseline assessments of sensory deficits by Ms Brigitte Tampin, neurological physiotherapist, as well as neuropsychological status, functional status and quality of life as assessed by Miss Megan Thorburn. These assessments are repeated in long-term follow-up. Prof. Lind, his fellows and Miss Thorburn are responsible for stimulator programming.

The effectiveness of brain stimulation surgery for painful conditions has not been subjected to large-scale clinical trials. Our work seeks to improve the evidence base concerning these treatments and provide hope for alleviation of suffering in those we treat. There may be a role for surgery in select circumstances including:

• Atypical facial pain
• Postherpetic neuralgia
• Intractable severe cluster headache
• Severe intractable cancer pain (brain lesions may be more appropriate than DBS in some cases)
• Phantom limb pain
• Pain from brain or spinal cord damage in some situations

There are many factors to consider before being recommended for surgery. We therefore spend significant time with candidates as a multidisciplinary team. We have a lot to discuss with candidates, including the status of scientific evidence in the options being presented, opportunities for participation in research protocols, and the predicted risks and benefits.

Brain structures potentially targeted for electrical stimulation include the sensorimotor cerebral cortex, centromedian/parafascicular and Vc nuclei of the thalamus, periventricular and periaqueductal grey matter, and the hypothalamus depending on the cause and nature of the pain. All surgery is performed at Sir Charles Gairdner Hospital in our academic environment in which advanced functional neurosurgery techniques are applied without out-of-pocket costs to our patients. For subjects undergoing cortical stimulation, the surgery is performed with the help of MRI-stereotaxis and intraoperative neurophysiology by Professor John Dunne. Deep brain stimulation is performed under general anaesthesia using the innovative MRI-directed guide tube technique. Treatment does require a commitment to postoperative programming and assessment sessions to optimise and gauge the effectiveness of the surgery. Where possible we are offering treatments in the context of ethics-approved research projects to advance the science of neurosurgery and evaluate the effectiveness of sophisticated neurosurgical treatments.