Functional Neurosurgery
- Developing novel techniques of direct intracranial drug delivery: The blood-brain barrier profoundly limits the access of potentially therapeutic agents into the brain. Our goal is to develop innovative, minimally-invasive techniques for delivering therapies directly into the brains of patients with a range of neurological conditions. We are particularly interested in the delivery of viral and non-viral vectors, monoclonal antibodies and neurotrophic factors to patients with Parkinson’s disease and brain tumours. To date, we have undertaken pioneering studies into the delivery of growth factors directly into the brains of patients with Parkinson’s disease. In the near future, we plan to undertake a number of trials of direct intracranial delivery of novel chemotherapeutic agents in patients with primary brain tumours. We have a number of industrial and academic collaborators providing expertise in medical engineering, fluid dynamics, software engineering, medical imaging and drug development. This research is funded by the Medical Research Council, the Cure Parkinson’s Trust and the Friend’s of Bristol Oncology Centre and is based in the Avon Orthopaedic Centre at Southmead Hospital.
- Deep Brain Stimulation Surgery: The Bristol Functional Neurosurgery team has been performing DBS for over 10 years and during this time we have pioneered advances in this treatment. At Frenchay hospital we have developed a unique method of implanting deep brain stimulating electrodes using high resoultion MRI scans. At present, our research is focusing on the following novel targets:
Parkinson’s Disease - The Caudal Zona Incerta:
In depth analysis of our clinical outcomes and corresponding electrode position has shown the most effective contacts to be located dorsal to the conventional target site, the subthalamic nucleus (STN). This region, known as the Zona Incerta (ZI), is less than 1mm in diameter. Subsequent to this finding we have operated on approximately 70 patients with PD, targeting the ZI. We have found this new target to provide a 20% additional improvement in the cardinal symptoms of PD when compared to the STN. (Plaha P, Gill SS, Brain. 2006 Jul; 129:1732-47)
Parkinson’s Disease - The Pedunculopontine Nucleus:
Axial symptoms (gait disturbance, postural instability and falls) are some of the most disabling and treatment resistant symptoms of PD. These symptoms have a limited response compared to the currently available medical and surgical therapies. Human post-mortem studies and experiments in animal models of PD have shown the Pedunculopontine Nucleus, a small region of the midbrain, to be a potential target for the treatment of axial symptoms in PD.
Our group was the first to publish on DBS of this region in humans showing improvements in the previously treatment resistant axial symptoms of PD. (Plaha P, Gill SS Neuroreport. 2005 Nov 28;16(17):1883-7). Following our early positive experience we are now proceeding to a trial of combined ZI and PPN stimulation in patients with Parkinson’s disease.
Epilepsy:
We are currently undertaking the only trial of DBS for epilepsy in the UK, which is open to both adult and pediatric patients. The trial aims to treat patients with hypothalamic hamartomas or dominant hemisphere mesial temporal sclerosis, in whom traditional resective surgery carries a high a risk of complications such as memory, speech or endocrine disturbance.
We are at the early stages of this trial and have operated on two patients, who have shown promising results.