Functional Neurosurgery

Organisation profile

Organisation profile

Part of the University of Bristol's Institute of Clinical Neurosciences, the Functional Neurosurgery Research Group is focussed on developing novel techniques of direct intracranial drug delivery and deep brain stimulation surgery.

Funded by the Medical Research Council, The Cure Parkinson's Trust and the Friends of Bristol Oncology Centre, our drug delivery research programme is based at the Avon Orthopaedic Centre at Southmead Hospital.


The work of the Functional Neurosurgery Research Group, headed by Professor Steven Gill has two key elements.

Developing novel techniques of direct intracranial drug delivery

The blood-brain barrier profoundly limits the access of potentially therapeutic agents into the brain.  We 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. 

So far, 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 work with 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

We have been performing Deep Brain Stimulation (DBS) at Frenchay Hospital for more than ten years. During this time we have pioneered advances in this treatment. developing a unique method of implanting deep brain stimulating electrodes using high resoultion MRI scans.  Our current research is focusing on the following novel targets:

  • Parkinson’s Disease. The Caudal Zona Incerta
  • Parkinson’s Disease. The Pedunculopontine Nucleus
  • Epilepsy

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 per cent 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 such as 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.


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.

How to find us

Functional Neurosurgery research group
Google map and directions
Southmead Hospital site map - Learning & Research (PDF, 314kB)

Department of Neurosurgery
Southmead Hospital site map (PDF, 313kB)

Our pioneering work in deep brain stimulation surgery is based at Frenchay Hospital where we have developed a unique method of implanting deep brain stimulating electrodes using high resolution MRI scans.


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