Movement Disorders, Stereotactic And Restorative Surgery Program

Treatments and Diagnostic Techniques

The Role of Stereotaxis and Computer Guided Neuro-Navigation

Central to the surgical management of movement disorders is the technique of 'stereotaxis' whereby imaging studies are used to create a three dimensional map of the skull and brain or other anatomical structure. This map is co-registered with the patient in the operating room and a surgical plan is created allowing for the precise placement of a surgical device, instrument or beam of radiation. The synchronization of the virtual 'brain map' to the patient may be achieved by 'frame based' or 'frameless' systems. In the former, a metal frame is secured to the lightly anaesthetized patient's head. Each point in space within the boundary of the frame may be ascribed a definable co-ordinate and is targetable. Imaging studies are subsequently obtained thereby creating a unique map. Alternatively, with frameless systems, a map may be created albeit with less accuracy by inputting the unique landmarks of a patient's face and forehead. Stereotactic techniques are often used for obtaining tissue samples (stereotactic biopsy), for laser mediated thermal obliteration of deep seated tumors (Laser interstitial thermal therapy - LITT), for focusing of therapeutic radiation energy i.e. radiosurgery or to treat movement disorders.

Classical Surgical Treatment of Movement Disorders

The modern era of movement disorder surgery began with observations gleaned from a surgical complication in the 1950's by Dr. Irving S. Cooper. During surgery for treatment of a cerebral aneurysm, a patient with Parkinson's disease suffered an injury to a small but vital artery. The clinical changes in neurological function from this operative complication resulted in an unanticipated improvement in the patient's previously intractable tremor. This observation led to the formulation of a procedure designed to create a discrete therapeutic injury by freezing a small volume of brain tissue ie 'cryotherapy'. The success of this treatment led to the development of a variety of ablative procedures that until relatively recently wre the surgical treatments of choice for patients suffering from movement disorders.