MRI guided and MRI verified deep brain stimulation: accuracy, safety and efficacy.
Doctoral thesis, UCL (University College London).
This thesis investigates a systematic approach to the use of MRI-guided and MRI-verified deep brain stimulation (DBS) in clinical practice. The concept of individual targeting of visualised brain structures without microelectrode recording (MER) was examined with respect to accuracy, safety and efficacy. Accurate MRI localisation of the pedunculopontine nucleus, an investigational new DBS target for parkinsonian gait disorders, is described and proof-of-principle confirmed in a cadaver study using MR-microscopy and histological examination. The impact of surgical trajectory on stereotactic accuracy in routine clinical practice was examined at two centres using MER: trajectories involving the ventricle suffered from significantly greater targeting errors compared to those that did not (p<0.001) and multiple brain-passes were more likely to be required to reach the intended target (p<0.01). Subcortical brain shift between pre and postoperative stereotactic images was minimal after MRI-verified procedures without MER (136 procedures); the observed shift did not adversely affect targeting accuracy or clinical outcome. A simple calibration process improved mean targeting errors by 0.6 mm (p<0.001) to 0.9 ± 0.5 mm from the intended target point. A large patient series was compared to a systematic literature review to determine factors associated with haemorrhage; an image-guided and image-verified approach carried a significantly lower risk of haemorrhage and associated permanent deficit than other surgical methodologies (p=0.001). Another study confirmed that, when observing certain precautions, cranial MR images could be obtained with an extremely low risk in patients with implanted DBS hardware. Outcome data from patients undergoing MRI-guided and MRI-verified surgery for Parkinson’s disease and primary generalised dystonia compared favourably to reports from the literature. Mode of anaesthesia did not impact on surgical outcome. In conclusion, this thesis demonstrates that a meticulous approach to MRI-guided and MRIverified DBS is safe and accurate, with clinical outcomes comparable to other techniques.
|Title:||MRI guided and MRI verified deep brain stimulation: accuracy, safety and efficacy|
|Open access status:||An open access version is available from UCL Discovery|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Institute of Neurology > Motor Neuroscience and Movement Disorders|
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