Department of Neurosurgery, Northwestern University DBS for Dystonia: Stereotactic Technique Joshua...
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Transcript of Department of Neurosurgery, Northwestern University DBS for Dystonia: Stereotactic Technique Joshua...
Department of Neurosurgery, Northwestern University
DBS for Dystonia:Stereotactic Technique
Joshua M. Rosenow, MD, FAANS, FACSDirector, Functional Neurosurgery
Associate Professor of Neurosurgery, Neurology and
Physical Medicine and Rehabilitation
Northwestern Memorial Hospital
Department of Neurosurgery, Northwestern University
Disclosures
I have no relationship, financial or otherwise, relevant to this presentation
I do surgery for dystonia and feel that it is very effective for the appropriate patients
I am very nervous about the Yankees 2013 season (Although Arod’s hip surgery will increase their OPS through June)
Department of Neurosurgery, Northwestern University
Dystonia Surgery 1641 – Minnius sections the sternocleidomastoid muscle in a
patient with cervical dystonia
1891 – Keen performs first selective rhizotomy for cervical dystonia
1924 – McKenzie performs sectioning of both anterior and posterior spinal roots as well as spinal accessory nerve
1930 – Dandy performs first selective sectioning of spinal roots for cervical dystonia
Department of Neurosurgery, Northwestern University
Dystonia Surgery 1940 – Myers – destructive procedures in the basal
ganglia alleviate tremor
1950 – Spiegel and Wycis – adapt their stereotactic frame for pallidothalamotomies for chorea
1960s – Thalamotomies and Pallidotomies for dystonia
Department of Neurosurgery, Northwestern University
Dystonia Surgery 1960s - Cooper begins performing cerebellar stimulation
for dystonia and other movement disorders and epilepsy
1991 – Intrathecal baclofen infusion
1999 – Kumar – pallidal stimulation in single patient for primary dystonia
1999 - Krauss - pallidal stimulation for cervical dystonia
Department of Neurosurgery, Northwestern University
DBS History - 1971
Harry Benson suffers from painful, violence-inducing seizures. In an effort to alleviate this problem, Benson undergoes an experimental medical procedure, Stage 3, in which electrodes are attached to his brain's trouble spots -- if all goes well, timed jolts of electricity will correct his disability. But when Benson learns to turn up the juice whenever he pleases, his murderous rampage begins.
Department of Neurosurgery, Northwestern University
DBS for Dystonia: FDA Approval
2003 – HDE – Humanitarian Device Exemption granted
Approved for primary dystonia only GPi or STN DBS
Requires IRB approval but is not research
Department of Neurosurgery, Northwestern University
Severe, disabling symptoms from primary dystonia
Should have failed several modalities of treatment
Inadequate response or unacceptable side effects
Good support system
No medical contraindications
No significant untreated depression or anxiety
No significant cognitive deficits
Dystonia DBS: Candidates
Department of Neurosurgery, Northwestern University
Gpi Targeting1. T1 inversion recovery (IR)
sequences very useful do delineate GPI borders
2. Anatomic GPI targetRelative to intercommissural line
18-22 mm lateral 2-3 mm anterior 4 mm inferior
3. Trajectory AP Angle ~600
Coronal angle 0-50
Department of Neurosurgery, Northwestern University
Gpi Targeting
Putamen
Anterior commissure
Pallidum
Another method of choosing/verifying anatomic target is to start over lateral border of optic tract and set target just above that
Department of Neurosurgery, Northwestern University
•Start at anatomic target•Want to record at least 6-7mm Gpi
•Good kinesthetic activity
•Determine posterior border •Move posteriorly in 3 mm increments per MER track until internal capsule is reached (as determined by microstimulation-evoked contractions)
•Determine ventral border•Obtain evoked potentials from optic tract
•Final positioning of DBS electrode tip: • at least 2 mm dorsal to OT• at least 4 mm anterior to capsular border
Gpi MER
Department of Neurosurgery, Northwestern University
•Compared to Gpi in PD, Gpi in dystonia:
•has lower neuronal firing rate
•is characterized by less distinction between GPe and Gpi in terms of MER characteristics, making the transition determination more challenging
Gpi MER
Department of Neurosurgery, Northwestern University
Striatum Sparse Cells Firing Rates: 0.1Hz to
50Hz Low Amplitude
Department of Neurosurgery, Northwestern University
GPe
Denser Cellularity Spontaneous
Background Activity Two Distinct Cellular
Patterns Pauser Cells Burster Cells
Department of Neurosurgery, Northwestern University
Pauser Cells
Irregular firing pattern Frequency: 30-200 Hz Moderate to high
amplitude
Department of Neurosurgery, Northwestern University
Burster Cell
Cluster rate slow (10-20 Hz)
Burst Frequency high (> 500 Hz)
Medium to high amplitude
Department of Neurosurgery, Northwestern University
Border Cells
Firing rates 10-40 Hz Large amplitudes No movement initiated
responses
Department of Neurosurgery, Northwestern University
GPi
Dense Cellularity Spontaneous Background
Activity Two Distinct Cellular
Patterns Tremor Cells High Frequency Cells
Kinesthetic Responses
Department of Neurosurgery, Northwestern University
High Frequency Cells
Frequency: 50-300 Hz Kinesthetic responses Large Amplitudes
Department of Neurosurgery, Northwestern University
Pallidal MER
Optic
GPi
Laminae
Laminae
GPe
Putamen
Department of Neurosurgery, Northwestern University
Physiologic Verification
Intraoperative test stimulation Clinical benefits - NONE
Side effects • Muscle contractions too close to IC• Flashing lights – too close to OT• Slurred speech – too close to IC
Department of Neurosurgery, Northwestern University
Programming
• Begin 4 weeks after surgery
• Effects may not be seen for days
Department of Neurosurgery, Northwestern University
DBS for Dystonia
Surgical selection needs refinement Primary dystonia does best
Multiple targets have been tried over the years GPi, STN, Voa, Vop
Intraoperative physiology differs from PD Programming more complex
Higher current than PD Delays to improvement
While prospective studies are emerging, more are needed to refine the procedure
Department of Neurosurgery, Northwestern University
DBS: Risks
Not everyone experiences the same amount of improvement Inability to guarantee a certain level of improvement
Stimulation-related side effects
Infection – 5% per side
Hardware breakage Rare in general but higher in dystonia patients due to abnormal movements (esp.
cervical dystonia)
Bleeding – 1-3%
Anesthesia risks