Frameless DBS For Movements Disorders

Pablo J Acebal MDConsultants In Neurological Surgery

Parkinson’s Disease

• Depletion of Dopaminergic neurons in The Substantia Nigra• In the Direct Pathway results in decrease inhibitory activity of

the striatum on the Globus Pallidus internus leading to increase inhibition of the thalamus and ultimately the neocortex

• In The Indirect Pathway results in decrease inhibition of the striatum

• Increase Globus Pallidus externus inhibition • Decreased STN (Subthalamic nucleus) Inhibition• Increased Gpi activity• Finally increase inhibition of the Thalamus and neocortex

Basal Ganglia Connections

An overly simplified explanation

• Excessive inhibition of the thalamus by an overactive Gpi

• Results in clinical rigidity and bradykinesia

This model explains the rational for pallidotomy

Pallidotomy

• Lessioning of the Gpi relieves excessive inhibition to the thalamus

• Which leads to improvent in bradykinesia and rigidity

Parkinson’s tremor

• Relieved by Pallidotomy• Thalamotomy has been more successfull

Surgical Strategies in Parkinson’s Disease

• Progressive Disease Despite Maximal medical Efforts

Medication Side Effect

• Nausea ,Vomiting, Hypotension• Motor fluctuations• Dyskinesias• Psychiatric problems• Hallucinations• Pulmunary and retroperitoneal Fibrosis

Dyskinesias

Motor Fluctuations

• About 50% of patients on levodopa for more than five years experience MF

• Especially in patients with young onset PD• As the Disease Advances the the effects of

Levodopa begin to wear off by four hours after each dose

• Leaving patients anticipating next dose

Three Surgical Techniques

• Radiosurgical Ablation (more of a historical procedure now with the advent of reversible DBS techniques)

• Thalamotomy ( good for tremor but not very effective for bradykinesia and rigidity) bilateral thalamotomies have high risk of dysarthria and gait disturbance

• Pallidotomy (idiopathic Parkinson’s , moderately disabled, dopa responsive and bradykinesia and rigidity as major feature

Deep Brain stimulation DBS

• Dramatic and Beneficial Effects of Both Subthalamic Nucleus (STN)

• And• Globus Pallidus Internus Gpi reported • Potentially Reversible Procedure• Both techniques reduce MFs, ans dyskinesias as well as

rigidity and bradikynesia STN target adds better control of Parkinson’s tremor

• STN may be better in helping reduce amt of post op Parkinson’s meds

On time without dyskinesia during waking hours 25-30 % at baseline

to 65-75% at six month (DBS Study Group)

DBS results in PD

• In the PD Clinical Study 87% of Patients demonstrated improved motor scores in the OFF medication state at the end of 12 month evaluation

• Improvent varies but can be as high as 90% reduction in levodopa induced diskynesias ,Bradikinesia improved 85%, rigidity in 75% and Tremor 57 %

• DBS is adjustable by the clinician to meet the patient’ specific needs

• Reversible ( the stimulator can be turned off and the DBS lead removed)

Frameless DBS

DBS with Frame

Nexframe DBS

• Accuracy as good as frame based for DBS• Clinical results equal b/w DBS lead implantion

with framelss vs traditional frame based• Patient friendly• Allows for patient repositioning during

surgery• Computer software innovation have allowed

theses advances

Stimpilot

TargetsSTN for PD

TargetsThalamus Vim ET

3 Tesla MRI Direct Targetting

Surgical Plan

Assembly of Nexframe Tower

Microelectrode recordings

DBS Electrode Implantation

Pacemaker Implantation

Programmingthis is your patient!

Partnership between neurology and neurosurgery for the benefit of

the patient with movement disorders