The Neurosurgery Center：Surgical Procedure for Parkinson’s Disease and Essential Tremor

■Deep Brain Stimulation: DBS

At our Center, we have been performing Deep Brain Stimulation (DBS) since May 2010. We were the first hospital in Shiga Prefecture to offer this procedure to our patients. DBS is performed using the Leksell stereotactic apparatus. This is the same apparatus used in Gamma Knife surgery, and therefore the treatment plan is also similar. We have performed over 1,000 procedures using this apparatus.

1.What is Deep Brain Stimulation?

Using stereotactic surgery, an electrode (also called the lead) is placed into the deep region of the brain (figure 1), and the electricity sent through the electrode reduces excessive suppression, rebalances neuronal excitation, and helps to improve symptoms (figure 2).
It should be noted that this procedure helps improve the symptoms, but is not a curative treatment of the disease.


Figure 1	Figure 2

	【Before the stimulation】

	【After the stimulation】

２.Candidates for DBS Treatment

DBS is suitable when symptoms cannot be controlled with medication or when the patient cannot tolerate the side effects of the medication and its use is no longer appropriate, and when the potential effectiveness of the stimulation appears promising.

【Conditions in which DBS is appropriate】

Parkinson’s Disease (most often treated)
Involuntary Movement Disorders such as Essential Tremor and Dystonia

３.How is DBS Performed?

①The frame is attached		②MRI Scan


		③The target is set


④The electrode is inserted and microelectrode recording is done


⑤The electrode is placed		⑥The pulse generator is implanted

４.Postoperative Management - Adjusting the Stimulation

As the patient’s medication is gradually reduced,the stimulation parameter is reprogrammed each time the medication is adjusted.


	The various stimulation settings can be adjusted through the skin. The optimal setting will be determined after the surgery.
			※The patient turns the pulse generator ON/OFF.

５.Complications/Side-Effects of the Treatment

【Complications related to surgery】
　　　→Intracerebral hemorrhage, infection, etc.
【Side-effects of the stimulation】
　　　→Temporary psychoneurosis such as hallucinations
　　　　　Dyskinesia (temporary), etc.
【Equipment related issues】
　　　→Infection, malfunction such as wire disconnecting, etc.

■Parkinson’s Disease

1.Causes of Symptom　Manifestation

The part (tonsil) of the cerebellum descends causing the obstruction of the flow of the spinal fluid, which causes the fluid to be retained in the spinal cord creating a cavity. The symptoms tend to include neurotrophic pain on the hands and in the lateral region of the abdomen, deformed joints, scoliosis, and muscle atrophy in the hands. It is often possible to slow the progression of the disease by a procedure called Foramen Magnum Decompression.

【Cerebral Cortex - Basal Ganglia Loop】



Black：inhibitory	Red：excitatory
Bald arrow：hyperactivity	Narrow arrow：hypoactivity


substantia nigra pars compacta	Produces dopamine which functions as a driving force for bodily movements
↓
striatum	One of the basal ganglia. Control center for bodily movements. Needs dopamine to function well.
↓
direct/indirect pathways	Sends inhibitory signals to the thalamus via cerebral basal ganglia (globus pallidus medial segment - subthalamic nucleus - globus pallidus medial segment/substantia nigra pars reticulate)
↓
thalamus	Transmits signals from the striatum to the cerebral cortex.
↓
cerebral cortex	Transmits signals from the thalamus to the spinal cord.
↓
spinal cord	Transmits signals from the cerebral cortex to each muscle
↓
muscle	Moves the body by contracting according to the signals from the nerves.

２.Main Symptoms

【Shaking (Tremor)】：Relatively slow tremor at rest - movement resembles rolling a pill on fingertips. Often starts in either right or left hand or leg.
【Muscle stiffness (rigidity)】：Muscles become rigid making it difficult to move smoothly. Bending and extending arms and legs are difficult and when someone else tries to assist in moving the limbs, there is a resistance that feels “jerky.” Difficulty turning the neck.
【Slowness of movement (Akinesia/Bradykinesia)】：Decreased movements. All movements become slow. Difficulty moving the legs forward and walking. Lack of facial expressions, voice becomes quiet and monotonous.
【Postural reflex disorder】：Reflex that prevents one from falling when loss of balance is obstructed. Falling easily, even from a slight push. Inability to stop a fall, even when intending to.

３.When to Choose DBS Surgery

【When side effects force one to reduce medication】
　　　→By stimulating the subthalamic nucleus, symptoms improve and the patient is able to reduce the dosage of oral medication.
【When everyday life becomes extremely difficult】
　　　→By improving symptoms during the “off” period (period when a medication’s effect wears off and symptoms increase), the quality of life improves.
【When “wearing off” phenomenon or on/on-off effect becomes prominent】
　　　→When there is a large fluctuation in the symptoms and difficulty in controlling them with oral medication, DBS can reduce the “off” symptoms and maintain a well-controlled period.

４.Expected Outcome from Surgery




Difficulty controlling with oral medication	There is a large fluctuation of symptoms with oral medication, and the dyskinesia and “off” period last for a long time

Post-DBS	After starting the stimulation, the dosage of oral medication is reduced, dyskinesia disappears, and the worsening of symptoms during “off” period disappears due to “bottom-lifting effect,” and the patient is able to maintain a mostly well-controlled state.

５.Complications from surgery and side-effects of DBS

Concerning the rate of complications, while safety and efficacy of the surgery have been established, complications can occur in 1-2% of the cases.

【Cerebral Hemorrhage】：If the hemorrhage is large, there could be subsequent complications.
【Infection】：Localized infection could occur around the implanted foreign objects.
　　　　　　If the infection is not well controlled using antibiotics, it may become necessary to remove the implanted electrodes, etc.
【Breakage】：If there is a hardware breakage, surgery may be necessary to replace the component.

As for side effects, the patient may experience psychiatric symptoms including hallucinations or worsening of symptoms including temporary dyskinesia.
In many cases, these problems can be alleviated by reprogramming the pulse generator.

■Essential Tremor

1.What is Essential Tremor

Essential tremor is an involuntary tremor that occurs in any part of the body, but often in hands.
Tremor is induced when trying to hold the hand in the air. It also often occurs when one is actively moving.
(Graphospasm: becomes apparent in hand writing)
Family history cases often reflect increased susceptibility
In many cases, symptoms increase when under mental stress
Mild tremor is common (20 times more common than Parkinson’s Disease), and is slower to progress
Various medication treatments are available

２.Diagnosis of Essential Tremor

Requirements
	Bilaterality
	Postural or action tremor ranging from the forearms to the hands
	Tremor is continuous and can be visually confirmed
Exclusions
	Other neurological manifestations
	High probability that the tremor is psychogenic based on medical history or clinical manifestation
	Sudden onset tremor or tremor that rapidly progresses
	Orthostatic tremor that occurs in the lower limbs when standing
	Tremor limited to vocalization, tongue and jaw, or lower limbs

３.Treatment Options for Essential Tremor

【Medications】
　　　→Beta-blocker including propranolol
　　　　　Variety of antiepileptic agents including Mysoline
　　　　　Antianxiety agents including benzodiazepine
【Lifestyle changes】
　　　→Reduce consumption of caffeine, and increase relaxation
【Local administration of botulinum】
【Surgery】
　　　→If the tremor is severe and cannot be adequately controlled through various lifestyle changes and medications, and the patient has difficulty functioning in everyday life, surgery (deep brain stimulation in the thalamus) is indicated.

４.DBS for Essential Tremor

Advantages and disadvantages of stimulation therapy over thalamotomy
　　　　Advantage: 1) Less invasive, reversible, and can be performed bilaterally 2) Adjustable Disadvantage: Pulse generator is implanted under the skin + batteries need to be changed
The VIM thalamus nucleus is targeted for stimulation. Tremor often reduces immediately after the stimulation begins.
Given that essential tremor is generally slower to progress compared to Parkinson’s Disease, long-term positive outcome of the stimulation therapy can be expected.
Other than side effects that accompany general stimulation therapy, dysesthesia and articulation disorders can occur, but they can be reduced through adjustments.
Mild tremor is more common (20 times more common than Parkinson’s Disease), and is slower to progress.

Physicians on staff

Fumio Suzuki, M.D., Ph.D.
	１９８２	Department of Neurosurgery, Shiga University of Medical Science
	１９８９	Department of Neurosurgery, Rakusai Shimizu Hospital
	１９９１	Department of Neurosurgery, Shiga University of Medical Science
	１９９２	Studied at Hopital Henri-Mondor (France)
	１９９４	Department of Neurosurgery, Shiga University of Medical Science
	１９９９	Professor, Universite de Strasbourg
	２００４	Kalorinska University (Sweden)
	２０１０	Department of Neurosurgery, Kotoh Kinen Hospital

Hisao Hirai, M.D., Ph.D.
	１９９１	Department of Neurosurgery, Shiga University of Medical Science
	１９９２	Department of Neurosurgery, Nagahama Red Cross Hospital
	１９９５	Department of Neurosurgery, Rakusai Shimizu Hospital
	１９９９	Department of Neurosurgery, Hino Kinen Hospital
	２００１	Department of Neurosurgery, Kotoh Kinen Hospital
	２００４	Trained at Kalorinska University (Sweden)

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