Deep brain stimulation

The Deep Brain Stimulation ( DBS engl. Deep Brain Stimulation ) is a neuro- surgical intervention in the brain, should be corrected with the sickness absence benefits. Popular, but misleading is the term brain pacemaker.

For chronic brain stimulation to the patient one or two thin electrodes are usually implanted, which are connected via cables laid subcutaneously with a pulse generator in the chest or upper abdomen. This pulse is permanently electrical pulses to the target region in the brain, making them - depending on the current frequency - can be either disabled or stimulated.

Worldwide, about 75,000 patients were treated surgically with a brain pacemaker. Prospective Controlled and randomized studies in recent years demonstrate the continuing effectiveness of the therapeutic procedure in the individual course of the disease: Not only disease symptoms such as shaking (tremor ), stiffness (rigidity ) and physical inactivity ( bradykinesia ) can be improved, but has also been shown in a holistic sense, the quality of life.

In recent years, possible psychological side effects have been reported in numerous publications, the spectrum comprises mainly easier cognitive deterioration, depression, (hypo ) mania. Also, personality changes have been documented.

Established areas of application include Parkinson 's disease, Essential tremor or dystonia. In clinical trials there are applications in the fields of epilepsy, depression, obsessive compulsive disorder, cluster headaches and Tourette's syndrome.

Areas of application

Movement disorders

The method is currently used mainly for the treatment of various movement disorders, such as the symptoms of Parkinson 's disease, essential tremor, tremor in multiple sclerosis and dystonia.

Deep brain stimulation and its application areas are the subject of current research:

• Parkinson 's disease: The most common application of deep brain stimulation. Researchers at the Research Centre Jülich and the University of Cologne working on the development of a brain pacemaker, which not only suppress the symptoms of Parkinson's, but they correct and the brain back to functioning normally. For this idea, they received the 2005 Erwin Schrödinger Prize.

• Günther Deuschl ( Department of Neurology of the University Hospital of Schleswig -Holstein in Kiel ) and team published a paper in the U.S. journal " New England Journal of Medicine " in February 2013.

Depression

• The application of deep brain stimulation in depression is in the experimental stage. Positive results were shown in very small groups of treatment-resistant patients with a stimulation of the Area subgenualis ( Brodmann's area 25 ) and the nucleus accumbens. Thomas E. Schlaepfer and Volker A. Coenen achieved good results by positioning the electrode to the nerve cord, which connects the low-lying brainstem to the frontal cortex with the structures subgenualis area and nucleus accumbens.

Other areas of application

• Also in the experimental stage is the use of deep brain stimulation in the treatment of epilepsy, dependence syndrome, obsessive compulsive disorder, or cluster headache.

Operation

The functioning of deep brain stimulation in detail is not yet clear. However, the operation is the subject of intense research, and are currently four general theory will be discussed:

• Functional block of axons by depolarization
• Synaptic inhibition
• Depletion of neurotransmitters by continued excitation of neurons
• Stimulation induced by the change of the pathological activity of the brain neural network

As a control is a small battery-powered and chip- controlled pulse generator, which is used under the skin of the chest muscles or the upper abdomen. The electrodes are inserted through small holes in the skull to the target region of the basal ganglia of the left and right brain.

In the treatment of patients with advanced Parkinson 's disease, the nucleus is driven subthalamic or the medial globus pallidus pallidus in essential tremor of the thalamus ventralis and dystonia of the globe. A study at the University Hospital of Cologne and Bonn on efficacy in depression examined the stimulation of the nucleus accumbens.

Operation

In Germany, every year about 400 brain pacemakers are implanted at 30 clinics. The implant is reversible.

The operation is performed in two steps. In the first, the patient to be drilled in a stereotactic surgery, small holes in the cranium through which the electrodes are inserted into the brain. Here, the patient is usually fully conscious. Only in this way can be checked by means of test stimuli the effectiveness of each electrode and thus their exact location. The pulse generator ( brain pacemaker ) is implanted either during this engagement, or in a second, shorter surgery the next day.

Originally four contacts were used on each side of the brain. End of 2010, a brain pacemaker model were implanted at the University Hospital of Cologne for the first time, which has eight contacts on each side of the brain. A higher number of electrodes in the brain to make the device more efficient and have fewer side effects on other brain regions.

Side effects

However, successful surgery may grant a temporary or long-term dysarthria or a usually temporary manic behavior with inadequate elevated mood, abnormal increased drive, material waste behavior and severe restriction of personal performance following (initial ). Some patients, however, is depressed despite improvement in motor disorders by deep brain stimulation.

Ethical discussion

Since the exact mechanism of action in the brain is unknown and it is possible to influence mood and behavior (depression, obsessive compulsive disorder, mania ), deep brain stimulation is also subject to ethical discussions. The National Ethics Council held a discussion on neural implants in January 2006. It was in the sense of self-determination considered advantageous that deep brain stimulation is reversible and the neurostimulator can be off at any time.