Brain pacemaker
Encyclopedia
"Brain pacemakers" are used to treat people who suffer from epilepsy
, Parkinson's disease, major depression and other diseases. The pacemaker is a medical device that is implanted into the brain to send electrical signals into the tissue. Depending on the area of the brain that is targeted, the treatment is called deep brain stimulation
, or cortical stimulation
. Brain stimulation may be used both in treatment and prevention. Pacemakers may also be implanted outside the brain, on or near the spinal cord (spinal cord stimulation), and around cranial nerves such as the vagus nerve (vagus nerve stimulation
), and on or near peripheral nerves.
refers to a wide variety of neurological disorders characterized by sudden recurring attacks of motor, sensory, or psychic malfunction with or without loss of consciousness or convulsive seizures. The implantation of pacemakers in the brain may control or eliminate epileptic seizures with programmed or responsive stimulation.
can help reduce symptoms such as tremors, rigidity, stiffness, slowed movement, and walking problems. The procedure also treats essential tremor
, a neurological movement disorder. After the pacemaker is surgically implanted into the brain, electrical impulses are sent to the stimulator and into the brain. The procedure is generally only used for patients whose symptoms cannot be controlled with medication. The exact mechanism of action of DBS is not known. There exist three hypotheses to explain the mechanisms of DBS:
Deep brain stimulation represents an advance on previous treatments which involved pallidotomy
(i.e., surgical ablation of the globus pallidus
) or thalamotomy
(i.e., surgical ablation of the thalamus). Instead, a thin electrode with four contacts is implanted in the globus pallidus, nucleus ventralis intermedius thalami (Vim) or the subthalamic nucleus
and electric pulses are used to block the abnormal activity. The lead from the implant is extended to the pacemaker under the skin in the chest area.
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
, Parkinson's disease, major depression and other diseases. The pacemaker is a medical device that is implanted into the brain to send electrical signals into the tissue. Depending on the area of the brain that is targeted, the treatment is called deep brain stimulation
Deep brain stimulation
Deep brain stimulation is a surgical treatment involving the implantation of a medical device called a brain pacemaker, which sends electrical impulses to specific parts of the brain...
, or cortical stimulation
Cortex (anatomy)
In anatomy and zoology the cortex is the outermost layer of an organ. Organs with well-defined cortical layers include kidneys, adrenal glands, ovaries, the thymus, and portions of the brain, including the cerebral cortex, the most well-known of all cortices.The cerebellar cortex is the thin gray...
. Brain stimulation may be used both in treatment and prevention. Pacemakers may also be implanted outside the brain, on or near the spinal cord (spinal cord stimulation), and around cranial nerves such as the vagus nerve (vagus nerve stimulation
Vagus nerve stimulation
Vagus nerve stimulation is an adjunctive treatment for certain types of intractable epilepsy and treatment-resistant depression.- Mechanism of action :...
), and on or near peripheral nerves.
Epilepsy
EpilepsyEpilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
refers to a wide variety of neurological disorders characterized by sudden recurring attacks of motor, sensory, or psychic malfunction with or without loss of consciousness or convulsive seizures. The implantation of pacemakers in the brain may control or eliminate epileptic seizures with programmed or responsive stimulation.
Parkinson's disease
The deep brain stimulation used in pacemakers to treat Parkinson's diseaseParkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
can help reduce symptoms such as tremors, rigidity, stiffness, slowed movement, and walking problems. The procedure also treats essential tremor
Essential tremor
Essential tremor is a slowly progressive neurological disorder whose most recognizable feature is a tremor of the arms that is apparent during voluntary movements such as eating and writing...
, a neurological movement disorder. After the pacemaker is surgically implanted into the brain, electrical impulses are sent to the stimulator and into the brain. The procedure is generally only used for patients whose symptoms cannot be controlled with medication. The exact mechanism of action of DBS is not known. There exist three hypotheses to explain the mechanisms of DBS:
- Depolarization blockade: Electrical currents block the neuronal output at or near the electrode site.
- Synaptic inhibition: This causes an indirect regulation of the neuronal output by activating axon terminals with synaptic connections to neurons near the stimulating electrode.
- De-synchronization of abnormal oscillatory activity of neurons.
Deep brain stimulation represents an advance on previous treatments which involved pallidotomy
Pallidotomy
Pallidotomy is a procedure where a tiny electrical probe is placed in the globus pallidus , which is then heated to 80 degrees celsius for 60 seconds, to destroy a small area of brain cells...
(i.e., surgical ablation of the globus pallidus
Globus pallidus
The globus pallidus also known as paleostriatum, is a sub-cortical structure of the brain. Topographically, it is part of the telencephalon, but retains close functional ties with the subthalamus - both of which are part of the extrapyramidal motor system...
) or thalamotomy
Thalamotomy
First introduced in the 1950s, thalamotomy is an invasive procedure, primarily effective for tremors such as those associated with Parkinson's Disease , where a selected portion of the thalamus is surgically destroyed...
(i.e., surgical ablation of the thalamus). Instead, a thin electrode with four contacts is implanted in the globus pallidus, nucleus ventralis intermedius thalami (Vim) or the subthalamic nucleus
Subthalamic nucleus
The subthalamic nucleus is a small lens-shaped nucleus in the brain where it is, from a functional point of view, part of the basal ganglia system. Anatomically, it is the major part of subthalamus. As suggested by its name, the subthalamic nucleus is located ventral to the thalamus. It is also...
and electric pulses are used to block the abnormal activity. The lead from the implant is extended to the pacemaker under the skin in the chest area.
Clinical depression
Pacemakers are also being used to treat depression. Electrical stimulation has been shown to eliminate chronic depression in some patients. Some patients report an immediate improvement in mood and in their sleeping habits after implantation. CG25, a brain region involved in somatovisceral control, is speculated to play a role in depression. People with depression have abnormally high levels of activity in CG25.See also
- Brain implantBrain implantBrain implants, often referred to as neural implants, are technological devices that connect directly to a biological subject's brain - usually placed on the surface of the brain, or attached to the brain's cortex...
- Deep brain stimulationDeep brain stimulationDeep brain stimulation is a surgical treatment involving the implantation of a medical device called a brain pacemaker, which sends electrical impulses to specific parts of the brain...
- NeurotechnologyNeurotechnologyNeurotechnology is any technology that has a fundamental influence on how people understand the brain and various aspects of consciousness, thought, and higher order activities in the brain...
- Vagus nerve stimulationVagus nerve stimulationVagus nerve stimulation is an adjunctive treatment for certain types of intractable epilepsy and treatment-resistant depression.- Mechanism of action :...
- Wirehead