Neuromodulation The treatment is an emerging technology that encompasses a variety of methods that target the brain or nervous system at specific locations in the body, delivering electrical stimulation or drugs to restore function or relieve pain. It is fast becoming the standard for treatment of refractory seizures, Parkinson’s disorder and chronic pain management.
Columbia Asia Referral Hospital Yeshwanthpur, Bangalore has a team of specially trained neurosurgeons and neurologists, who have trained in some of the best institutes globally and have vast experience and skill in performing these procedures.
In general, neuromodulation systems deliver electrical currents and typically consist of the following components:
An epidural, subdural or parenchymal electrode placed via minimally invasive needle techniques (so-called percutaneous leads), an open surgical exposure to the target (surgical 'paddle' or 'grid' electrodes), or stereotactically placed electrodes deep inside the brain specifically targeting the nucleus to improve motor function in Parkinson’s disease and various other movement disorders
Stereoelectroencephalography is the recording of EEG via electrodes placed surgically in the brain. Intracranial monitoring also facilitates mapping of the brain. This means that the same electrodes that monitor the electrical activity of the brain can be used to deliver electrical stimulation to interrupt the function of specific brain regions and assess whether they are responsible for some essential functions such as speech or movement. This mapping is essential for avoiding the surgical removal of brain areas that serve essential functions.
Neuromodulation for refractory epilepsy
Epilepsy, a seizure disorder, is considered refractory when at least two anti-epileptic drugs have been tried and are found to be ineffective. In such cases, after evaluation the option of surgery is considered. Surgery can be:
- Resection: where a specific area of the brain which is thought to cause the seizures is removed. This can be done in both adults and children. Surgery is chosen if the focus area can be clearly identified and it is possible to remove the area without causing any additional problems. The surgeon will also ensure that there is no other medical condition which will affect the outcome of surgery.
- Ablation: where cold temperature and diathermy is used and the focus area is damaged so that abnormal electrical impulses are not discharged
- Deep brain stimulation (DBS) is the selected modality to reduce seizures which are not controlled by medication and where surgery to treat the cause of seizures is not possible. DBS involves implanting electrodes into specific areas of the brain and then stimulating these areas with small regular electrical impulses.
Neuromodulation for Parkinson’s disease
Deep brain stimulation (DBS)
Deep brain stimulation is a therapy that involves surgical treatment to implant a medical device in the brain that sends electrical impulses to specific parts of the brain, providing benefits to patients with Parkinson’s disease and its related symptoms. The medical device consists of two electrodes that stimulate the subthalamic nucleus of the brain. The two electrodes are connected by wires to a pacemaker like device, called the impulse generator or IPG. The IPG is implanted under the skin of the chest, just below the collarbone. When active, the device sends continuous electrical pulses to the target area in the brain, blocking impulses that cause the tremors.
The IPG can easily be programmed using a computer that sends radio signals to the device. Patients are given special magnets or other devices so they can externally turn the IPG on or off. Depending on use, the stimulators may last five to six years. The IPG replacement procedure is relatively simple.
Stimulation of the subthalamic nucleus has been recognised as the most effective treatment for Parkinson’s disease. The treatment addresses tremors, rigidity, stiffness, as well as gait and walking concerns. The successful stimulation of the subthalamic nucleus allows patients to considerably reduce their medication and they also see an improvement in disease related symptoms.
Deep brain stimulation (DBS) is a surgical procedure used to treat a variety of disabling neurological symptoms — most commonly the debilitating symptoms of Parkinson’s disease. DBS uses a surgically implanted, battery-operated medical device called a neurostimulator — like a heart pacemaker and approximately the size of a stopwatch — to deliver electrical stimulation to targeted areas in the brain that control movement, blocking the abnormal nerve signals that cause tremors and Parkinson’s disease symptoms. DBS is also the selected modality for refractory epilepsy.
DBS directly changes brain activity in a controlled manner and its effects are reversible.
Neuromodulation for chronic pain
This is used to treat and enhance quality of life in individuals who suffer from severe, persistent pain, spasticity, movement disorders, epilepsy, ischemia, cardiac, bladder dysfunction, spinal injury, visual, chronic critical limb ischaemia, chronic pancreatitis, chronic painful bladder syndrome and chronic abdominal pain
The most common modality is spinal cord stimulation and the most common indication is the persistent severe neuropathic pain found in those who have had technically successful spinal decompression surgery, but who have had recurrence or persistence of symptoms. This provides immense relief to those with nerve injury of either the spine and brain or peripheral nervous system. Patients who benefit from spinal cord stimulation include those who exprerience pain after nerve root injury in spinal disorders (commonly known as failed back surgery syndrome [FBSS]), post amputation pain, other traumatic neuropathies, complex regional pain syndrome and metabolic and viral neuropathies.
In spinal cord stimulation, mild electric currents applied to the spine through small medical devices interrupt pain signals and replace the sensation with a mild tingling known as paraesthesia. Spinal cord stimulation involves placing a series of electrical contacts in the epidural space near the spine in the region that supplies nerves to that area. Stimulation is supplied by a rechargeable, implantable pulse generator which is placed under the skin just above the hip pocket of trousers.
Intrathecal baclofen pump
It is a neuromodulation modality using a chemical stimulation through injection of a drug into the intrathecal space. The fluid-filled space around the spinal cord is called the subarachnoid or intrathecal space. The intrathecal pump system consists of a pump / reservoir implanted between the muscle and skin of the abdomen and a catheter that carries pain medication from the pump to the spinal cord and nerves.