Drilling holes in the skull and implanting slim electrodes in the brain may sound a little too similar to those infamous lobotomies of the 1940s. But neuroscience has come a long way since, and a neurosurgical procedure known as deep-brain stimulation (DBS) is increasingly being used by doctors today to treat a variety of movement disorders.

Movement disorders are neurological conditions that interfere with a person’s movements. They include Parkinson disease, essential trem​ors, dystonia as well as tic.

Associate Professor Prakash Kumar​, Senior Consultant Neurologist at the Department of Neurology, National Neuroscience Institute (NNI) (Singapore General Hospital​ campus), a member of the SingHealth group, specialises in DBS. He explains: “DBS basically involves securing electrodes in the affected regions of the brain, such as the subthalamic nucleus in Parkinson patients. Wires connect these electrodes to the neurostimulator, which is a small battery pack placed beneath the skin layer below the collarbone."

How deep-brain stimulation is performed

There are two stages of DBS surgery:

Stage 1: Placed under local anaesthesia, the patient’s head is secured in a rigid frame. One or two holes are then drilled in the skull and the electrode is placed in a particular part of the brain. As this is being done, tiny electrical impulses are delivered throughthe electrodes while the patient is awake to ensure that they are placed accurately.

Stage 2: During this stage, the patient is placed under general anaesthesia and is unconscious. An incision is made to create a small space beneath the skin below the collarbone so that the neurostimulator can be implanted in the upper chest area. The neurostimulator is then connected to the brain electrode via a connecting wire that is passed under the skin of the head, neck and shoulder.

Before DBS surgery can be performed, the patient has to undergo a physical and neuropsychological examination, as well as a brain CT or MRI scan to identify and locate the exact target within the brain.

Dr Kumar adds: “The doctor will also remind the pati​ent to share details about his or her health conditions (such as hypertension, diabetes and heart disease) and any current medications. In the d​ays leading up to the surgery, certain medications may need to be stopped, while lifestyle hab​​its like smoking and alcohol should be avo​ided.”

See next page for the uses of deep brain stimulation and​ medical conditions​ that can benefit from it​.​​​

​​Ref: P16