• Symptoms of Parkinson's disease

• Treatment Options

  • Treating Parkinson's disease with medication
  • Medication options for Parkinson's disease
  • Surgery for Parkinson's disease
  • Complementary / alternative treatments for PD
  • PD Treatment Team
  • Tips for managing Parkinson's disease medications

• PD: What you need to know

Surgery for PD

Currently, no surgical operations provide a cure for Parkinson’s disease (PD), although they can offer benefits for some people by improving certain symptoms and sometimes reducing the need for medications. However, even following successful surgery, a person with PD is still required to take continuous medication.

The three areas of the brain currently targeted during PD surgery are:

• thalamus – can improve tremor
• globus pallidus – can improve levodopa-induced dyskinesia, rigidity and sometimes tremor
• subthalamic nucleus – can improve tremor, slowness and stiffness, and may allow PD medication to be reduced

New targets that may be helpful for treating people with PD are also being researched, including an area of the brain called the pedunculopontine nucleus (PPN), which may be targeted to help relieve symptoms related to walking pattern (gait).

Who will benefit from surgery?

Surgery can be used to treat Parkinson’s disease (PD), but it is not suitable for everybody.

Any person with PD who is being considered for surgery will undergo a very detailed assessment of their condition, often over 1–2 days. These assessments are carried out to make sure that the person has symptoms that would respond well to surgery, without any unusually high risk of complications. They also provide a valuable opportunity for the healthcare team to discuss all aspects of surgery and ensure that the person with PD and their family have realistic expectations of what the proposed operation can achieve.

People with PD who are likely to benefit from surgery are those who respond well to their PD medication but in whom this response has become unpredictable and/or short-lived, has led to troublesome dyskinesias (restless movements), or has been poorly tolerated (i.e., causing unacceptable side effects).

Surgery has not been shown to improve symptoms that do not respond to dopamine medication – apart from tremor, which can be resistant to medication but generally responds well to surgery.

Types of surgery

Surgery in Parkinson’s disease (PD) may be necessary for practical reasons. Surgery can also be used to directly address symptoms by targeting specific areas of the brain. There are two main forms of brain surgery currently used for PD:

Deep brain stimulation (DBS)

The most commonly used procedure at present. It involves implanting wires into the specific areas of the brain that are overactive in PD and connecting these wires to a device that delivers electrical pulses. This device, called a pulse generator, is implanted under the skin on the chest wall or abdomen. The pulses interfere with and block out the electrical signals that cause PD symptoms. (source) This technique does not destroy any brain tissue and is reversible, but is usually intended as a long-term measure (may be permanent). DBS can be referred to as thalamic, pallidal, or subthalamic, depending upon which brain area is targeted.

Lesioning

Lesioning involves destroying part of the specific brain region that is causing PD symptoms. The operation is named after the part of the brain that is targeted i.e., thalamotomy, pallidotomy, or subthalamotomy. Because it is destructive, lesional surgery is rarely performed for PD nowadays and, indeed, in most centres, subthalamotomy is not offered at all. Thalamotomy can only be carried out on one side of the brain and is therefore not usually very helpful for people with PD, whose symptoms almost always affect both sides of the body. Pallidotomy may be considered for a few people with very severe dyskinesias who cannot have subthalamic nucleus DBS, but it is also, generally, only performed on one side of the brain.

Techniques in development

Surgical therapies are being developed to try to restore the normal function of the brain rather than just treating the symptoms of Parkinson’s disease (PD). These are still in the early experimental phase and include:

Stem cell transplantation 

Stem cell transplantation involves implanting dopamine-producing cells (from human embryos) into the brain to replace those that have been lost in PD

Transplantation of genetically-engineered cells

Transplantation of genetically-engineered cells similar aim as stem cell transplantation, but using cells that have been synthetically altered to produce dopamine

Infusion of growth factors

Infusion of growth factors are infused into specific areas of the brain to stimulate growth of dopamine-producing cells in these areas

In the future, these and other experimental restorative procedures, may offer improved treatment for people with PD.

Complications

As with any neurosurgery, brain surgery for Parkinson’s disease (PD) can be associated with complications. There are risks associated with the operation itself, including a small risk of bleeding into the brain, or causing other problems with speech or balance, for example.

It is generally considered that the likelihood of these complications is less with deep brain stimulation (DBS) than with lesioning. However, there are some risks associated with DBS and its stimulator system, for example, infection or hardware failure. Side effects of DBS can occur. Specifically, subthalamic DBS is associated with memory difficulties and other thought-related problems, and pallidal DBS is associated with emotional disorders (e.g., depression, anxiety). These complications are mostly reversible over time, and may be avoided by careful programming of the stimulator, although some people can experience permanent complications.

Because of the risks, surgery is only considered for people whose symptoms are not controlled adequately by medication and, aside from their PD, are in a generally good state of health.