Parkinson’s Disease

Sir William Richard Gowers, neurologist, researcher and artist, drew this illustration in 1886 as part of his documentation of Parkinson’s Disease. The image appeared in his book, A Manual of Diseases of the Nervous System. (Source: Wikipedia)

This information is designed only to help patients talk with their physicians about Parkinson’s disease (PD) and is not intended to provide treatment guidelines.  Some peer-reviewed medical papers on the surgery for Parkinson’s Disease are provide below for background information:

1. Honey CR. and Ranjan M., Deep Brain Stimulation for Parkinson’s Disease—A Review. Touch Briefings (2012) US Neurology 12-19.

Click the link to download the paper: Honey and Ranjan DBS for PD paper

2. Honey CR. and Palur RS. Surgery for Parkinson’s Disease. British Columbia Medical Journal (2001) 4:210-213.

Click the link to read the paper: Read at BCMJ

The April and May issues of the BCMJ in 2001 were devoted to Parkinson’s Disease. Excerpts from the article we wrote about the surgery for Parkinson’s Disease are reprinted below with permission from the Editor.


It is important to understand that the majority of patients with Parkinson’s disease (PD) are treated effectively with medications. Only a small group of patients need surgery. This section tries to outline the following:

  • Which patients can benefit from surgery
  • The benefit and risk of those surgeries

A word of caution: the benefits and risks of surgery vary with the individual patient and with the centre where the procedure is being performed. Success comes only when the correct patient receives an operation done correctly. Failure follows both the incorrect patient receiving a flawless operation and the ideal patient receiving a flawed operation.

We have found that patients will appreciate the outcome of their operation if their expectations are met. That seems an obvious statement but the goal of the patient and the goal of the (less experienced) surgeon are often different! The patient wants an improvement in their quality of life. The surgeon can only provide an improvement in a specific symptom. Whether a reduction in a specific symptom leads to an improvement in quality of life depends on a great many factors. The ability to make that prediction (“if that symptom is reduced your life will be better”) is the art of medicine. The ability to perform the operation without error is the science of medicine. I have found that most neurosurgeons can perform an operation safely after exposure to about 30 cases (observing and then participating with supervision). I still occasional struggle with the decision for surgery after 400 cases. The art is harder than the science.

Which Patients Benefit from Surgery

There are three symptoms that can be dramatically improved with surgery: tremor, dyskinesia and motor fluctuations. If a patient is suffering from one of those symptoms then alleviating that symptom will improve their quality of life. Tremor is the easiest symptom to understand. It is a rhythmic shaking of the arm (or the leg or jaw) and is a hallmark of Parkinson’s disease. Tremor usually occurs when medications are low, i.e. towards the end of a dose. The tremor in PD is a ‘resting’ tremor – occurring more when the arm is at rest then when moving. If tremor is controlled by medications then surgery is unnecessary. When tremor is not controlled by medications it will begin to interfere with the patient’s quality of life. Initially the tremor is an irritation or embarrassment. If the tremor worsens it will begin to interfere with eating (as well as writing, hobbies, dressing, and cleaning). Once tremor interferes with eating and drinking, patients often feel that their quality of life has been reduced too much and begin to consider surgery. The degree of impairment before an individual considers surgery varies dramatically. It is a personal choice. The same degree of tremor will be considered intolerable by the teacher who must write legibly on the blackboard but considered a minimal nuisance to the retired pensioner.

The surgery for tremor is described in the pages for thalamotomy or thalamic deep brain stimulation. Each operation has its own set of benefits and risks although both can be expected to reduce tremor about 80%.

The second symptom effectively treated by surgery is dyskinesia. Dyskinesia is a side effect of PD medications. It is an uncontrolled excess of movements throughout the body that looks like wiggling, dancing or writhing. Dyskinesia will stop if the medications are stopped (or more commonly just reduced). Unfortunately, when the medications are reduced the other symptoms of PD will worsen – slowness or bradykinesia for example. Some patients are therefore stuck between a metaphorical rock and a hard place: reducing medications helps dyskinesia but makes bradykinesia worse, while increasing medications helps bradykinesia and worsens dyskinesia. If all medication adjustments have failed to provide adequate quality of life then surgery can be considered. Mild dyskinesia is often unnoticed by the patient but will usually be recognized by their partner as wiggling of their hands or neck. More moderate dyskinesia will tend to pull the arm behind the back while walking and severe dyskinesia can produce violent, ballistic movements that can throw the patient off balance or injury bystanders. Any dyskinesia of an arthritic limb will be painful and the constant movement associated with dyskinesia can cause weight loss.

The surgery for dyskinesia is described in the pages for pallidotomy or pallidal deep brain stimulation. Each operation has its own set of benefits and risks although both can be expected to reduce dyskinesia about 90%.

The third symptom of PD that can be dramatically helped with surgery is ‘motor fluctuation’. Motor fluctuation is a term used to describe a condition of advanced Parkinsonism where the patient’s ability to move fluctuates during the day. They typically wake up stiff (we call this ‘rigid’) and slow (we call this ‘bradykinetic’) because they have not had their PD meds overnight. They are “off” – a term we use to describe the state of low medications when patients are rigid, bradykinetic, off balance, stooped in posture and sometimes tremulous. After taking their PD meds (and waiting a variable time for the meds to work) they feel their rigidity melt away and are able to move more normally. Their meds have started to work and they are “on”. At this time, movement is good, balance is fine and they are able to do what they want. As long as the patient is “on” their quality of life is good. Sometimes the medications are too strong and they develop dyskinesia. Unfortunately the meds wear off and the patient slips back into an “off” state. They take another set of medications (usually every 3 hours) and the cycle repeats. They are fluctuating between “on” and “off”. The surgery for motor fluctuation is described in the page for subthalamic nucleus deep brain stimulation.

The benefits and risks of surgery

Once again, it is very important to know that the benefits and risks of surgery vary tremendously between individual patients and between surgeons. Patients should talk to their surgeons to understand their own personal risks and the success rate (or complication rate) of their own surgeon.

Surgeries for Parkinson’s Disease

The following surgeries are available for Parkinson’s Disease: