One cannot paint Parkinson’s Disease with a broad brush and say that people with this condition should not dive. In some cases, the body is affected very little by the disease in it’s early stages and a person should not be deprived of this pleasure. Of course, there are those in the later stages of the condition who certainly should not dive for several reasons. These include tremor, muscle rigidity, ability to task adequately; medication effects are other factors that need to be considered, as some side effects are adverse to diving (confusion, drowsiness, hallucinations).
There is no ill effect of depth or pressure on the condition itself, but there might be serious consideration of the additive effects of increased partial pressures of nitrogen on the medications used to treat the disease.
Should cognition, tremors and balance problems reach the point where there is difficulty with donning gear, entrances and exits from the water or personal fears about safety and that of others others – then one should think strongly about discontinuing diving.
Also, people with Parkinson’s may dive if their condition is controlled so that they can manage their gear and all of the multi-tasking that is required even on simple dives. Diving and the effects of depth/pressure would not have any effect on the condition.
Levodopa is the main medication used in the treatment of PD. It may cause some people to become dizzy, confused, or have blurred or double vision. Make sure you know how you react to this medicine before you dive, drive, use machines, or do anything else that could be dangerous if you are not alert or not able to see well. Postural hypotension may occur with dizziness, lightheadedness, or fainting.
Selegiline enhances L-dopa but has adverse effects when taken with nearly every antidepressant, some very serious. It can also cause orthostatic hypotension. Benserazide or Prolopa, has effects similar to L-dopa. If your medications have been taken long enough to find out how they effect you personally, and if you have none of the side effects, then you should be able to dive, given the go-ahead by your personal physician.