I have onset of Parkinson’s, so I have bad hand tremors. Do any round the neck, eye level supports exist which can help me stop camera shakes?
This would be for a bridge (superzoom) style camera with a normal tripod thread.
If your tremors are too severe for existing Image Stabilization systems to compensate, you might want to look into having something made, since I don't know of an existing device such as you describe.
Start with the devices musicians sometimes use to hold a harmonica while they play a guitar with their hands -- those will give you the correct type of body support. To that, you'll add a platform in which the tripod screw can mount. A spacer may be needed to raise the eyepiece to the correct height. You may need to extend the support to run further down your chest (to offset the leverage of the camera's weight compared to a relatively light harmonica), and would likely find it helpful to have an adjustable strap behind your neck to provide the other end of the lever arm.
You could use a mono pod, that will reduce a lot of shaking. They can be quite small and compact when folded down.
What may also help is using a remote shutter (cable or wireless).
A steady cam rig, used for professional handheld video may help. There are several sorts. But I understand some work by adding weights and moving the center of gravity, other work by activly (computer controled) keeping the camera stable.
Finally there is adapting your technique (sorry if you already know this). Put your camera into shutter priority mode and shoot at 1/500 or 1/1000 of a second. This will limit the more dimly lit shots sadly. Using a wider angle lens which can go down to a wider aperture, with good/fast autofocus may help.
Stabilization glove prototype?
I did some Google search about 'mechanical compensating parkinson tremor' which led me to look for 'Wearable Tremor Suppression glove' which led me to http://gyrogear.co/ 'GyroGlove'.
Gyrogear is a company trying to develop a wearable glove which can help to stabilize the tremor. The glove works by using the gyroscopic effect as a stabilizer.
Here is a video that show a prototype https://www.youtube.com/watch?v=LbxqNMf97G8
Still, this is not a product that you can buy now... but they say they are working on it.
Other scientific research
From the former research, it seem that there are various scientific papers on the matter, so I hope that someone may come to a practical solution.
Here I list some links to the scientific research I've found:
Try a cinematic camera rig to stabilize the camera
There are a lot of product to stabilize a handheld camera. They are mainly used by videomaker. Maybe you can find something that can suit what you need.
Maybe those could stabilize your tremor.
If something like this could works, probably depend on the speed/almplitude/type of tremor vs. the stabilization capablity of the cinematic rig.
Maybe you could also try a chest/shoulder camera mount, and then click the shutter with a remote control.
You might wish to investigate the professional film making options in this area. There are a number of vest-based ('body mounted') camera stability platforms out there, many now for DSLRs, which have seen use as replacements for dedicated video cameras. Do a quick search for body mounted camera stabilizers or brands like FLYCAM or GlideCam. These are designed specifically to counter body/camera movement so should be of significant help.
Of course if motor control/dexterity becomes an issue, look for a camera system that accepts IR/Bluetooth or wired external triggers, which can make it easier to hit the shutter button without disturbing the camera, as well as put the button in a more comfortable body position.
Good luck and keep on shooting!
The answers here are quite good and I hope you find value in investigating these venues. In the end a good tripod with a remote shutter release would provide great value. A remote shutter would either be wireless, or it would be wired but the wire would only have limited impact on the tremors that are transmitted to the camera. But for handheld shooting it would offer no solution.
So here's another thought. Not one that truly answers the crux of your question but something I wish to state anyway. Perhaps embrace the tremors. Take the slightly blurred pictures. Your photos are not just the scene you capture, they are an expression of you as a person as well. As tragic as it is, your affliction is part of you. Your photography is an extension of your being. All of us are to some extent limited by our situation in our photography. And it can result in a beautiful insight into our lives. The formidable Ludwig van Beethoven was struck with deafness for much of his life yet continued to compose some of the greatest works of music to grace mankind. Coming to terms with our restrictions and incorporating them into our lives can be powerful.
I have had intentional tremors for several years and it is getting worse. I have noticed the time goes by it's more and more difficult to handhold my cameras without help. I've tried different kinds of grips, weights, wrist supports, arm supports, and even handheld gimbals. And as you know, monopods or tripods can be cumbersome or not allowed in some public areas. Here is my last resort: after some bit of research and a couple of opinions from Parkinson's or trimmer sufferers, and a little trial and error, I found that Sony's higher and cameras (a6600 and a7 series) all have 'in-body stabilization' systems. Now combine that with Sony lenses that have OOS optical stabilization feature, And I think you're about as good as it gets. Canon may have an equivalent system but I have not investigated it. And not to promote any special dealership, but I found a Sony alpha 7 Camera with a "OOS" lens For under $1700 by Adorama and BandH How did at the same exact price. As of today (Sept 9, 2020), There was a good price drop by Sony for these cameras. And the only reason why I chose Sony over Canon was that I am already in the Sony system and I've had pretty good success with their products. Extra weights on your camera never will work, they get tiresome so fast, and a gimbal system is best for a video, not for still shots. We can also be grateful for higher ISO ratings that can aid in freezing objects in motion, or hands in motion. If you are traveling, as I do, and take meds for your shakes, remember to plan ahead and maybe you can time is to that you get better results.