Can Botox be used in the management of Parkinson’s disease ?

This interesting question was recently posed by a patient. While it may seem counter-intuitive, the short answer is, YES  !

But first, a little bit about Parkinson’s disease. The basic problem is a progressive loss of neurons in deep brain area. These neurons (mainly) produce the transmitter dopamine. The end result is an abnormally increased activity certain parts of the brain, which causes the characteristic motor problems. Other problems may include depression, memory and concentration problems, and behavioral problems. Another neglected facet of the disease is malfunction of the autonomic nervous system, termed dysautonomia.

The symptoms that are manageable with Botox include the following:
Drooling
Blepharospasm - spasm of the eyelid muscles causing a permanent wink ;-)
Constipation (due to spasm of the anal sphincter muscle)
Dystonic rigidity. This often troubles younger patients. Neck, hand and foot muscles go into spasm which is often painful. Classically, the foot goes into inversion with curling of the toes.

Drooling

While there are surgical operations to reduce drooling as well as certain medications, Botox is very effective and minimally invasive. Between 5 and 15 units (usually 10) is given into each parotid gland via 1-3 injection sites. Care should be taken to inject just within the gland capsule and not too deeply or paralysis of the muscle which help with chewing will be affected (unless of course these muscles are in spasm and the teeth grind inappropriately – termed bruxism). It is prudent to wait about a month and assess the result before giving more botox. Additionally, 5 units may be given into each submandibular gland. Good effects are noted for about 4-6 months.

Blepharospasm

The permanent wink is not cute. It may be very distressing and cause loss of visual field in the affected eye. Very small doses of botox, 1-2 units should be given just subdermally to affect the obicularis occuli muscle. It is very important to not overdo the Botox, since ectropion (drooping eyelid) may occur, especially in older patients.

Constipation

Partial paralysis of the anal sphincter is often achieved by multiple injections of more diluted Botox (100 units in 10ml). 20 to 60 units are used at the discretion of the physician (usually a gastroenterologist). Again, it is better to be more conservative than have incontinence.

Dystonic Rigidity

There are different types of rigidity and it is the patients with the “lead pipe” type (as opposed to the “cog-wheel” type) who benefit from Botox injections. The aim is to partially paralyse the affected muscles to relieve the spasm. Although the limb is weakened it is actually more functional, as the balance is improved. As it is critical to get this balance right, where smaller muscles are involved, EMG (electromyelogram) localization done in conjunction with a neurologist is often useful to pin-point the problematic muscles.

Other Uses

Some Parkinson’s patients are unable to swallow properly (termed dysphagia) and some have excessive sweating due to the dysautonomia (see above). As with constipation, diluted Botox is injected under direct visualization with a gastroscope into the pharyngeal constrictors. The use of Botox to control excessive sweating is well known, however this requires multiple sub-dermal injections and between 100 and 200 units are used depending on the area to be treated. About 50 units should control one armpit.

So, in conclusion, there are many surprising uses for Botox in Parkinson’s patient.

Best Regards

Marshall

How Does Botox Work ?

What is Botox ? How does it work ? Will it make me gorgeous ? These are some of the questions that I am regularly asked. Below are some answers to the first 2 questions, as for the last one, well....

Botox is the crystalline form of the type A exotoxin of the bacteria Clostidium botulinum. It is this toxin that is responsible for the previously fatal disease botulism. The word is derived from the latin word botulus, which means sausage - since a particlarly nasty outbreak occured in Stuttgart as a result of tainted sausages!

It is purified from the Hall strain of the bacteria and amazingly all Botox sold throughout the world since 1997 comes from the same batch (BCB2024). Botox is the most potent biological neurotoxin known (one gram could kill every occupant in a major city) and so incredibly small doses are used for medical purposes.

Botox is sold in vials of 50 or 100 units. More correctly, it is sold in "mouse units". One mouse unit is the amount of Botox required to kill at least 50% of a group of 18-22 gram mice when injected to their abdomens. This is bad news for mice with wrinkles, but luckily these results can be extrapolated to human weights so that about 3000 units would be a similarly fatal dose. All cosmetic doses are nowhere near that figure and Botox is thus quite safe.

Botox works by preventing the release of the neurotransmitter from the end of a nerve to the muscle it innervates. It effectively "gags" the nerve to prevent the message from getting through. This effect lasts for several months (depending on the type of nerve).

Botox only works works on nerves which use the transmitter substance acetyl-choline (ACh) such as the nerves which control muscles and sweat glands. It does not affect sensory nerves. Well, that is not true. There are receptors in the sensory nerve endings which are also affected by Botox, but their specific purpose is not known. Normal sensation remains intact. It may be that the ability of Botox to relieve chronic migraines is related to these receptors.

When used correctly, partial or complete paralysis of the target muscle occurs. In the face, this has two consequences. Firstly, there is a decline (or absence) of muscle activity. This causes the appearance of wrinkles to diminish. Secondly, the facial muscles do not work singularly - they work in coordinated groups (unlike politicians). Weakening one member results in altered vectors. This is often unappreciated by inexperienced practitioners and may result in some pretty weird looking facial features. Jack Nicholson was born that way, most other people got Botox to look like that!

When properly executed and maintained, very pleasing results (and thus very pleased patients) are the norm. So in answer to the last question...

Best Regards

Marshall