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