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Something else I came across tonight...If it was posted before, my apologies.
Judith

http://pharminfo.com/pubs/msb/pd_foot.html

Parkinson's Disease: Treating Foot Cramps

Aching and cramping of the feet are common complaints, often occurring after
injury (strains and sprains) or excessive exercise, or in association with
arthritis or poor circulation in the legs. In Parkinson's disease (PD),
cramping of the feet is also very common, but the cause is central rather
than peripheral. Foot cramping is just one of several focal dystonias --
abnormal, sustained tightening of muscles -- that appear to be due to
neurochemical abnormalities in the basal ganglia, that part of the brain
involved in PD. Patients show a particular type of cramping characterized by
downward clenching of the toes or inward turning of the foot. Cramping can
occur throughout the day or night, and can be especially annoying when it
interferes with sleep. Foot cramping is more common among those individuals
whose PD affects just one side of the body.
Dystonias are often mistaken for other causes of cramping or painful muscles.
Some individuals with orthopedic foot problems, such as -hammer toes,- are
actually suffering from Parkinsonian dystonia. Patients with dystonias may
be entirely unaware of any Parkinsonism; indeed, muscle cramping can precede
the onset of Parkinsonian symptoms by years. There are no laboratory tests
that distinguish dystonia from other causes of cramping, although a thorough
neurologic examination and specialized tests should pinpoint the cause. Some
dystonic features -- such as blepharospasm (involuntary closing of the
eyelids) or torticollis (involuntary turning of the neck) -- are common in
the general population.
In the PD patient receiving levodopa/carbidopa (Sinemet), focal dystonias
may be caused by either too much of the drug or too little. Patients may
experience dystonia when peak drug levels are attained 1 to 2 hours after
administration, or hours later when drug effects wear off. Changing the dose
or dosage schedule of Sinemet, or using the sustained-release product
(Sinemet CR) may help. The monoamine-oxidase B inhibitor selegiline
(Eldepryl) may also help. A bedtime dose of Sinemet CR, pergolide (Permax),
or bromocriptine (Parlodel) may prevent foot dystonia during early-morning
hours. Some patients respond to anticholinergics such as
trihexyphenidyl (Artane), muscle relaxants such as cyclobenzaprine
(Flexeril) and baclofen (Lioresal), and the anticonvulsant clonazepam
(Klonopin). Another treatment giving excellent relief is botulinum toxin
(Botox). Injected into the dystonic or cramping muscle, botulinum toxin
reduces the intensity of the spasms; the effects may last
months after injection. The toxin is also used for Parkinsonian tremors,
benign essential tremor, and a number of dystonias not always associated
with PD. These include blepharospasm, torticollis, dysphonia (cramping of
the vocal cords), strabismus (wandering eye), stuttering, and large-muscle
spasms associated with conditions such as stroke, head trauma, and multiple
sclerosis.
A careful evaluation of the temporal relationship between foot cramping and
the levodopa dosage schedule should help the physician decide how best to
treat this uncomfortable manifestation of PD. Modifying the levodopa regimen
or adding other anti-PD agents can alter signals from the brain that trigger
the contractions, or the muscle itself can be "paralyzed" with botulinum toxin.