Multiple
sclerosis (MS) is
a complex disease that is thought to arise when the immune system
malfunctions and attacks the nervous system. Estimates suggest that
around 200 people are in the U.S. are diagnosed with the condition each
week, with women affected twice as often as men.
People with
MS
experience symptoms that can range in severity and duration. One of the
most common symptoms of MS is
spasticity,
which causes painful, uncontrollable muscle spasms. Spasticity can
affect any part of the body, but it occurs most often in the legs. Other
symptoms of MS include clumsiness, vision problems, tingling or numbness
in the limbs, weak muscles and bladder control problems. Often, people
with MS have periods when they experience symptoms, called attacks,
followed by periods without symptoms, called remission.
Conventional Therapies Cause Adverse Effects
There is no known cure for MS, but a combination of treatments can help
manage the disease. Treatment of MS has two aspects: immunomodulatory
therapy (IMT), which reduces the frequency of attacks and slows the
progression of the disease, and therapies to relieve symptoms.
Conventional treatments for MS often put patients at risk for a variety
of side effects, including drowsiness, dizziness, weakness, nausea and
diarrhea. Thus, the need for new treatments that relieve the symptoms of
the disease with fewer side effects is clear.
Cannabis Offers Effective Relief From MS Symptoms
Numerous studies have revealed the benefits of medicinal cannabis, or
marijuana, for alleviating multiple MS symptoms. In 2003, Zajicek et
al. conducted one of the
largest studies investigating the effect of medicinal cannabis on
patients with the disease. The results revealed self-reported
improvements in pain, spasms, spasticity and sleep quality in
participants who used whole-plant cannabis-based medicine (CBM) extracts
or tetrahydrocannabinol (THC). A study by Collin et
al. in 2007 supported the
findings of Zajicek et al. In a trial of CBM for the treatment of
spasticity caused by MS, researchers found that participants who used
CBM recorded significantly improved scores on the Numerical Rating
Scale, an 11-point scale for self-reporting of spasticity. Additionally,
research by
Corey-Bloom
of the University of California, San Diego revealed a significant
reduction in spasticity in participants who were already on medication
for MS and who smoked cannabis once daily for three days during the
trial.
Multiple studies have also shown the efficacy of medicinal cannabis in
treating neuropathic
pain,
the most
common
type of pain experienced by people with MS. A
study conducted
by researchers at the University of California, Davis between 2009 and
2011 revealed that vaporized cannabis significantly reduced neuropathic
pain in people with MS, without affecting mood. The majority of the
participants in the study were experiencing neuropathic pain despite
traditional therapy. Research by Wade et
al. in 2013 produced
similar findings to those of the University of California study. In a
study of 24 patients with neurogenic symptoms unresponsive to standard
treatments, Wade et al. found that whole-plant cannabis extracts
provided significantly superior pain relief compared with placebo.
Additionally, the results of research by Wilsey et
al. in 2008 and Ware et
al. in 2010
contribute to mounting evidence that cannabis may be effective at
relieving neuropathic pain and may be an alternative for people who do
not respond to, or cannot tolerate, conventional therapies.
Medicinal Cannabis as Treatment of MS, Not Just the Symptoms
A review by Pertwee et
al.
in 2007 found evidence to suggest that medicinal cannabis may be useful
beyond symptom control in people with MS. The chemicals, or
cannabinoids, in medicinal cannabis are structurally similar to
endogenous
cannabinoids,
which are naturally occurring chemicals that help to regulate nerve
impulse transmission. Because of this similarity, it is hypothesized
that they can attach themselves to molecules called CB2 cannabinoid
receptors on immune cells within the nervous system and activate them,
decreasing inflammation and suppressing some of the changes that give
rise to the progression of MS. Research by Ben-Shabat et
al.
in 1998 revealed that cannabinoids may work more effectively in
combination than alone: an observation termed the entourage
effect.
Thus, whole-plant CBM may relieve the symptoms of MS better than a
medicine containing only one or two cannabinoids.
Evidence for Cannabis’s Safety and Efficacy Grows
Given its high efficacy and low risk of adverse effects, whole-plant CBM
may be an effective add-on treatment for people with MS; however,
federal law still classifies cannabis as a Schedule I drug with no
medicinal benefit. As a result, many people with MS are being denied
access to a potentially life-changing therapy. Proponents of medicinal
cannabis are campaigning for a change to federal law so that the
thousands of Americans who live with MS can have safe, legal access to
medical marijuana under a physician’s guidance. Many high-profile
national and international health organizations, including the Montel
Williams MS Foundation and the American Academy of Family Physicians,
support the outright legalization of medicinal cannabis. Legalization
would enable people with MS to use cannabis to manage their symptoms
more effectively and perhaps even delay progression of the disease,
without fearing the potential legal repercussions.
