Sleep and Health... Connecting the Dot - Part 2

  

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Restless Leg Syndrome and Low Back Pain

In a previous article we discussed how our research uncovered a link between headache and sleep disorders and how sleep related breathing disorders, left untreated, led to a high incidence of cervical radiculopathy (pinched nerve in the neck) - and then to migraines in those predisposed to them.  
The analysis of our electronic medical records data, merged with our digitized sleep center database, showed that sleep disorders can lead to cervical radiculopathy.  However, when we began looking for an association between lumbar radiculopathy (pinched nerve in the back), we didn’t find sleep disorders as a major underlying cause.  However, we found a striking relationship between Restless Legs type movements (a sleep disorder) possibly being caused by back problems. 

Patients with Restless Leg Syndrome (RLS) and/or Periodic Limb Movement Disorder (PLMD) had a high incidence of lumbar radiculopathy.

Patients with lumbar radiculopathy (LR) tended to be awake more throughout their sleep study than those without LR and many had abnormal leg movements that corresponded with the side of their radiculopathy. 
The implications of this finding could be substantial to those suffering with RLS or PLMD who are commonly treated with powerful dopaminergic agents (like ropinerole or pramipexole), drugs used to treat symptoms of Parkinson’s disease and cerebral palsy.  These drugs may be heavily overused in patients with Restless Legs Syndrome secondary to other causes, like problems with the nerves going from the back into the legs.

Lumbar Radiculopathy and Low Back Pain

Low back pain is the second most common symptom-related reason for seeing a physician in the United States, affecting up to 85% of adults at some point during their lifetime.  There are many causes of low back pain and most resolve with rest and time.  As neurologists, patients come see us when they have symptoms like one-sided numbness and tingling in the leg, foot or toes.  With these symptoms we suspect a radiculopathy.

Webster’s Online defines radiculopathy as: irritation of or injury  to a nerve root (as from being compressed) that typically causes pain, numbness, or weakness in the part of the body which is supplied with nerves from that root.

With this type of patient the questions we try to answer are:
1. Exactly where is a nerve being affected?
2. How severe is it?
3. What likely led to this?
4. What is the best option to fix it?

MRI is ideally suited for determining exactly where the nerve root(s) are being irritated.  For instance a herniated disc between the 4th and 5th lumbar vertebrae would show up beautifully on MRI films.  The next thing we would like to know is how bad is it?  The MRI is very specific to pointing out where the problem is but it does not give us great information about how bad it is affecting the nerve, or in ruling out other causes of nerve involvement.  Electromyogram (EMG) is a more sensitive study, though it is less anatomically specific, to show severe the damage is to these nerves that branch away from the spinal cord.  Now the pieces of the puzzle start coming together to help answer questions number three and four from above.

Besides having board certifications in both neuroimaging and Electrodiagnostic Medicine, I am also board certified in sleep medicine.  These qualifications are unique among neurologists in this region and it is why we are the first ones to discover this relationship between lumbar radiculopathy and RLS/PLMD.

The solution to low back pain is never an easy process but with an exact diagnosis and all the information in front of us we can begin to make a treatment plan based upon solid information.  Physical therapy is often a good place to start, once you know what you are treating.  Physical therapy is a broad discipline covering nearly as many aspects as there are specialty physicians.  That is why MidAmerica Neuroscience Institute has a P.T. practice with three DPT’s that are highly skilled and passionate about working with neurologically impaired patients.  We see many folks starting to get better after just a few sessions of physical therapy, when months or years of chiropractic only alleviated their symptoms temporarily.  Similarly, we have found other PT programs don’t always arm patients with the knowledge they need to continue keeping themselves out of trouble for the rest of their lives.

Most patients with lumbar radiculopathy could benefit by losing excess weight.  This is a societal problem affecting more than just those with low back pain.  Ironically, if back problems are causing sleep problems, as our research shows, these patients are facing an uphill battle.  More and more scientific research is connecting poor sleep quality with the body’s inability to regulate insulin, and this inevitably leads to obesity.  It can be a vicious cycle that will only be remedied with a multidisciplinary approach that accounts for all of these factors.   Stay tuned to this blog for more on the impact of poor sleep quality.

This series originates from a Grand Rounds presentation to Neurology and Neurosurgery residents and staff at the University of Kansas Medical Center. Adjunct Professer, Vernon Rowe, MD, presented his research and experiences as a neurologist and sleep medicine physician, to impress upon those in attendance, the underappreciated connection that sleep disorders have on many common neurological and neurosurgical diseases.