Neurological disorders: bad to the bone.

It can be tempting to think of the brain, nervous system and the practice of neurology in general as existing in their own discrete compartment, separate from the rest of the body and from other facets of medicine. After all, there is a blood-brain barrier and a blood-nerve barrier and I can’t think of any other organ system that has such a well-developed system of insulation. Neurologists also like to separate themselves from the masses and this is readily achieved by throwing around names of anatomical structures that no one has ever heard about. The clinical reality however is quite different. We know that systemic diseases, such as diabetes, kidney failure and vascular disease all have the propensity to affect the nervous system but there is now increasing evidence that neurological illness can have significant impact on other organs, especially bone. Neurologists therefore need to now, more than ever, look at the patient as a whole.

There is significant evidence that epilepsy and multiple sclerosis are associated with osteoporosis and the current issue of JNNP has an interesting meta-analysis that explores the association of Parkinson’s Disease (PD) and osteoporosis http://jnnp.bmj.com/content/85/10/1159.abstract . The authors put forward a number of potential explanations, including vitamin D deficiency and also address the possible deleterious effects of levodopa, the most effective treatment for PD. Could it be that patients who are taking levodopa are more mobile and therefore at a greater risk of falls?

This review is timely, given that bone health is critical in elderly patients, particularly given the potentially fatal consequence of fractures in that group. These days we routinely assess patients taking anti-epileptic medications for changes in bone health. Should we be doing the same for our PD patients?