Association between restless legs syndrome and Chiari type 1 malformation.

Chiari type 1 malformations (CM-1) consist of the downward displacement of the cerebellar tonsils out of the inferior opening of the skull and into the spinal canal. In relation to this, a few studies in the literature have drawn attention to the possible role of the upper brainstem, diencephalon, red nucleus, and cerebellum in the pathogenesis of restless legs syndrome (RLS). Herein, we present five cases of RLS who were also found to have CM-1 malformations. The cases were notable for an early onset of RLS and a poor response to dopaminergic treatment. The patients fulfilled the diagnostic criteria for RLS according to the International RLS Study Group. None of the patients had a family history of RLS or any other condition known to be associated to RLS. The patients ranged in age from 20 to 31 years old. Four of the patients indicated occasional pain in the occipital-suboccipital area upon questioning about CM-1-related symptoms. All cases had used at least two different drugs known to be effective in RLS treatment. Our opinion is that CM-1-related involvement of the cerebellum and/or connections of the cerebellum with the basal ganglia may have contributed to the development of RLS in these cases.