Case report
Association between restless legs syndrome and Chiari type 1 malformation

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Abstract

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.

Introduction

Chiari malformations are characterized by the displacement of the tonsils and posterior vermis of the cerebellum through the foramen magnum and the resultant compression of the spinomedullary junction. Chiari malformations are classified by type to reflect the degree of displacement as well as the varying etiology of the malformation. The least complicated form is termed a Chiari type 1 malformation (CM-1) [1].

The cause of restless legs syndrome (RLS) is unknown. RLS may be idiopathic or secondary. Idiopathic RLS appears to run in families, suggesting a genetic basis for the syndrome. Separate chromosomal loci have been linked to the disease in longitudinal family genetic studies [2]. A strong family history of RLS is more closely correlated with a younger age at onset [2], [3].

Secondary RLS may be associated with various diseases. Iron deficiency with and without anemia, uremia, pregnancy, rheumatoid arthritis, peripheral neuropathy, radiculopathy, myelopathies, spinal cord compression, multiple sclerosis, Parkinsons disease, spinocereballar ataxia, drugs, caffeine, and alcohol have all been associated with RLS [3], [4]. However, a possible relationship between Chiari malformations and RLS has not been reported in the literature, but a few studies have suggested a possible role for the upper brainstem, diencephalon, red nucleus, and cerebellum in the pathogenesis of RLS [5].

In the present study, we discuss five cases of RLS that had early onsets and poor responses to therapies, and were also considered to be possibly related to CM-1.

Section snippets

Case report

We are following five RLS patients at our neurology outpatient clinic who have also been diagnosed with CM-1. The patients fulfilled the diagnostic criteria for RLS according to the International Restless Legs Syndrome Study Group [6]. Four of these patients are female, and one is male. They range in age from 20 to 31 years old. The duration of RLS in these patients was from 2 to 12 years. None of the patients had a family history of RLS or any other condition that is known to be related to

Conclusions

The RLS symptoms in our cases all began prior to the age of 20. RLS prevalence increases with age. Walters et al. reported that the first symptoms appear in 45% of patients before the age of 20 [7]. Montplaisir et al. reported that the average age of symptom onset is 27, but that symptoms appear in 13% of RLS patients before the age of 10 [8].

The intriguing characteristics of the present cases were that the patients had poor responses to RLS treatments and CM-1 was present in all subjects.

The

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