Restless legs syndrome (RLS): An unrecognized cause for bedtime problems and insomnia in children
Article Outline
To the Editor:
There have been few detailed reports about children with restless legs syndrome (RLS) [1], [2]. We describe five pediatric RLS patients with emphasis on the diagnostic and treatment processes. Each patient came to us upon their parents having complained about their bedtime problems.
Case 1: A six-year-old boy came to our clinic because he was hyperactive at his bedtime. His parents had a difficult time every night, trying to get him to sleep for two hours since the time he was 10 months old. A home video showed that he touched and gripped his legs around his bedtime (supplementary video). Once he became spontaneously aroused in the middle of the night, he moved his legs and feet continually.
Case 2: A six-year-old girl was brought to our clinic because it had been taking her one hour before initiating sleep at night for the past three months. She had frequent tonsillitis, and she complained that someone touched her legs, causing discomfort exclusively at bedtime.
Case 3: A four-year-old boy presented with irritability at bedtime and difficulty initiating sleep. He was not able to keep still and displayed a bad mood in bed.
Case 4: A four-year-old girl was referred to our clinic because her mother found it difficult to get her to sleep. She tossed and turned in bed, asking her mother to rub her legs to relieve the uncomfortable feeling in them. The patient was also restless in the consultation room at our clinic, but her mother said that it was much worse at night.
Case 5: A two-year-old girl came to our clinic because her mother had noticed snoring and occasional cessation of breathing. In addition, she had been irritable and restless around her bedtime since the age of 10 months, and her mother was at a loss for how to soothe her. It seemed to her mother as if her character changed at night. Polysomnogram demonstrated moderate obstructive sleep apnea (apnea-hypopnea index
=5.5/h).
Laboratory data and treatment along with clinical features of the five described cases are summarized in Table 1.
Table 1. Clinical features and treatment of the patients
| Case 1 | Case 2 | Case 3 | Case 4 | Case 5 | |
|---|---|---|---|---|---|
| Age at onset | 10 months | 6 years | 2 years | 3 years | 10 months |
| Age at diagnosis | 4 years | 6 years | 4 years | 4 years | 2 years |
| Patients’ own words describing the uncomfortable feelings | Creepy-crawly | Someone is touching my legs | A caterpillar is creeping in the legs | Monya-monya∗1 | Muzu-muzu∗1 |
| Difficulty initiating sleep | + | + | + | + | + |
| Family history | Mother, grand mother, mother’s cousin | − | Mother | (Possibly brother)∗2 | Mother |
| Hemoglobin (g/dl) | 11.9 | 11.8 | 14 | 13.4 | 9.4 |
| Fe (ng/ml) | 132 | 105 | 101 | 183 | 12 |
| Ferritin (mg/dl) before/after oral iron supplementation | 9/30 | 35/131 | 21/NA | 14/23 | 9/37 |
| PLMS Index∗3 | 0 | N/A | N/A | N/A | 6.9 |
| Iron supplementation | No effect | Effective | Effective | Effective | No effect |
| Pramipexole | Effective | N/A | N/A | N/A | Effective |
| Observation period | 3 years 1 month | 8 months | 5 months | 12 months | 9 months |
All of the parents of our patients had a difficult time getting their children to sleep due to irritability, restlessness, and demanding bedtime routines. All patients asked their parents to rub their feet in bed, and it took more than half an hour to soothe them until they fell asleep. Their mother had been exhausted from this nighttime routine.
Cases 1 and 5 were not yet articulate enough to describe their symptoms at their first visit to our clinic, which caused some difficulty using the present diagnostic criteria [3]. Therefore, it is important to consider the possibility of RLS in cases of children whose parents have unusual difficulty getting them to sleep.
As some parents were too distressed or embarrassed to describe the symptoms of their child properly, video-recording of their behaviors at home was very helpful.
In all patients, ferritin concentration was low, and iron was effective in three cases. Higher iron demand in children than adults and accelerated iron metabolism caused by repeated inflammation [4] may be one of the factors predisposing a certain group of individuals to transient RLS.
In the two most severe patients (Cases 1 and 5), ferritin concentration was lowest, and iron was not effective. Instead pramipexole dramatically relieved symptoms [5]. Both patients started to show RLS symptoms in very early days of their lives, which may suggest in them more severe hereditary dopamine hypometabolism.
In summary, children with RLS may present with bedtime problems to pediatricians, and RLS should be considered as a possible differential diagnosis.
Appendix A. Supplementary data
Segment 1: Case 1 at age 4. He was continually touching and grasping the right foot while playing cards before bedtime. Segment 2: Case 1 at age 4. He was vigorously rolling over on the futon mattress and continuously waving his feet.
References
- Restless legs syndrome in childhood and adolescence. Pediatr Neurol. 1994;11:241–245
- . Autosomal dominant restless legs syndrome in a young girl with symptom onset at 12 months. Sleep Res. 1996;25:391
- Restless legs syndrome: diagnostic criteria, special considerations, and epidemiology. A report from the restless legs syndrome diagnosis and epidemiology workshop at the National Institutes of Health. Sleep Med. 2003;4:101–119
- . Iron, infections, and anemia of inflammation. Clin Infect Dis. 1997;25:888–895
- Efficacy of pramipexole in restless legs syndrome: a six-week, multicenter, randomized, double-blind study (effect-RLS study). Mov Disord. 2007;22:213–219
PII: S1389-9457(07)00308-5
doi:10.1016/j.sleep.2007.08.005
© 2007 Elsevier B.V. All rights reserved.
