March 2007, Volume 57, Issue 3

Letter to the Editor

Restless legs syndrome: common but frequently unrecognized disorder in pregnancy

Madam, I would like to direct the attention of medical community about the eminence of 'Rest Legs Syndrome (RLS) in Pregnancy' by using the platform of this prestigious medical journal.

The prevalence of RLS in the general population ranges from 10 to 15%,1 however, pregnant women have at least two or three times a higher risk of experiencing RLS than the general population.2 Epidemiological data shows 26% prevalence of RLS during pregnancy,3 although it is nevertheless frequently unrecognized and undiagnosed.

RLS is a sensory-motor disorder2 characterized by unpleasant sensation in the limbs, usually the legs (between ankle and knees) but may also affect thighs and feet. Patients describe the sensations of unpleasant feeling as expressing "creepy, crawly, tingling, bubbly" and like "bugs tunneling" and desire to move the legs to relieve the sensation. RLS's symptoms are usually bilateral and symptoms typically occur when the patient is at rest; severity increase at bedtime while symptoms are relieved temporarily by moving, stretching and shaking the limbs. The majority of the patients with RLS complain of difficulty in falling asleep.

Primary cause of RLS is unknown. However, some evidences suggest that the syndrome may be caused due to the imbalance of certain neurotransmitters. Reduced ferritin and elevated transferrin levels in the cerebrospinal fluid and in the substantia nigra have been noted.4 Factors that found to worsen this condition are iron deficiency (with/without anaemia), stress, diabetes, hypertension, obesity and prolonged exposure to cold.

The association between RLS and pregnancy is unknown. The most debated hypotheses are: metabolic alteration, with particular regard to iron and folate deficiency; hormonal influences related to the increase of prolactin; progesterone and estrogens during late pregnancy; and psychological state of pregnant women.2 RLS symptoms have a poor impact on sleep during pregnancy, with affected women reporting a reduced total sleep time, longer sleep latency, frequent insomnia, nocturnal waking and excessive daytime sleepiness with the highest degree of severity in the third trimester.1

Diagnosis of RLS is usually clinical,5 hence is simple and cheap. However, it is essential to rule out other possible organic disease which may have the same presentation. In this regard, patients need to have some investigations like complete blood picture, serum iron, serum ferritin, folate, cobalamin and creatinine levels. Fasting blood sugar and thyroid function tests are also advisable.

Treatment of RLS is conservative, mainly during pregnancy with counseling and psychotherapy (reassurance, relaxation, sleep hygiene, regular gentle exercise and massage therapy). Avoidance of associated and aggravating factors/ drugs; schedule bedtime and wake-time and proper nutrition is advisable. Simple over-the-counter medicines like paracetamol and nutrient supplements like iron, folic acid, vitamins and minerals should be tried before prescribing second-line drugs in pregnancy.

Alia Nasir1, Ali Khan Khuwaja2
Institute of Nursing, Dow University of Health Sciences1, Karachi, Departments of Family Medicine and Community Health Sciences2, Aga Khan University, Karachi.

References

1. Zucconi M, Ferini-Strambi L. Epidemiology and clinical findings of restless syndrome. Sleep Med 2004; 5: 293 - 9.

2. Manconi M, Govani V, De Vito A, Economou NT, Cesnik E, Mollica G, et al. Pregnancy as a risk factor for rest legs syndrome. Sleep Med 2004; 5: 305 - 8.

3. Manconi M, Govoni V, De Vito A, Economou NT, Cesnik E, Casetta I, et al. Rest legs syndrome and pregnancy. Neurology 2004; 63: 1065 - 9.

4. Earley CJ, Connor JR, Beard JL, Malecki EA, Epstein DK, Allen RP. Abnormalities in CSF concentration of ferritin and transferring in restless legs syndrome. Neurology 2000; 54: 1698 - 700.

5. Garcia-Borreguero D, Odin P, Schwarz C. Restless legs syndrome: an overview of the current understanding and management. Acta Neurol Scand 2004;109: 303 - 17.

Journal of the Pakistan Medical Association has agreed to receive and publish manuscripts in accordance with the principles of the following committees: