Restless legs syndrome in subjects with a knee prosthesis: evidence that symptoms are generated in the periphery

Abstract

OBJECTIVE:There are no data adressing the prevalence of restless legs syndrome in subjects who have knee prosthesis. Therefore, we conducted a cross-sectional survey of subjects who underwent knee prosthesis surgery.METHOD:A total of 107 subjects (30 male, 77 female) were interviewed over the telephone regarding restless legs syndrome symptoms. If the patients exhibited symptoms of the syndrome, we conducted face-to-face interviews. Lastly, a therapeutic test with pramipexole was proposed for each subject.RESULTS:In our cohort, 7 males (23%) and 30 females (39%) had restless legs syndrome. Of these, 6 males and 23 females were submitted to face-to-face-interview. Of the males, 5 (83%) had restless legs after the knee surgery- exclusively in the operated leg- and reported no family restless legs history. One man had a prior case of bilateral restless legs syndrome, a positive family history and claimed exacerbation of symptoms in the operated leg. Among the females, 16 (69%) had restless legs prior to surgery. A total of 10 female patients reported bilateral symptoms, with fewer symptoms in the operated leg, while 6 displayed a worse outcome in the operated leg. The 7 females (31%) without restless legs prior to surgery and without a family history experienced symptoms only in the operated leg. All subjects responded favorably to the pramipexole therapeutic test.CONCLUSION:Our results suggest that secondary unilateral restless legs syndrome may ensue from knee prosthesis surgery and that the symptoms are generated in the peripheral nervous system.

Restless Legs Syndrome, and symptoms of Restless Syndrome in patients with Graves' disease: a cross-sectional survey

“…Among the hypofunctioning dopaminergic systems that could contribute to RLS, the tuberoinfundibular pathway and the diencephalon spinal dopaminergic system are the most promising (4,(9)(10)(11)(12). In the tuberoinfundibular pathway, one of the four major dopaminergic systems in the brain, dopamine is secreted as a neurohormone in the pituitary stalk.…”

“…DA inhibits the secretion of TSH by the pituitary, consequently diminishing TSHinduced actions on the thyroid gland, thereby decreasing thyroid hormone (TH) release. Thus, the excitability of the peripheral somatosensory system also decreases (10,(16)(17)(18)(19)(20)(21)(22).…”

“…These two pharmacological facts suggested that an increase in the activity of the thyroid axis might be involved in the genesis of RLS symptoms. Besides, numerous reports indicated the peripheral nervous system as the neuroanatomical site wherein RLS symptoms are initiated (10,(25)(26)(27).…”

Saint John's wort, an herbal inducer of the cytochrome P4503A4 isoform, may alleviate symptoms of Willis-Ekbom's disease

“…Phantom WED in patients with leg amputation and in WED patients secondary to total knee arthroplasty are examples of the importance of low-threshold sensitivity to stimulation of the peripheral sensory receptors (30-32). On their way to the cortex, the sensory axons synapse in various relay nuclei, in which electrochemical signals are regulated by a number of interspersed neurons (18,23).…”

Are symptoms of restless legs syndrome generated in the periphery of the nervous system or are they born centrally?

“…[5] However, many insights derived from clinical observations of RLS also influence us to assume that RLS symptoms are generated in the periphery: 1) In amputees, frequently, symptoms are ‘phantom’, that is, felt as if generated from the leg that is missing, 2) if RLS patients move or stretch their legs they experience some relief (seems logical because if the symptoms were central, therestlessness would not cease with movement), 3) massagingthe affected limb or applying cold pads lead frequently to ameliorationof symptoms (very little probability that such commonplacenonpharmacologicalmeasures would alleviate the symptoms if they were generated centrally), and 4) in some subjects submitted to total knee arthroplasty, RLS may ensue only after the surgery and only in the knee articulation with the prosthesis device. [67] Also, the mechanisms underpinning RLS pathophysiology are considered unknown; however, recently we theorized that the RLS symptoms are secondary to an imbalance between two forces, the hypothalamus-pituitary-thyroid axis and the dopaminergic system,[8] a hypothesis based on sufficient circumstantial evidence.…”