Abstract.
Objectives
Neurophysiological studies have shown an impairment of temperature perception in secondary and idiopathic restless legs syndrome (RLS). It is unclear whether these deficits are caused by peripheral nerve fibre damage or by central impairment of somatosensory processing. The aim of the present study was (1) to determine the frequency of thermal hypaesthesia in a large population of secondary and idiopathic RLS patients; (2) to differentiate between a peripheral and central disturbance of somatosensory processing and (3) to correlate these findings with the clinical manifestation of the disease.
Methods
From the results of clinical examination, nerve conduction studies and blood samples the patients were divided into secondary and idiopathic RLS groups. The severity of RLS symptoms was assessed by standardized questionnaires. Quantitative sensory testing (QST) assessing temperature perception was performed in all patients. The peripheral function of small nerve fibres was evaluated by the quantitative nociceptor axon reflex test (QNART).
Results
22 secondary and 20 idiopathic RLS patients participated in the study. Impairment of temperature perception (QST) was found in 72% of the secondary RLS patients and in 55% of idiopathic RLS patients. The peripheral C–fibre function (QNART) was normal in idiopathic RLS patients. In contrast it was significantly impaired in secondary RLS patients compared with idiopathic RLS patients and age matched controls. There was no correlation between the results obtained in QST and clinical scores.
Conclusion
Impairment of temperature perception is present in a high percentage of RLS patients. In secondary RLS the sensory deficits are at least in part caused by small fibre neuropathy. In idiopathic RLS a functional impairment of central somatosensory processing is present.
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References
Baron R, Saguer M (1993) Postherpetic neuralgia. Are C-nociceptors involved in signalling and maintenance of tactile allodynia? Brain 116:1477–1496
Bliwise DL, Ingham RH, Date ES, Dement WC (1989) Nerve conduction and creatinine clearance in aged subjects with periodic movements in sleep. J Gerontol 44(5):164–167
Bucher SF, Trenkwalder C, Oertel WH (1996) Reflex studies and MRI in the restless legs syndrome. Acta Neurol Scand 94(2):145–150
Bucher SF, Seelos KC, Oertel WH, Reiser M, Trenkwalder C (1997) Cerebral generators involved in the pathogenesis of the restless legs syndrome. Ann Neurol 41(5):639–645
Claus D, Mustafa C, Vogel W, Herz M, Neundorfer B (1993) Assessment of diabetic neuropathy: definition of norm and discrimination of abnormal nerve function. Muscle Nerve 16(7):757–768
Craig AD (1998) A new version of the thalamic disinhibition hypothesis of central pain. Pain Forum 7:1–14 982
Earley CJ, Yaffee JB, Allen RP (1998) Randomized, double-blind, placebocontrolled trial of pergolide in restless legs syndrome. Neurology 51(6):1599–1602
Ekbom KA (1945) Restless Legs Syndrome. Acta Med Scand 156:4–122
Fruhstorfer H, Lindblom U, Schmidt WC (1976) Method for quantitative estimation of thermal thresholds in patients. J Neurol Neurosurg Psychiatry 39(11):1071–1075
Herrmann DN, Griffin JW, Hauer P, Cornblath DR, McArthur JC (1999) Epidermal nerve fiber density and sural nerve morphometry in peripheral neuropathies. Neurology 53(8):1634–1640
Iadarola MJ, Berman KF, Byas-Smith M, Gracely RH, Max M, Seffirio T, et al. (1993) Positron emission tomography (PET) studies of pain and allodynia in normals and patients with chronic neuropathic pain. Soc Neurosci Abstr 19:1074
Iannaccone S, Zucconi M, Marchettini P, Ferini-Strambi L, Nemni R, Quattrini A, et al. (1995) Evidence of peripheral axonal neuropathy in primary restless legs syndrome. Mov Disord 10(1):2–9
Jaaskelainen SK, Rinne JO, Forssell H, Tenovuo O,Kaasinen V, Sonninen P, et al. (2001) Role of the dopaminergic system in chronic pain – a fluorodopa-PET study. Pain 90:257–260
Kennedy WR, Wendelschafer-Crabb G (1999) Utility of the skin biopsy method in studies of diabetic neuropathy. Electroencephalogr Clin Neurophysiol 50(Suppl):553–559
Mosko SS, Nudleman KL (1986) Somatosensory and brainstem auditory evoked responses in sleep-related periodic leg movements. Sleep 9(3):399–404
Navarro X, Kennedy WR (1991) Evaluation of thermal and pain sensitivity in type I diabetic patients. J Neurol Neurosurg Psychiatry 54(1):60–64
Navarro X, Kennedy WR, Fries TJ (1989) Small nerve fiber dysfunction in diabetic neuropathy. Muscle Nerve 12(6):498–507
Ondo W (1999) Ropinirole for restless legs syndrome. Mov Disord 14(1):138–140
Ondo W, Jankovic J (1996) Restless legs syndrome: clinicoetiologic correlates. Neurology 47(6):1435–1441
Polydefkis M, Allen RP, Hauer P, Earley CJ, Griffin JW, McArthur JC (2000) Subclinical sensory neuropathy in lateonset restless legs syndrome. Neurology 55(8):1115–1121
Rutkove SB, Matheson JK, Logigian EL (1996) Restless legs syndrome in patients with polyneuropathy. Muscle Nerve 19(5):670–672
Salvi F, Montagna P, Plasmati R, Rubboli G, Cirignotta F, Veilleux M, et al. (1990) Restless legs syndrome and nocturnal myoclonus: initial clinical manifestation of familial amyloid polyneuropathy. J Neurol Neurosurg Psychiatry 53(6):522–525
Schüller TB, Hermann K, Baron R (2000) Quantitative assessment and correlation of sympathetic, parasympathetic, and afferent small fiber function in peripheral neuropathy. J Neurol 247(4):267–272
Smith RC, Gouin PR, Minkley P, Lyles J, Van Egeren L, Adams T, et al. (1992) Periodic limb movement disorder is associated with normal motor conduction latencies when studied by central magnetic stimulation–successful use of a new technique. Sleep 15(4):312–318
Tergau F, Wischer S, Paulus W (1999) Motor system excitability in patients with restless legs syndrome. Neurology 52(5):1060–1063
Trenkwalder C (1997) Restless Legs Syndrom. Springer, Berlin Heidelberg New York
Trenkwalder C, Wetter TC, Stiasny K, Clarenbach P (2001) [Restless legs syndrome and periodic limb movements in sleep]. Nervenarzt 72(6):425–436
Turjanski N, Lees AJ, Brooks DJ (1999) Striatal dopaminergic function in restless legs syndrome: 18F-dopa and 11Craclopride PET studies. Neurology 52(5):932–937
Verdugo R, Ochoa JL (1992) Quantitative somatosensory thermotest.A key method for functional evaluation of small calibre afferent channels. Brain 115(Pt 3):893–913
Walters AS (1995) Toward a better definition of the restless legs syndrome. The International Restless Legs Syndrome Study Group. Mov Disord 10(5):634–642
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Schattschneider, J., Bode, A., Wasner, G. et al. Idiopathic restless legs syndrome:. J Neurol 251, 977–982 (2004). https://doi.org/10.1007/s00415-004-0475-3
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DOI: https://doi.org/10.1007/s00415-004-0475-3