Cutaneous sensibility assesment in hemodialysis- related carpal tunnel syndrome

Original Article CUTANEOUS SENSIBILITY ASSESSMENT IN HEMODIALYSISRELATED CARPAL TUNNEL SYNDROME Hugo Alberto Nakamoto, Paulo Tuma Junior, Dimas André Milcheski, Marcus Castro Ferreira Abstract Objective: The aim of this study is to describe the use of the PSSD (Pressure specified sensory Device) for the diagnosis of carpal tunnel syndrome. Methods: The PSSD is a tool that incorporates a pressure transducer with two prongs, linked to a computer capable of measuring the cutaneous pressure thresholds. The patients were divided in two groups: Group 1- patients neither with superior limb neuropathy nor renal insufficiency. Group 2- patients with carpal tunnel syndrome related to hemodialysis. Group 2 - patients with carpal tunnel syndrome but no renal insufficiency. Results: The results showed, for two of the four parameters measured, that the group 2 had more benefits for the diagnosis of carpal tunnel syndrome than group 3. Conclusion: The PSSD is useful as a diagnostic tool in hemodialysis-related carpal tunnel syndrome Level of Evidence: Level II, development of diagnostic. Keywords: Carpal tunnel syndrome/diagnosis. Renal dialysis. Nerve compression syndromes Citation: Nakamoto HA, Tuma Junior P, Milcheski DA, Ferreira MC. Cutaneous sensibility assesment in hemodialysis- related carpal tunnel syndrome. Acta Ortop Bras. [online]. 2011;19(5):268-72. Available from URL: http://www.scielo.br/aob. IntroduCTION Carpal tunnel syndrome is the most common compressive neuropathy of the upper limb. It is usually related to compression of the median nerve in the carpal tunnel due to a variety of factors,1 including amyloidosis related to hemodialysis.2,3 About 5% of patients with chronic renal failure submitted to hemodialysis present carpal tunnel syndrome.3 There is controversy regarding the most reliable test for the diagnosis of this condition, whereas most specialists agree that there is no gold standard. In this scenario, clinical history and physical examination continue to be the most suitable tools.1,4-6 Electrodiagnostic tests remain the most common way to objectively find evidence of disease. However, about 10 to 15% of patients with normal electrodiagnostic studies present clinical evidence of the syndrome as well as relief of symptoms with surgical release of the carpal tunnel.1,4 Quantitative cutaneous sensibility tests can assist in the diagnosis of carpal tunnel syndrome in situations where physical examination leaves room for doubt, but especially when there are contradictory results between physical examination and electroneuromyography. However, there are problems such as non-universalization of the tests used, lack of precision and standardization of some types of test and absence of consensus regarding relevant information within the forms of sensibility to be assessed (temperature, pressure, movement, two-point discrimination).7 In an attempt to bypass these problems, Dellon et al described the PPSD (Pressure Specified Sensory Device®) in 1992.8 The PSSD consists of an apparatus that incorporates a pressure transducer with two prongs, linked to a computer capable of measuring the cutaneous pressure thresholds. (Figure 1) This allows the continuous measurement of pressure between 0.1 and 100 g/mm2 and at the same time two-point discrimination capacity, with greater sensibility and precision than other tests developed previously.9 The use of PSSDs for diagnosing Carpal Tunnel Syndrome was described in 1997, in a study of 72 patients with suggestive clinical history, physical examination (provocative tests and Tinel’s sign positive) and abnormal perception of diapason of 256 Hz.10 OBJECTIVE To describe PSSD use for cutaneous sensibility assessment in chronic patients with Carpal Tunnel Syndrome submitted to hemodialysis, when compared to patients with carpal tunnel syndrome without renal failure. All the authors declare that there is no potential conflict of interest referring to this article. Plastic Surgery Discipline of Hospital das Clínicasof the Faculty of Medicine of Universidade de São Paulo – São Paulo, Brazil. Study conducted in the Plastic Surgery Discipline of the Faculty of Medicine of Universidade de São Paulo. Mailing address Av. Doutor Silva Melo 132, edifício Aru, apartamento 301. FAV .São Paulo- SP CEP 04675-010. E-mail: Article received on 6/25/2009 and approved on 11/29/2009. 268 Acta Ortop Bras. 2011;19(5): 268-72 Figure 1. Pressure transducer of the PSSD (Pressure specified-sensory Device®) – Presents two rhomboid metal prongs with distance adjustment between them, allowing variations between 2.5 and 20 mm. The transducer in turn is linked to a computer, which records the data PATIENTS AND METHODS Cutaneous sensibility assessments were carried out on patients monitored in the Hand Surgery Group of the Plastic Surgery Discipline of Hospital das Clínicas of the Faculty of Medicine of Universidade de São Paulo. This project was approved by the Commission of Ethics for Analysis of Research Projects of the Hospital das Clínicas of the Faculty of Medicine of Universidade de São Paulo, under number 1247, project CAPPesq 1088/07. The patients with a suspect diagnosis were asked to complete a standard questionnaire, containing data on history and physical examination, and always applied by the same professional. Clinical history data (nocturnal paresthesia) and compatible findings in the physical examination (Tinel’s sign, Phalen’s sign) were gathered for inclusion in the protocol. Patients with inconsistent clinical history and doubtful questionable physical examination were referred for electrodiagnostic testing. The diagnosis was considered positive when the patient presented improvement of symptoms in the postoperative period. The patients were divided into three groups: Group 1 - Patients without proven pathology, both renal and in peripheral nerves of the upper limbs, as a control group. Group 2 – patients with carpal tunnel syndrome and with chronic renal failure in hemodialysis program. Group 3 – patients with carpal tunnel syndrome without renal failure. Patients with carpal tunnel syndrome already operated previously, patients with a prior history of upper motor neuron lesion, patients unable to perform the necessary motor functions for performance of the test and patients unable to understand instructions were excluded from the protocol. Fifty-three patients were included in the study. Of these, 29 had carpal tunnel syndrome. In group 1 there were 24 patients included in the study, with 45 hands evaluated. In group 2 there were 14 patients studied, with 22 hands evaluated. In Acta Ortop Bras. 2011;19(5): 268-72 group 3, 15 patients were included with 21 hands examined. The mean age of the patients in the groups with carpal tunnel syndrome was 51.1 years, ranging from 28 to 77 years (51.7 years for group 2 and 50.5 years for group 3). In the control group, the mean age was 41.4 years, ranging from 19 to 72 years. The pat (...truncated)