Poster Abstracts Thursday, November 10, 2005 $461

Fangonilo, R l, Espiritu, G 1, Chua, ja, Villarama-Cellona, CD :. 1University of the Philippines-Philippine General Hospital, Manila, Philippines

Background: Leprosy causes a "mononeuri t is multiplex" of inmmno- logical origin that results in autonomic, sensory and motor neuro- pathy. Irreversible, progressive damage to peripheral nerves and consequently, tissue damage, are the most important consequences of leprosy. Objective: To be able to establish the electro-diaguostic profile of patients with Hansen ' s Disease being seen in a tertiary hospital, through Nerve Conduction Studies. Methods: In this prospective descriptive study, we included patients aged 13-70 years old, diagnosed with Leprosy by skin biopsy who con- sulted or followed up at the Outpatient Depar tment from January 1 to June 30, 2004, and underwent Nerve Conduct ion Studies at the Neurophysiology Unit f rom June 1 to August 31, 2004. Motor studies were carried out on both left and right median, ulnar, fibial and common peroneal nerves while median, ulnar, radial, sural and superficial peroneal nerves were examined for sensory studies. Results: The study populat ion was composed of 20 males and 9 females (mean age of 36 y/o). Sixty two percent have more than one nerve involved, 77'% have a mixed motor and sensory neuropathy, and 68% have a mixed demyelinating and axonal degeneration neuropathy. Sensory abnormalities predominate motor , and the lower extremities are more affected than the upper. Conclusion: Our study results indicate that leprosy causes a predomi- nant ly mixed axonal and demyelinating sensory polyneuropathy that is more severe in the lower extrenfifies, with Sural and Superficial Peroneal nerves having the greatest involvement.

1420 Hand Neuropathy: a correlation of Clinical and Electrophysiological testing among Hansen's patients

Espiritu, G 1, Fangotdlo, R 1, Chua, j1, Villarama-Cellona, CD a. ZUniversity of the Philippines-Philippine General Hospital, Manila, Philippines

Background: In most parts of the Philippines, Nerve Conduct ion Studies (NCS) are either unavailable or costly to the patient. The Semmes-Weinstein (SW) Monofi lament Test seems to be a reliable alternative to s tandard NCS in the early detection of neuropathy wlfich is essential for the prevention of disability in Hansen 's Disease. Objective: This study aims to determine the sensitivity and specifidty of monofi lament testing compared to the s tandard NCS. Methods: In this Prospective study, included were 29 diagnosed Hansen ' s patients by biopsy, 13-70 years old, who consulted or followed up and underwent a s tandard SW Monofi lament testing of the hands at the Outpatient Depar tment from January 1 to June 30, 2004 and underwent Nerve Conduct ion Studies (NCS) of both median, ulnar, and radial nerves at the Neurophysiology Unit from June 1 to August 31, 2004. Sensitivity and specificity of the Semmes-Weinstein Monofi lament Test in diagnosing neuropathy (compared with NCS as gold standard) were computed using the two by two table analysis. Results: Tested were 174 nerves from 29 diagnosed Hansen 's patients. The sensitivity o f the Semmes-Weinstein Monofi lament Test was 0.72 (95% CI 0.57, 0.84), specifidty 0.96 (95% CI 0.91, 0.99), positive predictive value o f 0.87, negative predictive value o f 0.90, positive likelihood ratio of 18.37 and a negative likelihood ratio of 0.2870. Conclusion: The Senmles-Weinstein Monofi lament Test, with 72% sensitivity and 96% specificity, is an effective clinical tool for moni- toring and diagnosing hand neuropathy among Hansen ' s patients.

1421 Carpal Tunnel Syndrome (CTS): how many tests lie beyond tile truth?

D.F.Ghougassian 1. 1Prince of Wales, Sutherland Hospitals, Sydney, Australia

Background: Problems occur with interpretation o f test results in electrophysiology in general and CTS in particular: however, each test's false positive and negative rates have been erroneously thought to affect the total error (after sequential tests). Methods: Review of the Neurophysiologic literature seeking sensitivity and specificity of tests used in diagnosing carpal tunnel syndrome; as well as methods of interpreting the additional inaccuracy due to multiple tests being performed. Results: Diagnostic standards for nerve conduction studies in CTS report sensitivities of 49% to 84% and specificifies o f 95% to 99%. It has been noted that inter-observer and intra-observer (as well as repeated tests') differences vary in the diseased and non-diseased populations. However, when citing further sequential tests, error rates were added: whether as false positives/negatives or Type 1 a n d T y p e 11 errors or discriminant analysis. Discussion: Ascribing loss of diagnostic accuracy to the sequential use of tests for carpal tunnel syndrome is mathematically inaccurate as the event (measurement of a single phenomenon) is not an independent event for sequential tests. Abnormalit ies picked up by different test procedures merely reflect a different abnormality detected for the specific neurophysiologic dysfunction elicited.

1422 Nerve Conduction Tests (NCTs): inter-equipment and intra-exandner assessment

Hamilton-Bruce NIA ~, Tsni A 1 , Donk MB ~, Dowling KJ ~, Jones JA ~, Lee A 1, Purdie GH ~. 1Department of Neurology, The Queen Elizabeth Hospital arid Health Service, Adelaide, Australia; 2BiometricsSA, University of Adelaide/SARDI, Adelaide, Australia

The use o f normative reference ranges forms an integral part of clinical NCTs. As we use reference ranges established from our normative database, purchase of new N C T equipment necessitated determining whether there was a significant difference between NCTs performed on the two maclfines. We therefore aimed to assess inter-equipment and intra-exanfiner consistency. Each N C T was performed on the right median nerve of volunteer subjects, twice with the old and once with the new N C T machine. The hand and forearm were pre-warmed and temperature was recorded. Motor , mixed and sensory nerve studies were performed, with machine settings and electro de positions the same for all studies. Statistical significance was declared at p < 0.05, while cliuical significance was considered to be a difference > 10% for latencies and conduction velodties (CVs), and > 25% for amplitudes. 26 subjects were tested. In the inter-equipment study, motor latencies, amplitudes, F-wave and all sensory responses, as well as the mixed nerve peak latency, showed a statistically significant difference. Tlfis was less than 10% for all except the sensory amplitude (20%) - temperature differences were not statistically siguificantly different. In the intra- examiner study, no statistically significant differences were detected for NCTs - these differences being less than 3%. We conclude that the differences between the machines were no t due to the operator and none were clinically significant. Furthermore, old normative reference ranges should not be used for new maclfines without careful consideration.

1423 Pattern of nerve conduction parameters of Diabetic patients

Haque A l, Bhowmik NB ~, Hassan Z ~, R a h m a n HZ 3, Islam R 3, Haque S a . 1Dept. of Neurology, Bangladesh Institute of Research arid Rehabilitation in Diabetes, Endocrine & Metabolic Disorders (BIRDEM), Bangladesh; :Research Division, BIP,_DEM, Bangladesh; 3Deptartment of Neurology, Bangabandhu Sheikh Mujib iVledieal University, Dhaka, Bangladesh

Introduction: In order to see pattern of conduction parameters of diabetic patients with neuropathy and their association with hypergly- cemia we have studied a group of diabetic patients attending NCV, EMG Lab of BIRDEM Hospital.