Gold Coast diagnostic criteria increase sensitivity in amyotrophic lateral sclerosis

Objective: This study evaluates diagnostic accuracy of the proposed ‘Gold Coast’ (GC) diagnostic criteria for amyotrophic lateral sclerosis (ALS). Methods: Five European centres retrospectively sampled consecutive patients referred for electromyography on suspicion of ALS. Patients were classified according to the GC criteria, the revised El Escorial (rEE) criteria and the Awaji (AW) criteria without and with the ‘Possible’ category (+ Poss). Reference standard was ALS confirmed by disease progression at follow-up. Results: Of 404 eligible patients 272 were diagnosed as ALS, 94 had mimicking disorders, 35 were lost for follow-up, and three had insufficient data. Sensitivity for the GC criteria was 88.2% (95% CI: 83.8-91.8%), which was higher than for previous criteria, of which the AW + Poss criteria reached the highest sensitivity of 77.6% (95% CI: 72.2–82.4%) (p < 0.001). Specificity was high for all criteria. The increase in sensitivity for the GC criteria was mainly due to the inclusion of 28 patients with progressive muscular atrophy (PMA). Conclusions: The simpler GC criteria increase the sensitivity, primarily due to considering PMA as a form of ALS with high specificity preserved. Significance: This validation study supports that GC criteria should be used in clinical practice and may be used for inclusion in trials

Comparison of figure-of-8 and circular coils for threshold tracking transcranial magnetic stimulation measurements

OBJECTIVES: The transcranial magnetic stimulation (TMS) technique of threshold-tracking short-interval intracortical inhibition (T-SICI) has been proposed as a diagnostic tool for amyotrophic lateral sclerosis (ALS). Most of these studies have used a circular coil, whereas a figure-of-8 coil is usually recommended for paired-pulse TMS measurements. The aim of this study was to compare figure-of-8 and circular coils for T-SICI in the upper limb, with special attention to reproducibility, and the pain or discomfort experienced by the subjects. METHODS: Twenty healthy subjects (aged: 45.5 ± 6.7, mean ± SD, 9 females, 11 males) underwent two examinations with each coil, in morning and afternoon sessions on the same day, with T-SICI measured at interstimulus intervals (ISIs) from 1-7 ms. After each examination the subjects rated degree of pain/discomfort from 0 to 10 using a numerical rating scale (NRS). RESULTS: Mean T-SICI was higher for the figure-of-8 than for the circular coil at ISI of 2 ms (p < 0.05) but did not differ at other ISIs. Intra-subject variability did not differ between coils, but mean inhibition from 1-3.5 ms was less variable between subjects with the figure-of-8 coil (SD 7.2% vs. 11.2% RMT, p < 0.05), and no such recordings were without inhibition (vs. 6 with the circular coil). The subjects experienced less pain/discomfort with the figure-of-8 coil (mean NRS: 1.9 ± 1.28 vs 2.8 ± 1.60, p < 0.005). DISCUSSION: The figure-of-8 coil may have better applicability in patients, due to the lower incidence of lack of inhibition in healthy subjects, and the lower experience of pain or discomfort

Impact of medical audit on electrodiagnostic medicine in polyneuropathy.

Objective: The aim of the study was to investigate whether experienced physicians’ electrodiagnostic practice and criteria can be influenced by international collaboration involving peer review medical audit. Methods: Data was obtained from the ESTEEM project, an ongoing collaboration since 1991 among European neurophysiologists concerned with quality improvement in electrodiagnostic medicine. Three sets of the physicians’ polyneuropathy examinations performed with intervals of 2–4 years were analysed. Results: Changes towards increased homogeneity among the physicians were found in (1) the average number of studies performed per patient and the number of abnormal studies required for accepting the diagnosis of polyneuropathy, with the most pronounced changes seen for abnormal motor nerve segments, abnormal F-wave studies, and electromyographic studies, and (2) the agreement on pathophysiological interpretation of nerve conduction studies and classification of polyneuropathy. Conclusions: Changes towards increased homogeneity contributed to years of participation in peer review medical audit, were seen among a group of experienced physicians. Peer review medical audit as carried out here is however difficult to scale up. Therefore guidelines or minimal criteria should ideally supplement a medical audit process to disseminate the results obtained to a larger audience. Significance: These results support the role of international peer review medical audit in quality improvement of electrodiagnostic medicine

Impact of medical audit on electrodiagnostic medicine in polyneuropathy.

Objective: The aim of the study was to investigate whether experienced physicians\u2019 electrodiagnostic practice and criteria can be influenced by international collaboration involving peer review medical audit. Methods: Data was obtained from the ESTEEM project, an ongoing collaboration since 1991 among European neurophysiologists concerned with quality improvement in electrodiagnostic medicine. Three sets of the physicians\u2019 polyneuropathy examinations performed with intervals of 2\u20134 years were analysed. Results: Changes towards increased homogeneity among the physicians were found in (1) the average number of studies performed per patient and the number of abnormal studies required for accepting the diagnosis of polyneuropathy, with the most pronounced changes seen for abnormal motor nerve segments, abnormal F-wave studies, and electromyographic studies, and (2) the agreement on pathophysiological interpretation of nerve conduction studies and classification of polyneuropathy. Conclusions: Changes towards increased homogeneity contributed to years of participation in peer review medical audit, were seen among a group of experienced physicians. Peer review medical audit as carried out here is however difficult to scale up. Therefore guidelines or minimal criteria should ideally supplement a medical audit process to disseminate the results obtained to a larger audience. Significance: These results support the role of international peer review medical audit in quality improvement of electrodiagnostic medicine