Development of a new high sensitivity mechanical switch for augmentative and alternative communication access in people with amyotrophic lateral sclerosis.

BACKGROUND: People with Amyotrophic Lateral Sclerosis (PwALS) in the advanced phase are critically affected by an almost total loss of mobility and severe communication problems. Scanning access based on the patient's interaction with a sensor (or switch) that intercepts even a weak body movement is a valid communication aid. However, its use becomes limited with the progressive decline of residual movements. To overcome this problem, we designed a new sensor, the Lever Magnetic-spring Mechanical Switch (LeMMS), allowing repeated activation/release cycles requiring a very small activation force. METHODS: The LeMMS was applied and validated in a group of 20 PwALS in an advanced stage of disease. All subjects were regular users of communication aids employing other sensors, but which they could no longer operate their sensors (different from LeMMS). Patients were assessed at baseline (t0) and after one (t1), 6 (t2) and 12 (t3) months. Assessment at t0 included administration of standardized clinical scales, the Click-Test-30 counting the maximum number of LeMMS activations in 30 s, and thumb/fingers strength assessment with the Kendall scale. The QUEST 2.0-Dev questionnaire was administered at t1. Some use-related information and the Click-Test-30 were collected at t1, t2 and t3. RESULTS: After one training session, all patients could operate the LeMMS with minimal residual movement of one finger. At t1, they used it on average 5.45 h/day. The mean score of the QUEST 2.0-Dev was 4.63, suggesting strong satisfaction with the LeMMS. Regarding Click-Test-30 scores, no significant difference was found between t0 and t1, but performance at t2 and t3 declined significantly (p < 0.005 vs. t0). At t3, 9/20 patients were still able to use their communication aid. CONCLUSIONS: This new switch sensor can enable PwALS to use their communication aids for a prolonged time even in the advanced phase of disease. It is easy to use, reliable and cheap, thus representing an intermediate alternative to more sophisticated and costly devices.

Effects of creatine supplementation on exercise performance and muscular strength in amyotrophic lateral sclerosis: preliminary results.

Creatine supplementation in humans has been reported to enhance power and strength both in normal subjects and in patients with various neuromuscular diseases. The purpose of this study was to examine the effects of supplementation on exercise performance and maximal voluntary isometric muscular contraction (MVIC) in Amyotrophic Lateral Sclerosis (ALS) patients. We report the results obtained in 28 patients with probable/definite ALS. In each patient we acquired the dynamometric measurement of MVIC in 10 muscle groups of upper and lower limbs and a measure of fatigue by means of an high-intensity intermittent protocol in elbow flexors and knee extensors muscles. All patients completed the protocols at the baseline and after supplementation of 20 g per day for 7 days and after supplementation of 3 g per day for 3 and 6 months. MVIC increased after 7 days of supplementation in 20 patients (70%) in knee extensors and in 15 (53%) of them also in elbow flexors. A statistically significant difference between pre and post-treatment mean values of MVIC was found both in elbow flexors (P<0.05) and knee extensors (p<0.04). The analysis of the slopes of fatigue test showed a statistically significant improvement after 7 days of supplementation in 11 patients (39%) in elbow flexors and in 9 patients (32%) also in knee extensors muscles. During the 6-month follow-up period all the examined parameters showed a linear progressive decline. In conclusion, our preliminary results have demonstrated that supplementation temporary increases maximal isometric power in ALS patients so it may be of potential benefit in situations such as high intensity activity and it can be proposed as a symptomatic treatment.