Biomedical subjects

Arminda Lopes

Publications and source records attributed to Arminda Lopes.

4 recordsLinked to original sources

PubMed2005

Quantitating progression in ALS.

The authors prospectively studied the value of clinical and neurophysiologic measurements in assessing progression in ALS. Motor unit number estimation (MUNE) and the neurophysiologic index (NI) were significantly correlated with ADM strength (maximal voluntary isometric contraction force in the abductor digiti minimi muscle [MVIC-ADM]). MUNE and the NI were reliable, but the NI showed a lower variation. On assessing progression at 3, 6, and 12 months, MUNE, NI, and MVIC-ADM showed the highest rate of change. The NI is a potentially useful new neurophysiologic measurement.

Adult↗

PubMed2003

Clinical and neurophysiological evaluation of progression in amyotrophic lateral sclerosis.

There is a need for a sensitive neurophysiological measure of disease progression in following the course of patients with amyotrophic lateral sclerosis (ALS). We studied two groups of nine ALS patients, one with slow progression (Group A) and the other with rapid progression (Group B). We evaluated muscle strength scores using the Medical Research Council (MRC) scale in limb and trunk muscles, forced vital capacity (FVC), and ALS functional rating scale (ALS-FRS) scores. Maximal voluntary isometric contraction (MVIC) of the abductor digiti minimi muscle (ADM) was measured, using a digital device. We also measured M-wave amplitude and area in the ADM, and the distal motor latency and F-wave frequency in the ulnar nerve; from these data, the neurophysiological index (NI) was calculated, as described previously. In both groups, the NI was the most sensitive measure of change, with the smallest coefficient of variation. We conclude that the NI, which requires no special technology and no new clinical or technical skills to use, is sensitive to change, and therefore may be useful in clinical trials, as well as in a clinical setting.

Adolescent↗

PubMed2003

Nocturnal pulse oximetry: a new approach to establish the appropriate time for non-invasive ventilation in ALS patients.

Previous studies have supported non-invasive ventilation (NIV) in amyotrophic lateral sclerosis (ALS), indicating that it prolongs survival. However, criteria for the use of NIV are yet to be defined. The aim of the present study was to evaluate the potential use of nocturnal pulse oximetry (NPO) as a tool for determining the most appropriate time at which to initiate NIV in ALS patients. We conducted a prospective, comparative, historical-controlled clinical study of 64 consecutive ALS patients. Group 1 (historical control group) comprised 44 patients, 14 women and 30 men, with a mean age of 60+/-13 years, in whom we used NIV after detecting early signs of diurnal respiratory insufficiency (RI). Group 2 had 20 ALS patients, 8 women and 12 men, with a mean age of 56+/-11 years, for whom we started NIV after detecting more than 15 periods of nocturnal desaturation/hour by NPO. All patients were periodically evaluated with Norris spinal and bulbar scores, respiratory function tests (RFT) and NPO at three month intervals for one year. They were subsequently followed until death or loss of autonomy from the ventilator. We compared survival time or time to loss of autonomy from the ventilator between both groups. Survival was longer in Group 2 (p<0.002). We concluded that NPO is a valuable screening test to establish the need for NIV. Our results also suggest that the early diagnosis of RI and the early use of NIV increase patient compliance with NIV.

Amyotrophic Lateral Sclerosis↗

PubMed2002

F-Waves and the corticospinal lesion in amyotrophic lateral sclerosis.

INTRODUCTION: In upper motor neuron (UMN) syndromes, F-waves are of higher amplitude, increased duration, and increased latency. Increased F-wave frequency in UMN syndromes is not well documented. We have studied the effect of corticospinal lesion on F-wave frequency, M-wave amplitude, distal motor latency and on the Neurophysiological Index (CMAP amplitude/DML x % F-wave frequency) which we have described previously in amyotrophic lateral sclerosis (ALS). METHOD: We studied 145 abductor digiti minimi (ADM) muscles in 75 patients with ALS. Six groups of hands were defined, based on strength of the ADM, as assessed clinically by the MRC scale, and the presence or absence of UMN signs in the same upper limb. RESULTS: CMAP amplitude and area were decreased, and DML increased, in weaker muscles (MRC < 3) causing a change in the ALS Neurophysiological Index. In general, UMN signs were not correlated with increased F-wave frequency. In five weak hands F-responses were studied in individual motor units. A larger number of responding motor units in these weak limbs with UMN signs was observed. CONCLUSION: F-wave excitability is largely dependent on the size of the lower motor neuron pool.

Action Potentials↗