Predictive factors and screening strategy for obstructive sleep apnea in patients with advanced multiple sclerosis.

BACKGROUND: Obstructive sleep apnea (OSA) screening questionnaires have been evaluated in Multiple Sclerosis (MS) but not yet validated in patients with advanced disease. The aim of this study is to identify OSA predictive factors in advanced MS and to discuss screening strategies. METHODS: Oximetry data from 125 patients were retrospectively derived from polysomnographic reports. Univariate and multivariate analysis were used to determine predictive factors for OSA. A two-level screening model was assessed combining the oxygen desaturation index (ODI) and a method of visual analysis. RESULTS: multivariate analysis showed that among the clinical factors only age and snoring were associated with OSA. Usual predictive factors such as sleepiness, Body mass index (BMI) or sex were not significantly associated with increased Apnea Hypopnea Index (AHI). The ODI was highly predictive (p < 0.0001) and correctly identified 84.1 % of patients with moderate OSA and 93.8 % with severe OSA. The visual analysis model combined with the ODI did not outperform the properties of ODI used alone. CONCLUSION: As the usual clinical predictors are not associated with OSA in patients with advanced MS, questionnaires developed for the general population are not appropriate in these patients. Nocturnal oximetry seems a pertinent, ambulatory and accessible method for OSA screening in this population.

Motion analysis for the evaluation of muscle overactivity: A point of view.

Muscle overactivity is a general term for pathological increases in muscle activity such as spasticity. It is caused by damage to the central nervous system at the cortical, subcortical or spinal levels, leading to an upper motor neuron syndrome. In routine clinical practice, muscle overactivity, which induces abnormal muscle tone, is usually evaluated by using the Modified Ashworth Scale or the Tardieu Scale. However, both of these scales involve testing in passive conditions that do not always reflect muscle activity during dynamic tasks such as gait or reaching. To determine appropriate treatment strategies, muscle overactivity should be evaluated by using objective measures in dynamic conditions. Instrumental motion analysis systems that include 3-D motion analysis and electromyography are very useful for this purpose. The method can be used to identify patterns of abnormal muscle activity that can be related to abnormal kinematic patterns. It allows for objective and accurate assessment of the effects of treatments to reduce muscle overactivity on the movement to be improved. The aim of this point-of-view article is to describe the utility of instrumental motion analysis and to outline both its numerous advantages in evaluating muscle overactivity and to present the current limitations for its use (e.g., cost, the need for an engineer, errors relating to marker placement and cross talk between electromyography sensors).

Respiratory rehabilitation in multiple sclerosis: A narrative review of rehabilitation techniques.

BACKGROUND: Respiratory disorders in multiple sclerosis (MS) are an important issue. They can occur early during the course of the disease, are associated with the neurological impairment, and can lead to pneumonia and respiratory failure, which are the main causes of death in advanced MS. Prevailing impaired expiratory muscles and cough abilities has been demonstrated in this population and might constitute a specific target for rehabilitation interventions. However, international guidelines lack recommendations regarding respiratory rehabilitation in MS. Here we performed a systematic review of the published literature related to respiratory rehabilitation in MS. METHODS: We searched the databases MEDLINE via PubMed, PEDro and Cochrane Library for English or French reports of clinical trials and well-designed cohorts published up to December 2016 with no restriction on start date by using the search terms "multiple sclerosis", "respiratory rehabilitation", "respiratory muscle training", "lung volume recruitment", "cough assistance", and "mechanical in-exsufflation". Literature reviews, case reports and physiological studies were excluded. The Maastricht criteria were used to assess the quality of clinical trials. We followed the Oxford Centre for Evidence-Based Medicine guidelines to determine level of evidence and grade of recommendations. RESULTS: Among the 21 reports of studies initially selected, 11 were retained for review. Seven studies were randomized controlled trials (RCTs), 2 were non-RCTs, and 2 were observational studies. Respiratory muscle training (inspiratory and/or expiratory) by use of a portable resistive mouthpiece was the most frequently evaluated technique, with 2 level-1 RCTs. Another level-1 RCT evaluated deep-breathing exercises. All reviewed studies evaluated home-based rehabilitation programs and focused on spirometric outcomes. The disparities in outcome measures among published studies did not allow for a meta-analysis and cough assistance devices were not evaluated in this population. CONCLUSION: Although respiratory muscle training can improve maximal respiratory pressure in MS and lung volume recruitment can slow the decline in vital capacity, evidence is lacking to recommend specific respiratory rehabilitation programs adapted to the level of disability induced by the disease.

Respiratory impairment in multiple sclerosis: a study of respiratory function in wheelchair-bound patients.

BACKGROUND AND PURPOSE: Respiratory disorders are a major cause of morbidity and mortality in multiple sclerosis (MS). Mainly reported in walking patients, they are poorly explored when walking is severely impaired. To characterize respiratory impairment in patients with advanced MS. METHODS: From 2012 to 2015, patients with MS with an Expanded Disability Status Scale (EDSS) score of ≥7 who were referred for functional and rehabilitation evaluation underwent pulmonary function tests to study lung volumes, cough efficacy and respiratory muscle pressures. RESULTS: Among 73 patients with a median EDSS score of 8 [7.5; 8.5], 72.6% had impaired respiratory function with a mean vital capacity (VC) of 57.9 ± 33.5% of theoretical value. Severe impairment (VC < 50%) was found for 34 (46.6%) patients. Cough was impaired in 45 (61.6%) patients, with a mean cough peak flow of 3.14 ± 1.9 L/s and severe impairment (cough peak flow < 2.67 L/s) in 27 (37.0%) patients. Overall, the results suggested predominant expiratory muscle dysfunction and non-predominant diaphragm impairment. EDSS score was correlated with VC but not with any other clinical data. CONCLUSION: Restrictive respiratory failure is frequent in severely impaired patients with MS, predominantly involves expiratory muscles, does not involve diaphragm weakness and is associated with cough impairments.

Text input speed in persons with cervical spinal cord injury.

STUDY DESIGN: This is a prospective clinical study. OBJECTIVES: The objectives of this study were to determine text input speed (TIS) in persons with cervical spinal cord injury (SCI) and to study the influence of personal characteristics and type of computer access device on TIS. SETTING: This study was conducted in the Rehabilitation Department, Garches, France. METHODS: People with cervical SCI were included if their level of injury was between C4 and C8 Asia A or B, and if they were computer users. In addition, able-bodied people were recruited from the hospital staff. Each participant underwent a single evaluation using their usual computer access devices. TIS was evaluated during a 10- min copying task. The relationship between the characteristics of participants with cervical SCI, type of computer access device and TIS were analyzed using a Scheirer-Ray-Hare test (nonparametric test similar to a two-way analysis of variance). RESULTS: Thirty-five participants with cervical SCI and 21 able-bodied people were included. Median TIS of participants with cervical SCI was 11 (6; 14) words per minute (w.p.m.) and of able-bodied participants was 19 (14; 24) w.p.m. (P=0.001). Median TIS of participants with lesions at or above C5 was 12 (4; 13) w.p.m. and of those with lesions below C5 was 10 (9; 18) w.p.m. (P=0.38) [corrected]. The Scheirer-Ray-Hare test showed that only the type of computer access device significantly influenced TIS. Surprisingly, none of the person's characteristics, including the level of cervical lesion, affected TIS. CONCLUSION: This is the first study to analyze TIS in a group of participants with cervical SCI. The results showed that only the type of computer access device influenced TIS.

Relationship between hip flexion and ankle dorsiflexion during swing phase in chronic stroke patients.

BACKGROUND: During the clinical examination of stroke patients, it is common to observe that involuntary hip flexion occurs during voluntary ankle dorsiflexion (synkinesia). This suggests that there is a relationship between these two joints. We hypothesized that there may be a relationship between hip and ankle flexion during swing phase of the gait cycle. The objective of this study was to determine if there is a biomechanical relationship between peak hip flexion and peak ankle dorsiflexion during the swing phase of the gait cycle following stroke. METHOD: The paretic lower limbs of 60 patients with stroke were evaluated using clinical tests and 3D-gait analysis. The clinical assessment included muscle strength, spasticity and passive range of ankle motion. The gait analysis focused on sagittal frontal and transverse kinematic gait parameters during swing. FINDINGS: A stepwise-linear-regression indicated that peak hip flexion and gait speed were the only 2 parameters which accounted for peak ankle dorsiflexion. There was also a significant negative correlation between peak hip flexion and peak ankle dorsiflexion during swing, and a significant positive correlation between hip flexor and ankle dorsiflexor muscle strength. INTERPRETATION: These results suggest that the biomechanical behaviour of hip and ankle joints during the swing phase of the gait cycle is linked in patients with stroke. They also suggest that two strategies exist: if sufficient ankle dorsiflexion is present, less hip flexion is required (distal-strategy) whereas if dorsiflexion is reduced, it is compensated for by an increase in peak hip flexion (proximal-strategy).

[Selective Laser Trabeculoplasty in the treatment of chronic open-angle glaucoma: retrospective analysis 12 years after treatment in a cohort of 28 patients]. / Trabéculoplastie sélective au Laser Selecta (SLT) dans le traitement du glaucome chronique à angle ouvert : analyse rétrospective 12 ans après traitement d'une cohorte de 28 patients.

PURPOSE: To determine long-term efficacy of selective Laser Trabeculoplasty (SLT) over 12 years in chronic open-angle glaucoma (OAG) patients. METHODS: In this retrospective study, all patients treated by SLT between 1997 and 1999 for OAG were included and followed up every 6 months. The procedure was performed with a Coherent Selecta 7000 Nd:YAG with 100 ± 10 non overlapping 400 µm spots over 360 degrees centered on the trabecular meshwork. Patients were excluded in the case of prior filtration surgery or Argon laser trabeculoplasty. Our primary study parameter was the number of patients requiring filtration surgery within the follow-up period. Our secondary parameters were intraocular pressure (IOP) and SLT-related complications. RESULTS: We included 46 eyes of 28 patients. The 12-year success rate was 26.1%. Thirty-nine percent of all eyes underwent filtration surgery (failure) during the follow-up period, and 34.8% were lost to follow-up. In the pigmentary glaucoma (PG) subgroup, the 12-year success rate was 16%, while it was 37.5% in the Primary OAG subgroup. The overall mean IOP was 22.8 mm Hg (D.S. 3.78) prior to laser, 16.08 mm Hg (D.S. 2.7) at 1 year and 15 mm Hg (D.S. 1.8) at 12 years. The mean number of medications was 1.6 (D.S. 0.8) prior to SLT, 1.36 (D.S. 0.8) at 1 year, and 1.3 (D.S. 1.2), 12 years after SLT respectively. No patients had a second SLT treatment. No significant complications occurred during follow-up. CONCLUSION: Selective laser trabeculoplasty may at times be a useful resource to lower IOP in patients with OAG. Nonetheless, the failure rate is significant especially in PG, which requires confirmation by larger prospective studies.

Effects of a dynamic-ankle-foot orthosis (Liberté®) on kinematics and electromyographic activity during gait in hemiplegic patients with spastic foot equinus.

BACKGROUND: A dynamic-ankle-foot orthosis has recently emerged and consists of an elastic band allowing the variation of stiffness degree and adjusts dorsiflexion assistance in swing. The aim of this study was to quantify the biomechanical adaptations induced by this orthosis during gait in hemiplegic patients. METHODS: Twelve hemiplegic patients performed two gait analyses (without and with the ankle-foot orthosis). Spatiotemporal, kinematic, kinetic and electromyographic gait parameters were quantified using an instrumented gait analysis system during the stance and swing phases. RESULTS: During swing, peak ankle dorsiflexion was greater with the orthosis and associated with a decrease of pelvic obliquity angle. In stance, peak ankle plantarflexion and dorsiflexion were greater with the orthosis and associated with an increase of ankle angle at heel strike and toe-off. Electromyographic activities of both the tibialis anterior and the medial gastrocnemius were greater with the orthosis. CONCLUSIONS: This dynamic-ankle-foot orthosis improved gait in hemiplegic patients with spastic foot equinus. The spatiotemporal adaptations seem to be caused mainly by the increase of ankle dorsiflexion during stance and swing phases. The changes in electromyographic activity were related to an active dorsiflexion in stance and swing phases and an active plantarflexion in stance phase.

Isokinetic assessment of the effects of botulinum toxin injection on spasticity and voluntary strength in patients with spastic hemiparesis.

BACKGROUND: Peak knee flexion during swing phase is frequently reduced following stroke. The main treatment is botulinum toxin injection (BoNT-A) of the Rectus Femoris (RF) muscle. BoNT-A injections have been shown to decrease spasticity (assessed using the modified Ashworth scale) and to improve peak knee flexion during swing phase. Although the effect of BoNT-A has been clearly demonstrated on kinematic parameters during gait, the direct effects on spasticity and strength have been little studied using objective and sensitive outcome measures. AIM: The aim of this study was to use an isokinetic dynamometer to assess the effects of BoNT-A injection in the RF on stretch reflex-related torque at the knee joint and peak voluntary knee flexor and extensor torque and to evaluate the effect on functional capacity. DESIGN: Before-after trial: Assessments were carried out pre and post (four weeks) RF BoNT-A injection. Clinical and isokinetic evaluations were carried out. SETTING: Ambulatory care in a hospital setting. Participants. Population-based sample of fourteen chronic spastic hemiparetic patients with stiff knee gait. METHODS: Primary outcome measurements were stretch reflex-related torque at the knee joint and peak voluntary knee flexor and extensor torque. Secondary outcomes were knee angle at peak torque, the slope of the torque velocity curve, stiffness and functional outcomes. RESULTS: Peak knee extensor torque was significantly decreased and peak knee flexor torque was significantly increased during maximal voluntary concentric and isometric contractions following BoNT-A injection of the RF. Stretch reflex-related torque evaluated during passive stretching movements was reduced and the angle of occurrence of the peak was greater. Functional outcomes did not change. CONCLUSIONS AND CLINICAL REHABILITATION IMPACT: The results of this study indicate that BoNT-A injection reduced RF spasticity but also reduced quadriceps strength. In contrast, knee flexor strength increased. These changes did not, however, lead to functional gait changes.

Changes in electromyographic activity after botulinum toxin injection of the rectus femoris in patients with hemiparesis walking with a stiff-knee gait.

PURPOSE: This study was designed to evaluate the effects of botulinum toxin type-A (BoNTA) injection of the rectus femoris (RF) muscle on the electromyographic activity of the knee flexor and extensor and on knee and hip kinematics during gait in patients with hemiparesis exhibiting a stiff-knee gait. METHOD: Two gait analyses were performed on fourteen patients: before and four weeks after BoNTA injection. Spatiotemporal, kinematic and electromyographic parameters were quantified for the paretic limb. RESULTS: BoNTA treatment improved gait velocity, stride length and cadence with an increase of knee angular velocity at toe-off and maximal knee flexion in the swing phase. Amplitude and activation time of the RF and co-activation duration between the RF and biceps femoris were significantly decreased. The instantaneous mean frequency of RF was predominantly lower in the pre-swing phase. CONCLUSIONS: The results clearly show that BoNTA modified the EMG amplitude and frequency of the injected muscle (RF) but not of the synergist and antagonist muscles. The reduction in RF activation frequency could be related to increased activity of slow fibers. The frequency analysis of EMG signals during gait appears to be a relevant method for the evaluation of the effects of BoNTA in the injected muscle.

Effects of a gait training session combined with a mass on the non-paretic lower limb on locomotion of hemiparetic patients: a randomized controlled clinical trial.

BACKGROUND: Results of recent studies have suggested that restraint of non-paretic lower limb movement could improve locomotion in hemiplegic patients. The aim of this study was therefore to determine if a mass applied to the non-paretic lower limb during a single gait training session (GTS) would specifically improve spatio-temporal, kinematic and kinetic gait parameters (GP) of the paretic lower limb. METHODS: Sixty chronic hemiplegic subjects were included in this randomized study. Each participated in one of four GTS conditions: overground or on a treadmill while wearing or not wearing an ankle mass. All subjects were assessed before, immediately after and 20 min after the end of the GTS using 3D gait analysis. RESULTS: The results showed that restraining the non-paretic lower limb during a GTS had no specific effect on GP of the paretic limb, whereas it increased braking force of the non-paretic limb. CONCLUSION: Restraining the non-paretic lower limb of hemiparetic patients with a mass applied to the ankle does not seem to be an effective approach to improve paretic lower limb parameters during a single GTS.

Effects of a knee-ankle-foot orthosis on gait biomechanical characteristics of paretic and non-paretic limbs in hemiplegic patients with genu recurvatum.

BACKGROUND: A knee-ankle-foot orthosis may be prescribed for the prevention of genu recurvatum during the stance phase of gait. It allows also to limit abnormal plantarflexion during swing phase. The aim is to improve gait in hemiplegic patients and to prevent articular degeneration of the knee. However, the effects of knee-ankle-foot orthosis on both the paretic and non-paretic limbs during gait have not been evaluated. The aim of this study was to quantify biomechanical adaptations induced by wearing a knee-ankle-foot orthosis, on the paretic and non-paretic limbs of hemiplegic patients during gait. METHODS: Eleven hemiplegic patients with genu recurvatum performed two gait analyses (without and with the knee-ankle-foot orthosis). Spatio-temporal, kinematic and kinetic gait parameters of both lower limbs were quantified using an instrumented gait analysis system during the stance and swing phases of the gait cycle. FINDINGS: The knee-ankle-foot orthosis improved spatio-temporal gait parameters. During stance phase on the paretic side, knee hyperextension was reduced and ankle plantarflexion and hip flexion were increased. During swing phase, ankle dorsiflexion increased in the paretic limb and knee extension increased in the non-paretic limb. The paretic limb knee flexion moment also decreased. INTERPRETATION: Wearing a knee-ankle-foot orthosis improved gait parameters in hemiplegic patients with genu recurvatum. It increased gait velocity, by improving cadence, stride length and non-paretic step length. These spatiotemporal adaptations seem mainly due to the decrease in knee hyperextension during stance phase and to the increase in paretic limb ankle dorsiflexion during both phases of the gait cycle.

[Epidemiology and clinical assessment of spasticity in multiple sclerosis]. / Épidémiologie et évaluation clinique de la spasticité dans la sclérose en plaques.

Spasticity is a commonly seen symptom in patients with multiple sclerosis (MS). The vast majority of patients will suffer from this symptom during the course of the disease, and one- third of patients considers that spasticity contributes to a greater part of their disability. The symptom is frequently disabling. It can, however, allow some activities to be performed. Treatment of the symptom is sometimes deleterious, which is why strict assessment of the consequences of spasticity and anticipation of the outcome of antispastic treatment are necessary. Clinical scales, such as the Ashworth and Tardieu scales, are used in clinical practice. The essential element is not, however, assessment of the symptom, but its repercussions on activities of everyday life. It is important to make a list of what patients consider to be disabling situations to verify that they are truly consequences of spasticity. Considering the heterogeneity of clinical expression of spasticity in patients with MS, the use of a scale such as goal attainment scaling (GAS) can probably be totally adapted for the assessment of the effects of antispastic treatment.

Arbitrary visuomotor mapping in the grip-lift task: dissociation of performance deficits in right and left middle cerebral artery stroke.

The ability to rapidly establish a memory link between arbitrary sensory cues and goal-directed movements is part of our daily motor repertoire. It is unknown if this ability is affected by middle cerebral artery stroke. Eighteen right-handed subjects with a first unilateral middle cerebral artery stroke were studied while performing a precision grip to lift objects of different weights. In a "no cue" condition, a noninformative neutral visual stimulus was presented before each lift, thereby not allowing any judgment about the object weight. In a "cue" condition arbitrary color cues provided advance information about the weight to be lifted in the subsequent trial. Subjects performed both conditions with either hand. During "no cue" trials subjects scaled their grip force according to the weight of the preceding lift, irrespective of the hand performing the lift or the hemisphere affected. The presentation of color cues allowed patients with right hemispheric stroke, but not those with left hemispheric stroke, to scale their grip force according to the weight in the upcoming lift when lifting the weight with the unaffected hand. Color cues did not allow for a predictive scaling of grip force according to the weight of the object to be lifted when lifting with the affected hand, irrespective of the affected hemisphere. These data imply that the ability of visuomotor mapping in the grip-lift task is selectively impaired in the affected hand after right middle cerebral artery stroke, but in both hands after left middle cerebral artery stroke.