Dropped head presentation in ALS

Preliminary Study on Effects of Neck Exoskeleton Structural Design in Patients With Amyotrophic Lateral Sclerosis

Neck muscle weakness due to amyotrophic lateral sclerosis (ALS) can result in dropped head syndrome, adversely impacting the quality of life of those affected. Static neck collars are currently prescribed to hold the head in a fixed upright position. However, these braces are uncomfortable and do not allow any voluntary head-neck movements. By contrast, powered neck exoskeletons have the potential to enable head-neck movements. Our group has recently improved the mechanical structure of a state-of-the-art neck exoskeleton through a weighted optimization. To evaluate the effect of the structural changes, we conducted an experiment in which patients with ALS were asked to perform head-neck tracking tasks while using the two versions of the neck exoskeleton. We found that the neck muscle activation was significantly reduced when assisted by the structurally enhanced design compared to no assistance provided. The improved structure also improved kinematics tracking performance, allowing users to better achieve the desired head poses. In comparison, the previous design did not help reduce the muscle effort required to perform these tasks and even slightly worsened the kinematic tracking performance. It was also found that biomechanical benefits gained from using the structurally improved design were consistent across participants with both mild and severe neck weakness. Furthermore, we observed that participants preferred to use the powered neck exoskeletons to voluntarily move their heads and make eye contact during a conversation task rather than remain in a fixed upright position. Each of these findings highlights the importance of the structural design of neck exoskeletons in achieving desired biomechanical benefits and suggests that neck exoskeletons can be a viable method to improve the daily life of patients with ALS.

Health Status Perspectives in Amyotrophic Lateral Sclerosis

BACKGROUND/AIMS

The global perception of the health status (HS) of amyotrophic lateral sclerosis (ALS) patients before the initial diagnosis has not been addressed previously.

METHODS

We recorded the following at the first visit, before diagnostic information: (1) visual analog scale (VAS) of the EQ-5D; (2) the revised ALS functional rating scale (ALSFRS- R), bulbar (ALSFRSb), upper limb (ALSFRSul), lower limb (ALSFRSll), and respiratory (RofALSFRS-R) subscores; and (3) forced and slow vital capacities. Correlations were tested by the Pearson correlation test. Variables were compared between groups defined by the VAS median value. p < 0.05 was considered significant.

RESULTS

Of the 156 patients included in the study (91 spinal-onset, 49 bulbar-onset, 16 axial/respiratory-onset; 95 men; mean onset age 63.9 ± 13 years; mean disease duration 18.4 ± 26.5 months), HS VAS was significantly lower in spinal-onset patients (p = 0.047), and particularly in spinal-onset women (p = 0.027). Disease duration had no influence. HS VAS was moderately correlated with ALSFRS, ALSFRSul and ALSFRSll (0.4 < r < 0.5, p < 0.01), weakly correlated with RofALSFRS-R in the whole population (r = 0.171, p < 0.05), and not correlated with ALSFRSb or the respiratory tests. ALSFRSb was similar between groups defined by the HS VAS median value, but the other scores were significantly lower for poorer HS values.

CONCLUSION

HS before diagnosis is mostly dependent on the perception of upper and lower limb function. A tool tailored to evaluate HS in bulbar-onset patients should be developed.

Amyotrophic lateral sclerosis or not: Keys for the diagnosis

Amyotrophic lateral sclerosis (ALS) is a degenerative motor neuron disease (MND) which prognosis is poor. Early diagnosis permit to set up immediately adapted treatment and cares. Available diagnostic criteria are based on the detection of both central and peripheral motor neuron injury in bulbar, cervical, thoracic and lumbar regions. Electrodiagnostic (EDX) tests are the key tools to identify peripheral motor neuron involvement. Needle examination records abnormal activities at rest, and looks for neurogenic pattern during muscle contraction. Motor unit potentials morphology is modified primary to recruitment. Motor evoked potentials remain the test of choice to identify impairment of central motor neurons. In the absence of diagnostic biomarker of ALS and among essential investigations of suspected MND, a careful clinical and neurophysiological work-up is essential to rule out the differential diagnosis.