Neurophysiological Differences between Flail Arm Syndrome and Amyotrophic Lateral Sclerosis

<div><p>There are many clinical features of flail arm syndrome (FAS) that are different from amyotrophic lateral sclerosis (ALS), suggesting they are probably different entities. Studies on electrophysiological differences between them are limited at present, and still inconclusive. Therefore, we aimed to find clinical and neurophysiological differences between FAS and ALS. Eighteen healthy control subjects, six FAS patients and forty-one ALS patients were recruited. The upper motor neuron signs (UMNS), split-hand index (SI), resting motor threshold (RMT), central motor conduction time (CMCT) were evaluated and compared. There was no obvious upper motor neuron signs in FAS. The SI and RMT level in FAS was similar to control subjects, but significantly lower than that of in ALS. Compared with control group, the RMT and SI in ALS group were both significantly increased to higher level. However, no significant difference of CMCT was found between any two of these three groups. The differences in clinical and neurophysiological findings between FAS and ALS, argue against they are the same disease entity. Since there was no obvious UMNS, no split-hand phenomenon, and no obvious changes of RMT and CMCT in FAS patients, the development of FAS might be probably not originated from motor cortex.</p></div

Comparison of CMCT among three groups.

<p>The CMCT of FAS and ALS patients was not significantly changed, compared with control.</p

Difference of the amplitude of CMAPs of ADMs between three groups.

<p>Fig 2 showed the CMAPs amplitude of ADMs in ALS and FAS groups were significantly decreased, compared with control group (*<i>p</i><0.05).</p

Demographic and clinical characteristics of patients and controls.

<p>ALS, amyotrophic lateral sclerosis; ALSFRS-R, revised ALS functional rating scale; ALSSS, ALS severity scale; HC, healthy controls; PMA, progressive muscular atrophy; the disease progression rate was calculated according to the formula of (48-ALSFRS-R score)/disease duration (month).</p><p>Data were means±SD.</p><p>Demographic and clinical characteristics of patients and controls.</p

Behavioral impairment and mood differences between PMA and ALS.

<p>ALS, amyotrophic lateral sclerosis; FBI, frontal behavioral inventory; HAMA, Hamilton Anxiety Scale; HAMD, Hamilton Depression Rating Scale; PMA, progressive muscular atrophy.</p><p>Data were means±SD.</p><p>Behavioral impairment and mood differences between PMA and ALS.</p

Demographic and clinical characteristics of ALS-NC, ALS-ECI and ALS-FTLD.

<p>ALS, amyotrophic lateral sclerosis; ALSFRS-R, revised ALS functional rating scale; ALSSS, ALS severity scale;ALS-NC, ALS with normal cognition; ALS-ECI, ALS with executive cognitive impairment; ALS-FTLD, ALS with frontotemporal lobe degeneration; the disease progression rate was calculated according to the formula of (48-ALSFRS-R score)/disease duration(months).</p><p>Data were means±SD.</p><p>Demographic and clinical characteristics of ALS-NC, ALS-ECI and ALS-FTLD.</p

Spectrum of MND registered in Peking Union Medical College Hospital (n = 143).

<p>ALS, amyotrophic lateral sclerosis; MND, motor neuron disease; PBP, progressive bulbar palsy; PLS, progressive lateral sclerosis; PMA, progressive muscular atrophy.</p

Categorization of Chinese patients with sporadic ALS according to cognitive status (n = 106).

<p>ALS, amyotrophic lateral sclerosis; ALS-ECI, ALS with executive cognitive impairment; ALS-FTLD, ALS with frontotemporal lobe degeneration; ALS-NC, ALS with normal cognition; ALS-NECI, ALS with non-executive cognitive impairment.</p

Demographic and clinical characteristics of captured and non-captured ALS cases.

<p>ALS, amyotrophic lateral sclerosis; ALSFRS-R, revised ALS functional rating scale; ALSSS, ALS severity scale; the disease progression rate was calculated according to the formula of (48-ALSFRS-R score)/disease duration(month).</p><p>Data were means±SD.</p><p>Demographic and clinical characteristics of captured and non-captured ALS cases.</p

Comparison of neuropsychological performances among patients with PMA, ALS and HC.

<p>3 PMA patients did not complete Stroop Color-Word Task; 2 PMA in copy tests and 1 PMA in digit span and Symbol Digit Modalities Test. ABC, Aphasia Battery Chinese; ALS, amyotrophic lateral sclerosis; CDT, clock drawing test; CMT, Clinical Memory Test; HC, healthy controls; PMA, progressive muscular atrophy; SIE, Stroop interference effect; time for SIE was calculated according to the formula of (Stroop C time-Stroop B time) and correct number for SIE was calculated according to the formula of (Stroop B correct number- Stroop C correct number); WAIS, Wechsler Adult Intelligence Scale; WMS, Wechsler Memory Scale.</p><p>Data were means±SD.</p><p>*p value remained to be significant after Bonferroni correction (α = 0.05/3 = 0.017).</p><p>Comparison of neuropsychological performances among patients with PMA, ALS and HC.</p