[Ventilation function disorder of flail arm syndrome].

Area of Science:

• Neurology
• Pulmonology
• Clinical Medicine

Background:

• Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting motor neurons.
• Flail arm syndrome (FAS) is a variant of ALS characterized by predominant weakness in the arms.
• Ventilation dysfunction is a critical complication in ALS, impacting patient prognosis.

Purpose of the Study:

• To investigate and compare the ventilation function features between patients with flail arm syndrome (FAS) and classical amyotrophic lateral sclerosis (ALS).
• To analyze differences in forced vital capacity (FVC) between FAS and classical ALS cohorts.
• To inform prognosis assessment and treatment planning for FAS patients.

Main Methods:

• Retrospective review of clinical data from 351 patients diagnosed with sporadic ALS between 2009 and 2013.
• Categorization of patients into classical ALS (329 patients) and FAS (22 patients).
• Statistical analysis of forced vital capacity percent predicted (FVC% pred) values and proportions of abnormal FVC% pred between the groups.

Main Results:

• FAS patients demonstrated significantly higher FVC% pred values (88.0 ± 9.5)% compared to classical ALS patients (84.3 ± 16.8)% (P < 0.05).
• The proportion of patients with abnormal FVC% pred (< 80%) was significantly lower in FAS (18.2%) than in classical ALS of upper limb onset (42.8%) and those with duration over one year (48.5%).
• FVC% pred levels were significantly higher in FAS subjects than in classical ALS subjects with bulb or upper limb onset and duration over 12 months.

Conclusions:

• Impaired ventilation function occurs less frequently and at a later stage in FAS compared to classical ALS, particularly those with upper limb onset and longer disease duration.
• These findings suggest a potentially later and less frequent requirement for non-invasive positive pressure ventilation (NIPPV) in FAS patients.
• Differentiating FAS from classical ALS is crucial for accurate prognosis assessment and tailored treatment strategies, including NIPPV initiation.