Clinical findings:
(1) rapid disease progression
(2) bulbar dysfunction (includes impaired gag reflex, dysarthria, and/or dysphagia)
(3) bilateral facial weakness
(4) dysautonomia (autonomic dysfunction includes unexplained dysrhythmia, blood pressure fluctuations, significant bowel involvement or bladder involvement)
"Threshold" pulmonary function findings:
(1) vital capacity < 20 mL per kg
(2) maximal inspiratory pressure < 30 cm H2O
(3) maximal expiratory pressure < 40 cm H2O
where:
• The change in vital capacity, maximal inspiratory pressure and maximal expiratory pressure is referred to as the "20/30/40 rule".
Serial pulmonary function findings (performed 3 or more times daily to detect deterioration):
(1) reduction > 30% in vital capacity from baseline levels
(2) reduction > 30% in maximal inspiratory pressure from baseline levels
(3) reduction > 30% in maximal expiratory pressure from baseline levels
