Respiratory apraxia in amyotrophic lateral sclerosis.

Respiratory dysfunction is a critical problem in amyotrophic lateral sclerosis (ALS). We report a patient with ALS who had respiratory apraxia. A 74-year-old female presented with progressive dysarthria and dysphagia. Clinical signs and evidence of widespread denervation on electromyography (EMG) confirmed the diagnosis of ALS. She had no signs of dementia. Irregular volitional inspiratory movements on verbal command were noticed, in contrast with rhythmic automatic inspiration - respiratory apraxia. Limb and buco-facial movements showed no signs of apraxia. EMG of respiratory muscles was normal, apart from irregular phasic activity of the diaphragm on volitional inspiration; this was confirmed by recording respiratory movements with a percutaneous sensor transducer. Sleep study was normal. She deteriorated rapidly; nonetheless, no clinical sign of dementia or other apraxic findings were observed. ALS, particularly when of bulbar onset, can cause respiratory apraxia and EMG of the respiratory muscles can be useful to detect this condition.