Respiratory inhibitory apraxia.

Ten patients have been described showing inability to stop breathing on command, spontaneous respiration and voluntary respiratory stimulation being unaffected. This abnormality not previously described in the literature, we feel should be named respiratory inhibitory apraxia (R.I.A.). The anatomical organization of respiration is briefly reviewed. R.I.A. is often associated with other forms of apraxia or motor impersistence. It is thought that the urinary and bowel incontinence present in some of these cases might also represent a form of inhibitory apraxia. Information is presented which supports the view that respiratory inhibitory apraxia is due to a minor hemisphere lesion, usually deepseated. Our one autopsied case showed a lesion in the descending motor pathways in the internal capsule, in middle cerebral artery branch territory, disconnecting the voluntary respiratory inhibitory center in the cortex in anterior and middle cerebral cortical branch territories.