Respiratory inhibitory apraxia.

Area of Science:

• Neurology
• Respiratory Medicine
• Neuroscience

Background:

• Voluntary control over respiration is crucial for various functions.
• Involuntary breathing mechanisms are distinct from voluntary respiratory control.
• Previous literature lacks a defined condition for the inability to voluntarily inhibit breathing.

Purpose of the Study:

• To describe a newly identified neurological disorder: respiratory inhibitory apraxia (R.I.A.).
• To investigate the clinical characteristics and potential underlying pathophysiology of R.I.A.
• To explore associations between R.I.A. and other neurological deficits.

Main Methods:

• Clinical observation and description of ten patients presenting with inability to stop breathing on command.
• Review of respiratory system anatomy and voluntary control mechanisms.
• Neurological examination and assessment for associated motor or inhibitory deficits.
• Detailed neuropathological examination of one autopsied case.

Main Results:

• Ten patients exhibited a consistent inability to voluntarily cease respiration, while spontaneous and stimulated breathing remained unaffected.
• Respiratory inhibitory apraxia (R.I.A.) was observed to co-occur with other forms of apraxia and motor impersistence in some patients.
• Urinary and bowel incontinence were noted in some cases, potentially representing a related inhibitory apraxia.
• The autopsied case revealed a deep-seated lesion in the internal capsule affecting descending motor pathways, disconnecting the cortical respiratory inhibitory center.

Conclusions:

• Respiratory inhibitory apraxia (R.I.A.) is a distinct neurological condition characterized by the inability to voluntarily inhibit breathing.
• R.I.A. is likely associated with lesions in the minor (typically left) cerebral hemisphere, often affecting deep structures.
• The findings suggest that R.I.A. results from a disconnection between voluntary respiratory control centers and the descending motor pathways.