Consultation with the specialist

Abstract

Case Presentation A 2-year-old boy is brought to the emergency room by ambulance after being found "unresponsive" by his parents. He has been in good general health, has had no fever or other symptoms of infectious processes, has been taking no medications, and was "his normal self" until immediately prior to being found. Patients who are unresponsive and unarousable are in coma. The term altered consciousness represents the spectrum of abnormalities that exists between the immediate capability for normal wakefulness and true coma. For the purposes of this review, the two terms will be used interchangeably because their causes are similar and usually differ only in severity. Pathophysiology Two areas of the brain are responsible for consciousness: the ascending reticular activating system (ARAS) and the cerebral cortex. The ARAS is located in the brain stem from the level of the medulla to the level of the midbrain and sends multiple afferent neurons to the cortex. Disruption of this system can lead to disorders of consciousness. The cerebral cortex is the much more common site where dysfunction can cause coma. Any injury or illness that affects the cerebral cortex globally can cause coma or altered consciousness. Differential Diagnosis Altered consciousness in children can be caused by injuries or illnesses that affect the central nervous system directly or can be a manifestation of other systemic disease (Table 1).