Checking serum ammonia is particularly advised in neonatal coma to discern inborn errors of metabolism. Differential diagnosis
A lowered level of consciousness indicate a deficit in brain function. Level of consciousness can be lowered when the brain receives insufficient oxygen (as occurs in hypoxia); insufficient blood (as occurs in shock, in children for example due to intussusception); or has an alteration in the brains chemistry. Metabolic disorders such as diabetes mellitus and uremia can alter consciousness. Hypo- or hypernatremia (decreased and elevated levels of sodium, respectively) as well as dehydration can also produce an altered LOC. A pH outside of the range the brain can tolerate will also alter LOC. Exposure to drugs (e.g. alcohol) or toxins may also lower LOC, as may a core temperature that is too high or too low (hyperthermia or hypothermia). Increases in intracranial pressure (the pressure within the skull) can also cause altered LOC. It can result from traumatic brain injury such as concussion. Stroke and intracranial hemorrhage are other causes. Infections of the central nervous system may also be associated with decreased LOC; for example, an altered LOC is the most common symptom of encephalitis. Neoplasms within the intracranial cavity can also affect consciousness, as can epilepsy and post-seizure states. A decreased LOC can also result from a combination of factors. A concussion, which is a mild traumatic brain injury (MTBI) may result in decreased LOC. Treatment
Treatment depends on the degree of decrease in consciousness and its underlying cause.
An altered level of consciousness is any measure of arousal other than normal. Level of consciousness (LOC) is a measurement of a persons arousability and responsiveness to stimuli from the environment. A mildly depressed level of consciousness or alertness may be classed as lethargy; someone in this state can be aroused with little difficulty. People who are obtunded have a more depressed level of consciousness and cannot be fully aroused. Those who are not able to be aroused from a sleep-like state are said to be stuporous. Coma is the inability to make any purposeful response. Scales such as the Glasgow coma scale have been designed to measure the level of consciousness. An altered level of consciousness can result from a variety of factors, including alterations in the chemical environment of the brain (e.g. exposure to poisons or intoxicants), insufficient oxygen or blood flow in the brain, and excessive pressure within the skull. Prolonged unconsciousness is understood to be a sign of a medical emergency. A deficit in the level of consciousness suggests that both of the cerebral hemispheres or the reticular activating system have been injured. A decreased level of consciousness correlates to increased morbidity (sickness) and mortality (death). Thus it is a valuable measure of a patients medical and neurological status. In fact, some sources consider level of consciousness to be one of the vital signs.