III./12.1. General aspects of management of neurological emergencies
Neurological emergencies arise in the following situations:
A nervous system lesion causes central or peripheral respiratory failure
A nervous system disease leads to life threatening complications (infections, thrombotic events)
Nervous system dysfunction is caused by diseases and abnormal states originating outside the nervous system (metabolic disturbances, global cerebral ischemia, hypoxia, intoxication)
Respiratory failure may be caused by damage to central (e.g. raised intracranial pressure) or peripheral (myasthenia, Guillan-Barré syndrome) neural structures, including the muscles. On the other hand, respiratory failure from any cause may lead to the secondary damage of parts of the central nervous system (CNS), which are sensitive to hypoxia (cortex, basal ganglia).
Circulatory failure originating from a neural cause is rare (e.g.
neurogenic pulmonary edema, spinal shock), but CNS complications of circulatory failure are common and serious (e.g. in global cerebral ischemia, complete destruction of the brain occurs in five minutes in normal ambient temperature). Global cerebral functional disturbance occurs in case of impairment of parenchymal organs (e.g. renal or hepatic failure).
Urgent intervention is needed when a nervous system disease is associated with serious complications related to immobility.
After these examples, it may be stated as a general rule that a neurological emergency arises in all cases associated with disorders of consciousness, respiratory and/or circulatory failure, and/or epileptic activity. These three groups of symptoms interact with each other, i.e. any of them may lead to the other two or augment their effects within a short period of time.
If nervous system symptoms deteriorate within a short time, it is always an indication of a serious disease associated with poor prognosis.
