The Transition Stage from Midbrain Syndrome to Traumatic Apallic Syndrome

Abstract

In those cases of apallic syndrome which occur after acute brain injury, an acute midbrain syndrome is observed as a preliminary stage. This syndrome, caused by tentorial strangulation, develops into the complete stage in three phases. It is characterized clinically by increased curtailment of consciousness to a comatose state, release of the motor functions of the midbrain with increased stretching of the extremities and trunk, and finally, by accompanying stretch synergisms in the complete state of the syndrome, as well as a release of the vegetative systems of the midbrain (with hyperpnea, trachycardia, hypertonia, and hyperthermia (Gerstenbrand, 1967). If intracranial pressure persists, a strangulation in the foramen occipitale magnum can develop and thereby an acute syndrome of the medulla oblongata (bulbar brain syndrome) can occur, which develops after subsidence of the symptoms of midbrain damage (McNeal and Plum, 1962; Müller, 1965). When the strangulation pressure decreases, a development from the bulbar brain syndrome to the midbrain syndrome is possible only if the bulbar brain symptoms have not existed longer than about 30 min. The acute midbrain syndrome can revert back through the same phases which are to be observed in the development of the complete state of the disease. The acute bulbar brain syndrome, however, can also develop into a irreversible loss of brain function, a condition which corresponds clinically to the death of the brain.