ABNORMAL STATES OF CONSCIOUSNESS AND MUSCLE TONE IN INFANTS BORN TO SCHIZOPHRENIC MOTHERS

The evaluation of the changing pattern of consciousness can be used as a measure of the growing integrative capacity of the central nervous system in infancy. In the first months of life, at least two skills develop which are necessary for the maintenance of the quiet, open-eyed alert state. There is an increased general level of arousal(17) sufficient to permit responses to minimal visual and auditory stimuli. There is also a gradual modulation of spontaneous excitability and an increase in the toleration of proprioceptive stimuli. This permits a continuing stable state of awareness and prolonged, focused attention. These abilities are essential prerequisites for the well-integrated development of specffic alerting responses(17), which involve differentiated attentiveness, perceptual discrimination, patterns of accommodation, and the more complex functions which modify the accessibility of the CNS to different stimuli.

The organization of a stable, sustained state of alertness by 8 weeks of age, as measured in a standard sample of timed behavior, precedes the organization of consolidated waking-sleeping patterns in 24-hour behavior samples(12, 16, 18). It also antedates the qualitative increase in organization noted in infants's EEGs at 3 months of age(3, 4).

As part of an ongoing study into abnormal development and early schizophrenia, consciousness and sensory responsiveness were studied in infants of schizophrenic mothers. Four infants showed marked deviations in the direction of excessive apathy or irritability. At 2 years of age, only the most irritable infant has shown grossly maladaptive behavior. The quiet infants had attentuated motor impulses, minimal response to proprioceptive stimuli, and in the most extreme case, flaccid muscle tone and irregular postural development. This quiet state clinically resembles the "adynamia" which Hess produced in cats by electrical stimulation of the lateral anterior hypothalamus (15).

These deviations in the state of consciousness, motility and muscle tonus as early as the first day of life, and continuing into the early months of infancy, provide additional evidence of some early disturbance of functioning of the nervous system in this population, which was genetically loaded for schizophrenia. It is postulated that these dysfunctions are related to the disturbances of motility, excitability and perception which are seen in older schizophrenic children (1, 8).