Dermatoembryological Antecedents in Schizophrenics

Neuroimaging techniques have consistently revealed various cortical and subcortical structural variances for individuals with schizophrenia. Established findings include enlargement of the lateral ventricles and discrete anatomic deficits in temporobasal s tructures of the cerebrum. Epidemiology and developmental studies suggest that a significant proportion of cases of schizophrenia have their origins in the perinatal period. " The mechanisms involved in the errant neurodevelopment remain obscure, but some disruption in neuronal migration is suggested. It is noteworthy that an increase in synaptic interconnections between layers I and II has been reported in the brains of schizophrenics. Normally these initial interconnections drop out as surrounding neurons and those that are still arriving begin to differentiate, mature, and grow axons and dendrites. Presumably, in schizophrenics, layer I neurons maintain these interconnections with layer II and III because of the failure of their normal counterparts to successfully complete their migration. This would also explain the lack of gliosis and argue against a degenerative process. Fetal organogenesis is largely completed by the first trimester. The second trimester is a critical period of massive neuronal migration from the periventricular germinal matrix to the cortex.Peripherally, the distal upper limb develops simultaneously with this neural migration. The ectodermal cells of the fetal upper limbs will migrate to form the epidermis during the fourth and fifth months of gestation. Second trimester environmental exposure has been associated with physical anomalies, dermatoglyphic asymmetry, and an increased risk of schizophrenia.A disturbance in anatomical and functional connection between migrating cells could seriously impede the integration, processing, and filtering of information that perhaps is reflected in dermatoglyphics.Fingerprint identification is the most positive form of personal identification known. It is well established that the ridge arrangement is different on every finger of every individual. Significant dermatoglyphic differences have been observed for fingerprint patterns in schizophrenics. Total finger ridge counts and 'atd' angle between schizophrenics—both those with and those without a positive family history of schizophrenia—suggest a genetic component in familial cases of schizophrenia. Dermatoglyphic features of isolated schizophrenics also significantly differ from those of reference controls, which supports the genetic heterogeneity of schizophrenia and the existence of congenital factors in the absence of a family history. Considerable progress has been made in the understanding of the associations between dermatoglyphics and various medical disorders. As a result, dermatoglyphic analysis has been established as a useful diagnostic and research tool in medicine, providing important insights into the inheritance pattern and embryological development of certain clinical syndromes. Embryologic and experimental dermatoglyphic studies clearly hold considerable potential for a present understanding of the factors influencing the development of epidermal ridge pat terns , as they relate to neurodevelopmental disorders and environmental offense. Although schizophrenia afflicts only 1% of the population, the costs are staggering. In the United States alone, direct and indirect costs approximate $40 billion annually. Medication expenses account for only 2.3% of this amount, which is far lower than the drug costs of many other medical illnesses. " If central embryological antecedents can establish a clinical association for dermatoglyphics and schizophrenia, those at risk or individuals with incipient disease may be identified and offered a structured, nurturing, and undemanding developmental period so as to diminish the severity of societal dislocation, and presumably costs. [MM