Objective and quantitative equilibriometric evaluation of individual locomotor behaviour in schizophrenia: Translational and clinical implications.

Psychiatry is the only medical specialty that lacks clinically applicable biomarkers for objective evaluation of the existing pathology at a single-patient level. On the basis of an original translational equilibriometric method for evaluation of movement patterns, we have introduced in the everyday clinical practice of psychiatry an easy-to-perform computerized objective quantification of the individual locomotor behaviour during execution of the Unterberger stepping test. For the last 20 years, we have gradually collected a large database of more than 1000 schizophrenic patients, their relatives, and matched psychiatric, neurological, and healthy controls via cross-sectional and longitudinal investigations. Comparative analyses revealed transdiagnostic locomotor similarities among schizophrenic patients, high-risk schizotaxic individuals, and neurological patients with multiple sclerosis and cerebellar ataxia, thus suggesting common underlying brain mechanisms. In parallel, intradiagnostic dissimilarities were revealed, which allow to separate out subclinical locomotor subgroups within the diagnostic categories. Prototypical qualitative (dysmetric and ataxic) locomotor abnormalities in schizophrenic patients were differentiated from 2 atypical quantitative ones, manifested as either hypolocomotion or hyperlocomotion. Theoretical analyses suggested that these 3 subtypes of locomotor abnormalities could be conceived as objectively measurable biomarkers of 3 schizophrenic subgroups with dissimilar brain mechanisms, which require different treatment strategies. Analogies with the prominent role of locomotor measures in some well-known animal models of mental disorders advocate for a promising objective translational research in the so far over-subjective field of psychiatry. Distinctions among prototypical, atypical, and diagnostic biomarkers, as well as between neuromotor and psychomotor locomotor abnormalities, are discussed. Conclusions are drawn about the translational and clinical implications of the new approach and its future perspectives.

Computerized ultrasonographic craniocorpography and abnormal psychomotor activity in psychiatric patients.

A new version of craniocorpography (CCG), called computerized ultrasonographic CCG (Comp-USCCG), has been clinically applied for objective recording, documentation, and quantitative evaluation of abnormal psychomotor activity in psychiatric patients. Implications of this completely new approach to psychopathology are discussed. An original representation of Comp-USCCG data (introducing the time dimension as a new CCG parameter) is used to illustrate better the atypical abnormal stepping Comp-USCCG movement patterns in psychotic patients, some of which have not been described in neurootological patients to date. These atypical abnormal stepping Comp-USCCG movement patterns are prolonged longitudinal or shortened or backward longitudinal displacement; dysrhythmic longitudinal or lateral sway; and longitudinal or lateral directional changes. Reflecting the abnormal psychomotor activity, Comp-USCCG also provides for possible indirect evaluation of the underlying subjective psychotic experience. The contribution of the approach could be defined as an application of a known neurootological method into a new field of medicine (psychiatry) with a new purpose (to record and measure abnormal psychomotor activity). Our conclusion is that Comp-USCCG could become the first objective and quantitative method available for use in the field of clinical psychiatry.