Objective assessment of patients diagnosed as having tardive dyskinesia
Assessment of tardive dyskinesia (TD) is usually done using clinical rating scales. These techniques have been criticized as possibly contributing to inconsistent research findings. Of more immediate relevance to the patient, the scales are useful only after the disorder has become clinically pronounced, by which time it may be irreversible. What is needed is a more sensitive assessment device, which could detect abnormal movement earlier. Such a device might also clarify the issue of variability in the overt manifestations of TD; this variability has led some researchers to suggest that TD may be a family of disorders, possibly with differing etiologies. A distinction between limb and oral TD has been proposed in this regard. Objective assessment techniques such as accelerometer records can detect movement invisible to the unaided eye, and would therefore seem suited to the task of identifying incipient abnormal movement. They should similarly prove useful in the detection of possible underlying commonality amoung the various clinical manifestations of TD. The present study addressed the latter issue by assessing abnormal movement at apparently unaffected body sites in TD patients. It was hypothesized that such movement would be apparent in accelerometric recordings. Experimental groups consisted of patients whose abnormal movement focussed on the limb (group TDL, n = 15) or the oral region (TDO, n = 14). A control group (n = 16) was equated with the other groups for age, sex, psychiatric diagnosis, and neuroleptic dosage. Three dependent measures found to discriminate TD from NTD subjects in pilot research were used in the present study. Accelerometric recordings were taken in one oral and three limb postures, yielding 12 dependent measures. Significant differences emerged between TD and NTD subjects on seven dependent measures. Only one measure showed a significant difference between the two TD groups. Discriminant analysis resulted in accurate discrimination of TD from NTD subjects using data combined from all postures. Many NTD subjects, however, were also assigned to TD groups on at least one posture; these may represent cases of subclinical abnormal movement. Discrimination between the two TD groups was inconsistent, over half of each group assigned to the other on at least one posture. (Abstract shortened with permission of author.)
Pologe, Bennett, "Objective assessment of patients diagnosed as having tardive dyskinesia" (1988). ETD Collection for Fordham University. AAI8809480.