The effects of antipsychotic medication on factor and cluster structure of neurologic examination abnormalities in schizophrenia.
This study extends a previous study of the factor structure of the neurologic examination in unmedicated schizophrenia, utilizing cluster analysis and adding a medicated condition. We administered a modified version of the Neurologic Evaluation Scale (NES) on two occasions to 80 patients with schizophrenia or schizoaffective disorder, once while on antipsychotic medications and once while off medication. Data were distilled by combining right- and left-side scores, and by excluding rarely abnormal and unreliable items from the analysis. Principal components analysis yielded an intuitive four-factor solution in the unmedicated condition, but an inscrutable five-factor solution during medication. Cluster analysis revealed three groups: normal, cognitively impaired, and diffusely impaired. These results were also less interpretable with data from the medicated condition. Neurologic performance was better in the medicated than in the unmedicated condition. As is the case with other domains of symptoms and performance in schizophrenia, relationships among neurologic exam variables are altered by the presence of antipsychotic medication.
Goldstein
Gerald
G
VA Pittsburgh HCS, 7180 Highland Drive, Pittsburgh, PA 15206, USA. ggold@nb.net
Sanders
Richard D
RD
Forman
Steven D
SD
Tarpey
Thaddeus
T
Gurklis
John A
JA
Van Kammen
Daniel P
DP
Keshavan
Matcheri S
MS
D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology*; D016000:Cluster Analysis; D005163:Factor Analysis, Statistical; D006801:Humans; D009460:Neurologic Examination / Q000187:drug effects*; D011597:Psychomotor Performance / Q000187:drug effects; D011618:Psychotic Disorders / Q000145:classification / Q000175:diagnosis* / Q000188:drug therapy; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000145:classification / Q000175:diagnosis* / Q000188:drug therapy; D012565:Schizophrenic Psychology
D014150:Antipsychotic Agents