Extrapyramidal Rating Scale Effectively Measures Tardive Dyskinesia Symptoms

Photo Credit: Galeanu Mihai

The Extrapyramidal Symptom Rating Scale and an abbreviated version of the scale were both validated for measuring the impact of tardive dyskinesia.

“The Extrapyramidal Symptom Rating Scale–Abbreviated (ESRS-A) is an abbreviated version of the Extrapyramidal Symptom Rating Scale (ESRS) with instructions, definitions, and a semi-structured interview that follows clinimetric concepts of measuring clinical symptoms,” Fiammetta Cosci, MD, MSc, PhD, and colleagues wrote. “Similar to the ESRS, the ESRS-A was developed to assess four types of drug-induced movement disorders (DIMD).”

This includes tardive dyskinesia (TD), according to the researchers. They published a study in Psychotherapy and Psychosomatics that reviewed the literature on relevant clinimetric properties seen with the ESRS and ESRS-A in clinical studies. The review included comprehensive ESRS-A definitions, basic instructions, and information on ESRS inter-rater reliability that two pivotal studies and additional multicenter international studies assessed.

Questions in the ESRS-A related to dyskinesia focused on patients’ awareness of their symptoms and included follow-up questions about others’ recognition of these symptoms.

Validity & Sensitivity Seen With ESRS & ESRS-A

The ESRS demonstrated high concurrent validity, with 96% agreement between the Abnormal Involuntary Movement Scale (AIMS) for TD- and ESRS-defined cases. In addition, concurrent validity for ESRS-A total and subscores for dyskinesia ranged from good to very good.

The study team found ESRS was particularly sensitive for identifying differences in movement related to drug-induced movement disorders after treatment with antidyskinetic medications. It was also able to differentiate between extrapyramidal symptoms and psychiatric symptoms, according to the study results.

“The ESRS and ESRS-A are valid clinimetric indices for measuring DIMD,” Dr. Cosci and colleagues wrote. “They can be valuably implemented in clinical research, particularly in trials testing antipsychotic medications, and in clinics to detect the presence, severity, and response to treatment of movement disorders.”