Krankheitsreste: The residual signs of catatonia. A case series.

Background: Catatonic signs were first described by 19th- and 20th-century researchers. An important concept known as "Krankheitsreste," or the residual signs of catatonia, was described by Kraepelin in 1896. Modern researchers describe patients who demonstrate "partial response to the treatment of catatonia with residual signs." Kraepelin observed that these signs occurred between catatonic episodes as part of the natural course of illness. Modern psychiatrists see residual signs after intervention or treatment. The determination of residual signs of catatonia is necessary to evaluate the most effective treatment approach to the patient.

Methods: In this case series, we describe 3 patients whose catatonia improved with treatment, but each exhibited continued residual signs of the syndrome. Appropriate consent was obtained from the patients and we identified the varying levels of catatonic signs using the Bush-Francis Catatonia Rating Scale (BFCRS) and the KANNER scale.

Results: Scores on both the BFCRS and KANNER scale decreased on followup in all 3 patients, with varying levels of success. The BFCRS score for the patient in Case 1 dropped 4 points upon follow-up, and their score on Part 2 of the KANNER scale decreased 12 points. The patient in Case 2 experienced a 5-point drop in their BFCRS score at follow-up and their score on Part 2 of the KANNER scale decreased 4 points. In Case 3, the patient's BFCRS score dropped 10 points at follow-up and their score on Part 2 of the KANNER scale decreased 20 points.

Conclusions: These 3 patients demonstrate Krankheitsreste, or "partial response to the treatment of catatonia with residual signs." Each patient had a developmental disorder and 2 had autism spectrum disorder. They exhibited improved self-care and greater independence and required less restrictive living environments.