La catatonie progressive par accès périodiques ou « catatonie périodique » de Karl Leonhard. 1er partie. Description du phénotype et diagnostic neuropsychiatrique

Abstract

While the correlation between the phenotype of periodic catatonia and two biomarkers, one genetic and the other brain imaging, has attracted the attention of international psychiatry, there has been little clinical or etiopathological research on this phenotype. The main reason is probably that this phenotype described by the Wernicke-Kleist-Leonhard (WKL) school has been defined in a paradigmatic framework so far removed from that of the ICD or DSM, and that even its name is problematic. Here, ‘periodic catatonia’ has nothing to do with a simple recurrence of relapsing-remitting ICD-catatonia. Hence, we will refer to it as ‘periodic catatonia by progressive access’ (PCPA) to distinguish it from remitting forms. In PCPA, catatonic manifestations are often inconspicuous, and more than half of the patients advance in a step-like progression towards a kind of disabling ‘deficit schizophrenia’. Preliminary results indicate that this symptomatology, which is usually resistant to psychopharmacological treatments, could respond to a personalized neuromodulation treatment specific to PCPA. This is what a national study seeks to confirm in France. In this context, this two-part article aims to make those psychiatrists who have been trained in ICD/DSM psychopathology aware of PCPA and to enable them to diagnose it correctly. The objective of this article is therefore twofold. In the first part, it seems essential to present the problem. PCPA is a product of systems neuropsychiatry, whose diagnostic approach is at odds with the atheoretical and polythetic approach of the international classifications. This first part is intended to present an idea of the diagnostic procedure and to stress the impossibility of diagnosing ‘periodic catatonia’ without reference to its conceptual framework. This is emphasized by changing the name: PCPA is not periodic catatonia, but an operationalization of the original concept. PCPA is intended to be sharable without recourse to a theoretical corpus which is not universally accepted. Therefore, we will describe PCPA using ICD-11 terminology to present an overall picture of the symptomatology and to introduce the elements on which it will be possible to rely when performing the probabilistic diagnosis that will be presented in part II.