Karl Kleist (1879-1960) - the man behind the map

Frontotemporal dementia: Past, present, and future

INTRODUCTION

The history of frontotemporal dementia (FTD) is both old and new. This study explores its historical roots, dating back to the 19th century, while recognizes it as a distinct neurological entity only a few decades ago.

METHODS

This qualitative study and literature review provides an overview of FTD's historical background, birth, evolution, and future directions.

RESULTS

Recognition of FTD was hindered by rigid perceptions of dementia, the division between neurology and psychiatry, reliance on IQ-based assessment, limited neuroimaging capabilities, and lack of pathological proof. Overcoming these barriers involved revisiting early pioneers' approaches, focusing on focal impairment, establishing non-Alzheimer's disease cohorts, fostering collaboration, and developing diagnostic criteria. Current gaps include the need for biology-oriented psychiatry education, biological biomarkers, and culturally sensitive, objective clinical instruments predicting underlying pathology.

DISCUSSION

Independent multidisciplinary centers are essential. The future of FTD lies in disease-modifying therapies, presenting new opportunities for healthcare professionals and researchers.

[Between affirmation and negation: Karl Kleist and Viktor von Weizsäcker between 1933 and 1945]

In 1954 Karl Kleist (1879-1960) became an honorary member of the German Neurological Society (DGN), an honor that was granted 2 years earlier to his colleague Viktor von Weizsäcker (1886-1957). The attempt to classify and assess their careers between 1933 and 1945 led to diametrically opposed results in historical research. This article summarizes the main lines of argumentation and draws a preliminary conclusion. After 1933 Kleist is said to have felt more and more accountable for his non-Aryan colleagues and that he treated his Jewish patients as long as he could. Publications and third party testimonies confirmed that he circumvented at least occasionally the Law for the Prevention of Genetically Diseased Offspring (GzVeN). Furthermore, he is said to have saved patients from "euthanasia" actions by prudently formulated diagnoses. Simultaneously, he worked as an expert at the Appelate Hereditary Health Court in Frankfurt am Main, in 1940 he joined the National Socialist German Workers' Party (NSDAP) and in 1942 the NS Medical Association. Von Weizsäcker used his scope of action in a similarly contradictory way. Certainly, he kept away from central Nazi organizations and was considered "politically unreliable" by those colleagues who had a penchant for the system. But as professor of neurology he formally headed from 1941 onwards exactly that Neuropathological Research Institute in Breslau (Wroclaw) where one of his colleagues examined the brains of minors who had been killed in the course of "child euthanasia", in what was called "concomitant research". To a certain extent von Weizsäcker was also an advocate of the GzVeN. In his lectures and publications between 1933 and 1935 he chose the pertinent NS terminology and he was the first to speak of a "theory of extermination". In either case, even meticulous research could not answer the question where to exactly assign both biographies in a spectrum between criticism and affirmation of National Socialism.

Constructional apraxia from the roots up: Kleist, Strauss, and their contemporaries

The concept and the term of constructional apraxia have been proposed by Karl Kleist and described in his impressive book "Gehirnpathologie", published in 1934. However, the first ever paper under the heading of constructional apraxia was written by Hans Strauss, one of Kleist's pupils, and published in 1924. Nowadays, the term constructional apraxia is still in use to refer to all disorders observed in drawing and assembling activities; its assessment, performed as it was in early studies, is part of common practice in behavioral neurology and neuropsychology. Nonetheless, the concept and the neural underpinnings of constructional apraxia have been deeply revisited with respect to the original proposal. Modern studies demonstrated that drawing and assembling are based on very large and complex brain networks extending in both hemispheres, including the left angular gyrus (as hypothesized by Kleist) but well beyond the original ideas about localization of constructional apraxia. From a clinical point of view, constructional apraxia has poor localizing value but provides valuable diagnostic information for conditions of cognitive impairment.