Alzheimer's disease: A conceptual history

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  • INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, VOL. 5: 355-365 (1990)

    ALZHEIMERS DISEASE: A CONCEPTUAL HISTORY

    G. E. BERRIOS Consultant and University Lecturer in Psychiutry, University of Cambridge: Director of Medical Studies and Fellow,

    Robinson College, Cambridge; Honorary Librarian, Royal College of Psychiatrists; Department of Psychiatry, University of Cambridge, Addenbrookes Hospital (Level 4), Hills Road, Cambridge, UK

    KEY woRDs-Alzheimers disease, dementia, history.

    In the 1969 Ciba symposium on Alzheimers disease Professor McMenemey (1970) asked: How far are we justified in departing from the criteria originally laid down by the person who first described the malady? (p. 6). He went on to suggest that depar- tures in neuropathological characterization might be allowed provided that the case histories were typical, and that symptomatic (clinical) departures might be equally permissible when the neuropath- ology was typical. McMenemey concluded that both types of change might have taken place since the first description of Alzheimers disease.

    This article is about mapping the events that pre- ceded, and immediately followed, the first descrip- tion of this disease. To identify the boundaries of the original description is no easy matter. The writ- ings of Alzheimer, Fischer, Fuller, Lafora, Bon- figlio, Pcrusini, Ziveri, Kraepelin, and other protagonists in this story are deceptively fresh, and this makes anachronistic reading almost inevitable. And yet the psychiatry of the late nineteenth cen- tury is a remote country: even crucial concepts such as dementia, neuron, neurofibril or plaque had not yet been fully crystallized and meant difyerent things for different people.

    The mirage caused by an anachronistic reading can only be dispelled by exploring the history of the many terms and issues that played the support- ing cast to Alzheimers disease: these include dementia, ageing, neuronal theory, methods of visualizing brain tissue, academic psychiatry and departmental rivalries, senile psychosis, and cer- ebral artcriosclerosis. This might help to recon- struct the perception that alienists of the 1910s had of the new disease.

    Another way of dealing with anachronistic read- ings is to ask what clinical problem the creator was trying to solve. In this case, it would seem that

    Alzheimer was interested in the early onset of the condition, its uncommon severity, its focal symp- toms, and the simultaneous presence of plaques and tangles. If so, one must ask why it was these fea- tures, and not the simultaneous presence of, say, arteriosclerotic changes or of hallucinations and delusions, that bothered him.

    In answering this question the historian will come to realize that the 1906 debate was not about creating homogeneous diagnoses. It was about the building blocks of neurobiology: whether neurons were independent units, or whether they were cap- able of ameboid movements (Black, 1981; Billings, 1971), or whether staining techniques were reliable, and so on.

    HISTORIOGRAPHICAL ISSUES

    Two metaphors control the study of historical nos- ology. One pictures the clinician as cataloguing spe- cies in an exotic garden; the other sees him as a sculptor carving shapes out of formless matter, ie creating clinical forms. These metaphors impose different conceptual duties. The garden approach needs to explain why the naturalist happens to be there in the first place; the creational view requires an understanding of the sculptors inner vision. To achieve the latter the historian must examine scientific and social factors.

    To the consumers of disease, however, it matters little which allegory has been chosen: patients wear their illness in the most personal of ways; clinicians take as given ongoing textbook definitions which they regard as a reflection of some Platonic entity. Consequently, they see themselves more as clinical cartographers than as challengers of the putative immutability of disease. This was Professor

    0885-6230~90~060355-12$06.00 0 1990 by .john Wiley & Sons, Ltd.

    Received 24 January 1990

  • 356 G . E. BERRIOS

    McMenemeys point: what else it is permissible to add to the disease without upsetting its boundaries. But, is this right? Should we worry about upsetting the boundaries of any disease?

    One reason for this question is that the garden metaphor creates all manner of difficulties. For example, priority seekers may find that the origi- nal cases of Alzheimers disease bear limited resemblance to those defined by current criteria, or that it is not possible to identify the precise moment when the disease was first discovered. One way out of this impasse has been to assume that the discoverer did not get it quite right, for example that he included some wrong symptoms. Thus, some might claim that by insisting on the presence of hallucinations and delusions, or by not minding about major arteriosclerotic changes, Alz- heimer, Fuller, Bonfiglio, Lafora, and Perusini got it partially wrong.

    There has of late been a shift towards the creationist view. At its basis is the assumption that there is no such a thing as the jinal description for a disease, that clinical boundaries, symptom content, and even anatomical description consti- tute temporary scripts cribbed from the ongoing medical discourse. In other words, a disease is defined not only by the power of resolution of the ongoing science, but also by periodic backroom decisions taken by her self-appointed mandarins.

    Thus, the clinician trying to understand why Alz- heimers disease is not called, for example, Fischers, Fullers or Perusinis disease would be wise to conceive of nosological categories as result- ing from the interaction between a descriptive (ver- bal or numerical) language and a biological process (bodily changes emitting signals in the shape of symptoms and signs). Because the language of description also reflects the beliefs of its users, dis- ease creation is also a social phenomenon. This explains why, for example, until recently the so- called behavioural or psychiatric symptoms of Alz- heimers disease were ignored (Berrios, 1989). Recent interest in this issue (eg Wragg and Jeste, 1989) reflects less a change in the presentation of the disease than in observer bias,

    THE ACTOR

    The scenario described above tends to emphasize ideas, and this may lead to neglecting the people who entertained them; most great alienists have

    been, however, good at grabbing the limelight. Not so Alzheimer, whose fame was thrust upon him by those who loved him well or had their own reasons to do so. He was born on 14 June 1864 in the small German village of Marktbreit am Main. He trained at Berlin, Wurzburg and Tubingen. In 1888 he became a county asylum officer in Frank- furt where he started his life long association with Nissl. Kraepelin called Nissl to Heidelberg in 1895 and Alzheimer joined them in 1903. In October the same year he moved to Munich, where Kraep- elin had accepted the Chair of Psychiatry at the Ludwig- Maximilians-Universitat. In 1912 Alz- heimer was appointed to the Breslau chair (now Wroclaw in Poland) and died on 19 December 191 5.

    Achucarro, Lafora, Jelliffe, and the many others who worked in his laboratory saw him as a humble and hard-working man, perhaps a better researcher than a clinician (Valenciano, 1977; Lewey, 1953). Kraepelin said of him: He posed a thoroughness in research which was stopped by no obstacles, by no difficulty, but above all, an almost cruel self- criticism which could not be corrupted and which controlled all his thinking, and a boundless caution in regard to all conclusions . . . (Young, 1935). Alzheimers main contribution was on the histol- ogy of general paralysis of the insane, and in the technical field on methods for the fixation and his- tology of the CSF. Although not a theoretician, he was particularly interested in what he called the disintegration (Abhau) of the nervous tissue and in the hypothesis that analysis of catabolic products might provide biological markers for the functional psychoses (Alzheimer, 1906). (For further details on his life see Hoff and Hippius, 1989; Kreutzberg and Gudden, 1988; Meyer, 1959).

    THE CONCEPTUAL BACKGROUND

    History of the notion of dementia

    At the end of the nineteenth century the term dementia was used to name any state of psycholo- gical dilapidation associated with chronic brain dis- ease (Guiraud, 1943; Blumer, 1907); traditionalists included within this term deficit states related to the functional psychoses, hence irreversibility was not considered as a criterion (Berrios, 1987; Marie, 1906). When dementia states occurred in the elderly they were called senile dementia, and had been

  • HISTORY OF ALZHEIMERS DISEASE 357

    so since the beginning of the century. In this regard, however, it must be remembered that even by 1900 the term dementia did not necessarily evoke an association with old age, as it tends to do nowa- days. This is why Morel in the 1860s and Kraepelin 40 years later had no difficulty in using the term dementia, as in dementia praecox, to refer to states of psychological dilapidation in young peo- ple (Berrios and Hauser, 1988).

    By the cnd of the nineteenth century this state of dilapidation was considered to result from a primary disorder in cognitive function, and defined almost entirely in terms of memory decline (Berrios, 1990; Toulouse and Mignard, 1914; DAllones, 1912; Jaspers, 1910). Again, some trad- itionalists still adhered to the older view that the psychosocial incompetence of dementia was not necessarily related to memory impairment. Cour- bon (1912) felt able to write: In dementia this faculty [memory] is in fact much less impaired than i t seems (p. 300). He believed that the central problem of dementia was one of chronic confusion which impeded the adequate use of all cognitive faculties. This explains why there was little diffi- culty in accepting that temporary or permanent remissions might occur in the course of a dement- ing disease; this although efforts had been made since the 1820s to tie up the concept of dementia with irreversible brain changes (on this see first- class paper by Kowalewski, 1886).

    The view that dementia was both a clinical and a neuropathological category was put on a firm footing by Bayle in 1822 (Berrios, 1985). However, no clear idea existed as to what type of lesions were involved or whether they affected the same area of the brarn. From the 1860s (particularly since the work of Marce, 1863) efforts began to be made to identify a separate brain pathology for senile dementia in subjects who had not previously suf- fered from mental illness. Research in this age group became important for it avoided the problem of having to decide whether the brain lesions were related to primary states of mania or melancholia. By the early 1900s efforts had also been made to: (a) measirre the symptoms and severity of dementia (Jaspers, 1910; Puillet and Morel, 1913; Berrios, 1990); (b) ascertain the differential importance of the senile and vascular aetiology of dementia (McGafin, 1910; Treadway, 1913); and (c) study the comparative prevalence of senile dementia in relation to other psychiatric disorders affecting the elderly (Pickett, 1904; Southard, 1910; Bolton, 1903). These enquiries were influenced by ongoing

    theories on ageing of brain tissue (Marinesco, 1900).

    Histological techniques

    Up to the middle of the nineteenth century puta- tive brain changes associated with psychiatric dis- ease were described in the language of gross anatomy (Parchappe, 1841; Wilks, 1865). They involved changes in colour, consistency, weight, volume, relative proportion of solids to fluids, etc. These observations, as indeed all the early micro- scopic descriptions, were hampered by inadequate brain preservation and fixation and staining tech- niques. The relevance of staining artifacts, for example, cannot be exaggerated. At the very end of the century the Cambridge anatomist Hardy wrote: It is, I think, one of the most remarkable facts in the history of biological science that the urgency and priority of this question should have appealed to so few minds. It is notorious that the various fixing reagents are coagulants of organic colloids, and that they produce precipitates which have a certain figure or structure. It can also be shown that the figure varies, other things being equal, according to the reagent used (Hughes, 1959).

    But the seeing also depended upon theory (Fou- cault, 1963), for the issue was not only agreeing on shapes and colours, but also on what they meant, on what structures these features were assumed to represent, on what Maulitz (1987) has aptly called the code of the body. After the 1880s, however, staining techniques improved in quality, and animal studies (like those carried out by Ram6n y Cajal (DeFelipe and Jones, 1988)) allowed a closer analysis of resolution power (for details see Conn, 1933).

    Alzheimer himself contributed to the develop- ment of staining methods. However, his descrip- tions of pathological changes, like everyone elses in his time, were hampered by the fact that there was not yet full agreement on what the units of change (eg neurons, glia, etc.) really looked like. For example, Nicolas Achucarro, the talented Spa- nish pathologist (who died very young), showed in Alzheimers own laboratory that glial cells could give rise to formations which mimicked neuro- fibrillary tangles (Moya, 1968).

    When Spielmeyer (191 1) published his classic work more than 100 techniques had become avail- able, out of which about 15 were dedicated to the visualization of neurofibrils. These included the

  • 358 G. E . BERRIOS

    techniques based on gold developed by Apathy, on molybdenum by Bethe, on pyridine-molybde- num by Donaggio, on silver by Bieslchowsky and Ramon y Cajal and on toluidine by Bethe and Lugaro (Spielmeyer, 191 1; Bertrand, 1930).

    The debate on the concept of neuron Between 1880 and the Great War two views vied

    for supremacy: the neuronal theory considered neurons as independent units, never touching or touching only sporadically, and had Ramon y Cajal as its champion; reticularism, on the other hand, held that brain cells formed a syncitium, a network of cells, and its leading proponent was Golgi (Ramon y Cajal, 1952; Clarke and Jacyna, 1987). Waldeyer is recognized as having coined the term neurone in 1891, although Hughes (1959) has reported that the term neuron had already been used by B.G. Wilder in 1884.

    The first round of the debate was won by the neuronists, but early in the twentieth century Held, Bethe and Apathy revived a version of the reticular- ist view. The latter two men were, interestingly enough, also important to the discovery of neuro- fibrils (Fuller, 1907). These structures, significant in the later definition of some forms of senile dementia, played an important role in the reticular- ism debate. Alzheimers position on neuronal theory is...