Introduction
Benign senescent forgetfulness (BSF) was a term introduced in 1958 by Voijtech Adalbert Kral (1903–1988), a Czech-Canadian psychiatrist and neurologist (Merskey, Reference Merskey1989; Lauter, Reference Lauter1991). Even though preceded by concepts of “normal senility” (Bleuler, Reference Bleuler1924), “normal senescent decline” (Dörken and Kral, Reference Dörken and Kral1951), “mild senescent memory decline” (Kral, Reference Kral1958) and others (Lautenschlager, Reference Lautenschlager2002), BSF is undisputedly believed to be the first among more than a dozen terms referring to mild changes in elderly cognition and is thus considered the original predecessor of mild cognitive impairment (MCI) (Lautenschlager, Reference Lautenschlager2002; Reisberg et al., Reference Reisberg, Ferris, Kluger, Franssen, Wegiel and de Leon2008). In his most cited reference – “Senescent forgetfulness: benign and malignant”(Kral, Reference Kral1962) – Kral suggested that in old age there appear to be at least two types of memory dysfunction distinguishable by their clinical symptoms, course and prognosis: (i) BSF, and (ii) malignant senescent forgetfulness (MSF). In contrast to current MCI, BSF was not considered a pathological entity, or a “pre-dementia” stage or even a risk factor for the development of dementia, but rather a variant of normal aging memory changes explainable as “senium naturale” (Kral, Reference Kral1962). MSF, on the other hand, formed the axis syndrome of psychosis with senile brain disease (Kral, Reference Kral1962). Clinically similar to the notion of “Korsakoff/amnestic symptom complex” transferred to senile dementia (Bleuler, Reference Bleuler1924), MSF (and malignant amnestic syndrome / typical amnestic syndrome, used interchangeably) was semantically designated by Kral to contrast BSF. All of them correspond to today's dementia of the Alzheimer's type with or without a vascular component.
BSF initially enjoyed about two decades of popularity. This is partly because it was found “valid in a general way” (LaRue, Reference LaRue1982), and because it “rang true” (Levy et al., Reference Levy1994) with those working with the nascent specialty of geriatric psychiatry, and consequently rapidly entered standard books on the subject (e.g. Pitt, Reference Pitt1974; Levy and Post, Reference Levy and Post1982). Towards the end of the 1970s the term BSF was criticized on conceptual, methodological and semantic grounds (Miller, Reference Miller1977; LaRue, Reference LaRue1982; Crook et al., Reference Crook, Bartus, Ferris, Whitehouse, Cohen and Gershon1986; Blackford and LaRue, Reference Blackford and LaRue1989), and it was concluded that “we may be dealing with a phantom or mythic disorder, a single symptom disorder that masquerades as a diagnostic entity” (Bamford and Caine, Reference Bamford and Caine1988). Alternative terms – e.g. very mild cognitive decline (Reisberg et al., Reference Reisberg, Ferris, Leon and Crook1982), age-associated memory impairment (Crook et al., Reference Crook, Bartus, Ferris, Whitehouse, Cohen and Gershon1986), age-consistent memory impairment and late-life forgetfulness (Blackford and LaRue, Reference Blackford and LaRue1989), and ageing-associated cognitive decline (Levy, Reference Levy1994) – were suggested.
From the 1990s onward, in parallel with the introduction of the term and later the concept of MCI (Flicker et al., Reference Flicker, Ferris and Reisberg1991; Zaudig, Reference Zaudig1992; Petersen, Reference Petersen1995; Petersen et al., Reference Petersen, Smith, Waring, Ivnik, Tangalos and Kokmen1999), the attitude toward BSF became characterized by “scholarly indifference”, and regarded merely as of historical interest.
This paper deals with the origins of BSF and MCI, a subject on which very little research has been published. I argue that not only BSF but also MCI originated with Kral and that much of the initial BSF/MCI conceptual history might be attributed to the interplay between two dynamic forces: Kral and the arena in which he operated. I begin with a short professional biography of Kral (based on the biography and publications provided by Merskey (Reference Merskey1989) and Lauter (Reference Lauter1991)), followed by a description of the locus operandi of Kral's research on BSF, before describing the surveys and classifications from which BSF and MCI supposedly derived.
A short professional biography of V. A. Kral
Voijtech Adalbert Kral was born to a Jewish family in 1903, in today's Czech Republic, then a part of the Austro-Hungarian Empire. His professional life can be divided into four major periods according to the locations at which he worked:
(1) Prague. In 1927 he received his MD degree from the German-language Charles University, and went on to specialize in psychiatry and neurology from 1928 to 1934. During the early 1930s he spent short periods at the Psychiatric Clinic in Zurich, the German Research Institute in Munich, and the Pharmacological Institute and Psychiatric Neurologic Clinic in Vienna, where he became acquainted with the Bleulers, Wagner-Jauregg, Essen-Möller, Stengel, and Mayer-Gross. Between 1934 and 1939 in Prague, Kral achieved Associate Professorship in the Department of Neurology and Psychiatry. His works during these years were published mostly in German-language periodicals, and demonstrated a wide interest in biological and organic psychiatry. Two of his publications at this time suggest that he was already interested in memory disorders (“Pathogenesis and psychopathology of the amnestic complex following head injuries” together with R. Klein in 1933)(Merskey, Reference Merskey1989), and borderline zones in psychiatric classifications (“The borderlines between neuroses and organic diseases of the nervous system”, in 1938)(Merskey, Reference Merskey1989)
(2) Theresienstadt. After the Nazi occupation of Czechoslovakia, and during the years 1942–45, Kral and his family were deported to the concentration camp at Theresienstadt, where he survived as a physician.
(3) Montreal. In 1947 the Kral family emigrated to Canada, and he worked at Verdun Protestant Hospital in Montreal for five years where, under Heinz Lehman, he experienced the introduction of chlorpromazine to North America (Shorter, Reference Shorter1997). Although Kral's interest in memory disturbances can be traced back to the early 1930s, his major initial research on amnestic syndromes and dementia was undertaken in the late 1940s and early 1950s while at Verdun (Kral, Reference Kral1951; Reference Kral1955; Reference Kral1956; Dörken and Kral, Reference Dörken and Kral1951; Reference Dörken and Kral1952; Kral and Durst, Reference Kral and Durost1953). Kral then moved to the Allan Memorial Institute of Psychiatry in Montreal where, from 1953 under D. Ewen Cameron, he served as Director of the Gerontologic Unit, the first of its kind inaugurated in North America in 1944 (Shorter, Reference Shorter2005). At the same time, he was consultant in the Geriatric Clinic of the Jewish General Hospital one of the first to use a multidisciplinary team approach (Kral and Wigdor, Reference Kral and Wigdor1957), and from 1955 he was also a consultant in the Montreal Hebrew Old People's and Sheltering Home (Heinik, Reference Heinik2006). Between 1952 and 1972 he was a lecturer and ultimately associate professor at McGill University. In these years, Kral investigated and published on various experimental and clinical issues: for example, psychological tests in brain injuries, influence of stress on young and old mice, stress and the mental disorders of the senium, the newly introduced psychiatric medications (e.g. imipramine, thioridazine), and the androgen effect on senescent memory (Merskey, Reference Merskey1989). During this period, while a consultant to the Montreal Hebrew Old People's and Sheltering Home (hereafter the Home), Kral composed his “core” works (Kral, Reference Kral1958; Reference Kral1962; Kral and Wigdor Reference Kral and Wigdor1961; Reference Kral and Wigdor1963; Wigdor and Kral, Reference Wigdor and Kral1961) on memory disorders in the elderly.
(4) London, Ontario. After retiring he was invited in 1972 to London, Ontario, where he continued his clinical and research activities until his death in 1988.
The Montreal Hebrew Old People's and Sheltering Home
The Home was established in 1912 by a benevolent Jewish agency. Based on a historical review of the Canadian Jewish Congress archives in Montreal, the Home's history has been described extensively in a previous article (Heinik, Reference Heinik2006).
An applicant to the home had to be of the Hebrew faith and willing to observe Kosher dietary laws. Religious views and practices were considered a private concern and residents were not obliged to attend religious services. Minimum admission age was 60 years for women and 65 for men. The admission process in the mid-1950s required a personal interview by a social worker with the applicant and a family member. Applicants underwent a medical examination by the resident physician, and a psychiatric examination (from about 1955). When deemed necessary by the social worker, the applicant's home was visited prior to admission. Admission was not granted to applicants who: (i) were psychotic or had advanced mental disease; (ii) were in an advanced state of senility or were mentally confused; (iii) suffered from acute infectious disease; (iv) had inoperable terminal cancers or other terminal stages of disease; or (v) had personality problems which would interfere with group living.
The typical applicant/resident was female (about 60%), widowed (about 80%), aged 75 to 80 years old, living in Montreal, a citizen of Canada though born in Central or Eastern Europe (about 90%), and had lived in Canada for more than 20 years (about 95%; about 70% more than 40 years). Women were mostly housewives, though some were previously employed in unskilled or semi-skilled jobs. Men were salesmen of small inexpensive items, small shopkeepers, or semi-skilled workers. Levels of education were generally low. Residents spoke mostly English and/or Yiddish. None was illiterate in survey 1 and only a few in survey 2. The typical female resident was able to care for herself. She presented with some form of minor mental aberration, usually associated with advancing age (49%). She needed continued light routine medical care, mostly for circulatory-cardiac disease (93%), arthritis (23%), anemia (19%) and diabetes (14%), and was not in contact with a social agency (Heinik, Reference Heinik2006).
In the mid-1950s the Home was an active institution. Four sets of factors worked to shape its character and development in the years to come:
(1) Demographic factors. In 1951, Jewish people aged over 65 years made up 6.4% of the population in Montreal; it was estimated that this proportion would double by 1981 (to 10.1%) (Heinik, Reference Heinik2006). However, the number of new applicants per year to the Home roughly doubled during the four years from 1954 to 1958 (from 60 to 108); with its fixed capacity of 140–145 beds, the Home was placed under enormous pressure.
(2) Professional/medical factors. Other “homes for the elderly” in other communities were providing or programming specialized services to the aged (e.g. the Home for Aged and Infirm Hebrews of New York, the “Baycrest Hospital” of Toronto), and constantly improving their services (Heinik, Reference Heinik2006). Geriatric medicine, psychogeriatrics and gerontology were developing and beginning to impact on public opinion (Morley, Reference Morley2004; Hilton Reference Hilton2005).
(3) Conceptual/ economic. From its inception, the basic services of the Home were to provide food, shelter, general medical care, and an environment which closely followed the Jewish tradition. However, whereas the Home cared initially for indigent persons only, the introduction of improved old age pensions legislation over the years meant that greater emphasis was placed on social and health reasons for admission.
(4) Physical facilities and living conditions. By 1954 the Home was overcrowded, privacy was non-existent and specialized care facilities were lacking. Development of new programs seemed essential. Pressure from the Home's overseeing agency for new programs and changes was constant. Long-term planning based on applied research was necessary.
Against this turbulent background Kral was hired as a neuropsychiatric consultant to the Home in 1955. His primary duties included neuropsychiatric examination of applicants and development of an applied research program to identify measures to improve conditions. Kral's appointment could be considered an excellent “acquisition”. Coming from a similar personal background as his patients, he also filled an important position in Montreal's newly established professional geriatric psychiatric community, not to mention his impressive knowledge and interest in amnestic syndromes and dementias of various etiologies (Heinik, Reference Heinik2006).
Two surveys conducted by Kral at the Home
Survey 1 was conducted between 1956 and 1957 and included all 162 residents of the Home. The primary purpose was to assess the mental health among the residents and to recommend measures to improve the conditions (Kral, Reference Kral1958; Reference Kral1962). In accordance with his duty to develop a research program, Kral welcomed the “rare” opportunity (rare for a clinician working mainly with hospitalized psychiatric patients with major pathologies) to study more closely certain aspects of mental functioning in a relatively large number of aged people, many of them “well preserved” (Kral, Reference Kral1962).
The basic medical data were already available (medical files containing physical examination, treatment notes, X-ray, serologic, hematologic and biochemical findings) as performed by the resident physician, medical co-directors and nursing staff, complemented by personal data, pre-admission history of the family and social situation as compiled by the social worker (Heinik, Reference Heinik2006). Kral added a meticulous comprehensive neurological and psychiatric examination (Kral, Reference Kral1955). The psychiatric interview was traditional, largely focusing on “certain aspects of mental functioning” (memory) by the “usual clinical methods” of orientation and general information (adapted to the background and educational level of the subject) and tests for recent memory and immediate recall (Kral Reference Kral1958). This was complemented by a modified version of the Wechsler Memory Scale (Wechsler, Reference Wechsler1945) administered to all subjects (Kral, Reference Kral1958). However, the latter test results were not used to classify subjects in Survey 1 and were not reported in the “core” BSF articles (Kral, Reference Kral1958; Reference Kral1962).
The accumulated data enabled Kral to suggest a classification system that introduced BSF (Kral, Reference Kral1958; Reference Kral1962). Kral departed from contemporaneous Continental and American psychiatric classifications, such as those of the DSM-1 (American Psychiatric Association, 1952) and Roth (Reference Roth1955). He maintained that criteria other than those based on nosologic diagnosis had to be used (Kral, Reference Kral1958). He was fully aware of Roth's classification (acute confusion, senile psychoses, arteriosclerotic psychoses, affective disorders, late paraphrenia) of mental disorders in the elderly (Roth, Reference Roth1955), the first of its kind, and acknowledged it as a step forward in the direction of better prognostication and treatment. However, for the evaluation of the Home's residents he suggested that a classification based purely on psychiatric nosology would be impractical for the following reasons: (i) it would not include those considered “normal” in the clinical sense; (ii) the differential diagnosis between arteriosclerotic and senile psychoses may present great difficulty in this population of elderly subjects (a notion suggested earlier by Bleuler (Reference Bleuler1924), which was later abandoned but is today undergoing something of a revival); and (iii) cases of mental disorder at the Home, unlike Roth's subjects, did not have to be committed to a mental hospital. A more formal psychiatric classification such as the DSM-1 was even less appropriate for his purposes.
Therefore, independent of any possible psychiatric diagnosis, each individual was considered on the basis of the following observational criteria:
• degree of preservation of personality, judgment and emotional responsiveness
• presence (or absence) and type of memory impairment
• presence (or absence) of psychotic or neurotic symptoms.
Based on these criteria, a classification of the entire population of the Home into five groups was suggested:
Group A (37 persons, 22.8%): well-preserved personality, appropriate emotional reactions, preserved judgment, no memory impairment, no history or signs of functional psychosis.
Group B (30 persons, 18.5%): well-preserved personality, preserved judgment, appropriate emotional reactions, no psychotic signs, “mild” memory impairment which was evident in difficulties at times in recalling relatively unimportant information from the past which was available at other times. The subjects were aware of their short-comings and tried to compensate for these by circumvention and were, at times, apologetic. Remote memory was otherwise not impaired nor was there any clinically ascertainable defect of recent memory or immediate recall. Orientation was largely maintained. Confabulations were absent. This group was classified as BSF, and was found with equal frequency in both sexes.
Group C (24 persons, 14.8%): residents without memory defect but with a definite history and/or signs of functional psychoses of either the affective or the paraphrenic type. This group also included several cases of “neuroses of later maturity” (Kral, Reference Kral1958).
Group D (49 persons, 30.2%): typical amnestic syndrome, namely impairment of recent memory and immediate recall, disorientation, particularly in time, and loss of remote memory. Confabulations were present in some cases. The amnestic syndrome varied from moderate to severe and, in the latter cases, was frequently connected with disturbances of thought, impaired judgment, and nominal aphasia.
Group E (22 persons, 13.6%): amnestic syndrome, but also with additional psychotic signs, like paranoid delusions, hallucinations, or depressive or manic mood swings. Groups D and E constitute Kral's MSF, which was more prevalent among women.
Aware that this was not a representative sample of the entire elderly population, Kral was nevertheless satisfied with the relative demographic and cultural homogeneity of the patient population which comprised the whole spectrum of senescence from complete preservation of personality to senile deterioration. From a cross-sectional aspect, the observational criteria used to evaluate and classify each individual were not defined operationally nor weighted (in fact, terms like “preserved personality” and “judgment” proved inherently difficult to define and were slowly excluded as diagnostic criteria from the psychiatric classifications in later years. The memory dysfunction of Group B (BSF) subjects was difficult to test directly and objectively (how can a personal experience forgotten one minute and recalled spontaneously some time later be tested?) and proved difficult to replicate. Nevertheless, from a longitudinal aspect, a four-year follow-up performed optimally at a relatively closed unit such as the Home could improve the validity of BSF. At follow-up, there were 61.7% deaths among MSF subjects, almost twice the deaths among normal and BSF subjects (27.5% and 38.5% respectively), the last two not significantly different, and survival time was only 15.2 months in MSF compared with 25 and 23.5 months in normal and BSF subjects, respectively (Kral, Reference Kral1962). Considering the benign nature attributed to BSF, the above course would have more in common with the unfavorable prognosis regarding incidence of dementia reported by Petersen et al. (Reference Petersen, Smith, Waring, Ivnik, Tangalos and Kokmen1999), even-though direct comparison is impossible owing to different methodology.
The primary purpose of Kral's study, namely the recommendation of measures to improve conditions in the Home, could be accomplished based on the data accumulated and the proposed classification. In fact, the great majority (125; 77%) of the Home's residents were found to suffer from memory disturbance and/or signs of psychosis or neuroses; 24 (14.8%) were psychiatric patients, and 71 (33.5%) had MSF, that is dementia, with or without additional psychiatric symptoms (despite the Home's strict screening procedure for new applicants). Possible explanations were that some subjects deteriorated over time, that assessment was less efficient before a neuropsychiatrist joined the staff, and that there are always “exceptional” admissions. Therefore, residents in Groups C and E could benefit from the new psychiatric medications, and the behavioral disturbances of psychotic individuals could consequently be treated more effectively, thereby avoiding transfer to a closed mental hospital. Residents in Groups D and E and some of Group C might require specific treatment settings, either in specific departments within the Home or in other institutions that provided closer observation. Group B BSF subjects could be reassured that their memory dysfunction was not progressive, and anxieties were thus relieved. Kral also searched for a pharmacological remedy for these subjects (Merskey, Reference Merskey1989).
Survey 2 was conducted between April 1957 and April 1961 by Kral and his psychologist colleague Blossom Temkin Wigdor. For the first time, the survey also included results of psychological tests, which were administered to 94 residents (those who were well preserved; with a history of functional psychosis; malignant amnestic syndrome). The modified Wechsler Memory Scale (WMS) was administered to all; however, the entire battery (see below) was administered only to the well-preserved residents. The articles based on this survey (Kral and Wigdor Reference Kral and Wigdor1961; Reference Kral and Wigdor1963; Wigdor and Kral, Reference Wigdor and Kral1961) are not well known. This is probably one of the earliest clinical and psychological studies of the border between mental functional decline of aging per se and the results of pathological changes essentially independent of the aging process. The issue of mental functioning in the well-preserved elderly, which was only secondarily referred to in Survey 1, was now directly confronted.
Fifty-two well-preserved subjects (Kral and Wigdor, Reference Kral and Wigdor1961; Reference Kral and Wigdor1963), screened at admission to the Home and in Survey 1, were found to be free of mental disorder (i.e. neither depressed at assessment nor demonstrating significant signs of a typical amnestic syndrome) or of any incapacitating neurological or medical disease. For Kral and Wigdor (Reference Kral and Wigdor1961; Reference Kral and Wigdor1963) “well preserved” referred to the “general behavior of the residents in the Home and to their relationship with the outside world. In the Home they were able to look after their personal needs, to take part in its social and religious activities, and frequently also to help the housekeeping, kitchen, and nursing staff in the daily routine and chores. They were able to visit with their relatives, or to enjoy their visits in the Home; some did their own shopping, visited a nearby library, or went to religious ceremonies or shows.”
Several psychological tests were administered by Wigdor, a certified psychologist with a doctorate, who was experienced in their administration. They were administered one-to-one in a private room (Wigdor, personal communication), with subjects being tested in the language in which they were most fluent (Wigdor and Kral, Reference Wigdor and Kral1961) as follows:
a. the verbal scale of the Wechsler Belleview Intelligence Scale I;
b. the Bender Gestalt Visual Motor Test (to assess the ability to deal with perceptual and organized material);
c. the Rorschach Test (a test of personality structure and the level of functioning); and
d. the modified Wechsler Memory Scale (WMS).
Kral had already performed some studies using the Rorschach test in various organic and dementia conditions (Dörken and Kral, Reference Dörken and Kral1951; Reference Crook, Bartus, Ferris, Whitehouse, Cohen and Gershon1952). After Rorschach in 1921, they were the first to study it in senile dementia, with the Wechsler Adult Intelligence Scale, the Bender Gestalt and the Rorschach test among referrals to the Geriatric Clinic of the Jewish General Hospital (Kral and Wigdor, Reference Kral and Wigdor1957), and with the WMS in a study of the amnestic syndrome in various organic conditions (Kral and Durost, Reference Kral and Durost1953). Kral, however, used a modified WMS that consisted of a combination of the WMS and recall data as used in clinical examinations as follows: orientation in the three fields (time, place, person); personal and current information; recent memory; remote memory; practical memory (Meyrat's test); immediate recall of logical material; digits forward and backward; recall of five objects presented visually and followed by a non-relevant question before verbal reproduction. The scores were the total number of things correctly recalled out of a highest possible score of 117; a score below 90 indicated a significant level of impairment (Kral and Durost, Reference Kral and Durost1953; Kral and Wigdor, Reference Kral and Wigdor1961; Reference Kral and Wigdor1963; Wigdor and Kral, Reference Wigdor and Kral1961).
Kral and Wigdor were aware of the difficulty of assessing this group using the above tests, and warned that actual intelligence quotient (IQ) should be regarded as a good approximation. They were convinced that, in general, it reflected the level of the group (Kral and Wigdor, Reference Kral and Wigdor1963).
From a clinical perspective, four patient subgroups were delineated according to memory functions: Group I (25, 48.1%): without any memory deficit or previous depression; Group II (13, 25%): with “mild” type of memory impairment (BSF); Group III (9, 17.3%): without memory deficit, but with a history of previous depression; Group IV (5, 9.6%): with signs of an incipient amnestic syndrome (IAS) of such a mild degree that it did not interfere with their social and personal functioning.
As for the psychological tests, intellectual assessment revealed low average IQs for the entire group, and the mean IQ of 87.5 (range 66–105) for the total group was at the “dull” normal level. Memory testing showed some memory impairment in all subjects with the average of 83.7 being under the “cutoff” of 90, with 98 being the highest score. Group I subjects had higher mean scores (87.7) than Groups II (81.7) and III (82.5). Group IV subjects had the lowest mean score (72.2). The scores on the Bender Gestalt drawings (total group mean 113, range 41–215) were for the most part indicative of a marked impairment in the capacity to perform such a task. There was, however, a very wide range in scores. On the Rorschach test the group as a whole generally confirmed the findings for an old age group. Since in the following years this personality test was progressively excluded from cognitive impairment and dementia research, I will not refer to it further.
Kral and Wigdor (Reference Kral and Wigdor1961; Reference Kral and Wigdor1963) emphasized the correlations between the findings and the capacity to adjust and function (i.e. to adapt). However, looking at the above findings from a different perspective, they represent a sample with the following clinical and (neuro) psychological characteristics: (a) all well-preserved aged people; (b) normal (dull) level of general intelligence as demonstrated by IQs; (c) subnormal performance on a specific memory test; (d) subnormal performance on a specific perceptual/organization test; and (e) no significant signs of malignant amnestic syndrome.
The above construct was very similar to the operational criteria of what today constitutes MCI: i.e. no or minimal impairment of activities of daily living; normal general cognitive level; impairment of memory and/or other cognitive domains; no dementia (Petersen et al., Reference Petersen, Smith, Waring, Ivnik, Tangalos and Kokmen1999; Winblad et al., Reference Winblad2004). Further interpretation would depend on how we hypothesize the influence of the demographic and social characteristics of the subjects on performance of the psychological tests. If we presume the existence of such an influence, IAS (a pre-MSF syndrome) in Group IV subjects might constitute amnestic MCI, as memory seemed to be more prominently impaired in this small group, and, as the name implies, were more prone to deteriorate. If we take the results as they are, then many if not the entire sample might be considered multidomain MCI amnestic. Regrettably, Kral's presentation of data precludes consistent comparison between the groups (e.g. it would be interesting to see how BSF was distinguished from IAS), and follow-up data for the above sample were never reported.
Conclusions
BSF and, as I have argued here, also the notion of MCI resulted from the interplay between the mind of a clinician/researcher ready to suggest innovative but practical ways to survey and classify the mental state of the elderly and a Home for the elderly, which at that particular time demanded and was ready to accept new solutions to improve the well-being of its residents. Kral promoted BSF (Kral, Reference Kral, Katzman, Terry and Bick1978) at the expense of the well-preserved elderly/IAS notion. It is, however, the relatively unknown part of Kral's work which emphasized the investigation of the well-preserved elderly sample using psychological tests of general intelligence and more specific tests for memory and non-memory functions, and the introduction of IAS, a pre-dementia syndrome, that freshly associates with the modern construct of MCI. Kral, working in the non-psychiatric and partial clinical setting of the Home, was faced with elderly individuals who had questionable or mild degrees of cognitive impairment and/or personality changes, and thus he was in a similar observational position as researchers on this subject decades later. Lacking clearly defined operational criteria for dementia (“no dementia” currently constitutes a crucial aspect of MCI), Kral was supposedly unable to develop this line of investigation further, despite the methodology he introduced. Following the publication of the DSM-III, the latter researchers, however, had both a valid methodology for early diagnosis of dementia as well as adequate criteria for dementia.
Conflict of interest
None.
Acknowledgments
I thank Mrs. Janice Rosen, Director of CJC National Archives, Montreal, Canada, for her gracious assistance in providing archival materials; Emeritus Professor Blossom Temkin Wigdor, Department of Public Health Sciences, University of Toronto, for her in-depth discussion with me regarding her work with Professor Kral; and Mrs. Rena Kurs for assistance in preparing the manuscript.
