Dementia
Dementia has become hot property. From a place in the shadows, a condition hardly daring to speak its name it has become high profile, the subject of interest to national and international leaders: a necessary reference for every informed and caring individual and organisation [1–3].
Logic has been pressing for this for decades as the epidemiology of dementia and the changing age profile of the world population determines that its incidence, prevalence, and cost implications, both personal and economic rise higher and higher [4, 5]. Somehow a threshold was passed within recent years as individuals, including well-known celebrities and their families, have come to experience dementia and began to share their experiences openly [6]. Lobbying by care organisations, including the Alzheimer’s societies of individual countries and at international level, have gathered information, encouraged research, and demanded better care and prospects for treatment [7, 8]. The pharmaceutical industry and research community have fanned the flames to encourage investment to improve understanding and knowledge, which can inform strategies that might reduce incidence, ameliorate symptoms, and improve care [9].
There are two strands to the campaigners’ message:
- Dementia can be a dreadful condition to live with and die with.
- There are things that can be done to make it less of a threat. This includes careful assessment to identify treatable or reversible components of the condition.
We have come to know dementia as a syndrome defined by Lishman [10] as “an acquired global impairment of intellect, memory and personality, but without impairment of consciousness. As such it is almost always of long duration, usually progressive and often irreversible, but these features are not included as part of the definition” (p. 9).
Thus dementia as a syndrome is a clinical concept, not one defined by neuropathology. It carries the possibility of “causation” by a number of underlying conditions and additional factors that may occur singly or in combination. Detailed symptomatology, experience, and outcome are thence a function of the individual’s constitution, the natural history, and interactions of the underlying and associated conditions, and of the interventions proffered: physical, psychological, and social interventions.
While Lishman caricatures the specific dementias of Alzheimer’s disease, Pick’s disease, and others as “progressive and widespread brain degeneration with, at the moment, a hopeless prognosis” (pp. 8–9). The same is not true of the syndrome. Careful assessment may identify reversible or ameliorable factors.
Berrios [11, 12] has traced the international and historical story of dementia, the usage of the word, and the concept being captured. The Latin word demens was used by Celsus in his writings in early Roman texts [13] and variations on this appeared in several medical traditions from then onward. The concept of dementia had a legal aspect: “those who are in this state are incapable of informed consent, cannot enter into contracts, write their wills or be members of a jury” (D’Argis, quoted by Berrios [12], p. 832 ) and a clinical aspect: “those affected by this condition exhibit foolish behaviour and cannot understand what they are told, cannot remember anything, have no judgement” (D’Aumont, quoted by Berrios [12], p. 832).
Differentiation from what we now look on as delirium when prolonged or sub-acute was not clear, nor was differentiation from life-long difficulty with learning. The term amentia was sometimes preferred and included all these states (Cullen, 1827, quoted by Berrios [12]). The belief developed that true dementia (amentia) was always irreversible and usually associated with progressive degeneration of the faculties and functions. Post-mortem examinations revealed shrunken and altered brains (Willis, 1684, quoted by Berrios [14]).
Pseudodementia
It was known that some people who presented with clinical features of dementia did not deteriorate and some might recover. This phenomenon of reversibility was accommodated by the term vesanic dementia (Ball and Chambard, 1882, quoted by Berrios, 1985 [14], p. 394) and later by pseudo-dementia, which is attributed to Wernicke [15] by Bleuler [16].
Pseudo is a descriptive term with origins in Greek and translates as “false,” “sham,” “spurious,” or “deceptively resembling” [17]. It is widely applied in medicine to capture conditions that have similarities to a well-known syndrome or diagnostic entity but that on closer inspection do not fulfil all its criteria: thus pseudo-hypoparathyroidism, pseudo-pseudo-hypoparathyroidism [18]. At the time that “General Paralysis of the Insane” was a common mental disorder and cause of hospitalisation, there was the concept of “Pseudo General Paralysis” [12].
Within a world that has been seized with terror and fascination with the prospects of inevitable deterioration to dependency and death by Alzheimer’s (now more feared than cancer among older people [19], the concept of pseudodementia with the possibility of recovery has real attractions.
Lishman devoted 14 pages to the topic of “The Pseudodementias” [10] (pp, 561–575) and identified four main varieties: the Ganser syndrome [20], hysterical pseudodementia, simulated dementia, and depressive pseudodementia. He pointed out that these are not mutually exclusive and that individuals are encountered whose condition does not fit into any of these categories.
The Ganser syndrome was originally described in prisoners. It includes the phenomenon of approximate answers. Answers are often absurd and may be accompanied by disturbance of consciousness, hallucinations, or other abnormal mental phenomena. There is often evidence of coarse brain disease.
Hysterical pseudodementia occurs in situations of psychological conflict or ambivalence. The relationship of its onset and course to stresses is often easily seen by an objective observer. It is more common in people with a learning disability or otherwise evidenced immaturity of emotional development or personality. Yet it can occur in anyone under great stress and is facilitated by coexistent brain damage or other illness.
Simulated dementia is probably rare. Such a diagnosis requires that an individual is knowingly falsifying symptoms and behaviour for a calculated gain.
Jaspers [21] had applied the label pseudodementia to patients with the Ganser Syndrome of Hysterical Amnesia, including “talking past the point” (Vorbeireden, pp. 194, 220, 391). He did not identify a depressive subtype.
Yet depressive pseudodementia must surely be the variant that demands the greatest attention. The presentation of severe depression often includes cognitive change with reduced concentration, slowness of thought, difficulty in registering current events, and a subjective feeling that the brain is not working as it should. This picture may appear in successive relapses. In middle-aged and older people the picture may be very suggestive of dementia, with slowness of movement, loss of confidence, weight-loss, and an appearance of a stooped, wrinkled persona much older than their chronological age [22].
Other causes of pseudodementia include the major psychoses: hypomania and schizophrenia, or other neurotic disorders.
Kiloh
Kiloh described ten cases of pseudo-dementia [23] in what has become a key and influential paper. He was writing just a short time after the publication of Roth’s studies, which made clear the differentiation in symptoms and outcomes for old people admitted to mental hospitals with depression, dementia, or delirium [24]. Kiloh’s cases illustrated the importance of careful clinical assessment and awareness that depression could sometimes mimic dementia and that it is treatable, especially with electroconvulsive therapy. This is a wonderful message and holds true.
The late Tony Whitehead [25], a great pioneer of services for old people, enthused to the paradox: “Where there is depression, there is hope.”
In his review of pseudodementia and tribute to Leslie Kiloh on the 50th anniversary of the 1961 publication, John Snowdon [26] chose to entitle his paper “Pseudodementia: A Term for Its Time.”
It was certainly an important corrective to any slackness of thought that might have taken Roth’s work to mean that dementia is always of hopeless prognosis. The implication that the term was useful then, but redundant now [27, 28], is surely incorrect.
Caine [29] certainly saw pseudodementia as an important and relevant concept, though he suggested a kinship with sub-cortical dementia.
Berrios, writing with Bulbena [30], accepted that pseudodementia was a phenomenon worthy of consideration. They noted at least 30 publications in scholarly journals but found most to be characterised by “anecdotal reporting, skewed series and speculation.”
Berrios concluded that they were describing, “A collection of clinical states rather than a process … the common denominator is an ability to impair cognition or to disable the mechanisms by which cognition is expressed” (p. 87).
The paper reviewed 61 cases from the literature and added 22 new cases. It was felt that most could be accommodated by a tripartite sub-classification: essentially hysterical pseudo-dementia after Madden [31], reversible dementia Kiloh [23] (after Wernicke), and delirium – reversible, symptomatic organic psycho-syndromes.
As in Kiloh’s series, Berrios’s 61 cases from the literature were relatively young (average age in their late 50s). Women outnumbered men. More than half had a history of previous mental illness, usually depression and more than half, where information was given, had evidence of a neurological deficit. Impaired memory was evident in two-thirds, depression in more than half, delusions, hallucinations, confusion, lability of mood, or admixture of elevated mood present in significant minorities. Twenty-six patients received ECT and all recovered. The additional 22 patients from Fulbourn Hospital were older, more likely to be female, but otherwise similar in symptom profile and outcomes.
In the previous edition of this Troublesome Disguises, Pitt [32] updated the review of the literature and considered the mechanisms which contribute to real or apparent memory disorder in association with depression. In these he included: poor motivation in tasks, negativism (taking against testing), response bias (“I don’t know”), over-caution, learned helplessness, anergy and retardation, preoccupation, agitated inattentions, iatrogenic factors (including medication), altered brain function and language impairment.
In addition he drew from a paper by Wells [33] a list of features favouring a diagnosis of depressive pseudodementia and anticipating good prognosis: short history, previous or family history of affective illness, definite time of onset, misery or lack of joy, disparity between subjective and objective assessment (with the patient feeling their memory is much worse than testing reveals), drawing attention to the disability, moderate (rather than severe) cognitive impairment, absence of confabulation (after Post [34]), ‘Don’t know’ answers, no ‘cortical’ features such as dyspraxia or dysphasia, no progression to disability, and good response to antidepressants or ECT. These fit well with Kiloh’s descriptions.
Pitt added four case histories to make particular important points:
A 50-year-old man presented with depression associated with ill health, a diagnosis of glaucoma, and learning of the unfaithfulness of his wife. Despite treatment in a psychiatric unit with antidepressants and ECT, he remained withdrawn, frail, and became incontinent of urine. A brain scan showed cortical atrophy and a diagnosis of presenile dementia was made and he was place in long-term care. Three years later there had been no further deterioration. Treatment with antidepressants resulted in recovery, discharge home, and return to work.
