Uncommon and/or bizarre features of dementia: part IV
It is well established that the clinical picture of dementias is not clinically homogeneous. For example, non-amnestic presentations of Alzheimer’s disease have been referred to as a typical variant. Careful examination of clinical characteristics contributes to understanding the neurobiology of Alzheimer’s disease and other dementias and may in turn enhance knowledge of the potential risk factors involved. This study aimed at describing uncommon or bizarre symptoms/syndromes observed in patients suffering from dementia. Medline and Google scholar searches were conducted for relevant articles, chapters, and books published before 2019. Search terms used included dementia, déjà vu, zoophilia, pathological lying, and somatic symptom disorder. Publications found through this indexed search were reviewed for further relevant references. Uncommon/bizarre features of dementia were described as case reports and there were no systematic investigations.
KeywordsDèja vù Zoophilia Pathological lying Somatic symptom disorder Dementia
Dementia is a chronic brain syndrome conceptualized as a multifactorial process  presenting a significant variability in terms of clinical presentations, neuroanatomical involvement, and neuropathological profiles. Although slowly progressive anterograde and retrograde amnesia is the commonest clinical presentation of Alzheimer disease (AD), other symptoms may sometimes be the most prominent in the early stages of disease [2, 3]. The heterogeneity of the clinical presentation of dementia presumably reflects a variable topographical distribution of the burden of brain pathology . In previous articles [5, 6, 7] we described unusual and/or bizarre features reported in patients suffering from dementia (Cotard’s syndrome, delusional jealousy or Othello syndrome, delusional misidentification syndrome, delusion of pregnancy, delusional parasitosis, Diogenes syndrome, erotomania or de Clérambault syndrome, folie à deux, lycanthropy, Ganser’s syndrome, manic syndrome, extracampine hallucination, obsessions and compulsions, gambling disorder, and altered sense of humour). With this article, we intend to continue in the description of further atypical or bizarre manifestations that occur during some dementing syndromes. We highlight a limitation that affects crosswise our work: the lack of pathological confirmation of the dementia subtype in the reported cases.
The déjà vu is typically a transient mental state in which there is a strange feeling of familiarity despite the perceived situation being novel to the person . Centuries ago, St. Augustine referred to the phenomenon as “falsae memoriae” . The individual is convinced that he/she is able to predict what is going to happen next . The French psychiatrist Francois-Léon Arnaud, whose 1896 case report was among the first pieces of scientific literature to use the term DV, originally documented this condition . The sensation of DV arises as a conjunction of two streams of cognition: the phenomenological experience of recognizing a current situation and the awareness that this feeling of recognition is inappropriate . The subjective nature of the typical DV experience lies in its one-sided resolution towards unfamiliarity; an individual feels that he or she has visited a place before but knows that he or she has not and acts accordingly . In other words, DV occurs when one feels as though a situation is familiar, despite evidence that the situation could not have been experienced before; in a DV experience, one has a feeling of recognition in the face of evidence that the situation was never before experienced, and the source of that feeling is unclear . The DV experience must be differentiated from phenomena such as flashbacks and vivid memory. Flashbacks include visual and auditory illusions and hallucinations, and give the sense that the subject has actually been transported into the midst of a prior experience . In a vivid memory, the past comes into focus, but there is nothing in the present that seems familiar . A DV hypothesis posits that to experience DV one needs intact recollection to produce the clash in evaluations . That is, an inappropriate feeling of recognition will be generated, driven by an erroneous feeling of familiarity (empirical studies that differentiate recollection from familiarity have typically found that recollection is slower, more accurate and associated with higher subjective confidence than familiarity; recollection can confirm that memoranda which elicit high familiarity are “old” by providing an unambiguous contextual memory from the moment of encoding ). But, in order for this to be experienced as déjà vu, it is critical that a separate memory monitoring process gives rise to the belief, knowledge or feeling that this is false. The phenomenon of DV can be regarded as the opposite of the jamais vu experience, in which there is an inappropriate absence of familiarity (jamais vu is French for “never seen”) . Compared with DV, jamais vu is less common in normal populations and much more prevalent in some neuropsychiatric conditions; this difference in prevalence suggests that novelty and familiarity may be signalled by different brain pathways . Twenty different types of DV experiences are described. Based on anecdotal accounts, the most common seems to be: déjà visité (already visited), déjà vécu (already lived through), déjà rêvé (already dreamt), déjà entendu (already heard), déjà éprouvé (already experienced), déjà lu (already read), and déjà senti (already felt). Numerous studies have attempted to discover the prevalence of DV experiences in the general population and patient groups: between 31% and 96% of “normal” people reported having experienced déjà vu [18, 19, 20, 21, 22]. According to some researchers, “minor” DV is transient and has a rapid onset, and can be thought of as a non-pathological, everyday memory error; “major” DV is pathological and prolonged . Many investigations have compared DV incidence in male and female participants, but no consistent gender difference has emerged . DV occurs more frequently in younger people, its prevalence increasing with education and skill of occupation . Authors stated that, despite suggestions that DV declines with age, déjà vécu increases with age and it is a common, although underreported symptom in patients with memory disorders . It has long been known that seizures in the temporal lobe region give rise to memory-like hallucinations and the sensation of DV . It was argued that the phenomenon is the result of faulty and isolated activity of a recognition memory system that consists of the parahippocampal gyrus and its neocortical connections . A case of persistent déjà vecu was reported following meningitis . Single-photon emission computed tomography revealed a marked hypoperfusion in the right temporal lobe and a lesser extent in the right frontal lobe, although magnetic resonance imaging demonstrated no abnormal findings. The DV experience has been associated with many psychopathological disorders—anxiety and dissociative neuroses, mood and personality disorders, schizophrenia, and organic brain syndromes and disorders . However, it is difficult to determine whether their DV experience is similar to that of non-schizophrenic individuals, because schizophrenia involves a variety of cognitive distortions . Moulin et al.  reported the case of MA, a 70-year-old woman who presented to her doctor, convinced that things had happened before, as evidenced by her memory for them happening as they happened. She also reported that she already knew news events such as the Bali bombing which she claimed to have already known about. She had déjà vécu for television programmes, even if they were a new series or programmes that her husband knew that she had not seen previously. On neuropsychological examination, MA initially scored 16/30 on the MMSE. A CT scan showed generalised atrophy. There was no infarct, space-occupying lesion or intracranial haemorrhage. MA was given a diagnosis of AD. Moulin  described the case of an 80-year-old man suffering from AD. The patient and his wife moved to a new area, and when they visited the hospital for the first time, he was certain that he had been there before and had sat in the same chair. Using data from patients with dementia, and healthy groups, a research suggested that in pathological DV, there is a critical failure to metacognitively interpret feelings of familiarity . Management of DV is essentially pragmatic. DV may be the sole manifestation of temporal lobe seizures and the attacks may resolve abruptly upon introduction of antiepileptic drugs.
Paraphilias are defined as persistent and intense atypical sexual arousal patterns that are accompanied by clinically significant distress or impairment. The behaviours occur over a period of at least 6 months . They are much more common in men than in women, but the reasons for this difference remain unknown . A large number of paraphilias have been described and catalogued, ranging from fetishism (the preferential use of particular objects for sexual gratification) to paedophilia (a sexual preference for children). Zoophilia is a paraphilia whereby the perpetrator gets sexual pleasure in having sex with animals. Many authors use the terms zoophilia, zoophilism, zooerasty, zooerastia, bestiality, and bestiosexuality interchangeably . Information about the prevalence of bestiality in different parts of the world are lacking, as well as information on the distribution of the different forms of zoophilia among the normal population . According to Grassberger , close contact with animals as well as the lack of human partners in connection with young age and impaired mental abilities were causes leading to sexual contacts with animals. Peretti and Rowan investigated reasons for sustaining the practice of zoophilia over a period of at least 4 years [35, 36]. Their data suggested that the variables most important were sexual expressiveness, sexual fantasy, enjoying not needing to negotiate about human sexual contact, no human social involvement, economic reasons, and emotional involvement with the animal. Othman et al.  described a 65-year-old divorced man who presented with a 4-year history of personality and behavioural changes with inappropriate sexual behaviour. He developed new and uncharacteristic use of profanity in which he frequently cursed and used obscene language toward others. He was frequently seen wandering around the village exposing his genitalia. The man was brought for psychiatric attention, as the villagers had been accusing him of sodomizing farm animals such as chicken, goat and cow. The family members noted slight cognitive deterioration in patient’s activities of daily living as well as his instrumental activities of daily living after he got the illness. His short-term memory, abstract thinking and insight were poor. Neuropsychological assessment showed poor melokinetic ability, delayed response, personality change and, poor visual learning and memory signifying frontal lobe with predominantly right temporal deficits. The patient’s diagnosis was behavioural variant frontotemporal dementia (bvFTD). Specific treatment modalities include cognitive behavioural therapies, selective serotonin reuptake inhibitors (SSRIs), and antiandrogen medications: SSRIs are indicated when one’s paraphilic behaviour and interest are mild and do not pose a danger to others, antiandrogen medications are indicated in cases of refractory paraphilic behaviour and when the behaviour poses a danger to others [38, 39]. Antipsychotics are considered another line of treatment .
The concept of lying is surprisingly difficult to define, mainly because lying is not a single entity, but rather a singular manifestation of an unknown quantity of mechanisms and beliefs across an extraordinary range of circumstances. According to Simpson and Weiner , to lie is to make a false statement with the intention to deceive. Psychological distinctions are evident between people who exhibit pathological or compulsive tendencies to lie compared with psychologically normal people who choose to lie on specific occasions. Pathological lying (PL) is a controversial topic. The German physician Anton Delbruck is credited with being the first to describe the concept of PL after an extensive examination of lies told by five of his patients . PL, “pseudologia fantastica”, mythomania and morbid lying are generally used interchangeably, although it remains debatable whether they all describe the same phenomenon . Currently, there are no systematic studies about PL based on a larger number of participants trying to elucidate the concept, and the research on this topic largely includes commentaries and case studies on various types of lying . Yang et al.  performed a research to provide initial empirical data on the structural brain imaging correlates of lying and deception. Liars had increased prefrontal white matter volumes and reduced grey/white ratios compared with normal controls. One interpretation of the white matter increase in the ventral and lateral non-superior frontal regions could be that a pre-existing variation in prefrontal structure may predispose individuals to engage in PL . Psychiatric conditions that have been traditionally associated with deception in one form or another include malingering, confabulation, Ganser’s syndrome, factitious disorder, borderline personality disorder, and antisocial personality disorder, histrionic and narcissistic personality disorders . Poletti et al.  described the case of a 57-year-old married and college-educated man who presented a behavioural pattern characterised by apathy, verbal aggressiveness, impulsivity, occasional compulsive shopping, frequent lies, and lack of insight. He reported to be an expert of software programming, an instructor of climbing, a radioamateur, and to have played on a famous soccer team. These stories were totally false. At the neuropsychological examination, the patient showed deficits suggestive of a progressive neurodegenerative bvFTD. There are similarities and differences between PL and other syndromes, such as confabulation. According to Dalla Barba , the term confabulation refers to a particular memory disturbance, observed in some brain-damaged patients, which consists of both actions and verbal statements that are unintentionally incongruous to history, background, and present situation. Authors enucleated three functions of confabulation: (1) making sense of the current situation (sense making); (2) maintaining a personal identity in interaction with others (self-making); and (3) organizing and legitimizing joint action in the world (world making) . What these three positive functions essentially are saying is that confabulation may help those with dementia to feel more positive about themselves and preserve some of their ability to communicate and interact with others. The identified functional elements of PL are: the repeated utterance of untruths; the lies are often repeated over a period of years, with the lies eventually becoming a lifestyle; material reward or social advantage does not appear to be the primary motivating force but the lying is an end in itself; an inner dynamic rather than an external reason drives the lies, but when an external reason is suspected, the lies are far in excess of the suspected external reason; and the lies are often woven into complex narratives . Unlike confabulations, in PL there is persistent quality of a story and there is no deficit of memory. The neuropsychological assessment of patients may help to shed light on the neurocognitive bases of PL. With few case studies and no clinical research on this subject, the optimal management strategy remains controversial and unclear .
Somatic symptom disorder
The diagnosis of somatic symptom disorder (SSD) is made when there are persistent (i.e., typically > 6 months) and clinically significant somatic complaints that are accompanied by excessive and disproportionate health-related thoughts, feelings, and behaviours regarding these symptoms . It involves a person having a significant focus on physical symptoms, such as pain, weakness or dizziness that results in major distress and/or problems with daily activities. In Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 , SSD appears in a new section, “Somatic symptoms and related disorders,” which replaces the “Somatoform disorders” section found in DSM-IV . Previous DSM criteria have always included reminders to clinicians to rule out other explanations before concluding that any mental disorder is present. The symptoms increase during perceived psychosocial stress and decrease as this perception is modified. In this case, according to some researchers, the dementia altered the ability to process these perceptions, with a resultant decline in the expression of unexplained somatic complaints . Knowledge that a substantial subset of frontotemporal dementia (FTD) patients exhibit excessive somatic complaints or an abnormal reaction to sensory stimuli is far from new . More than half a century ago, Robertson published detailed clinical descriptions of three cases with Pick’s disease where somatic complaints and generalised hyperalgesia were prominent clinical symptoms . Symptoms of unexplained somatic character (either somatic complaints and/or abnormal pain response) were found in 40.2% of neuropathologically verified FTD . It has been postulated that FTD is characterised by a loss of awareness of pain and that the patients do not show appropriate response to painful stimuli, since motivational–affective components of pain decrease . The somatic complaints are mostly observed in the early stages of this type of dementia: this may be related to the gradual deterioration of expressive language, often reaching the state of mutism . Semantic dementia (SD), one of the main clinical variants of FTD, characterised by the progressive and profound loss of semantic knowledge, was first described at the beginning of the twentieth century by Arnold Pick . The most prominent early feature and presenting complaint in typical SD is the reduction of expressive vocabulary, commonly described as a “loss of memory for words” . Spontaneous speech is consistently characterised by anomia, which is made especially salient by its embedding in relatively normal phonology and grammar . Researchers showed that patients with SD are particularly prone to somatic symptom disorder. In their opinion, this association results from alexisomia or the inability to accurately identify somatic sensations or symptoms, leading to their misinterpretation as signs of serious disease . The same authors asserted that “a presentation with somatic symptom disorder should lead to consideration of this dementia syndrome, as many of these patients are misdiagnosed or mischaracterized”. In FTD patients, somatic complaints were mostly observed in the early stages of dementia: this may be related to the gradual deterioration of expressive language, often reaching the state of mutism . Researchers stated that the prevalence of SSD in AD patients is 11.2% . SSD was identified in 12–18% of patients with dementia with Lewy bodies (DLB) at the time of primary neurologic diagnosis and can recur during follow-up [58, 59]. A frequent clinical phenomenology of somatic complaints observed in DLB patients is multilocalized pain with gastrointestinal symptoms . Other somatoform symptoms were described in DLB: unilateral or bilateral bent knee and tiptoeing gait, catatonic signs (including negativism, immobility, abnormal posturing, waxy flexibility and stereotypies), stiff leg hemiparetic gait, hemianesthesia or partial anaesthesia . Onofrj et al. hypothesized that to express somatization disorder, the frontal lobe should be dysfunctional but partly preserved, while a severe loss of frontal lobe function may abolish the ability of somatization . Medications used to treat somatic symptom disorder include antidepressants, antiepileptics, and antipsychotics. The effectiveness of many of these treatments has limited support . The management of patients with SSD and bodily distress works best when not only the patients but also their doctors achieve a reframing of the clinical problem: from cure to care and coping, from classical biomedical explanations to a broader view of biological and psychosocial aggravating and alleviating factors .
Heterogeneity in dementia syndrome needs to be recognized, because diagnoses are too often missed in patients with atypical presentations . Even within the same disease, there is considerable phenotypic heterogeneity with varying symptoms and disease trajectories. Furthermore, increasingly evidence from studies investigating neuropathology and molecular genetics has demonstrated that clinical symptoms are not always tightly linked with aetiology, as they can be influenced by a variety of other factors including prior experience, cognitive reserve, and epigenetics . Aberrant sexual behaviours such as zoophilia may be a rare symptom in the course of dementia syndrome. Other uncommon and bizarre features of dementia are SSD, DV experiences, and PL. Published studies on these features are limited to very short series or isolated cases. A decrease in the unexplained somatic complaints was observed while organically caused symptoms continue and dementia progresses [52, 53]. The DV phenomenon can occur in dementia, but is not a classic symptom of the disease. There are similarities and differences between PL and confabulations that are the expression of unconscious feeling of a person that he/she has some gaps in their memory which must be compensated with an imaginary experience. Recognizing the heterogeneity of symptoms within dementias and knowing the presence of bizarre and/or uncommon features of dementias imply opening the door to multifactorial intervention strategies and facilitating the tough endeavour of finding a cure for these diseases.
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Conflict of interest
The authors declared that they have no conflicts of interest.
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