Clinical Differences Among Three Common Dementia Syndromes
Angela Astri Eka Wahyuni Soemantri
[email protected] +31612210725
The variety of cause and behavioral manifestations displayed by people with dementia complicate the establishment of diagnosis. Although there are definitions and specific boundaries set to determine the cause of dementia, oftentimes the diagnosis is wrong because the symptoms are vague (Duff & Grabowski, 2008) and most likely there are overlap of symptoms between two or more pathologies (Pasquier, 1999). The extent of damage in the brain, the mental degradation after the onset, individual personality, and the nature of the living environment induce various manifestations of behavior (Erber, 2013). In order to determine the reason of cognitive decline, the examiner will make a review of certain factors such as health history of the patient, neuropsychological evaluation and laboratory tests, interview with family and close friends to know the patient’s interest, ability, and previous level of functioning (Erber, 2013; Rabin, Wishart, Fields, & Saykin, 2006). Correct diagnosis is needed to create the treatment plans for the patient and also to help patient contrives for the future (Rabin et al., 2006). Dementia is a general term used to describe a set of symptoms associated with cognitive decline that is sufficiently severe to interfere with someone’s social or occupational functioning (Chertkow, Feldman, Jacova, & Massoud, 2013). Early signs of dementia can vary greatly but memory impairment is one of the symptoms that can be observed and generally occurred (Erber, 2013; Rabin et al., 2006). CoreyBloom (as cited in Erber, 2013) indicated accompanying symptoms such as deficits in language, orientation, abstract thinking and reasoning, decision making, and problem solving which may occur lead people with dementia find difficulties in communicating with others, learning new material, and loss of orientation. Eventually, under more severe stage, they will forget the names of loved ones (Rabin et al., 2006). As consequence of diminished cognitive ability, people with dementia
will encounter impairment in basic and daily tasks as proposed by Cosentino, Brickman, and Manly (as cited in Erber, 2013). The general characteristics of dementias stated in The Diagnostic and Statistical Manual of Mental Disorders (as cited in Rabin et al., 2006) are (a) presence of multiple cognitive deficits including memory impairment and one or more of aphasia, apraxia, agnosia, or executive dysfunction; (b) cognitive deficits which interfere with the patient’s social or work-related functioning as a sign of degeneration of higher level functioning; (c) persistent loss of mental functions; (d) cognitive deficits cannot be credited to another illness in Axis I. There are many types of dementia. The sequence of onset of cognitive impairment along with related symptoms are varied within certain type of dementias. Therefore it is very important to provide possible etiology when diagnosis is made. (Rabin et al., 2006). Dugue et al. (as cited in Rabin et al., 2006) stated that the most common types of dementia are the Alzheimer’s disease (AD), Vascular dementia (VaD), and Dementia with Lewy bodies (DLB) with Alzheimer’s disease being the most frequent cause followed by Vascular dementia and then Dementia with Lewy bodies. Wegiel, Wisniewski, Reisberg, and Silverman (as cited in Rabin et al., 2006) defined Alzheimer’s disease as a neurodegenerative disorder characterized by (a) continuous cognitive decline, (b) an extensive range of brain pathology, (c) build-up of fibrillar amyloid-β protein in plaques and vessels, (d) development of neurofibrillary tangles, and (e) loss of synapse and neuron. Specifically, Hestad, Ellertsen, and Kløve (1998) explained that the development of neurofibrillary tangles that disrupt the cognitive function take place in cortical areas and also subcortical areas such as the hippocampus, gyrus cingulum, amygdala, nucleus basalis meynert,
dorsal raphe nucleus, substantia nigra, and locus coeruleus. Furthermore, Zec (as cited in Rabin et al., 2006) suggested although there are many forms of Alzheimer’s disease, the typical manifestations of symptoms include (a) a subtle onset, (b) untimely symptoms of memory loss, and (c) continuous impairment in other cognitive area. Despite specific definitions proposed by many researchers, McKhann et al. (as cited in Duff & Grabowski, 2008) said that the diagnosis of possible Alzheimer’s disease can be made clinically by referring to characteristic of AD proposed by The National Institute of Neurological and Communicative Disorders and Stroke and Alzheimer’s Disease and Related Disorders Association (NINDCDS-ADRDA) which include (a) the proof of dementia which is established by clinical examination and confirmed by mental status scales and neuropsychological tests, (b) patient has cognitive impairments in two or more domains, (c) progression of cognitive decline including memory, (d) no evidence of disruption in consciousness, (e) the onset starts between 40 and 90 years of age, and (f) there is no other brain disease that could cause the dementia. Being the second most common cause of dementia, Vascular dementia according to Skilbeck (2010) is a significant degradation of cognitive functioning caused by a disruption in cerebrovascular. This statement also verify the earlier proposal by Gorelick, Mangone, and Bozzola (as cited in Hestad, Ellertsen, & Kløve, 1998) which stated that the common cause of VaD is cerebral infarctions. Cognitive loss occur eventually as a result of lack of blood supply to the cerebral cortex (Skilbeck, 2010). Ramon et al. (as cited in Duff & Grabowski, 2008) pointed the diagnostic criteria for Vascular dementia proposed by the National Institute of Neurological Disorders and Stroke—Association Internationale pour la Recherce et
l’Enseignement en Neurosciences (NINDS-AIREN) which is now commonly used in research settings. The patient of Vascular dementia should have (a) cerebrovascular disease, (b) memory disturbances and other cognitive decline as a sign of dementia, (c) evidence of relationships between the dementia and the cerebrovascular disease, and (d) other characteristics that are in line with the diagnosis of Vascular dementia such as incontinency, gait disturbances which lead into falls, and mood changes. The third most common dementia is Dementia with Lewy bodies. The cause of DLB is abnormal microscopic protein deposits inside nerve cells which occur in brain stem and also in the cortex creating problems in both motor and cognitive functioning (Erber, 2013). The diagnostic criteria used to distinguish DLB with other type of dementias proposed by McKeith et al. (as cited in Duff & Grabowski, 2008). The criteria include (a) some signs of cognitive deficit that interfere normal functioning such as deficit in attention, frontal-subcortical, and visuospatial abilities; (b) at least two symptoms of these cognitive disturbances which include fluctuating consciousness, visual hallucinations from time to time, and parkinsonism; (c) other characteristics such as repeated falls, neuroleptic sensitivity, delusions, and other type of hallucinations. Referring to the arguments above, it is clear that cognitive deficits mark the early symptoms in all three types of dementia. However, the characteristic of the onset and the accompanying symptoms afterwards can help the examiner to distinguish the cause of dementia. Certainly, there are also variety of dementia test battery which can be administered accordingly to support the diagnosis such as MiniMental State Examination (MMS) and Mattis Dementia Rating Scale (DRS) to name a few (Pasquier, 1999). Unlike AD which has insidious onset, VaD is associated with a sudden onset such as a stroke. That is why the treatment plan for VaD include
treatment of hypertension as stated by Meter and Wilson (as cited in Rabin et al., 2006) and immediate clinical action is oftentimes needed (Duff & Grabowsky, 2008). Also found in the latter period, patients with VaD showed more sleep disturbances rather than patients with AD (Skilbeck, 2010). Another findings based on behavioral observations and formal testing by Tierney et al. (as cited in Rabin et al., 2006) specified that patients with VaD showed more comprehensive performance on recognition trials rather than patients with AD. Moreover, Rabin et al. (2006) stated that patients with VaD are better in storing information but perform more poorly on tasks related to phonemic fluency rather than patients with AD. Different from AD and VaD, patients with DLB show recurrent hallucinations and agnosia early in the course so these symptoms can help distinguish DLB from other dementias. Furthermore, Pasquier (1999) and Kaufer (as cited in Rabin et al., 2006) indicated patients with DLB perform better on test such as confrontation naming and verbal memory as compared with patients with AD, but worse in test of executive functioning and visuospatial abilities. Even though it is challenging to make differential diagnosis of the cause of dementia because some overlap of symptoms between these three common dementia syndromes, it is possible to make conclusion by looking carefully to the possible etiology, onset and subsequent symptoms, and also supported by yield of neuropsychological tests. In any case, follow-up of patients should be done to increase the fidelity of diagnosis (Pasquier, 1999).
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