Treatable and reversible dementias: an update

Risks and Benefits of Clinical Diagnosis Around the Time of Dementia Onset

Diagnostic delay in dementia is common in the U.S. Drivers of diagnostic delay are poorly understood, but appear related to misconceptions about dementia, stigma, concerns about autonomy, the nature of the diagnostic process, and provider-related factors. There is little quantitative evidence underlying cited risks and benefits of receiving a diagnosis around the time of dementia onset, including impacts on physical health, impacts on mental health, care partner interactions, costs of care, increased time for care planning, or earlier access to treatment. While various groups continue to push for reductions in diagnostic delay, realization of benefits and mitigation of harms will require new research on potential benefits and harms. Workforce and resource constraints, coupled with the expected growth in the number of persons living with dementia, may be a barrier to realization of potential benefits and mitigation of identified harms, which will require adequate access to providers, services, and supports.

Late-onset epilepsy and subsequent increased risk of dementia

Inflammation is considered as a key pathogenesis factor of dementia and epilepsy. However, epilepsy's association with dementia, particularly its role in the development of dementia, remains unclear. To evaluate the association between epilepsy and the risk of dementia, in Taiwan, we have now conducted a retrospective cohort study comprising 675 individuals (age, ≥50 years) with epilepsy and 2,025 matched control subjects without epilepsy. In order to match individuals diagnosed with epilepsy with those with no diagnosis of epilepsy (comparison cohort), we utilized exact matching at a ratio of 1:3. Compared with those in the comparison cohort, individuals in the epilepsy cohort had a significantly increased risk of developing dementia (adjusted hazard ratio = 2.87, p < 0.001). A similar result has been observed after stratifying for sex (adjusted hazard ratio in males = 2.95, p < 0.001; adjusted hazard ratio in females = 2.66, p < 0.001). To conclude, based on these data, epileptic individuals ≥50 years were at a greater risk of developing dementia than people who do not have epilepsy, which indicates that a diagnosis of epilepsy presents a greater risk for the development of dementia.

Cognitive Event-Related Potential Responses Differentiate Older Adults with and without Probable Mild Cognitive Impairment

Background: Older adults rarely seek cognitive assessment, but often visit other healthcare professionals (e.g., audiologists). Noninvasive clinical measures within the scopes of practice of those professions sensitive to cognitive impairment are needed. Purpose: This study examined the differences of probable mild cognitive impairment (MCI) on latency and mean amplitude of the P3b auditory event-related potential. Method: Fifty-four participants comprised two groups according to cognitive status (cognitively normal older adults [CNOA], n = 25; probable MCI, n = 29). P3b was recorded using an oddball paradigm for speech (/ba/, /da/) and non-speech (1000, 2000 Hz) stimuli. Amplitudes and latencies were compared from six electrodes (FPz, Fz, FCz, Cz, CPz, Pz) between groups across stimulus probability and type. Results: CNOA participants had larger P3b mean amplitudes for deviant stimuli than those with probable MCI. Group effects of latency were isolated to deviant stimuli at FCz only when those with unclear P3bs were included. Findings did not covary with age or education. Overall, CNOAs showed a large P3b oddball effect while those with probable MCI did not. Conclusions: P3b can be used to show electrophysiological differences between older adults with and without probable MCI. These results support the development of educational materials targeting professionals using auditory-evoked potentials.

Stroke, Vascular Dementia, and Alzheimer's Disease: Molecular Links

Stroke is a brain disease that occurs when blood flow stops, resulting in reduced oxygen supply to neurons. Stroke occurs at any time and at any age, but increases after the age of 55. It is the second leading cause of death and the third leading cause of disability-adjusted, life-years. The pathophysiology of ischemic stroke is complex and recent molecular, cellular, and animal models and postmortem brain studies have revealed that multiple cellular changes have been implicated, including oxidative stress/mitochondrial dysfunction, inflammatory responses, micro RNA alterations, and marked changes in brain proteins. These cellular changes provide new information for developing therapeutic strategies for ischemic stroke treatment. Research also revealed that stroke increases with a number of modifiable factors and most strokes can be prevented and/or controlled through pharmacological or surgical interventions and lifestyle changes. Ischemic stroke is the major risk factor for vascular dementia and Alzheimer's disease. This review summarizes the latest research findings on stroke, including causal factors and molecular links between stroke and vascular disease/Alzheimer's disease.

Longitudinal patterns of potentially inappropriate medication use following incident dementia diagnosis

INTRODUCTION

Potentially inappropriate medication (PIM) use in older adults with dementia is an understudied area. We assessed longitudinal changes in PIM exposure by dementia type following dementia diagnosis.

METHODS

We followed 2448 participants aged ≥65 years (52% women, 85.5% Caucasian, mean age 80.9 ± 7.5 years) diagnosed with dementia after enrollment in the National Alzheimer's Coordinating Center (2005-2014). We estimated the association between dementia type and PIM annually for 2 years after diagnosis, using Generalized Estimating Equations.

RESULTS

Participants with Lewy body dementia had more PIM use, and participants with frontotemporal dementia had less PIM use than participants with Alzheimer's disease. In the first year following diagnosis, total number of medications increased, on average, by 10% for Alzheimer's disease and 15% for Lewy body dementia (P < .05 for both).

DISCUSSION

A tailored approach aimed at optimizing drug therapy is needed to mitigate PIM exposure to improve medical care for individuals with dementia.

Do You Want to Hear the Bad News? The Value of Diagnostic Tests for Alzheimer's Disease

OBJECTIVE

The diagnosis of Alzheimer's disease (AD) remains difficult. Lack of diagnostic certainty or possible distress related to a positive result from diagnostic testing could limit the application of new testing technologies. The objective of this paper is to quantify respondents' preferences for obtaining AD diagnostic tests and to estimate the perceived value of AD test information.

METHODS

Discrete-choice experiment and contingent-valuation questions were administered to respondents in Germany and the United Kingdom. Choice data were analyzed by using random-parameters logit. A probit model characterized respondents who were not willing to take a test.

RESULTS

Most respondents indicated a positive value for AD diagnostic test information. Respondents who indicated an interest in testing preferred brain imaging without the use of radioactive markers. German respondents had relatively lower money-equivalent values for test features compared with respondents in the United Kingdom.

CONCLUSIONS

Respondents preferred less invasive diagnostic procedures and tests with higher accuracy and expressed a willingness to pay up to €700 to receive a less invasive test with the highest accuracy.

Characteristics of patients misdiagnosed with Alzheimer's disease and their medication use: an analysis of the NACC-UDS database

Background

This study compared individuals whose clinical diagnosis of Alzheimer’s disease (AD) matched or did not match neuropathologic results at autopsy on clinical and functional outcomes (cognitive impairment, functional status and neuropsychiatric symptoms). The study also assessed the extent of potentially inappropriate medication use (using potentially unnecessary medications or potentially inappropriate prescribing) among misdiagnosed patients.

Methods

Longitudinal data from the National Alzheimer’s Coordinating Center Uniform Data Set (NACC-UDS, 2005–2010) and corresponding NACC neuropathological data were utilized to compare 88 misdiagnosed and 438 accurately diagnosed patients.

Results

Following adjustment of sociodemographic characteristics, the misdiagnosed were found to have less severe cognitive and functional impairment. However, after statistical adjustment for sociodemographics, dementia severity level, time since onset of cognitive decline and probable AD diagnosis at baseline, the groups significantly differed on only one outcome: the misdiagnosed were less likely to be depressed/dysphoric. Among the misdiagnosed, 18.18% were treated with potentially inappropriate medication. An additional analysis noted this rate could be as high as 67.10%.

Conclusions

Findings highlight the importance of making an accurate AD diagnosis to help reduce unnecessary treatment and increase appropriate therapy. Additional research is needed to demonstrate the link between potentially inappropriate treatment and adverse health outcomes in misdiagnosed AD patients.

Physician-assisted suicide of patients with dementia. A medical ethical analysis with a special focus on patient autonomy

For many years there has been a controversial international debate on physician-assisted suicide (PAS). While proponents of PAS regularly refer to the unbearable suffering and the right of self-determination of incurably ill patients, critics often warn about the diverse risks of abuse. In our article, we aim to present ethical arguments for and against PAS for patients in an early stage of dementia. Our focus shall be on ethical questions of autonomy, conceptual and empirical findings on competence and the assessment of mental capacity to make health care decisions. While the capacity to make health care decisions represents an ethically significant precondition for PAS, it becomes more and more impaired in the course of the dementia process. We present conditions that should be met in order to ethically justify PAS for patients with dementia. From both a psychiatric and an ethical perspective, a thorough differential diagnosis and an adequate medical and psychosocial support for patients with dementia considering PAS and their relatives should be guaranteed. If, after due deliberation, the patient still wishes assistance with suicide, a transparent and documented assessment of competence should be conducted by a professional psychiatrist.

Prevalence of potentially reversible conditions in dementia and mild cognitive impairment in a geriatric clinic

AIM

To examine the prevalence of potentially reversible conditions in dementia and mild cognitive impairment (MCI) patients in a geriatric clinic.

METHODS

We retrospectively reviewed the medical records of patients who attended the outpatient geriatric clinic at Siriraj Hospital, Bangkok between January 2005 and December 2010. We collected the data regarding potentially reversible conditions of cognitive impairment.

RESULTS

There were 233 patients newly diagnosed with dementia and 60 patients diagnosed with MCI. We found potentially reversible causes of dementia in 17 patients (7.3%). The causes were hypothyroidism (2.6%), B12 deficiency (1.7%), normal pressure hydrocephalus (NPH) (0.9%), depression (0.9%), folate deficiency (0.4%), reactive Venereal Disease Research Laboratory (VDRL; 0.4%) and chronic subdural hematoma (CSH; 0.4%). The patients with NPH and CSH were clinically suspicious for having such conditions before the investigations, while patients with low B12 level, low folate level, hypothyroidism and VDRL+ were not. In the MCI group, we found potentially reversible causes in two patients (3.3%), these were B12 deficiency (1.7%) and hypothyroidism (1.7%). Clinical improvement after treatment of the potentially reversible conditions was seen in four patients (one NPH, one subdural hematoma and two with depression) in dementia group (1.7%) and none in the MCI group. All were partially reversed.

CONCLUSION

Routine investigations might be more warranted for metabolic conditions (B12 level and hypothyroidism) as clinical presentations are not suggestive of the conditions. However, reversibility of dementia might not occur in these cases. Neuroimaging should be performed selectively as clinically indicated. Truly reversible conditions are rare and occur in surgical and depressive patients.

Prevalence of treatable and reversible dementias: A study in a dementia outpatient clinic

Dementia is a syndrome characterized by the development of multiple cognitive deficits and behavioral changes that leads to impairment of functional activities. There are primary degenerative, progressive and irreversible dementias, and other dementias resulting from a progressive but potentially reversible dementia of secondary origin.

Objective

To assess the prevalence of cases with a diagnosis of potentially reversible dementia at a Behavioral Neurology Outpatient Unit.

Methods

A retrospective study based on a review of 340 medical records of patients seen from 1999 to 2009 was conducted. All patients received a thorough diagnostic assessment to verify the etiological hypothesis proposed.

Results

Of the 340 patients seen in the study period, 172 (50.5%) were females and 168 (49.5%) males, 90 patients (26.4%) were under 60 years of age, and 250 (73.6%) were over 60 years of age. Alzheimer's disease, with 89 cases (26%), followed by vascular dementia with 39 cases (11.47%), were the leading etiological diagnoses. A total of 193 patients had dementia and 37 of these (19.17%) were found to have potentially reversible dementias, distributed as follows: head injury: 15 patients; alcohol-related dementias: 11 patients; meningoencephalitis: 2 patients; hypothyroidism: 2 patients; neurosyphilis: 2 patients; normal pressure hydrocephalus: 2 patients; AIDS: 1 patient; Korsakoff's syndrome: 1 patient, and Post-anoxic dementia: 1 patient.

Conclusions

A significant number of patients were found to have potentially reversible dementias (19.17%). These data show an urgent need for more extensive diagnostic investigation, and indicate the possibility of reversing some dementias, especially cases detected early.

Reversible dementia and corresponding CSF alterations due to intraspinal lumbosacral metastasis of a prostate carcinoma

We report, for the first time, how intraspinal carcinoma metastasis can cause reversible dementia accompanied by distinct cerebrospinal fluid (CSF) alterations. A 73-year-old male patient who suffered from rapidly progressive dementia and gait disturbance showed marked abnormalities of CSF tau protein, amyloid beta(1-42), and prostate-specific antigen. A lumbosacral, intraspinal metastasis from a prostate carcinoma was found, and after microsurgical removal, CSF alterations normalized and the clinical symptoms regressed. This case illustrates how malignant tumors can disturb brain function via indirect mechanisms.

Brain biopsy in dementia

Brain biopsy has an uncertain role in the diagnosis of dementia. Here we report a retrospective analysis of 90 consecutive cerebral biopsies undertaken for the investigation of dementia in adults at a tertiary referral centre between 1989 and 2003. In most cases (90%), biopsy consisted of a right frontal full thickness resection of cortex, white matter and overlying leptomeninges. Fifty-seven per cent of biopsies were diagnostic: the most frequent diagnoses were Alzheimer's disease (18%), Creutzfeldt-Jakob disease (12%) and inflammatory disorders (9%). Other diagnoses in individual patients included Pick's disease, corticobasal degeneration and other tauopathies, Lewy body dementia, multiple sclerosis, Whipple's disease, progressive multifocal leucoencephalopathy, cerebral autosomal dominant arteriopathy with subcortical ischaemic leucoencephalopathy, vasculopathies and paraneoplastic encephalopathy. The most frequent biopsy finding in the non-diagnostic group and for the series as a whole (37%) was non-specific gliosis variably affecting both cortex and white matter. Complications (11%) included seizures, intracranial and wound infections, and intracranial haemorrhage; there were no deaths or lasting neurological sequelae attributable to the procedure. No trends in diagnostic yield or complication rate over the course of the series were identified. Information obtained at biopsy determined treatment in 11%. A raised cerebrospinal fluid cell count was the only robust predictor of a potentially treatable (inflammatory) process at biopsy. The constellation of behavioural change, raised CSF protein and matched oligoclonal bands in CSF and serum was associated with non-specific gliosis at biopsy. This series underlines the value of cerebral biopsy in the diagnosis of dementia, and suggests that certain clinical and laboratory features may be useful in guiding the decision to proceed to brain biopsy where a treatable disease cannot be excluded by other means.

Prevalence of potentially reversible dementias in a dementia outpatient clinic of a tertiary university-affiliated hospital in Brazil

The importance of investigating the etiology for dementia lies in the possibility of treating potentially reversible dementias. The aims of this retrospective study are to determine the prevalence of potentially reversible dementias among 454 outpatients seen at the Cognitive and Behavioral Neurology Unit, Hospital das Clínicas, São Paulo University School of Medicine - Brazil, between the years of 1991 and 2001, and observe their evolution in follow-up. Among the initial 454 patients, 275 fulfilled the DSM-IV criteria for dementia. Alzheimer's disease was the most frequent diagnosis (164 cases; 59.6%). Twenty-two cases (8.0%) of potentially reversible dementia were observed, the most frequent diagnoses being neurosyphilis (nine cases) and hydrocephalus (six cases). Full recovery was observed in two patients and partial recovery in 10 patients. Two cases were not treated and eight cases were lost on follow-up. The prevalence found in the present study falls within the range reported in previous studies (0-30%).

Dementia

Alzheimer's disease is the most common cause of dementia, but often several other conditions causing dementia are present on brain autopsies. Palliative care medical issues are similar in all late stage progressive degenerative dementias and include; cardiopulmonary resuscitation, transfer to acute care setting, antibiotic therapy, and tube feeding. Behavioral symptoms of dementia include agitation and resistiveness to care. Quality of life of individuals suffering from dementia is enhanced by availability of meaningful activities and by avoidance of restraints. Family support and involvement are crucial for optimal care. Formulation of advanced directives or an advance proxy plan is important for assuring the patient's previous wishes or best interests are considered when decisions about treatment strategies are made.

Observations on dementias with possibly reversible symptoms

While the evaluation of patients with dementia must also address the possibility of treatable illnesses, recent studies found that reversible diseases are detected in only about 1% of dementia cases. Data on the frequency and evolution of potentially reversible dementias (PRD) in defined clinical settings can be useful in order to optimize diagnostic protocols, thus reducing over-investigation and waste of resources. We reviewed a series of 513 patients (mean age 69.3 +/- 4.2 years, mean education level 7.4 +/- 4.5 years, sex ratio M/F 217/296) referred to a memory clinic by their general practitioner, in order to identify PRD. All the subjects had undergone neurological and neuropsychological examination, and laboratory tests. Patients considered to be demented also underwent CT brain scan. 362 patients (70.6%) met the criteria for dementia. We identified 26 PRD cases (7.2% of dementia cases, 5.1% of the entire sample). In 13 patients (3.6% of dementia cases), a complete clinical and neuropsychological reversal of dementia was seen after treatment. In 5 of them (1.4%), a partial regression was obtained, while 8 showed no improvement. We conclude that potential and actual reversibility do not coincide, and that "true" reversibility is rare (even if not negligible) in clinical practice. Careful clinical history and examination appeared the most useful part of the evaluation to identify PRD. Standard blood tests and vitamin B12 assay were also useful, while CT scan detected PRD causes only in patients with evidence of neurological signs.