Diagnosis and management of dementia with Lewy bodies: Fourth consensus report of the DLB Consortium

Progress and Challenges in the Diagnosis of Dementia: A Critical Review

Longer life expectancies have led to an increased number of neurodegenerative disease cases globally. Accurate diagnosis of this devastating disorder is of crucial importance but is still feasible only by a brain biopsy after death. An enormous amount of attention and research has been in place over the years toward the better understanding of the mechanisms, as well as the early diagnosis, of neurodegeneration. However, numerous studies have been contradictory from time to time, while new diagnostic methods are constantly developed in a tireless effort to tackle the disease. Nonetheless, there is not yet a conclusive report covering a broader range of techniques for the diagnosis of different types of dementia. In this paper, we critically review current knowledge on the different hypotheses about the pathogenesis of distinct types of dementia, as well as risk factors and current diagnostic approaches in a clinical setting, including neuroimaging, cerebrospinal (CSF), and blood tests. Encouraging research results for the diagnosis and investigation of neurodegenerative disorders are also reported. Particular attention is given to the field of spectroscopy as an emerging tool to detect dementias, follow-up patients, and potentially monitor the patients' response to a therapeutic approach. Spectroscopic techniques, such as infrared and Raman spectroscopy, have facilitated numerous disease-related studies, including neurodegenerative disorders, and are currently undergoing trials for clinical implementation. This review constitutes a comprehensive report with an in-depth focus on promising imaging, molecular biomarker and spectroscopic tests in the field of dementive diseases.

CT-based attenuation correction and resolution compensation for I-123 IMP brain SPECT normal database: a multicenter phantom study

OBJECTIVE

Statistical image analysis of brain SPECT images has improved diagnostic accuracy for brain disorders. However, the results of statistical analysis vary depending on the institution even when they use a common normal database (NDB), due to different intrinsic spatial resolutions or correction methods. The present study aimed to evaluate the correction of spatial resolution differences between equipment and examine the differences in skull bone attenuation to construct a common NDB for use in multicenter settings.

METHODS

The proposed acquisition and processing protocols were those routinely used at each participating center with additional triple energy window (TEW) scatter correction (SC) and computed tomography (CT) based attenuation correction (CTAC). A multicenter phantom study was conducted on six imaging systems in five centers, with either single photon emission computed tomography (SPECT) or SPECT/CT, and two brain phantoms. The gray/white matter I-123 activity ratio in the brain phantoms was 4, and they were enclosed in either an artificial adult male skull, 1300 Hounsfield units (HU), a female skull, 850 HU, or an acrylic cover. The cut-off frequency of the Butterworth filters was adjusted so that the spatial resolution was unified to a 17.9 mm full width at half maximum (FWHM), that of the lowest resolution system. The gray-to-white matter count ratios were measured from SPECT images and compared with the actual activity ratio. In addition, mean, standard deviation and coefficient of variation images were calculated after normalization and anatomical standardization to evaluate the variability of the NDB.

RESULTS

The gray-to-white matter count ratio error without SC and attenuation correction (AC) was significantly larger for higher bone densities (p < 0.05). The count ratio error with TEW and CTAC was approximately 5% regardless of bone density. After adjustment of the spatial resolution in the SPECT images, the variability of the NDB decreased and was comparable to that of the NDB without correction.

CONCLUSION

The proposed protocol showed potential for constructing an appropriate common NDB from SPECT images with SC, AC and spatial resolution compensation.

18F-AV-1451 in Parkinson's Disease with and without dementia and in Dementia with Lewy Bodies

Mixed pathologies of α-synuclein, β-amyloid and tau are relatively common in Parkinson’s disease (PD) and Dementia with Lewy Bodies (DLB). We therefore wanted to study the retention patterns of ¹⁸F-AV-1451 in PD, PD-dementia (PDD), and DLB. To do this 44 healthy controls, 11 non-demented patients with PD, 18 patients with PDD, and six patients with DLB underwent MRI and ¹⁸F-AV-1451 PET scanning and cognitive testing. We found that parietal ¹⁸F-AV-1451 retention was increased in patients with DLB compared to controls and PD patients, while ¹⁸F-AV-1451 uptake was reduced in the substantia nigra in PDD. Increased parietal ¹⁸F-AV-1451 PET uptake was associated with impaired performance on verbal fluency tests, and the decreased uptake in the substantia nigra correlated with worse motor function. We found no effect of the monoamine oxidase B inhibitor rasagiline on ¹⁸F-AV-1451 binding. In conclusion DLB patients have increased parietal ¹⁸F-AV-1451 uptake. Increased parietal tau is associated with executive impairment in patients with synucleinopathies, while decreased uptake in the substantia nigra is associated with parkinsonism. Further, our data indicate that ¹⁸F-AV-1451 does not significantly bind to MAO-B in vivo.

Electroencephalographic derived network differences in Lewy body dementia compared to Alzheimer's disease patients

Dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD) require differential management despite presenting with symptomatic overlap. Currently, there is a need of inexpensive DLB biomarkers which can be fulfilled by electroencephalography (EEG). In this regard, an established electrophysiological difference in DLB is a decrease of dominant frequency (DF)—the frequency with the highest signal power between 4 and 15 Hz. Here, we investigated network connectivity in EEG signals acquired from DLB patients, and whether these networks were able to differentiate DLB from healthy controls (HCs) and associated dementias. We analysed EEG recordings from old adults: HCs, AD, DLB and Parkinson’s disease dementia (PDD) patients. Brain networks were assessed with the minimum spanning tree (MST) within six EEG bands: delta, theta, high-theta, alpha, beta and DF. Patients showed lower alpha band connectivity and lower DF than HCs. DLB and PDD showed a randomised MST compared with HCs and AD in high-theta and alpha but not in DF. The MST randomisation in DLB and PDD reflects decreased brain efficiency as well as impaired neural synchronisation. However, the lack of network topology differences at the DF between all dementia groups and HCs may indicate a compensatory response of the brain to the neuropathology.

Parkinson's Disease Dementia and Dementia with Lewy Bodies Have Similar Neuropsychological Profiles

Parkinson’s disease dementia (PDD) and dementia with Lewy bodies (DLB) are common causes of dementia worldwide. Although considered separate entities based on the relative temporal onset of motor symptoms vs. diagnosis of dementia, it is unknown if these diseases truly have distinct cognitive profiles. We hypothesized that patients divided into PDD and DLB categories strictly by temporal criteria would have different neuropsychological profiles. We investigated this question via neuropsychological testing of PDD and DLB patients at the University of Iowa. We performed retrospective chart analysis and review of neuropsychological testing of clinically diagnosed patients with PDD or DLB, who had presented to University of Iowa’s dementia and movement disorder clinics. Forty-seven patients diagnosed by the treating neurologist as PDD or DLB were included. Neuropsychological performance was compared between groups, and as a function of the relative timing of the motor diagnosis vs. diagnosis of dementia. We found that both PDD and DLB patients showed severe deficits in executive function, visual–spatial processing, and verbal learning. However, we found no significant differences in neuropsychological performance between groups, and neuropsychological performance could not reliably account for the relative timing of motor diagnosis vs. diagnosis of dementia. Our data support the idea that DLB and PDD are on a neuropsychological spectrum.

Mild Cognitive Impairment in Parkinson's Disease-What Is It?

PURPOSE OF REVIEW

Mild cognitive impairment is a common feature of Parkinson's disease, even at the earliest disease stages, but there is variation in the nature and severity of cognitive involvement and in the risk of conversion to Parkinson's disease dementia. This review aims to summarise current understanding of mild cognitive impairment in Parkinson's disease. We consider the presentation, rate of conversion to dementia, underlying pathophysiology and potential biomarkers of mild cognitive impairment in Parkinson's disease. Finally, we discuss challenges and controversies of mild cognitive impairment in Parkinson's disease.

RECENT FINDINGS

Large-scale longitudinal studies have shown that cognitive involvement is important and common in Parkinson's disease and can present early in the disease course. Recent criteria for mild cognitive impairment in Parkinson's provide the basis for further study of cognitive decline and for the progression of different cognitive phenotypes and risk of conversion to dementia. Improved understanding of the underlying pathology and progression of cognitive change are likely to lead to opportunities for early intervention for this important aspect of Parkinson's disease.

Are dementia with Lewy bodies and Parkinson's disease dementia the same disease?

BACKGROUND

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), which share many clinical, neurochemical, and morphological features, have been incorporated into DSM-5 as two separate entities of major neurocognitive disorders with Lewy bodies. Despite clinical overlap, their diagnosis is based on an arbitrary distinction concerning the time of onset of motor and cognitive symptoms, namely as early cognitive impairment in DLB and later onset following that of motor symptoms in PDD. Their morphological hallmarks - cortical and subcortical α-synuclein/Lewy body plus β-amyloid and tau pathologies - are similar, but clinical differences at onset suggest some dissimilar profiles. Based on recent publications, including the fourth consensus report of the DLB Consortium, a critical overview is provided herein.

DISCUSSION

The clinical constellations of DLB and PDD include cognitive impairment, parkinsonism, visual hallucinations, and fluctuating attention. Intravitam PET and postmortem studies have revealed a more pronounced cortical atrophy, elevated cortical and limbic Lewy body pathologies, higher Aβ and tau loads in cortex and striatum in DLB compared to PDD, and earlier cognitive defects in DLB. Conversely, multitracer PET studies have shown no differences in cortical and striatal cholinergic and dopaminergic deficits. Clinical management of both DLB and PDD includes cholinesterase inhibitors and other pharmacologic and non-drug strategies, yet with only mild symptomatic effects. Currently, no disease-modifying therapies are available.

CONCLUSION

DLB and PDD are important dementia syndromes that overlap in many clinical features, genetics, neuropathology, and management. They are currently considered as subtypes of an α-synuclein-associated disease spectrum (Lewy body diseases), from incidental Lewy body disease and non-demented Parkinson's disease to PDD, DLB, and DLB with Alzheimer's disease at the most severe end. Cognitive impairment in these disorders is induced not only by α-synuclein-related neurodegeneration but by multiple regional pathological scores. Both DLB and PDD show heterogeneous pathology and neurochemistry, suggesting that they share important common underlying molecular pathogenesis with Alzheimer's disease and other proteinopathies. While we prefer to view DLB and PDD as extremes on a continuum, there remains a pressing need to more clearly differentiate these syndromes and to understand the synucleinopathy processes leading to either one.

Improving the identification of dementia with Lewy bodies in the context of an Alzheimer's-type dementia

BACKGROUND

Dementia due to Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) are the two most common neurodegenerative causes of dementia. They commonly occur together, especially in older people, but clinical identification of these diseases in dementia is difficult in such circumstances. We therefore conducted a study using cases with both comprehensive prospective clinical assessments and complete neuropathological examination to determine if it is possible to identify such mixed cases clinically and to determine features which may identify DLB in the presence of AD dementia.

METHODS

At Newcastle Brain Bank we identified subjects who had a clinical diagnosis of dementia and who also had autopsy diagnoses of pure AD, pure DLB, or mixed AD+DLB. All subjects had undergone prospective longitudinal clinical assessments. Mixed AD+DLB patients met neuropathological criteria for both DLB (limbic/neocortical Lewy body disease) and AD (Braak stage V/VI and CERAD B/C). The records of these subjects were carefully reviewed by two specialists in old-age psychiatry blind to autopsy findings to determine baseline and final clinical diagnoses based on these detailed records. The presence of characteristic Lewy body symptoms and other clinical information was also recorded.

RESULTS

Of 59 subjects included, 19 were AD, 18 DLB, and 22 mixed AD+DLB. At baseline no subjects were correctly identified as having mixed AD+DLB and by final diagnosis only 23% were identified. The only symptom which helped in identifying the presence of Lewy body disease in the context of a mixed AD+DLB dementia was complex visual hallucinations.

CONCLUSIONS

Whilst the identification of DLB in the context of a dementia with an AD pattern is difficult, the emergence of complex visual hallucinations in the context of such a degenerative dementia suggests the presence of Lewy body disease and should encourage a careful assessment. Biomarkers appear likely to be necessary to help improve identification of different disease subtypes underlying dementia.

Orthostatic heart rate changes in patients with autonomic failure caused by neurodegenerative synucleinopathies

OBJECTIVE

Blunted tachycardia during hypotension is a characteristic feature of patients with autonomic failure, but the range has not been defined. This study reports the range of orthostatic heart rate (HR) changes in patients with autonomic failure caused by neurodegenerative synucleinopathies.

METHODS

Patients evaluated at sites of the U.S. Autonomic Consortium (NCT01799915) underwent standardized autonomic function tests and full neurological evaluation.

RESULTS

We identified 402 patients with orthostatic hypotension (OH) who had normal sinus rhythm. Of these, 378 had impaired sympathetic activation (ie, neurogenic OH) and based on their neurological examination were diagnosed with Parkinson disease, dementia with Lewy bodies, pure autonomic failure, or multiple system atrophy. The remaining 24 patients had preserved sympathetic activation and their OH was classified as nonneurogenic, due to volume depletion, anemia, or polypharmacy. Patients with neurogenic OH had twice the fall in systolic blood pressure (SBP; -44 ± 25 vs -21 ± 14 mmHg [mean ± standard deviation], p < 0.0001) but only one-third of the increase in HR of those with nonneurogenic OH (8 ± 8 vs 25 ± 11 beats per minute [bpm], p < 0.0001). A ΔHR/ΔSBP ratio of 0.492 bpm/mmHg had excellent sensitivity (91.3%) and specificity (88.4%) to distinguish between patients with neurogenic from nonneurogenic OH (area under the curve = 0.96, p < 0.0001). Within patients with neurogenic OH, HR increased more in those with multiple system atrophy (p = 0.0003), but there was considerable overlap with patients with Lewy body disorders.

INTERPRETATION

A blunted HR increase during hypotension suggests a neurogenic cause. A ΔHR/ΔSBP ratio < 0.5 bpm/mmHg is diagnostic of neurogenic OH. Ann Neurol 2018;83:522-531.

Pharmacological interventions for psychosis in Parkinson's disease patients

INTRODUCTION

Psychosis is a common problem for people treated for Parkinson's disease. The syndrome is quite stereotypic, with hallucinations being the most common, followed by delusions. While the hallucinations are usually not very bothersome, the delusions are typically paranoid in nature. Treatment is often, but not always, required.

AREAS COVERED

This article reviews the therapeutic approaches of this syndrome focusing on drug treatments used once contributory factors have been removed. This includes a review of the evidence supporting the use of clozapine and, most recently, pimavanserin, the first drug with antipsychotic efficacy that has no effect on dopamine. Treatment with second generation antipsychotic drugs and cholinesterase inhibitors are also reviewed.

EXPERT OPINION

Clozapine and pimavanserin have proven efficacy for Parkinson's disease psychosis (PDP), without impairing motor function. In clozapine's favor are its antipsychotic benefits seen within 1 week and its effectiveness in improving tremor in PD. However, this is counterbalanced by the need for blood monitoring, despite the extremely low doses used, and sedation. Pimanvanserin is well tolerated, without sedation or other significant side effects. Its onset of benefit, however takes 4-6 weeks. While quetiapine is also frequently used, its efficacy is not supported by double blinded, randomized trials.

[A case of severe obstructive sleep apnea mimicking REM sleep behavior disorder]

The rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by dream-enacting behaviors related to the loss of the normal generalized skeletal muscle atonia during REM sleep, and shows REM sleep without atonia (RWA) during polysomnography (PSG). Patients with idiopathic RBD have been known to have a siginificantly increased risk of developing one of the α-synucleiopathies later in life, therefore the diagnosis of RBD is very important and must be dealt with carefully. A 51-year-old man was identified presenting dream-enacting behaviors and unpleasant dreams suggesting the diagnosis of RBD, in addition to snoring and excessive daytime sleepiness. Attended video-PSG excluded RBD showing REM sleep with atonia and without increased phasic EMG activity, and diagnosed with severe obstructive sleep apnea (OSA) with an apnea-hypopnea index of 30.1 demonstrating that the reported abnormal sleep behaviors occurred only during respiratory event-induced arousals. Continuous positive airway pressure therapy eliminated the abnormal behaviors, unpleasant dreams, snoring and daytime hypersomnolence. This case shows that severe OSA mimic the symptoms of RBD and that attended video-PSG is necessary to establish the diagnosis of RBD, and identify or exclude other causes of dream-enacting behaviors.

Psychotropic and anti-dementia treatment in elderly persons with clinical signs of dementia with Lewy bodies: a cross-sectional study in 40 nursing homes in Sweden

BACKGROUND

Elderly persons with a dementia diagnosis often suffer from different neuropsychiatric symptoms (NPS) such as delusions, hallucinations, depression, anxiety, irritability and agitation. Currently, the medical treatment for NPS consists mostly of psychotropic medication such as hypnotics/sedatives, anxiolytics and antipsychotics. In elderly persons with dementia, usage of antipsychotics is less appropriate because of the risk of side effects such as parkinsonism, rapid cognitive decline, cerebrovascular events and finally mortality. Furthermore, elderly persons with dementia with Lewy bodies (DLB) are often hypersensitive to antipsychotics with numerous serious adverse events such as somnolence, sedation, extra-pyramidal symptoms, delirium and increased mortality. The aim of this study was to investigate the usage of psychotropics with a focus on antipsychotics and anti-dementia medication (according to the Anatomical Therapeutic Chemical Classification System) in elderly persons with clinical signs of DLB living in dementia nursing homes (NHs) in Sweden.

METHODS

Between 2012 and 2013, we applied a specially designed questionnaire that covered the clinical DLB features according to the consensus criteria of DLB. We also collected computerized medical lists from the Swedish National Medication Dispensing System from the same period. All dementia NHs (n = 40) in Malmö, the third largest city in Sweden, were covered. Of 650 eligible residents, 610 (94%) were included with 576 medical lists. The mean age was 86 years and 76% were women.

RESULTS

Treatment with antipsychotics was seen in 22% of residents, hypnotics/sedatives in 41%, antidepressants in 50% and anxiolytics in 58%. We also found an increasing usage of antipsychotics from 25% to 43% in residents with the increasing number of DLB features. Anti-dementia medications were found in 45% of the elderly with a dementia diagnosis. However, residents with two or more DLB features had less anti-dementia medication (37%) than the rest of the dementia-diagnosed NH residents (62-69%).

CONCLUSIONS

Residents with 2-4 DLB clinical features in Swedish NHs receive an unfavourable medical treatment with high antipsychotic usage and insufficient anti-dementia medication. These findings show the importance of identifying elderly persons with DLB features more effectively and improving the collaboration with nursing care to provide better medical prescription.

Clinical prevalence of Lewy body dementia

Background

The prevalence of dementia with Lewy bodies (DLB) and dementia in Parkinson’s disease (PDD) in routine clinical practice is unclear. Prevalence rates observed in clinical and population-based cohorts and neuropathological studies vary greatly. Small sample sizes and methodological factors in these studies limit generalisability to clinical practice.

Methods

We investigated prevalence in a case series across nine secondary care services over an 18-month period, to determine how commonly DLB and PDD cases are diagnosed and reviewed within two regions of the UK.

Results

Patients with DLB comprised 4.6% (95% CI 4.0–5.2%) of all dementia cases. DLB was represented in a significantly higher proportion of dementia cases in services in the North East (5.6%) than those in East Anglia (3.3%; χ² = 13.6, p < 0.01). DLB prevalence in individual services ranged from 2.4 to 5.9%. PDD comprised 9.7% (95% CI 8.3–11.1%) of Parkinson’s disease cases. No significant variation in PDD prevalence was observed between regions or between services.

Conclusions

We found that the frequency of clinical diagnosis of DLB varied between geographical regions in the UK, and that the prevalence of both DLB and PDD was much lower than would be expected in this case series, suggesting considerable under-diagnosis of both disorders. The significant variation in DLB diagnostic rates between these two regions may reflect true differences in disease prevalence, but more likely differences in diagnostic practice. The systematic introduction of more standardised diagnostic practice could improve the rates of diagnosis of both conditions.

Cognitive fluctuations in Parkinson's disease dementia: blood pressure lability as an underlying mechanism

Background

Cognitive fluctuations refer to alterations in cognition, attention, or arousal occurring over minutes to hours, most commonly in patients with dementias associated with advanced Lewy body pathology. Their pathophysiologic underpinning remains undetermined.

Case presentation

We documented serial blood pressure (BP) measurements in an 86-year-old man with Parkinson’s disease dementia experiencing cognitive fluctuations during an office visit. This patient’s associated dysautonomia included labile BP with orthostatic hypotension and nocturnal hypertension. A spontaneous episode of unresponsiveness occurred while his BP was 72/48. His mental status began to recover immediately as his BP increased to 84/56 when he was placed in a recumbent position; it fully returned to baseline when it reached 124/66 within 1 min. His heart rate remained in the mid-to-high 60s throughout. Subsequent treatment with midodrine markedly reduced the frequency of cognitive fluctuations.

Conclusions

Paroxysmal hypotension may represent an explanatory mechanism for cognitive fluctuations, a common clinical feature in patients with Parkinson’s disease dementia and dementia with Lewy bodies.

Daytime sleepiness in dementia with Lewy bodies is associated with neuronal depletion of the nucleus basalis of Meynert

INTRODUCTION

Excessive daytime sleepiness is a commonly reported clinical feature of dementia with Lewy bodies (DLB) that can occur early in the disease. Cholinergic depletion is known to be severe in DLB, even when dementia severity is mild. The nucleus basalis of Meynert serves as a primary source of cortical acetylcholine, and has a role in facilitating cortical activation and arousal. We sought to determine whether daytime sleepiness at the initial evaluation of patients with DLB was associated with neuronal loss in the nucleus basalis of Meynert.

METHODS

Autopsy-confirmed patients who met clinical criteria for probable DLB at their initial evaluation and who were administered the informant-completed Epworth Sleepiness Scale were included in the study (n = 40). Each patient had a dementia at baseline (80% with mild severity) and two or more features of parkinsonism, visual hallucinations, fluctuations, or probable REM sleep behavior disorder. Quantitative digital pathology of the nucleus basalis of Meynert was performed in the DLB group and in 20 non-DLB autopsy controls.

RESULTS

DLB had greater neuronal depletion in the nucleus basalis of Meynert (p < 0.0001) than pathologic controls. Sleepiness was present in 58% of the DLB group and those with daytime sleepiness had significantly lower neuron counts in the nucleus basalis of Meynert than their non-sleepy counterparts (p = 0.001). Regression modeling revealed that sleepiness was a stronger predictor of neuronal loss in the nucleus basalis of Meynert than visual hallucinations, fluctuations or dementia severity (p = 0.003).

CONCLUSIONS

Excessive daytime sleepiness in early DLB is indicative of a more profound loss of basal forebrain cholinergic integrity.

Functional cortical source connectivity of resting state electroencephalographic alpha rhythms shows similar abnormalities in patients with mild cognitive impairment due to Alzheimer's and Parkinson's diseases

OBJECTIVE

This study tested the hypothesis that markers of functional cortical source connectivity of resting state eyes-closed electroencephalographic (rsEEG) rhythms may be abnormal in subjects with mild cognitive impairment due to Alzheimer's (ADMCI) and Parkinson's (PDMCI) diseases compared to healthy elderly subjects (Nold).

METHODS

rsEEG data had been collected in ADMCI, PDMCI, and Nold subjects (N = 75 for any group). eLORETA freeware estimated functional lagged linear connectivity (LLC) from rsEEG cortical sources. Area under receiver operating characteristic (AUROC) curve indexed the accuracy in the classification of Nold and MCI individuals.

RESULTS

Posterior interhemispheric and widespread intrahemispheric alpha LLC solutions were abnormally lower in both MCI groups compared to the Nold group. At the individual level, AUROC curves of LLC solutions in posterior alpha sources exhibited moderate accuracies (0.70-0.72) in the discrimination of Nold vs. ADMCI-PDMCI individuals. No differences in the LLC solutions were found between the two MCI groups.

CONCLUSIONS

These findings unveil similar abnormalities in functional cortical connectivity estimated in widespread alpha sources in ADMCI and PDMCI. This was true at both group and individual levels.

SIGNIFICANCE

The similar abnormality of alpha source connectivity in ADMCI and PDMCI subjects might reflect common cholinergic impairment.

FDG-PET and CSF biomarker accuracy in prediction of conversion to different dementias in a large multicentre MCI cohort

Background/aims

In this multicentre study in clinical settings, we assessed the accuracy of optimized procedures for FDG-PET brain metabolism and CSF classifications in predicting or excluding the conversion to Alzheimer's disease (AD) dementia and non-AD dementias.

Methods

We included 80 MCI subjects with neurological and neuropsychological assessments, FDG-PET scan and CSF measures at entry, all with clinical follow-up. FDG-PET data were analysed with a validated voxel-based SPM method. Resulting single-subject SPM maps were classified by five imaging experts according to the disease-specific patterns, as "typical-AD", "atypical-AD" (i.e. posterior cortical atrophy, asymmetric logopenic AD variant, frontal-AD variant), "non-AD" (i.e. behavioural variant FTD, corticobasal degeneration, semantic variant FTD; dementia with Lewy bodies) or "negative" patterns. To perform the statistical analyses, the individual patterns were grouped either as "AD dementia vs. non-AD dementia (all diseases)" or as "FTD vs. non-FTD (all diseases)". Aβ42, total and phosphorylated Tau CSF-levels were classified dichotomously, and using the Erlangen Score algorithm. Multivariate logistic models tested the prognostic accuracy of FDG-PET-SPM and CSF dichotomous classifications. Accuracy of Erlangen score and Erlangen Score aided by FDG-PET SPM classification was evaluated.

Results

The multivariate logistic model identified FDG-PET "AD" SPM classification (Expβ = 19.35, 95% C.I. 4.8-77.8, p < 0.001) and CSF Aβ42 (Expβ = 6.5, 95% C.I. 1.64-25.43, p < 0.05) as the best predictors of conversion from MCI to AD dementia. The "FTD" SPM pattern significantly predicted conversion to FTD dementias at follow-up (Expβ = 14, 95% C.I. 3.1-63, p < 0.001). Overall, FDG-PET-SPM classification was the most accurate biomarker, able to correctly differentiate either the MCI subjects who converted to AD or FTD dementias, and those who remained stable or reverted to normal cognition (Expβ = 17.9, 95% C.I. 4.55-70.46, p < 0.001).

Conclusions

Our results support the relevant role of FDG-PET-SPM classification in predicting progression to different dementia conditions in prodromal MCI phase, and in the exclusion of progression, outperforming CSF biomarkers.

Clinicopathological and 123I-FP-CIT SPECT correlations in patients with dementia

The relationship between clinicopathologic diagnosis and ¹²³I‐FP‐CIT SPECT in 18 patients with dementia (12 with Lewy body disease) from one center in the United States was assessed. The sensitivity and specificity of abnormal ¹²³I‐FP‐CIT SPECT with reduced striatal uptake on visual inspection for predicting Lewy body disease were 91.7% and 83.3%, respectively. The mean calculated putamen to occipital ratio (mPOR) based on regions of interest was significantly reduced in Lewy body disease compared to non‐Lewy body disease cases (P = 0.002). In this study, abnormal ¹²³I‐FP‐CIT SPECT was strongly associated with underlying Lewy body disease pathology, supporting the utility of ¹²³I‐FP‐CIT SPECT in the clinical diagnosis of dementia with Lewy bodies.

Neuropathology correlates of cognitive assessments

BACKGROUND

Alzheimer's disease and other dementias are the fourth largest contributors to neurological disability and the second largest contributor to deaths from neurological disease. Described in the 1980s as 'the silent epidemic' these disorders principally, though not exclusively, affect persons 80 years or older, and in developed countries, this 'old old' population continues to grow. Definitive diagnosis of the underlying cause of the neurodegenerative disease relies on neuropathological evaluation.` AIMS: Herein, we review the sampling methods, analysis and interpretation of both pathological and immunocytochemical techniques in the diagnostic assessment of neurodegenerative disease.

FINDINGS

Neurodegenerative disorders are characterised by accumulation of pathologically altered protein in the human brain, and in some cases, in the peripheral tissues. Whilst it is suggested that a comprehensive review of the patient's clinical history, cognition and behaviour, together with a full clinical examination and radiological analysis, should lead to a high degree of confidence in the clinical diagnosis, the view persists that underlying pathology can only be predicted on clinical grounds especially in Alzheimer's disease, vascular brain injury and diffuse Lewy body disease with only limited accuracy.

CONCLUSIONS

Neuropathological assessment of well characterised clinical cases provides accurate data on the prevalence of neurodegenerative diseases. This will aid future biomarker, neuroimaging studies and clinical trials focussed on population based cohorts.

The CSF neurofilament light signature in rapidly progressive neurodegenerative dementias

Background

Neurofilament light chain protein (NfL) is a surrogate biomarker of neurodegeneration that has never been systematically tested, either alone or in combination with other biomarkers, in atypical/rapidly progressive neurodegenerative dementias (NDs).

Methods

Using validated, commercially available enzyme-linked immunosorbent assay kits, we measured cerebrospinal fluid (CSF) NfL, total tau (t-tau), phosphorylated tau, and β-amyloid 42 in subjects with a neuropathological or clinical diagnosis of prion disease (n = 141), Alzheimer’s disease (AD) (n = 73), dementia with Lewy bodies (DLB) (n = 35), or frontotemporal lobar degeneration (FTLD) (n = 44). Several cases with an atypical/rapidly progressive course were included in each group. We evaluated the diagnostic accuracy of every CSF biomarker and their combinations by ROC curve analyses.

Results

In each patient group CSF NfL showed higher levels than in control subjects, reaching the highest values in those with Creutzfeldt-Jakob disease (CJD). In the latter, NfL showed a divergent, subtype-specific correlation with t-tau, depending on the degree of subcortical involvement and disease duration. Most significantly, patients with classic sporadic CJD (sCJD) MM1 showed a significantly lower concentration of CSF NfL than those with sCJD MV2, despite the much higher t-tau levels and the more rapid clinical course. High NfL levels were also detected in most atypical CJD cases, showing a disease duration longer than 2 years and/or borderline/negative results in other CSF assays (e.g., 14-3-3, t-tau, and prion real-time quaking-induced conversion). Rapidly progressive/atypical cases showed higher NfL levels than typical patients in FTLD, but not in AD or DLB. NfL showed accuracy similar to that of t-tau in discriminating CJD from other NDs, but it had higher efficacy in differentiating atypical forms, especially in regard to Alzheimer’s disease.

Conclusions

The present data indicate that CSF NfL and t-tau levels reflect distinct pathophysiological mechanisms of neurodegeneration and support the clinical use of NfL as a fast screening biomarker for the differential diagnosis of atypical/rapidly progressive NDs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13195-017-0331-1) contains supplementary material, which is available to authorized users.

The Amygdala as a Locus of Pathologic Misfolding in Neurodegenerative Diseases

Over the course of most common neurodegenerative diseases the amygdala accumulates pathologically misfolded proteins. Misfolding of 1 protein in aged brains often is accompanied by the misfolding of other proteins, suggesting synergistic mechanisms. The multiplicity of pathogenic processes in human amygdalae has potentially important implications for the pathogenesis of Alzheimer disease, Lewy body diseases, chronic traumatic encephalopathy, primary age-related tauopathy, and hippocampal sclerosis, and for the biomarkers used to diagnose those diseases. Converging data indicate that the amygdala may represent a preferential locus for a pivotal transition from a relatively benign clinical condition to a more aggressive disease wherein multiple protein species are misfolded. Thus, understanding of amygdalar pathobiology may yield insights relevant to diagnoses and therapies; it is, however, a complex and imperfectly defined brain region. Here, we review aspects of amygdalar anatomy, connectivity, vasculature, and pathologic involvement in neurodegenerative diseases with supporting data from the University of Kentucky Alzheimer's Disease Center autopsy cohort. Immunohistochemical staining of amygdalae for Aβ, Tau, α-synuclein, and TDP-43 highlight the often-coexisting pathologies. We suggest that the amygdala may represent an "incubator" for misfolded proteins and that it is possible that misfolded amygdalar protein species are yet to be discovered.

Negative 11C-PIB PET Predicts Lack of Alzheimer's Disease Pathology in Postmortem Examination

Our aim was to assess whether in vivo11C-PIB negative memory-impaired subjects may nonetheless exhibit brain Alzheimer's disease (AD) pathology. We re-evaluated the PET images and systematically characterized the postmortem neuropathology of six individuals who had undergone clinically indicated amyloid PET. The single case with negligible amyloid-β (Aβ) pathology had Lewy body disease, where concomitant AD changes are often seen. Further, the subject's plaques were predominantly diffuse. The predictive value of a negative 11C-PIB scan appears to be good, even in memory-impaired populations. Our results suggest that considerable neuritic Aβ plaque pathology in the absence of specific/cortical 11C-PIB binding upon PET is unlikely.

Amsterdam Dementia Cohort: Performing Research to Optimize Care

The Alzheimer center of the VU University Medical Center opened in 2000 and was initiated to combine both patient care and research. Together, to date, all patients forming the Amsterdam Dementia Cohort number almost 6,000 individuals. In this cohort profile, we provide an overview of the results produced based on the Amsterdam Dementia Cohort. We describe the main results over the years in each of these research lines: 1) early diagnosis, 2) heterogeneity, and 3) vascular factors. Among the most important research efforts that have also impacted patients' lives and/or the research field, we count the development of novel, easy to use diagnostic measures such as visual rating scales for MRI and the Amsterdam IADL Questionnaire, insight in different subgroups of AD, and findings on incidence and clinical sequelae of microbleeds. Finally, we describe in the outlook how our research endeavors have improved the lives of our patients.

Abnormalities of resting-state functional cortical connectivity in patients with dementia due to Alzheimer's and Lewy body diseases: an EEG study

Previous evidence showed abnormal posterior sources of resting-state delta (<4 Hz) and alpha (8-12 Hz) rhythms in patients with Alzheimer's disease with dementia (ADD), Parkinson's disease with dementia (PDD), and Lewy body dementia (DLB), as cortical neural synchronization markers in quiet wakefulness. Here, we tested the hypothesis of additional abnormalities in functional cortical connectivity computed in those sources, in ADD, considered as a "disconnection cortical syndrome", in comparison with PDD and DLB. Resting-state eyes-closed electroencephalographic (rsEEG) rhythms had been collected in 42 ADD, 42 PDD, 34 DLB, and 40 normal healthy older (Nold) participants. Exact low-resolution brain electromagnetic tomography (eLORETA) freeware estimated the functional lagged linear connectivity (LLC) from rsEEG cortical sources in delta, theta, alpha, beta, and gamma bands. The area under receiver operating characteristic (AUROC) curve indexed the classification accuracy between Nold and diseased individuals (only values >0.7 were considered). Interhemispheric and intrahemispheric LLCs in widespread delta sources were abnormally higher in the ADD group and, unexpectedly, normal in DLB and PDD groups. Intrahemispheric LLC was reduced in widespread alpha sources dramatically in ADD, markedly in DLB, and moderately in PDD group. Furthermore, the interhemispheric LLC in widespread alpha sources showed lower values in ADD and DLB than PDD groups. At the individual level, AUROC curves of LLC in alpha sources exhibited better classification accuracies for the discrimination of ADD versus Nold individuals (0.84) than for DLB versus Nold participants (0.78) and PDD versus Nold participants (0.75). Functional cortical connectivity markers in delta and alpha sources suggest a more compromised neurophysiological reserve in ADD than DLB, at both group and individual levels.

Tau Imaging in Parkinsonism: What Have We Learned So Far?

Background

Positron emission tomography ligands are now available that bind to tau proteins in the brain, providing the exciting opportunity to assess the presence and distribution of tau in vivo in living patients.

Methods

This manuscript performed a systematic review of studies that have performed tau PET imaging in patients with parkinsonian disorders. Pubmed was searched up to November 2017, and the review included case reports and patient-control studies.

Results

Most tau-PET studies have utilized the [¹⁸F]AV-1451 ligand, with a few using the [¹¹C]PBB3 and [¹⁸F]THK-5351 ligands. Elevated cortical tau-PET uptake has been observed in Parkinson's disease dementia and dementia with Lewy bodies, presumed to be related to Alzheimer's disease-related pathology. Mild patterns of tau-PET uptake have been observed in subcortical structures in progressive supranuclear palsy and subcortical structures and motor cortex in corticobasal syndrome, although discrepancy with autoradiographic studies that show lack of binding to 4-repeat tau and "off-target" binding observed in subcortical structures limits interpretation of these findings. Findings in frontotemporal dementia with tau mutations are variable, but elevated signal is most pronounced in mutations with deposition of both 3 and 4-repeat tau. Elevated tau-PET uptake has also been observed in multiple system atrophy, a synucleinopathy.

Conclusion

The value of the current generation of tau-PET ligands varies across Parkinsonian syndromes depending upon underlying variability in tau pathology and "off-target" binding. More work is needed to understand the biological basis of binding and more specific tau PET ligands are needed to study parkinsonian disorders.

Hospitalization in people with dementia with Lewy bodies: Frequency, duration, and cost implications

Introduction

Increased hospitalization is a major component of dementia impact on individuals and cost, but has rarely been studied in dementia with Lewy bodies (DLB). Our aim was to describe the risk and duration of hospital admissions in patients with DLB, and compare these to those in Alzheimer's disease (AD) and the general population.

Methods

A large database of mental health and dementia care in South London was used to assemble a cohort of patients diagnosed with DLB. These were 1:4 matched with patients diagnosed with AD on age, gender, and cognitive status.

Results

Rates of hospital admissions in the year after dementia diagnosis were significantly higher in 194 patients with DLB than in 776 patients with AD (crude incidence rate ratio 1.50; 95% confidence interval: 1.28-1.75) or the catchment population (indirectly standardized hospitalization rate 1.22; 95% confidence interval: 1.06-1.39). Patients with DLB had on average almost four additional hospital days per person-year than patients with AD. Multivariate Poisson regression models indicated poorer physical health early in the disease course as the main driver of this increased rate of hospitalization, whereby neuropsychiatric symptoms additionally explained the higher number of hospital days.

Discussion

Patients with DLB are more frequently admitted to general hospitals and utilize inpatient care to a substantially higher degree than patients with AD or the general elderly population. These data highlight an opportunity to reduce hospital days by identifying DLB earlier and providing more targeted care focused on the specific triggers for hospitalization and associations of prolonged stay.

Practical Treatment of Lewy Body Disease in the Clinic: Patient and Physician Perspectives

This article describes the practical considerations in the clinical medical treatment in dementia with Lewy body (DLB) patients. It is illustrated with the voice of a DLB sufferer and his wife. According to our experience, emanating from a 15 year collaboration between a doctor and a nurse at a memory clinic, there are several possible therapeutical entrances. However, the order in which the medication is introduced is of great importance to avoid aggravation of other DLB symptoms. We start the treatment with cholinesterase inhibitor and memantine, and; thereafter, we treat the most disturbing symptom. Thereafter, we consider if orthostatic hypotension is present and treat it. In the treatment of depression and anxiety it is beneficial to use agents affecting both noradrenalin and serotonin. Dysphagia may be lethal but can be improved with carbohydrate drinks. These and other aspects are commented upon from our experience and are also reflected in relation to studies evaluating the existing level of evidence.

Dementia with Lewy bodies and Parkinson's disease-dementia: current concepts and controversies

Dementia with Lewy bodies (DLB) and Parkinson's disease-dementia (PDD), although sharing many clinical, neurochemical and morphological features, according to DSM-5, are two entities of major neurocognitive disorders with Lewy bodies of unknown etiology. Despite considerable clinical overlap, their diagnosis is based on an arbitrary distinction between the time of onset of motor and cognitive symptoms: dementia often preceding parkinsonism in DLB and onset of cognitive impairment after onset of motor symptoms in PDD. Both are characterized morphologically by widespread cortical and subcortical α-synuclein/Lewy body plus β-amyloid and tau pathologies. Based on recent publications, including the fourth consensus report of the DLB Consortium, a critical overview is given. The clinical features of DLB and PDD include cognitive impairment, parkinsonism, visual hallucinations, and fluctuating attention. Intravitam PET and post-mortem studies revealed more pronounced cortical atrophy, elevated cortical and limbic Lewy pathologies (with APOE ε4), apart from higher prevalence of Alzheimer pathology in DLB than PDD. These changes may account for earlier onset and greater severity of cognitive defects in DLB, while multitracer PET studies showed no differences in cholinergic and dopaminergic deficits. DLB and PDD sharing genetic, neurochemical, and morphologic factors are likely to represent two subtypes of an α-synuclein-associated disease spectrum (Lewy body diseases), beginning with incidental Lewy body disease-PD-nondemented-PDD-DLB (no parkinsonism)-DLB with Alzheimer's disease (DLB-AD) at the most severe end, although DLB does not begin with PD/PDD and does not always progress to DLB-AD, while others consider them as the same disease. Both DLB and PDD show heterogeneous pathology and neurochemistry, suggesting that they share important common underlying molecular pathogenesis with AD and other proteinopathies. Cognitive impairment is not only induced by α-synuclein-caused neurodegeneration but by multiple regional pathological scores. Recent animal models and human post-mortem studies have provided important insights into the pathophysiology of DLB/PDD showing some differences, e.g., different spreading patterns of α-synuclein pathology, but the basic pathogenic mechanisms leading to the heterogeneity between both disorders deserve further elucidation. In view of the controversies about the nosology and pathogenesis of both syndromes, there remains a pressing need to differentiate them more clearly and to understand the processes leading these synucleinopathies to cause one disorder or the other. Clinical management of both disorders includes cholinesterase inhibitors, other pharmacologic and nonpharmacologic strategies, but these have only a mild symptomatic effect. Currently, no disease-modifying therapies are available.

Alzheimer's Disease-Related Dementias Summit 2016: National research priorities

Goal 1 of the National Plan to Address Alzheimer's Disease is to prevent and effectively treat Alzheimer disease and Alzheimer disease-related dementias by 2025. To help inform the research agenda toward achieving this goal, the NIH hosts periodic summits that set and refine relevant research priorities for the subsequent 5 to 10 years. This proceedings article summarizes the 2016 Alzheimer's Disease-Related Dementias Summit, including discussion of scientific progress, challenges, and opportunities in major areas of dementia research, including mixed-etiology dementias, Lewy body dementia, frontotemporal degeneration, vascular contributions to cognitive impairment and dementia, dementia disparities, and dementia nomenclature.

The diagnosis of dementias: a practical tool not to miss rare causes

Dementia represents one of the most diffuse disorders of our Era. Alzheimer's disease is the principle cause of dementia worldwide. Metabolic, infectious, autoimmune, inflammatory, and genetic dementias represent a not negligible number of disorders, with increasing numbers in younger subjects. Due to the heterogeneity of patients and disorders, the diagnosis of dementia is challenging. In the present article, we propose a practical diagnostic approach following the two-step investigation procedure. The first step includes basic blood tests and brain neuroimaging, performed on all patients. After this first-line investigation, it is then possible to rule out metabolic causes of dementia and to identify three main subgroups in dementia: predominant gray matter atrophy, white matter disease, basal ganglia pathologies. The predominant gray matter atrophy subgroup includes neurodegenerative causes of dementia and some lysosomal storage disorders. The white matter subgroup indicates a comprehensive list of vascular dementia causes, mitochondrial diseases, and leukodystrophies. Whereas, the basal ganglia alterations are due to metal accumulation pathologies, such as iron, copper, or calcium. Each category has specific clinical hallmarks, accurately reported in the article, and requires specific second-line investigation. Thus, we indicate the distinct second diagnostic step of each disease. The proposed diagnostic flow-chart follows the clinical reasoning and helps clinicians through the differential diagnosis of dementia.

Propagation of alpha-synuclein pathology from the olfactory bulb: possible role in the pathogenesis of dementia with Lewy bodies

Olfactory limbic structures, like the amygdala, the entorhinal, and the piriform cortices, are closely involved in cognitive processes. Thus, besides olfactory dysfunctions, it is conceivable that the compromise of these structures can lead to cognitive impairment. The olfactory bulb is affected by alpha-synuclein pathology in almost all cases of both Parkinson's disease and dementia with Lewy bodies. The clinical distinction between these disorders relies on the timing in the appearance of dementia in relationship to motor symptoms. Typically, it occurs late in the course of Parkinson's disease, and within the first year in dementia with Lewy bodies. The close anatomical proximity of the olfactory bulb with limbic regions, together with the early occurrence of cognitive impairment that is observed in dementia with Lewy bodies, raise the question whether the propagation of alpha-synuclein pathology in this condition might originate in the olfactory bulb, spreading from there to other limbic structures, and thereby reaching the associative neocortex. This review will describe the anatomical basis of the olfactory system and discuss the evidence of potential spreading pathways from the olfactory bulb that could support the presence of early dementia in the setting of Lewy body disorders.

Hallucinations Are Real to Patients With Dementia

In this case study, we present a patient with preexistent posttraumatic stress disorder and psychosis who has been recently diagnosed with Dementia with Lewy Bodies. He is experiencing vivid hallucinations. What went wrong between him and his wife as a result of these hallucinations is presented. Alternative actions that could have been used are suggested.

MicroRNA expression patterns in human anterior cingulate and motor cortex: A study of dementia with Lewy bodies cases and controls

OVERVIEW

MicroRNAs (miRNAs) have been implicated in neurodegenerative diseases including Parkinson's disease and Alzheimer's disease (AD). Here, we evaluated the expression of miRNAs in anterior cingulate (AC; Brodmann area [BA] 24) and primary motor (MO; BA 4) cortical tissue from aged human brains in the University of Kentucky AD Center autopsy cohort, with a focus on dementia with Lewy bodies (DLB).

METHODS

RNA was isolated from gray matter of brain samples with pathology-defined DLB, AD, AD + DLB, and low-pathology controls, with n = 52 cases initially included (n  = 23 with DLB), all with low (<4 h) postmortem intervals. RNA was profiled using Exiqon miRNA microarrays. Quantitative PCR for post hoc replication was performed on separate cases (n = 6 controls) and included RNA isolated from gray matter of MO, AC, primary somatosensory (BA 3), and dorsolateral prefrontal (BA 9) cortical regions.

RESULTS

The miRNA expression patterns differed substantially according to anatomic location: of the relatively highly-expressed miRNAs, 150/481 (31%) showed expression that was different between AC versus MO (at p < .05 following correction for multiple comparisons), most (79%) with higher expression in MO. A subset of these results were confirmed in qPCR validation focusing on miR-7, miR-153, miR-133b, miR-137, and miR-34a. No significant variation in miRNA expression was detected in association with either neuropathology or sex after correction for multiple comparisons.

CONCLUSION

A subset of miRNAs (some previously associated with α-synucleinopathy and/or directly targeting α-synuclein mRNA) were differentially expressed in AC and MO, which may help explain why these brain regions show differences in vulnerability to Lewy body pathology.

Utility of Autonomic Function Tests to Differentiate Dementia with Lewy Bodies and Parkinson Disease with Dementia from Alzheimer Disease

Objective: We studied autonomic disturbance in patients with dementia with Lewy bodies (DLB), Parkinson disease with dementia (PDD), Alzheimer disease (AD), to determine whether autonomic function tests can be used to distinguish these disorders. Methods: Autonomic function was tested in 56 patients with DLB, 37 patients with PDD, and 59 patients with AD by using the sympathetic skin response, coefficient of variation in R-R interval, the head-up tilt test, serum norepinephrine concentration, and 123I-meta-iodobenzylguanidine cardiac scintigraphy. Symptoms of autonomic dysfunction, such as constipation, urinary symptoms, and orthostatic hypotension, were also noted. Results: The groups did not differ on baseline characteristics other than those associated with Parkinsonism and dementia. All patients with DLB and PDD had some dysautonomia, whereas rates were much lower for patients with AD (19%). Significantly more DLB and PDD patients than AD patients showed abnormalities on autonomic function tests. Conclusions: Autonomic function tests might be quite useful to distinguish DLB and PDD from AD.

Cingulate island sign temporally changes in dementia with Lewy bodies

The cingulate island sign (CIS) that reflects sparing of the posterior cingulate cortex (PCC) relative to the precuneus plus cuneus on FDG-PET and brain perfusion SPECT, has been proposed as a feature of dementia with Lewy bodies (DLB). As the CIS is influenced by concomitant Alzheimer's disease (AD)-type neurofibrillary tangle (NFT) pathology, we postulated that the CIS gradually disappears as DLB progresses. To determine temporal changes in the CIS, 24 patients with mild DLB and 7 with prodromal DLB underwent ¹²³I-IMP-SPECT and MMSE twice at an interval of two years. The CIS was evaluated as a ratio that was derived by dividing IMP accumulation in the PCC with that in the precuneus plus cuneus. We found that the CIS changed over time and that the relationship between CIS ratios and MMSE scores was inverted U-shaped. Thus, the CIS was most obvious in the vicinity of an MMSE score of 22 and it gradually diminished as the MMSE score decreased. Moreover, a lower CIS ratio in mild DLB was associated with a worse prognosis for cognitive decline, presumably due to concomitant AD-type NFT pathology. Our findings would provide a foundation for the appropriate usage of CIS as a biomarker.

Accumulation of 123I-Ioflupane Is a Useful Marker of the Efficacy of Selegiline Monotherapy in Drug-Naïve Parkinson's Disease

Background: Selegiline enhances the patient's endogenous dopamine by inhibiting dopamine metabolism. The efficacy of selegiline monotherapy for drug-naïve Parkinson's disease (PD) patients may depend on the degree of dopaminergic neuronal degeneration. ¹²³I-Ioflupane single photon emission computed tomography (SPECT) and ¹²³I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy are diagnostic methods to assess the pharmacological and pathological changes in PD. Objective: We examined the utility of these imaging methods to predict the efficacy of selegiline monotherapy for motor symptoms in drug-naïve PD patients. Methods: We observed the efficacy of selegiline monotherapy in 28 drug-naïve PD patients and compared the improvement in motor function and the imaging findings. These patients received selegiline monotherapy, and the amount was increased to the optimal dose in clinical practice. Motor function was assessed using the Unified Parkinson's Rating Scale (UPDRS) at baseline and at the stable dose. Imaging was performed before treatment, and the striatal Specific Binding Ratio (SBR) of the ¹²³I-Ioflupane SPECT and the Heart-to-Mediastinum (H/M) ratio of the ¹²³I-MIBG myocardial scintigraphy were calculated. Both ratios were compared with improvements in scores for motor assessment using Pearson's correlation coefficient. Results: The mean UPDRS part III score significantly improved with at least 5.0 mg/day of selegiline. Further dose escalation did not improve the mean motor score. The percent improvement in the motor score from baseline showed a significant negative correlation with the SBR of average of the right and left striatum, but not with the H/M ratio. Multiple regression analysis using patient's background factors showed that percent improvement in the UPDRS part III score directly correlate with the SBR (p = 0.04), but not with the age (p = 0.72), disease duration (p = 0.31), baseline UPDRS part III (p = 0.77) and the drug dose (p = 0.26). Conclusion: PD patients with a lower accumulation of ¹²³I-Ioflupane in the striatum can have greater improvement with selegiline monotherapy.

Diagnosis and Management of Cognitive and Behavioral Changes in Dementia With Lewy Bodies

OPINION STATEMENT

Proper diagnosis of dementia with Lewy bodies (DLB) in clinical practice remains suboptimal as many cases are misdiagnosed, usually as Alzheimer disease (AD) or Parkinson's disease (PD) and, in rare cases, psychosis. Therefore, it is important for patients with dementia to be thoroughly evaluated by a specialist who is familiar with current diagnostic tests and treatment options. New diagnostic criteria from the Dementia with Lewy Bodies Consortium have been developed to increase diagnostic sensitivity for DLB (Diagnosis and management of dementia with Lewy bodies: fourth consensus report of the DLB Consortium; McKeith et al.; Neurology, 89(1): 88-100). REM sleep behavior disorder (RBD) has been studied more thoroughly in correlation with DLB and is now considered a core feature. D2 receptor blocking antipsychotics, which can cause severe antipsychotic sensitivity, are now rarely prescribed for treatment. Therefore, severe antipsychotic sensitivity, which was a suggestive criterion for DLB diagnosis, is now listed as a supportive feature. Reduced DAT uptake in basal ganglia demonstrated by SPECT or PET imaging has high specificity (90%) for distinguishing DLB from AD. Reduced uptake on metaiodobenzylguanidine myocardial scintigraphy correlates with reduced postganglionic sympathetic cardiac innervation in Lewy body diseases, which can increase specificity for discriminating probable DLB from probable AD in milder cases of dementia. However, the latter is more commonly used in Japan and is not used in the USA. The evidence supporting the benefit of other therapeutic modalities is limited in DLB due to lack of extensive studies. There are no FDA-approved medications for the treatment of DLB, although some effective drugs have been used off label to treat various symptoms.

Alzheimer's Disease: Past, Present, and Future

Although dementia has been described in ancient texts over many centuries (e.g., "Be kind to your father, even if his mind fail him." - Old Testament: Sirach 3:12), our knowledge of its underlying causes is little more than a century old. Alzheimer published his now famous case study only 110 years ago, and our modern understanding of the disease that bears his name, and its neuropsychological consequences, really only began to accelerate in the 1980s. Since then we have witnessed an explosion of basic and translational research into the causes, characterizations, and possible treatments for Alzheimer's disease (AD) and other dementias. We review this lineage of work beginning with Alzheimer's own writings and drawings, then jump to the modern era beginning in the 1970s and early 1980s and provide a sampling of neuropsychological and other contextual work from each ensuing decade. During the 1980s our field began its foundational studies of profiling the neuropsychological deficits associated with AD and its differentiation from other dementias (e.g., cortical vs. subcortical dementias). The 1990s continued these efforts and began to identify the specific cognitive mechanisms affected by various neuropathologic substrates. The 2000s ushered in a focus on the study of prodromal stages of neurodegenerative disease before the full-blown dementia syndrome (i.e., mild cognitive impairment). The current decade has seen the rise of imaging and other biomarkers to characterize preclinical disease before the development of significant cognitive decline. Finally, we suggest future directions and predictions for dementia-related research and potential therapeutic interventions. (JINS, 2017, 23, 818-831).