Nigrostriatal dopaminergic activities in dementia with Lewy bodies in relation to neuroleptic sensitivity: comparisons with Parkinson's disease

Evaluation of Collimators in a High-Resolution, Whole-Body SPECT/CT Device with a Dual-Head Cadmium-Zinc-Telluride Detector for 123I-FP-CIT SPECT

The study aim was to evaluate the adaptation of collimators to 123I-N-fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl)nortropane (123I-FP-CIT) dopamine transporter SPECT (DAT-SPECT) by a high-resolution whole-body SPECT/CT system with a cadmium-zinc-telluride detector (C-SPECT) in terms of image quality, quantitation, diagnostic performance, and acquisition time. Methods: Using a C-SPECT device equipped with a wide-energy, high-resolution collimator and a medium-energy, high-resolution sensitivity (MEHRS) collimator, we evaluated the image quality and quantification of DAT-SPECT for an anthropomorphic striatal phantom. Ordered-subset expectation maximization iterative reconstruction with resolution recovery, scatter, and attenuation correction was used, and the optimal collimator was determined on the basis of the contrast-to-noise ratio (CNR), percentage contrast, and specific binding ratio. The acquisition time that could be reduced using the optimal collimator was determined. The optimal collimator was used to retrospectively evaluate diagnostic accuracy via receiver-operating-characteristic analysis and specific binding ratios for 41 consecutive patients who underwent DAT-SPECT. Results: When the collimators were compared in the phantom verification, the CNR and percentage contrast were significantly higher for the MEHRS collimator than for the wide-energy high-resolution collimator (P < 0.05). There was no significant difference in the CNR between 30 and 15 min of imaging time using the MEHRS collimator. In the clinical study, the areas under the curve for acquisition times of 30 and 15 min were 0.927 and 0.906, respectively, and the diagnostic accuracies of the DAT-SPECT images did not significantly differ between the 2 times. Conclusion: The MEHRS collimator provided the best results for DAT-SPECT with C-SPECT; shorter acquisition times (<15 min) may be possible with injected activity of 167-186 MBq.

Influence of brain atrophy using semiquantitative analysis in [123I]FP-CIT single-photon emission computed tomography by a Monte Carlo simulation study

The specific binding ratio (SBR) is an objective indicator of N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-[123I] iodophenyl) nortropane ([¹²³I]FP-CIT) single-photon emission computed tomography (SPECT) that could be used for the diagnosis of Parkinson’s disease and Lewy body dementia. One of the issues of the SBR analysis is that the setting position of the volume of interest (VOI) may contain cerebral ventricles and cerebral grooves. These areas may become prominent during the brain atrophy analysis; however, this phenomenon has not been evaluated enough. This study thus used Monte Carlo simulations to examine the effect of brain atrophy on the SBR analysis. The brain atrophy model (BAM) used to simulate the three stages of brain atrophy was made using a morphological operation. Brain atrophy levels were defined in the descending order from 1 to 3, with Level 3 indicating to the most severe damage. Projection data were created based on BAM, and the SPECT reconstruction was performed. The ratio of the striatal to background region accumulation was set to a rate of 8:1, 6:1, and 4:1. The striatal and the reference VOI mean value were decreased as brain atrophy progressed. Additionally, the Bolt’s analysis methods revealed that the reference VOI value was more affected by brain atrophy than the striatal VOI value. Finally, the calculated SBR value was overestimated as brain atrophy progressed, and a similar trend was observed when the ratios of the striatal to background region accumulation were changed. This study thus suggests that the SBR can be overestimated in cases of advanced brain atrophy.

When responsive and reactive meet organic? Treatment implications of language use in the era of #BanBPSD

The aetiopathogenesis of behaviours and psychological symptoms of dementia (BPSD) is often subjective, complex and multifaceted, produced by an array of contributing factors, including biomedical, psychological, environmental and/or social factors. Alongside other contributing factors, organic aetiology of BPSD should be considered when devising therapeutic management plans. Although considered last resort, time‐limited antipsychotic treatment (≤3 months) may have a vital adjunct role in managing intractable, refractory, distressing and/or life‐threatening BPSD, such as delusions and hallucinations; but only after person‐centred psychosocial interventions are exhausted and fail to deliver any therapeutic response. If prescribed, careful monitoring of therapeutic responses and adverse effects of antipsychotics with de‐prescribing plans should be a top priority, as these agents have limited efficacies and serious adverse outcomes (e.g., mortality).

Laterality of specific binding ratios on DAT-SPECT for differential diagnosis of degenerative parkinsonian syndromes

Motor symptoms of Parkinson's disease (PD) occur unilaterally and progress with asymmetry, while progressive supranuclear palsy (PSP) and multiple system atrophy of the parkinsonism subtype (MSA-P) lack this tendency. We assessed the laterality of specific binding ratios (SBRs) on dopamine transporter single-photon emission computed tomography (DAT-SPECT) for the differential diagnosis of these diseases in 311 PD, 33 PSP, 20 MSA-P, and 137 control patients. The average SBR in PD was higher than that in PSP (P = 0.035). Compared with Hoehn-Yahr (HY) stages, the average SBR in PD with HY stage I was only higher than that in PSP (P < 0.001). SBR laterality in PD with HY stage I was significantly higher than that in PSP (P = 0.001). This difference was not observed in PD with HY stage II. The average and laterality of SBRs in MSA-P were similar to those in PD and PSP. The asymmetry indices were similar among PD, PSP, and MSA-P. These data suggest that PSP shows a pattern of SBRs different from that in PD, attributed to HY stage I in PD. The limited usefulness of DAT-SPECT may be explained by the low discrimination between PD with bilateral motor symptoms and PSP.

Survival among the older adults with clinical signs of Lewy body dementia in 40 Swedish nursing homes: a 6-year follow-up study

OBJECTIVES

To investigate survival among elderly residents of Swedish nursing homes (NHs), with specific focus on those with two or more signs of Lewy body dementia (LBD).

DESIGN

Prospective observational study.

SETTING

NHs in Malmö, the third largest city in Sweden.

PARTICIPANTS

The study population was older adults (aged ≥65 years) living in the 40 NHs in Malmö. Clinical data were collected with a customised questionnaire assessing core clinical LBD signs. Patients were categorised based on 0-1 or 2-4 LBD signs. The head nurse at each NH collected the study data: LBD questionnaires, electronic medication lists and electronic medical records from 2012 to 2013.

MAIN OUTCOME MEASURES

80-month mortality.

RESULTS

Five hundred and fifty-eight (96%) of the residents were deceased at follow-up; among these, mean (95% CI) overall survival time was 29 (28-31) months. Mean survival differed between the LBD groups; those with 0-1 LBD signs lived 8 months longer than those with 2-4 LBD signs. Mortality risk for residents in the LBD 2-4 group was also significantly higher. HR adjusted for age and sex was HR (95% CI) 1.60 (1.30 to 1.97). Mortality risk was also significantly higher in residents with signs of fluctuating cognition 1.36 (1.15 to 1.62), rapid eye movement sleep behaviour disorder 1.49 (1.11 to 1.98), balance problems 1.36 (1.14 to 1.61) or rigidity 1.41 (1.18 to 1.68).

CONCLUSIONS

This large, longitudinal study shows the important survival effects of identifying and diagnosing older adults NH residents who have two or more LBD signs.

[Influence of the Each Correction Method for the Specific Binding Ratio and Standardized Uptake Value in the Dopamine Transporter SPECT]

This study was to reveal the characteristics for each correction effect of specific binding ratio (SBR) and standardized uptake value (SUV) in the dopamine transporter (DAT) single photon emission computed tomography (SPECT). We created the ¹²³I solution of five radioactive concentrations, which was filled with two types of striatum phantom such as separated or integrated caudate and putamen. We created 10 striatum accumulation models by combining the ¹²³I solution. Images were reconstructed using ordered subset expectation maximization (OSEM) incorporating attenuation correction (AC), scatter correction (SC) or resolution recovery (RR) for the collected data of 10 striatum accumulation models and 66 patients. Correction combinations were AC, ACSC, ACRR and ACSCRR. The SBR, SUV_mean and SUV_max were evaluated correlation and relative error between SBR, SUV_mean and SUV_max by each correction method. The SBR and SUV had a significant positive correlation with all correction methods. The minimum values of relative error for SBR, SUV_mean and SUV_max were 39.7% with ACSCRR, 18.4% with AC and 16.5% with ACSC, respectively. In addition, the ACSC of SBR and SUV_mean was almost same value. The SBR showed significantly higher values by incorporating SC, while the SUV was significantly higher values by incorporating RR. It was suggested that SUV could be used for the quantitative index of DAT SPECT. Furthermore, we demonstrated the characteristic among each correction for SBR and SUV.

Quantitation of specific binding ratio in 123I-FP-CIT SPECT: accurate processing strategy for cerebral ventricular enlargement with use of 3D-striatal digital brain phantom

This study aimed to evaluate the effect of ventricular enlargement on the specific binding ratio (SBR) and to validate the cerebrospinal fluid (CSF)-Mask algorithm for quantitative SBR assessment of ¹²³I-FP-CIT single-photon emission computed tomography (SPECT) images with the use of a 3D-striatum digital brain (SDB) phantom. Ventricular enlargement was simulated by three-dimensional extensions in a 3D-SDB phantom comprising segments representing the striatum, ventricle, brain parenchyma, and skull bone. The Evans Index (EI) was measured in 3D-SDB phantom images of an enlarged ventricle. Projection data sets were generated from the 3D-SDB phantoms with blurring, scatter, and attenuation. Images were reconstructed using the ordered subset expectation maximization (OSEM) algorithm and corrected for attenuation, scatter, and resolution recovery. We bundled DaTView (Southampton method) with the CSF-Mask processing software for SBR. We assessed SBR with the use of various coefficients (f factor) of the CSF-Mask. Specific binding ratios of 1, 2, 3, 4, and 5 corresponded to SDB phantom simulations with true values. Measured SBRs > 50% that were underestimated with EI increased compared with the true SBR and this trend was outstanding at low SBR. The CSF-Mask improved 20% underestimates and brought the measured SBR closer to the true values at an f factor of 1.0 despite an increase in EI. We connected the linear regression function (y = - 3.53x + 1.95; r = 0.95) with the EI and f factor using root-mean-square error. Processing with CSF-Mask generates accurate quantitative SBR from dopamine transporter SPECT images of patients with ventricular enlargement.

Dopamine transporter imaging predicts motor responsiveness to levodopa challenge in patients with Parkinson's disease: A pilot study of DATSCAN for subthalamic deep brain stimulation

Imaging studies are necessary prior to subthalamic deep brain stimulation (STN-DBS). Dopamine transporter (DAT) imaging is a powerful tool for visualizing dopamine terminals in the striatum, but its usefulness in STN-DBS is unclear. Here, we retrospectively investigated the relationship between motor symptoms and the specific binding ratio (SBR) on DAT imaging in patients with Parkinson's disease (PD). We included 23 consecutive patients (9 female; 14 male) who were evaluated for DBS eligibility between October 2013 and October 2014 and subsequently received bilateral STN-DBS. Correlation and simple regression analyses were performed on SBR values and clinical parameters before and after surgery. SBR value was negatively correlated with Unified Parkinson's Disease Rating Scale (UPDRS) motor score in the "ON" state before surgery (r_s=-0.637, p=0.001) and positively correlated with the reduction of the levodopa equivalent daily dose by surgery (r=0.422, p=0.045). A simple regression analysis revealed that SBR value was positively correlated with UPDRS motor score improvement after levodopa challenge before surgery (p=0.001, R²=0.423). DAT imaging may be useful in STN-DBS candidate selection and the identification of the therapeutic mechanism of STN-DBS in patients with advanced PD and motor symptom fluctuations.

Development of Realistic Striatal Digital Brain (SDB) Phantom for 123I-FP-CIT SPECT and Effect on Ventricle in the Brain for Semi-quantitative Index of Specific Binding Ratio

PURPOSE

This study aimed at developing the realistic striatal digital brain (SDB) phantom and to assess specific binding ratio (SBR) for ventricular effect in the ¹²³I-FP-CIT SPECT imaging.

METHODS

SDB phantom was constructed in to four segments (striatum, ventricle, brain parenchyma, and skull bone) using Percentile method and other image processing in the T2-weighted MR images. The reference image was converted into 128×128 matrixes to align MR images with SPECT images. The process image was reconstructed with projection data sets generated from reference images additive blurring, attenuation, scatter, and statically noise. The SDB phantom was evaluated to find the accuracy of calculated SBR and to find the effect of SBR with/without ventricular counts with the reference and process images.

RESULTS

We developed and investigated the utility of the SDB phantom in the ¹²³I-FP-CIT SPECT clinical study. The true value of SBR was just marched to calculate SBR from reference and process images. The SBR was underestimated 58.0% with ventricular counts in reference image, however, was underestimated 162% with ventricular counts in process images.

CONCLUSION

The SDB phantom provides an extremely convenient tool for discovering basic properties of ¹²³I-FP-CIT SPECT clinical study image. It was suggested that the SBR was susceptible to ventricle.

[Optimization of Reformatting Angle Using Orbitomeatal Base Line in Dopamine Transporter Scintigraphy]

Recently, dopamine transporter (DaT) scintigraphy, which contributes to the early diagnosis of Parkinson's disease and Lewy body dementia, has been widely spread. It has been revealed that analytical results can be affected by the image-reformatting angle, and a horizontal section is recommended for the anterior commissure-posterior commissure (AC-PC) line according to the clinical guidelines for ioflupane. However, it is difficult to identify AC-PC line visually, as there is no remarkable accumulation in the cerebral parenchyma in DaT scintigraphy with poor contrast resolution. The objective of this study was to establish and optimize an adjustment method for the image-reformatting angle by using orbitomeatal base line (OM line). Evaluations were made on items such as comparison of image reformatting angles by an analyst, comparison of measurement angles of OM line, the angle formed by the intersection of OM line and AC-PC line, and the change in specific biding ratio (SBR) according to the difference in the image-reformatting angle. Consequently, the difference in analytical results among technicians became smaller, and consistent results were obtained by adjusting the image-reformatting angle.

[Optimized Acquisition Time for Dopamine Transporter Imaging]

Excess acquisition counts were often obtained by the current image acquisition of 30 minutes after ¹²³I-ioflupane administration in a dopamine transporter study. The purpose of this study was to calculate the minimum acquisition time while retaining sufficient image quality, which could be adjusted for individual characteristics. Fifty patients who underwent dopamine transporter imaging were included in this retrospective study. The brain count density, determined by a striatum phantom, was compared to the participant's characteristics. The individual characteristics were divided into five categories of gender, age, height, weight, and body mass index. The values of 40 counts / voxel (brain count density) were set as the image quality criteria by the striatum phantom study. Weight was the characteristic that most correlated with brain count density in the 50 patients (correlation coefficient: -0.728). The acquisition time for the 50 patients was calculated as 23.4±2.6 minutes using the following formula: 0.332×W+5.42 minutes (W kg (individual weight)). A shorter acquisition time with sufficient image quality can be achieved by adjusting for individual patient weight.

Refractory bipolar disorder and neuroprogression

Immune activation and failure of physiologic compensatory mechanisms over time have been implicated in the pathophysiology of illness progression in bipolar disorder. Recent evidence suggests that such changes are important contributors to neuroprogression and may mediate the cross-sensitization of episode recurrence, trauma exposure and substance use. The present review aims to discuss the potential factors related to bipolar disorder refractoriness and neuroprogression. In addition, we will discuss the possible impacts of early therapeutic interventions as well as the alternative approaches in late stages of the disorder.

[(123)I]-Ioflupane SPECT in combination with MIBG myocardial scintigraphy in Parkinson's disease: a case series study

Metaiodobenzylguanidine (MIBG) myocardial scintigraphy is widely accepted as a beneficial tool for differentiating Parkinson's disease (PD) from other Parkinson-related disorders (PRD). In Japan, dopamine transporter (DAT) imaging, which can evaluate presynaptic degeneration of dopamine neurons, has been applied in clinics since 2014. The present study investigated the utility of [(123)I]-Ioflupane single photon emission computed tomography (SPECT) combined with MIBG myocardial scintigraphy for the diagnosis of PD. We performed [(123)I]-Ioflupane SPECT and MIBG myocardial scintigraphy in 63 PD patients, 8 PRD patients and 1 essential tremor patient, and obtained the specific binding ratio (SBR [cut-off: 4.5]) and the heart-to-mediastinum ratio (H/M [cut-off: 2.2]). In 70% of the PD patients, both parameters were significantly reduced. In 22% of the PD patients, the SBR was smaller than 4.5 with normal H/M, and H/M was less than 2.2 with normal SBR in 5% of all subjects. Either the SBR or H/M was significantly reduced in 97% of the study population. The SBR showed low disease specificity to PD (11%), and the SBR and H/M negatively correlated with disease duration. These findings indicate that [(123)I]-Ioflupane SPECT combined with MIBG myocardial scintigraphy can improve the detection rate of PD. However, careful interpretation of these results is required because [(123)I]-Ioflupane SPECT poorly differentiates PD from PRD. Progression of PD may reflect the gradual reduction of isotope accumulation, hence, both [(123)I]-Ioflupane SPECT and MIBG myocardial scintigraphy should be tested repeatedly even in clinically suspected PD cases showing negative results.

[Comparison of Quantitative Value of Dopamine Transporter Scintigraphy Calculated from Different Analytical Software]

In the dopamine transporter scintigraphy there are two quantitative analysis softwares, DaTView and DaTQUANT. The quantitative value of both software has to be treated independently because there is a difference between them in the point of how to set the region of interest on the striatum and the background, calculation formula of quantitation. And also DaTQUANT has a capability of performing anatomical standardization which DaTView does not have. The aim of this study was to evaluate the accuracy of registration on DaTQUANT using a phantom, and to evaluate the correlation between the quantitative values between DaTView and DaTQUANT using clinical data. As a result, the accuracy of registration was acceptable. Regardless of the degree of accumulation in the striatum, there was a high correlation to each analysis software (r>0.85).

Neuropsychiatric symptoms in patients with dementias associated with cortical Lewy bodies: pathophysiology, clinical features, and pharmacological management

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) are synucleinopathies that lead to neurodegeneration and dementia. Although they result in symptoms common to Alzheimer's disease, they are associated with early emergence of parkinsonism and high frequency of neuropsychiatric symptoms, most commonly hallucinations and delusions. This review summarizes the current understanding of the underlying biology of neuropsychiatric symptoms in DLB and PDD and the evidence base for treatment to address them. Disruption to cholinergic and serotonergic neurotransmission and synapse activity are highlighted as primary pathological factors in neuropsychiatric symptoms, particularly loss of key neurotransmitter functions, alterations to neuronal receptors in the serotonergic pathway, and regionally specific structural changes that are linked to specific symptoms. Review of options for pharmacological treatment of neuropsychiatric symptoms suggests that the best evidence for the value of treatment is for cholinesterase inhibitors, with an indication that people with visual hallucinations are particularly likely to benefit. Evidence for the benefits of antipsychotics other than clozapine is limited, and there are serious safety concerns about the use of antipsychotics in these patients. Evidence to support other pharmacological interventions is very preliminary. Nonpharmacological approaches based on person-centered care and cholinesterase inhibitors should be considered as the first-line treatment for neuropsychiatric symptoms except in extreme cases.

The role of α-synuclein in neurodegeneration — An update

Genetic, neuropathological and biochemical evidence implicates α-synuclein, a 140 amino acid presynaptic neuronal protein, in the pathogenesis of Parkinson’s disease and other neurodegenerative disorders. The aggregated protein inclusions mainly containing aberrant α-synuclein are widely accepted as morphological hallmarks of α-synucleinopathies, but their composition and location vary between disorders along with neuronal networks affected. α-Synuclein exists physiologically in both soluble and membran-bound states, in unstructured and α-helical conformations, respectively, while posttranslational modifications due to proteostatic deficits are involved in β-pleated aggregation resulting in formation of typical inclusions. The physiological function of α-synuclein and its role linked to neurodegeneration, however, are incompletely understood. Soluble oligomeric, not fully fibrillar α-synuclein is thought to be neurotoxic, main targets might be the synapse, axons and glia. The effects of aberrant α-synuclein include alterations of calcium homeostasis, mitochondrial dysfunction, oxidative and nitric injuries, cytoskeletal effects, and neuroinflammation. Proteasomal dysfunction might be a common mechanism in the pathogenesis of neuronal degeneration in α-synucleinopathies. However, how α-synuclein induces neurodegeneration remains elusive as its physiological function. Genome wide association studies demonstrated the important role for genetic variants of the SNCA gene encoding α-synuclein in the etiology of Parkinson’s disease, possibly through effects on oxidation, mitochondria, autophagy, and lysosomal function. The neuropathology of synucleinopathies and the role of α-synuclein as a potential biomarker are briefly summarized. Although animal models provided new insights into the pathogenesis of Parkinson disease and multiple system atrophy, most of them do not adequately reproduce the cardinal features of these disorders. Emerging evidence, in addition to synergistic interactions of α-synuclein with various pathogenic proteins, suggests that prionlike induction and seeding of α-synuclein could lead to the spread of the pathology and disease progression. Intervention in the early aggregation pathway, aberrant cellular effects, or secretion of α-synuclein might be targets for neuroprotection and disease-modifying therapy.

Neuropathology of sporadic Parkinson's disease: evaluation and changes of concepts

Parkinson's disease (PD), one of the most frequent neurodegenerative disorders, is no longer considered a complex motor disorder characterized by extrapyramidal symptoms, but a progressive multisystem or-more correctly-multiorgan disease with variegated neurological and nonmotor deficiencies. It is morphologically featured not only by the degeneration of the dopaminergic nigrostriatal system, responsible for the core motor deficits, but by multifocal involvement of the central, peripheral and autonomic nervous system and other organs associated with widespread occurrence of Lewy bodies and dystrophic Lewy neurites. This results from deposition of abnormal α-synuclein (αSyn), the major protein marker of PD, and other synucleinopathies. Recent research has improved both the clinical and neuropathological diagnostic criteria of PD; it has further provided insights into the development and staging of αSyn and Lewy pathologies and has been useful in understanding the pathogenesis of PD. However, many challenges remain, for example, the role of Lewy bodies and the neurobiology of axons in the course of neurodegeneration, the relation between αSyn, Lewy pathology, and clinical deficits, as well as the interaction between αSyn and other pathologic proteins. Although genetic and experimental models have contributed to exploring the causes, pathomechanisms, and treatment options of PD, there is still a lack of an optimal animal model, and the etiology of this devastating disease is far from being elucidated.

Prominent neuroleptic sensitivity in a case of early-onset Alzheimer disease due to presenilin-1 G206A mutation

OBJECTIVE

We describe atypical motor and cognitive features in a case of familial Alzheimer disease (FAD) due to presenilin-1 (PS-1) mutation.

BACKGROUND

Extrapyramidal signs (EPS) typically are a late-presenting feature of sporadic Alzheimer disease (AD), but relatively little data are available regarding EPS in FAD.

METHOD

A 59-year-old, right-handed man of Caribbean-Hispanic descent underwent brain imaging studies, laboratory tests for AD, and serial neurologic and neuropsychologic evaluations.

RESULTS

The patient presented with recent-onset delusional ideation associated with cognitive decline. Prominent EPS developed soon after initiation of an atypical neuroleptic agent. Neuropsychologic evaluation revealed global cognitive deficits; he was found to be a carrier of a PS-1 point mutation at position G206A. EPS resolved completely after discontinuing the neuroleptic agent and coincided with improved motor speed, set initiation, and verbal fluency.

CONCLUSIONS

Severe neuroleptic sensitivity and associated deficits of cognitive speed occurred in response to a dopaminergic antagonist agent; both responded readily to withdrawal of the offending agent. Patients with PS-1 AD may be at substantially increased risk of neuroleptic-induced EPS. That feature underscores the heterogeneity of the FAD clinical phenotype.

Neuropsychiatric symptoms in dementia: importance and treatment considerations

Neuropsychiatric symptoms are frequent in people with dementia, result in distress for the people experiencing them and their caregivers, and are a common precipitant of institutional care. The safe and effective treatment of these symptoms is a key clinical priority, but is a long way from being achieved. Psychological interventions are recommended as the first line treatment strategy in most good practice guidelines, and there is emerging evidence of efficacy for agitation and depression. Neuroleptics remain the mainstay of pharmacological treatment, although meta-analyses indicate that they are mainly of benefit for the short-term (up to 12 weeks) treatment of aggression in people with Alzheimer's disease, and there have been increasing concerns about serious adverse effects including mortality. The evidence is limited for other pharmacological approaches for the treatment of agitation, and psychosis in people with Alzheimer's disease is limited, but post-hoc analyses do indicate that memantine may be a promising therapy and aromatherapy may be a useful alternative. Autopsy studies indicate that the adrenergic system may be an important therapeutic target. Clinical experience suggests that antidepressants are effective in people with severe depression in the context of dementia, but the evidence base regarding the broader value of antidepressants is far from clear. There are very few trials specifically focusing upon the treatment of neuropsychiatric symptoms in common non-Alzheimer dementias, which is a major limitation and urgently needs to be addressed to provide an evidence base to enable the safe and effective treatment of these individuals.

Selective loss of dopamine D2 receptors in temporal cortex in dementia with Lewy bodies, association with cognitive decline

Dementia with Lewy bodies (DLB) is a progressive dementia frequently accompanied by psychotic symptoms. Similar symptoms can occur in Alzheimer's disease (AD) to a lesser extent. The use of neuroleptic medication to treat psychosis in both diseases is of modest efficacy and can induce severe adverse reactions in DLB. Dopamine D2 receptors in the cerebral cortex are the putative target for the antipsychotic action of these drugs, but the status of these receptors in DLB is unknown. Autoradiography was used to examine the density D2 receptors in postmortem temporal cortex tissue from prospectively assessed patients with neuropathologically confirmed DLB and AD. D2 receptors were substantially (over 40%) and significantly (P < 0.001) reduced in temporal cortex in DLB, and in DLB with concomitant Alzheimer pathology, but was not significantly changed in AD. This reduction correlated with greater cognitive decline (P < 0.01), but was not significantly related to visual or auditory hallucinations or delusions. D2 receptor density was inversely correlated with cortical Lewy body pathology in the neocortex (P < 0.001). The specific loss of D2 receptors associated with Lewy body pathology, in conjunction with our previous finding of low D2 receptors in striatum in DLB, provides a possible explanation for neuroleptic intolerance. That the reduction of D2 receptors correlated with cognitive decline suggests that neuroleptics, as dopamine D2 receptor antagonists, may have a deleterious effect on cognition in DLB.

Dementia with Lewy bodies

The advent of new immunostains have improved the ability to detect limbic and cortical Lewy bodies, and it is evident that dementia with Lewy bodies (DLB) is the second most common neurodegenerative dementia, after Alzheimer's disease (AD). Distinguishing DLB from AD has important implications for treatment, in terms of substances that may worsen symptoms and those that may improve them. Neurocognitive patterns, psychiatric features, extrapyramidal signs, and sleep disturbance are helpful in differentiating DLB from AD early in the disease course. Differences in the severity of cholinergic depletion and type/distribution of neuropathology contribute to these clinical differences.

Immunohistochemical localization of dopamine receptor subtypes (D1R-D5R) in Alzheimer's disease brain

Among the neurotransmitter abnormalities that have been investigated in Alzheimer's disease (AD), deficits in the cholinergic system have been the most intensively studied. Another key neurotransmitter system involved with emotion and cognition is the dopaminergic system. Here we have investigated alterations in all five dopamine receptor subtypes in AD brain. Using antipeptide rabbit antibodies for each of the five dopamine receptors (D1-D5) we mapped the distribution of these receptors in postmortem AD and age-matched control brains in the frontal cortex, utilizing biotin-avidin immunocytochemistry. All five DR subtypes were expressed as cell surface and cytoplasmic proteins. Receptor-specific changes in control and AD brain were identified as follows: D4R and D3R were the predominant receptor subtypes in age-matched controls followed by D2R and D1R; D5R is the least expressed receptor subtype. In AD brain, D2R and D5R are well expressed in comparison to D1R, D3R and D4R. Expression of D1R, D3R and D4R was severely reduced in AD cortex. D2R expression is moderately reduced in the frontal cortex of AD brain. D5R is the only receptor subtype whose expression is increased in AD frontal cortex. Furthermore, in AD, we found comparable expression of D3R in astrocytes, whereas D5R-like immunoreactivity is significantly increased in astrocytes, in comparison to normal frontal cortex, where it was predominantly neuronal. These results demonstrate subtype-specific changes in dopamine receptors in AD that may be important in disease pathophysiology and that may also serve as potential targets for therapeutic intervention in AD.

Neuroleptic drugs in dementia: benefits and harm

Neuroleptic (antipsychotic) drugs are often used to treat psychiatric symptoms frequently seen in dementia, but their use is controversial. We present a new meta-analysis to assess the efficacy of these drugs for the treatment of psychiatric symptoms in Alzheimer's disease, and discuss the more limited evidence for their potential benefits in other dementias. We recommend that these treatments be limited to the short-term treatment of psychiatric symptoms associated with serious distress or risk.

Dementia with Lewy bodies: current concepts

As life expectancy continues to increase over time, dementia is becoming an increasingly more common problem and a major cause of disability in older persons. It is now more important than ever to identify and manage common causes of dementia given variations in disease course, treatments and the possibility for modification of risk factors. Dementia with Lewy bodies (DLB) is a dementia syndrome characterized by progressive cognitive decline, with fluctuating cognition, recurrent detailed and well-formed hallucinations, and parkinsonism. This article aims to provide an overview of current concepts of DLB, including a description of the key clinical features and neuropathology, neurochemistry, and genetics of DLB, then a discussion of the relationship of DLB with Alzheimer's disease and Parkinson's disease, and, finally, a summary of current management strategies available for this disorder.

Les symptômes psychologiques et comportementaux de la démence : description et prise en charge

Behavioral and Psychological Symptoms in Dementia (BPSD) are, beside cognitive disorders, major features of Alzheimer's disease and related disorders. Diagnosis is important to enhance our knowledge of the pathophysiology of dementia and of their functional consequences for patients and caregivers. Pharmacological and non-pharmacological management of dementia depends to a large extent on the presence of BPSD. A committee of geriatricians, neurologists and psychiatrists specialized in dementia (THEMA 2) has promoted an epidemiological, diagnostic and therapeutic update in this field. This work was based on the BPSD Consensus Conference Report edited in 2000 by the International Psychogeriatric Association. This report was updated with the most recent literature reports, and was adapted to the French environment. This paper is a synthesis of this meeting, validated and corrected by the entire Thema 2 group.

Dementia with Lewy bodies: clinical characteristics and diagnostic criteria

Dementia with Lewy bodies (DLB) is increasingly recognized as a distinct clinical and pathologic entity. It is a progressive dementia characterized by persistent and well-formed visual hallucinations, marked second-to-second fluctuations in attention, and progressive extrapyramidal signs. The diagnostic value of additional clinical features such as delusions, depression, falls, anosmia, and rapid progression continues to be debated. Despite the growing acceptance of the diagnosis, DLB has not yet been included in either International Classification of Disease (ICD-10) or Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. However, the existing consensus diagnostic criteria continue to be validated. Most prospective studies to date indicate that their performance is acceptable, with specificity similar to the present diagnostic criteria for Alzheimer's disease. Nevertheless, at least one in five patients with DLB will continue to be misclassified.

Muscarinic receptors in basal ganglia in dementia with Lewy bodies, Parkinson's disease and Alzheimer's disease

Derivatives of the muscarinic antagonist 3-quinuclidinyl-4-iodobenzilate (QNB), particularly [123I]-(R,R)-I-QNB, are currently being assessed as in vivo ligands to monitor muscarinic receptors in Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), relating changes to disease symptoms and to treatment response with cholinergic medication. To assist in the evaluation of in vivo binding, muscarinic receptor density in post-mortem human brain was measured by autoradiography with [125I]-(R,R)-I-QNB and [125I]-(R,S)-I-QNB and compared to M1 ([3H]pirenzepine) and M2 and M4 ([3H]AF-DX 384) receptor binding. Binding was calculated in tissue containing striatum, globus pallidus (GPe), claustrum, and cingulate and insula cortex, in cases of AD, DLB, Parkinson's disease (PD) and normal elderly controls. Pirenzepine, AF-DX 384 and (R,S)-I-QNB binding in the striatum correlated positively with increased Alzheimer-type pathology, and AF-DX 384 and (R,R)-I-QNB cortical binding correlated positively with increased Lewy body (LB) pathology; however, striatal pirenzepine binding correlated negatively with cortical LB pathology. M1 receptors were significantly reduced in striatum in DLB compared to AD, PD, and controls and there was a significant correlation between M1 and dopamine D2 receptor densities. [3H]AF-DX 384 binding was higher in the striatum and GPe in AD. Binding of [125I]-(R,R)-I-QNB, which may reflect increased muscarinic M4 receptors, was higher in cortex and claustrum in DLB and AD. [125I]-(R,S)-I-QNB binding was higher in the GPe in AD. Low M1 and D2 receptors in DLB imply altered regulation of the striatal projection neurons which express these receptors. Low density of striatal M1 receptors may relate to the extent of movement disorder in DLB, and to a reduced risk of parkinsonism with acetylcholinesterase inhibition.

Vulnerability to neuroleptic side effects in frontotemporal lobar degeneration

BACKGROUND

Frontotemporal lobar degeneration (FTLD) is commonly associated with behavioural disturbances such as disinhibition and aggression; these often result in the use of neuroleptic medication.

METHODS

All available case notes of patients attending a specialist cognitive disorders clinic with a diagnosis of FTLD were selected. This gave 100 subjects (62 male, 38 female).

RESULTS

In 61 patients significant behavioural disturbances were present. Of these patients, 24 had been prescribed neuroleptics. Significant extrapyramidal side effects were reported in eight patients (33%); in five patients these were severe enough to cause severe mobility problems and in one patient resulted in impaired consciousness. In some instances the extrapyramidal side effects took weeks to wear off.

CONCLUSION

These results suggest that patients with FTLD may, as in Lewy body dementia, be particularly sensitive to the extrapyramidal side effects of neuroleptics. We suggest that neuroleptics should be used cautiously in FTLD and treatment should be started at low doses avoiding depot preparations until further prospective studies have been performed.

Visual hallucinations are associated with lower alpha bungarotoxin binding in dementia with Lewy bodies

Patients with dementia with Lewy bodies (DLB) commonly experience psychotic symptoms, most notably visual hallucinations. Previously, it has been shown that visual hallucinations in DLB are associated with reduced cortical choline acetyltransferase activity, a marker of cholinergic innervation, but not with predominantly postsynaptic muscarinic M1 receptor binding. In the present investigation, nicotinic acetylcholine receptor (nAChR) levels in the temporal cortex (Brodmann's areas [BA] 20 and 36) were measured in a group of 24 prospectively assessed DLB patients; comparisons were made between groups with or without visual and auditory hallucinations and delusional misidentification. Visual hallucinations and delusional misidentification were associated with lower [(125)I]alpha bungarotoxin binding in areas 36 and 20 (P<.05), but not with changes in [(3)H]epibatidine binding. There were no significant associations with auditory hallucinations. [(3)H]epibatidine, but not [(125)I]alpha bungarotoxin, binding for all DLB cases was reduced compared to controls (P<.001). Loss of cortical alpha 7 nicotinic receptors may contribute to hallucinations and delusional misidentification in DLB, with implications for treatment and understanding the mechanisms of psychotic symptoms in dementia.

Morphological substrates of mental dysfunction in Lewy body disease: an update

Mental dysfunction including cognitive, behavioural changes, mood disorders, and psychosis are increasingly recognized in patients with Parkinson's disease (PD) and related disorders. Their morphological correlates are complex due to multiple system degeneration. CNS changes contributing to cognitive changes in PD include 1. Dysfunction of subcorticocortical networks with neuron losses in a) the dopaminergic nigrostriatal loop, causing striato-(pre)frontal deafferentation and mesocortico-limbic system (medial substantia nigra, ventral tegmentum); b) noradrenergic (locus coeruleus), and serotonergic systems (dorsal raphe nuclei), c) cholinergic forebrain system (nucleus basalis of Meynert, etc), and d) specific nuclei of amygdala and limbic system (thalamic nuclei, hippocampus); 2. Limbic and/or cortical Lewy body and Alzheimer type pathologies with loss of neurons and synapses, 3. Combination of subcortical, cortical, and other pathologies. In general, degeneration of subcortical and striato-frontal networks causes cognitive, executive, behavioural, and mood disorders but less severe dementia than cortical changes which, when present in sufficient numbers, are important factors for overt dementia. In PD, cortical tau pathology with similar or differential patterns than in Alzheimer disease (AD) shows significant linear correlation with cognitive decline. In dementia with Lewy bodies (DLB), the second most frequent cause of dementia in the elderly, cortical Lewy bodies (LB) may or may not be associated with amyloid plaques and neuritic AD lesions. They predominantly affect the limbic system with less frequent isocortical Braak stages, whereas the cholinergic forebrain system is more severely affected than in AD. Both neuritic degeneration in limbic system in PD and DLB and the density of cortical synapse markers correlate with neuritic AD pathology and less with cortical LB counts. Apolipoprotein E epsilon4 allele frequency may represent a common genetic background for both AD and LB pathologies but there are different proportions of plaques between DLB (less Abeta1-40) and AD (more frequent Abeta1-40). Familial parkinsonism with dementia, linked to chromosome 17 (frontotemporal dementia with Parkinsonism (FTDP-17), and other tauopathies pathologically resembling PD plus AD, are often related to mutations of the tau gene, whereas familial PD with alpha-synuclein and Parkin mutations usually show no cognitive impairment. Mood disorders, in particular depression, and psychotic complications in both PD and DLB are related to complex involvement of noradrenergic and serotonergic systems, not confirmed in AD with depression, and both the prefrontal and limbic dopaminergic systems. The specific contributions of cortical and subcortical pathologies to mental dysfunction in PD and related disorders, their relationship to AD, and their genetic and aetiological backgrounds await further elucidation.

Nicotinic receptor abnormalities in Alzheimer's disease

Loss of cortical nicotinic acetylcholine receptors with high affinity for agonists (20-50%) in patients with Alzheimer's disease is a common finding. Recent immunochemical analyses indicate that this deficit is predominantly associated with the loss of alpha4 subunits (30-50%), although modest reductions of alpha3 may occur in some individuals (25-29%). No reduction of beta2 subunit protein expression or levels of alpha3 and alpha4 messenger RNA has been reported. Decline in cortical [(125)I]alpha-bungarotoxin binding and alpha7 protein expression does not appear to be as extensive or widespread as the loss of alpha4 (0-40%), with no reduction in messenger RNA expression. In the thalamus, there was a trend for reduced [(3)H]nicotine binding in the majority of nuclei (0-20%) in Alzheimer's disease; however, there was a significant decline in [(125)I]alpha-bungarotoxin binding in the reticular nucleus. In the striatum [(3)H]nicotine binding was reduced in Alzheimer's disease, and although neuroleptic medication accentuated this change, it occurred in those free of neuroleptics. Changes in nicotinic acetylcholine receptors in Alzheimer's disease are distinct from those in normal aging and are likely to contribute to clinical features and possibly neuropathology.

The utility of neuroSPECT imaging in the investigation of dementia and parkinsonism

Functional neuroimaging is playing an increasing role in psychiatry and has moved from academic isolation into clinical practice. This review examines the basis for the use of Single Photon Emission Computed Tomography, the most widely available functional modality, in the two important areas of dementia and parkinsonism. Its contribution to the diagnosis and management of patients is discussed and its likely impact in clinical trials indicated. As functional imaging moves closer to those most able to utilise its power its impact in these and other areas of psychiatry and neurology will increase further.

Risperidone, neuroleptic malignant syndrome and probable dementia with Lewy bodies

1. Conflicting reports are available regarding the sensitivity of patients with Dementia with Lewy bodies (DLB) to risperidone. 2. The authors studied a rare familial case of probable DLB, who developed a documented episode of neuroleptic malignant syndrome (NMS) following the exposure to risperidone. Previously, the patient had had an episode of NMS on trifluoperazine. 3. The discontinuance of risperidone, in combination with a mild increase of dopaminergic therapy, led to a complete recovery in few days. 4. In patients with DLB, a continued vigilance for extrapyramidal side effects, including NMS, would be advisable during the use of risperidone.

Nicotine binding in human striatum: elevation in schizophrenia and reductions in dementia with Lewy bodies, Parkinson's disease and Alzheimer's disease and in relation to neuroleptic medication

Striatal nicotinic acetylcholine receptors with high affinity for nicotinic agonists are involved with the release of a number of neurotransmitters, including dopamine. Previous findings as to whether these receptors are changed in Parkinson's disease and Alzheimer's disease are inconsistent and no previous investigations have focused on these receptors in dementia with Lewy bodies and schizophrenia, which are also associated with disorders of movement. The present autoradiographic study of striatal [3H]nicotine binding in Alzheimer's and Parkinson's diseases, dementia with Lewy bodies and schizophrenia was conducted with particular reference to the potentially confounding variables of tobacco use and neuroleptic medication. [3H]Nicotine binding in both dorsal and ventral caudate and putamen was significantly reduced in Parkinson's disease (43-67%, n=13), Alzheimer's disease (29-37%, n=13) and dementia with Lewy bodies (50-61%, n=20) compared to age-matched controls (n=42). Although tobacco use in the control group was associated with increased [3H]nicotine binding (21-38%), and neuroleptic treatment in dementia with Lewy bodies and Alzheimer's disease was associated with reduced [3H]nicotine binding (up to 29%), differences between neurodegenerative disease groups and controls persisted in subgroups of Alzheimer's disease cases (26-33%, n=6, in the ventral striatum) and dementia with Lewy body cases (30-49%, n=7, in both dorsal and ventral striatum) who had received no neuroleptic medication compared to controls who had not smoked (n=10). In contrast, striatal [3H]nicotine binding in a group of elderly (56-85 years) chronically medicated individuals with schizophrenia (n=6) was elevated compared with the entire control group (48-78%, n=42) and with a subgroup that had smoked (24-49%, n=8). The changes observed in [3H]nicotine binding are likely to reflect the presence of these receptors on multiple sites within the striatum, which may be differentially modulated in the different diseases. Further study is warranted to explore which nicotinic receptor subunits and which neuronal compartments are involved in the changes in [3H]nicotine binding reported, to aid development of potential nicotinic receptor therapy.

Striatal dopaminergic markers in dementia with Lewy bodies, Alzheimer's and Parkinson's diseases: rostrocaudal distribution

Dementia with Lewy bodies (DLB) is a neuropsychiatric disease associated with extrapyramidal features which differ from those of Parkinson's disease, including reduced effectiveness of L-dopa and severe sensitivity reactions to neuroleptic drugs. Distinguishing Alzheimer's disease from DLB is clinically relevant in terms of prognosis and appropriate treatment. Dopaminergic activities have been investigated at coronal levels along the rostrocaudal striatal axis from a post-mortem series of 25 DLB, 14 Parkinson's disease and 17 Alzheimer's disease patients and 20 elderly controls. [(3)H]Mazindol binding to the dopamine uptake site was significantly reduced in the caudal putamen in DLB compared with controls (57%), but not as extensively as in Parkinson's disease (75%), and was unchanged in Alzheimer's disease. Among three dopamine receptors measured (D1, D2 and D3), the most striking changes were apparent in relation to D2. In DLB, [(3)H]raclopride binding to D2 receptors was significantly reduced in the caudal putamen (17%) compared with controls, and was significantly lower than in Parkinson's disease at all levels. D2 binding was significantly elevated at all coronal levels in Parkinson's disease compared with controls, most extensively in the rostral putamen (71%). There was no change from the normal pattern of D2 binding in Alzheimer's disease. The only significant alteration in D1 binding ([(3)H]SCH23390) in the groups examined was an elevation (30%) in the caudal striatum in Parkinson's disease. There were no differences in D3 binding, measured using [(3)H]7-OH-DPAT, in DLB compared with controls. A slight, significant decrease in D3 binding in the caudal striatum of Parkinson's disease (13%) patients and an increase in Alzheimer's disease (20%) in the dorsal striatum at the level of the nucleus accumbens were found. The concentration and distribution of dopamine were disrupted in both DLB and Parkinson's disease, although in the caudate nucleus the loss of dopamine in DLB was uniform whereas in Parkinson's disease the loss was greater caudally. In the caudal putamen, dopamine was reduced by 72% in DLB and by 90% in Parkinson's disease. The homovanillic acid : dopamine ratio, a metabolic index, indicated compensatory increased turnover in Parkinson's disease, which was absent in DLB despite the loss of substantia nigra neurons (49%), dopamine and uptake sites. These differences between DLB, Parkinson's disease and Alzheimer's disease may explain some characteristics of the extrapyramidal features of DLB and its limited response to L-dopa and severe neuroleptic sensitivity. The distinct changes in the rostrocaudal pattern of expression of dopaminergic parameters are relevant to the interpretation of the in vivo imaging and diagnosis of DLB.

Dementia with Lewy bodies: review and pharmacotherapeutic implications

Alzheimer's disease accounts for 50-60% of dementia cases in older people. Dementia with Lewy bodies is now recognized as the second most common type of dementia. It is different from Alzheimer's disease and has important pharmacotherapeutic implications. Key features include early-onset, persistent, well-formed, visual hallucinations and motor features of parkinsonism. Pharmacologic management of neurobehavioral symptoms is complicated by an exaggerated response to neuroleptics, which causes excessive morbidity and mortality. Patients with dementia with Lewy bodies may be particularly responsive to cholinesterase inhibitors. When neurobehavioral symptoms are severe enough to require pharmacologic intervention, it is recommended that agents such as trazodone or cholinesterase inhibitors be considered first-line therapy. If these fail, neuroleptics may be prescribed with caution.