Examining Frontal Lobe Asymmetry and Its Potential Role in Aggressive Behaviors in Early Alzheimer's Disease.

Background: Neuropsychiatric symptoms (NPS) in patients with dementia lead to caregiver burdens and worsen the patient's prognosis. Although many neuroimaging studies have been conducted, the etiology of NPS remains complex. We hypothesize that brain structural asymmetry could play a role in the appearance of NPS. Objective: This study explores the relationship between NPS and brain asymmetry in patients with Alzheimer's disease (AD). Methods: Demographic and MRI data for 121 mild AD cases were extracted from a multicenter Japanese database. Brain asymmetry was assessed by comparing the volumes of gray matter in the left and right brain regions. NPS was evaluated using the Neuropsychiatric Inventory (NPI). Subsequently, a comprehensive assessment of the correlation between brain asymmetry and NPS was conducted. Results: Among each NPS, aggressive NPS showed a significant correlation with asymmetry in the frontal lobe, indicative of right-side atrophy (r = 0.235, p = 0.009). This correlation remained statistically significant even after adjustments for multiple comparisons (p < 0.01). Post-hoc analysis further confirmed this association (p < 0.05). In contrast, no significant correlations were found for other NPS subtypes, including affective and apathetic symptoms. Conclusions: The study suggests frontal lobe asymmetry, particularly relative atrophy in the right hemisphere, may be linked to aggressive behaviors in early AD. These findings shed light on the neurobiological underpinnings of NPS, contributing to the development of potential interventions.

[Overview of the Guidelines for Managing Idiopathic Normal Pressure Hydrocephalus].

Japanese guidelines for idiopathic normal pressure hydrocephalus (iNPH) (iNPHGL) are the first and only guidelines in the world that were revised following subsequent developments in iNPH research. We first discuss the virtuous cycle in which the development and revision of the iNPHGL and how the implementation of two consecutive multicenter prospective studies conducted in Japan, SINPHONIs, have worked together to advance iNPH practices. Subsequently, we explained the most characteristic features of the iNPHGL, such as "Positioning of iNPH," "Diagnostic Criteria," and "Algorithms for Diagnosis and Treatment." To classify iNPH, we categorized chronic adult-onset normal pressure hydrocephalus (NPH) as iNPH, secondary NPH, Congenital/Developmental NPH, and Familial NPH. In the diagnostic criteria and algorithm, we classified iNPH into four categories: Suspected iNPH, Possible iNPH, Probable iNPH, and Definite iNPH, depending on the certainty of the diagnosis. In addition, a positioned disproportionately enlarged subarachnoid space hydrocephalus (DESH) on head computed tomography and magnetic resonance imaging is an important finding for the diagnosis of iNPH. Finally, we presented the results of a survey on the treatment status of patients with suspected iNPH, awareness of DESH, and use of this iNPHGL among medical centers for dementia in Japan.

A deep learning model for the detection of various dementia and MCI pathologies based on resting-state electroencephalography data: A retrospective multicentre study.

Dementia and mild cognitive impairment (MCI) represent significant health challenges in an aging population. As the search for noninvasive, precise and accessible diagnostic methods continues, the efficacy of electroencephalography (EEG) combined with deep convolutional neural networks (DCNNs) in varied clinical settings remains unverified, particularly for pathologies underlying MCI such as Alzheimer's disease (AD), dementia with Lewy bodies (DLB) and idiopathic normal-pressure hydrocephalus (iNPH). Addressing this gap, our study evaluates the generalizability of a DCNN trained on EEG data from a single hospital (Hospital #1). For data from Hospital #1, the DCNN achieved a balanced accuracy (bACC) of 0.927 in classifying individuals as healthy (n = 69) or as having AD, DLB, or iNPH (n = 188). The model demonstrated robustness across institutions, maintaining bACCs of 0.805 for data from Hospital #2 (n = 73) and 0.920 at Hospital #3 (n = 139). Additionally, the model could differentiate AD, DLB, and iNPH cases with bACCs of 0.572 for data from Hospital #1 (n = 188), 0.619 for Hospital #2 (n = 70), and 0.508 for Hospital #3 (n = 139). Notably, it also identified MCI pathologies with a bACC of 0.715 for Hospital #1 (n = 83), despite being trained on overt dementia cases instead of MCI cases. These outcomes confirm the DCNN's adaptability and scalability, representing a significant stride toward its clinical application. Additionally, our findings suggest a potential for identifying shared EEG signatures between MCI and dementia, contributing to the field's understanding of their common pathophysiological mechanisms.

A short staff training system for behavioural and psychological symptoms of dementia in care facilities, based on functional analysis and positive behaviour support: a single-arm pre- and post-comparative study.

BACKGROUND: Work schedules can make it challenging for professional care workers to participate in long-term training programs on managing behavioural and psychological symptoms of dementia (BPSD). Simultaneously, it is necessary to prevent caregivers' negative responses to BPSD, provide a positive environment for people with dementia, and create a system for new management plans, since the initial one is often unsuccessful. Therefore, we developed a short manual-based training system for functional analysis including positive behaviour support and strategies when management plans do not function well. This study aimed to preliminarily examine the usefulness of this system. METHODS: Thirty-five staff members from 12 care facilities participated in the training. For each facility, off-the-job training was performed in two 120-min sessions held over 2 days. Then, care plans were implemented by staff members for a month, during which on-the-job training was provided. The study included 14 people with dementia and BPSD. This was a single-arm study without a control group. Pre- and post-tests were conducted to examine the effects of the training system using the Neuropsychiatric Inventory-Nursing Home Version. RESULTS: The results of the pre- and post-tests for the total scores on severity and occupational disruptiveness significantly improved, with large effect sizes. Regarding symptom domains, delusions, agitation/aggression, and aberrant motor behaviour significantly improved in both severity and occupational disruptiveness. Depression/dysphoria and anxiety significantly improved in severity; however, there were trends of improvement in occupational disruptiveness. In addition, the effect sizes for severity and occupational disruptiveness of delusions and agitation/aggression were large. CONCLUSIONS: This preliminary study suggests that the training system is promising. A randomised controlled trial with a larger sample size is necessary to confirm the findings.

Precise Discrimination for Multiple Etiologies of Dementia Cases Based on Deep Learning with Electroencephalography.

INTRODUCTION: It is critical to develop accurate and universally available biomarkers for dementia diseases to appropriately deal with the dementia problems under world-wide rapid increasing of patients with dementia. In this sense, electroencephalography (EEG) has been utilized as a promising examination to screen and assist in diagnosing dementia, with advantages of sensitiveness to neural functions, inexpensiveness, and high availability. Moreover, the algorithm-based deep learning can expand EEG applicability, yielding accurate and automatic classification easily applied even in general hospitals without any research specialist. METHODS: We utilized a novel deep neural network, with which high accuracy of discrimination was archived in neurological disorders in the previous study. Based on this network, we analyzed EEG data of healthy volunteers (HVs, N = 55), patients with Alzheimer's disease (AD, N = 101), dementia with Lewy bodies (DLB, N = 75), and idiopathic normal pressure hydrocephalus (iNPH, N = 60) to evaluate the discriminative accuracy of these diseases. RESULTS: High discriminative accuracies were archived between HV and patients with dementia, yielding 81.7% (vs. AD), 93.9% (vs. DLB), 93.1% (vs. iNPH), and 87.7% (vs. AD, DLB, and iNPH). CONCLUSION: This study revealed that the EEG data of patients with dementia were successfully discriminated from HVs based on a novel deep learning algorithm, which could be useful for automatic screening and assisting diagnosis of dementia diseases.

Normalized Power Variance: A new Field Orthogonal to Power in EEG Analysis.

To date, electroencephalogram (EEG) has been used in the diagnosis of epilepsy, dementia, and disturbance of consciousness via the inspection of EEG waves and identification of abnormal electrical discharges and slowing of basic waves. In addition, EEG power analysis combined with a source estimation method like exact-low-resolution-brain-electromagnetic-tomography (eLORETA), which calculates the power of cortical electrical activity from EEG data, has been widely used to investigate cortical electrical activity in neuropsychiatric diseases. However, the recently developed field of mathematics "information geometry" indicates that EEG has another dimension orthogonal to power dimension - that of normalized power variance (NPV). In addition, by introducing the idea of information geometry, a significantly faster convergent estimator of NPV was obtained. Research into this NPV coordinate has been limited thus far. In this study, we applied this NPV analysis of eLORETA to idiopathic normal pressure hydrocephalus (iNPH) patients prior to a cerebrospinal fluid (CSF) shunt operation, where traditional power analysis could not detect any difference associated with CSF shunt operation outcome. Our NPV analysis of eLORETA detected significantly higher NPV values at the high convexity area in the beta frequency band between 17 shunt responders and 19 non-responders. Considering our present and past research findings about NPV, we also discuss the advantage of this application of NPV representing a sensitive early warning signal of cortical impairment. Overall, our findings demonstrated that EEG has another dimension - that of NPV, which contains a lot of information about cortical electrical activity that can be useful in clinical practice.

Cerebrospinal fluid amyloid beta and response of cognition to a tap test in idiopathic normal pressure hydrocephalus: a case-control study.

OBJECTIVES: To examine the relationship between cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and tap test response to elucidate the effects of comorbidity of AD in idiopathic normal-pressure hydrocephalus (iNPH). DESIGN: Case-control study. SETTING: Osaka University Hospital. PARTICIPANTS: Patients with possible iNPH underwent a CSF tap test. MEASUREMENTS: Concentrations of amyloid beta (Aß) 1-40, 1-42, and total tau in CSF were measured. The response of tap test was judged using Timed Up and Go test (TUG), 10-m reciprocation walking test (10MWT), Mini-Mental State Examination (MMSE), and iNPH grading scale. The ratio of Aß1-42 to Aß1-40 (Aß42/40 ratio) and total tau concentration was compared between tap test-negative (iNPH-nTT) and -positive (iNPH-pTT) patients. RESULTS: We identified 27 patients as iNPH-nTT and 81 as iNPH-pTT. Aß42/40 ratio was significantly lower (mean [SD] = 0.063 [0.026] vs. 0.083 [0.036], p = 0.008), and total tau in CSF was significantly higher (mean [SD] = 385.6 [237.2] vs. 293.6 [165.0], p = 0.028) in iNPH-nTT than in iNPH-pTT. Stepwise logistic regression analysis revealed that low Aß42/40 ratio was significantly associated with the negativity of the tap test. The response of cognition was significantly related to Aß42/40 ratio. The association between Aß42/40 ratio and tap test response, especially in cognition, remained after adjusting for disease duration and severity at baseline. CONCLUSIONS: A low CSF Aß42/40 ratio is associated with a poorer cognitive response, but not gait and urinary response, to a tap test in iNPH. Even if CSF biomarkers suggest AD comorbidity, treatment with iNPH may be effective for gait and urinary dysfunction.

Association of right precuneus compression with apathy in idiopathic normal pressure hydrocephalus: a pilot study.

Apathy is frequently observed in idiopathic normal pressure hydrocephalus (iNPH) and worsens cognitive impairment and gait disturbance. In this study, we evaluated the regions associated with apathy in iNPH using statistical imaging analysis on the whole brain, both in terms of cerebral blood flow and gray matter volume. Twenty-seven patients with iNPH were assigned to two groups based on their scores on the neuropsychiatric inventory items related to apathy; 18 patients were assigned to the group with apathy (iNPH + APA) and 9 to the group without apathy (iNPH - APA). The magnetic resonance images and cerebral blood flow single-photon emission computed tomography data of the two groups were compared using statistical parametric mapping 12. The regional gray matter volume of the right precuneus was significantly larger in the iNPH + APA group than in the iNPH - APA group, but the regional cerebral blood flow in any region of the brain was not significantly different between the two groups. These results suggested that the larger gray matter volume, which is thought to reflect gray matter compression, in the precuneus might be involved in apathy in iNPH.

Risk factors for unfavourable outcomes after shunt surgery in patients with idiopathic normal-pressure hydrocephalus.

A number of vascular risk factors (VRFs) have been reported to be associated with idiopathic normal-pressure hydrocephalus (iNPH), but it remains unclear whether these VRFs are related to patient outcomes after shunt surgery. Therefore, we investigated the risk factors for unfavourable outcomes after shunt surgery in iNPH patients using two samples from Tohoku University Hospital and from a multicentre prospective trial of lumboperitoneal (LP) shunt surgery for patients with iNPH (SINPHONI-2). We enrolled 158 iNPH patients. We compared the prevalence of VRFs and clinical measures between patients with favourable and unfavourable outcomes and identified predictors of unfavourable outcomes using multivariate logistic regression analyses. The presence of hypertension, longer disease duration, more severe urinary dysfunction, and a lower Evans' index were predictors of unfavourable outcomes after shunt surgery. In addition, hypertension and longer disease duration were also predictors in patients with independent walking, and a lower Evans' index was the only predictor in patients who needed assistance to walk or could not walk. Our findings indicate that hypertension is the only VRF related to unfavourable outcomes after shunt surgery in iNPH patients. Larger-scale studies are needed to elucidate the reason why hypertension can affect the irreversibility of symptoms after shunt placement.

Evaluation of Patients With Cognitive Impairment Due to Suspected Idiopathic Normal-Pressure Hydrocephalus at Medical Centers for Dementia: A Nationwide Hospital-Based Survey in Japan.

Objective: Treatment of idiopathic normal-pressure hydrocephalus (iNPH) requires collaboration between dementia specialists and neurosurgeons. The role of dementia specialists is to differentiate patients with iNPH from patients with other dementia diseases and to determine if other dementia diseases are comorbid with iNPH. We conducted a nationwide hospital-based questionnaire survey on iNPH in medical centers for dementia (MCDs). Methods: We developed a questionnaire to assess how physicians in MCDs evaluate and treat patients with cognitive impairment due to suspected iNPH and the difficulties these physicians experience in the evaluation and treatment of patients. The questionnaire was sent to all 456 MCDs in Japan. Results: Questionnaires from 279 MCDs were returned to us (response rate: 61.2%). Patients underwent cognitive tests, evaluation of the triad symptoms of iNPH, and morphological neuroimaging examinations in 96.8, 77.8, and 98.2% of the MCDs, respectively. Patients with suspected iNPH were referred to other hospitals (e.g., hospitals with neurosurgery departments) from 78.9% of MCDs, and cerebrospinal fluid (CSF) tap test was performed in 44 MCDs (15.8%). iNPH guidelines (iNPHGLs) and disproportionately enlarged subarachnoid space hydrocephalus (DESH), a specific morphological finding, were used and known in 39.4% and 38% of MCDs, respectively. Logistic regression analysis with "Refer the patient to other hospitals (e.g., hospitals with neurosurgery departments) when iNPH is suspected." as the response variable and (a) using the iNPHGLs, (b) knowledge of DESH, (c) confidence regarding DESH, (d) difficulty with performing brain magnetic resonance imaging, (e) knowledge of the methods of CSF tap test, (f) absence of physician who can perform lumbar puncture, and (g) experience of being told by neurosurgeons that referred patients are not indicated for shunt surgery as explanatory variables revealed that the last two factors were significant predictors of patient referral from MCDs to other hospitals. Conclusion: Sufficient differential or comorbid diagnosis using CSF tap test was performed in a few MCDs. Medical care for patients with iNPH in MCDs may be improved by having dementia specialists perform CSF tap tests and share the eligibility criteria for shunt surgery with neurosurgeons.

Tap Test Can Predict Cognitive Improvement in Patients With iNPH-Results From the Multicenter Prospective Studies SINPHONI-1 and -2.

Background: We analyzed the predictive value of the tap test (TT) on the outcome of cerebrospinal fluid (CSF) shunting in patients with idiopathic normal pressure hydrocephalus (iNPH) and cognitive impairment up to 12 months postoperatively. Methods: We analyzed the data of two prospective multicenter studies on ventriculoperitoneal shunt (VPS) and lumboperitoneal shunt (LPS) use in iNPH patients. We selected patients with Mini-Mental State Examination (MMSE) scores ≤ 26 points as study subjects. We used a multivariate logistic regression model to obtain the optimal threshold of MMSE scores after TT to predict the score improvement at 12 months following shunting and that helped to control for confounding factors such as age and MMSE scores before TT. We used logistic regression models to identify variables with age-adjusted odds ratio (A-OR) and multivariate-adjusted OR (M-OR). Results: For an improvement of ≥3 points in the MMSE score cutoff 7 days following TT in VPS and LPS cohort studies, the MMSE scores improved by 6 points after 12 months. The VPS cohort had sensitivity, specificity, and area under the curve (AUC) of 69.2, 73.7, and 0.771%, respectively; however, for the LPS cohort, they were 86.2, 90.9, and 0.906%, respectively. For MMSE scores that improved by ≥3 points in patients after the TT, the possibility of an improvement by 6 points at 12 months following CSF shunt had A-OR 7.77 and M-OR 6.3 times for the VPS, and A-OR 62.3 and M-OR 59.6 times for the LPS cohort. Conclusion: CSF shunting contributes to improved cognitive function in iNPH patients. Furthermore, MMSE score evaluation at the TT can sensitively predict improvement in postoperative MMSE scores following LPS intervention. Clinical Trial Registration: SINPHONI-1 (ClinicalTrials.gov, no. NCT00221091), first posted: September 22, 2005. SINPHONI-2 [University Hospital Medical Information Network (UMIN) Clinical Trials no. UMIN000002730], the posted: February 1, 2010.

Clinical profiles of people with dementia exhibiting with neuropsychiatric symptoms admitted to mental hospitals: A multicenter prospective survey in Japan.

AIMS: Patients with severe behavioral and psychological symptoms of dementia (BPSD) are often admitted to mental hospitals, while, inpatient care could also lead to prolonged hospital stay. The present study aims to survey clinical profiles of patients who required inpatient treatment for BPSD, and then establish the criteria for introducing inpatient treatment through assessment by certified psychiatrists. METHODS: We performed a prospective survey about clinical characteristics of people with dementia who required treatment of BPSD at 12 mental medical institutions. All patients were assessed by certified psychiatrists to determine the optimal treatment settings: outpatient or inpatient. The multivariate logistic regression analysis was performed to specify factors contributed to the judgement of clinicians. Subsequently, the receiver operating characteristic curve analysis was conducted to explore a score derived from the Neuropsychiatric Inventory to divide patients into outpatient or inpatient groups. RESULTS: The present study included 386 patients, of which 242 were admitted to mental hospitals. BPSD were classified into four domains, and aggressive BPSD was significantly associated with assessment for inpatient treatment; the adjusted odds ratio was approximately 2 regardless of dementia severity. Furthermore, the composite score of agitation, irritability and aberrant behavior showed the highest area under the curve value (=0.706), which differentiated inpatients from outpatients with a sensitivity of 76% and a specificity of 54%. CONCLUSIONS: Aggressive BPSD was the risk factor for inpatient treatment. The composite score of the Neuropsychiatric Inventory subdomain-related aggressive BPSD could be a screening tool to introduce inpatient treatment for BPSD. Geriatr Gerontol Int 2021; 21: 825-829.

Improvement in the long-term care burden after surgical treatment of patients with idiopathic normal pressure hydrocephalus: a supplementary study.

Idiopathic normal pressure hydrocephalus (iNPH) is a surgically treatable syndrome commonly observed in older adults. However, it is unclear whether clinical improvements after surgery can effectively reduce the long-term care burden (LTCB). In this study, we determined whether shunt surgery was effective in decreasing LTCB. We also investigated the degree of variability in patients and hospitals, using data from the iNPH multicenter study. This study involved 69 participants who underwent lumboperitoneal shunt surgery with follow-up for 12 months. A generalized linear mixed model was applied to analyze the fixed and random effects simultaneously. Regarding LTCB, the disability grades improved significantly. Although the dementia grades also improved, it was not statistically significant. The differences in the LTCB grades in most patients were within the range of the 95% confidence intervals, while in the case of hospitals, some were often out of the range. Further studies are needed to improve dementia in patients with iNPH. The incorporation of random variables, such as hospitals, is important for the analysis of data from multicenter studies.

Correlation between cerebral blood flow and olfactory function in mild cognitive impairment and Alzheimer's disease.

OBJECTIVE: Olfactory dysfunction is common in patients with mild cognitive impairment (MCI) or Alzheimer's disease (AD). We sought to elucidate brain regions associated with olfactory dysfunction in patients with MCI and early AD by using 123I-IMP-SPECT to detect regional cerebral blood flow (CBF). METHODS: We included 218 patients diagnosed with AD or MCI, who underwent a comprehensive battery of neuropsychiatric and neuropsychological tests, Alzheimer's Disease Assessment Scale-Cognitive Part (ADAS-Cog), and forward- and backward-digit span. Olfactory function was assessed using T&T olfactometry of five odors; patients stated whether they experienced any smell (detection test) and identified the odor (identification test). The association between single-photon emission computerized tomography based regional CBF and olfactory function was examined by voxel-by-voxel multiple regression analysis, considering sex, age, and education as covariate parameters. RESULTS: Of the 218 patients, 78 had mildly impaired olfactory detection and 15 had olfactory detection loss; additionally, 213 had mild olfactory identification impairment. The odor detection score correlated significantly with the ADAS-Cog word recall score (r = 0.193, p = 0.004). The odor identification score correlated significantly with the ADAS memory (r = 0.408, p < 0.001) and ADAS orientation (r = 0.292, p < 0.001) scores. The odor identification score correlated negatively with CBF in the left temporal pole, entorhinal area, and bilateral frontal poles (p < 0.001). CONCLUSION: Olfactory identification dysfunction in patients with MCI and AD is attributable to reduced CBF of the left temporal pole, entorhinal area, and bilateral frontal pole.

Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus (Third Edition): Endorsed by the Japanese Society of Normal Pressure Hydrocephalus.

Among the various disorders that manifest with gait disturbance, cognitive impairment, and urinary incontinence in the elderly population, idiopathic normal pressure hydrocephalus (iNPH) is becoming of great importance. The first edition of these guidelines for management of iNPH was published in 2004, and the second edition in 2012, to provide a series of timely, evidence-based recommendations related to iNPH. Since the last edition, clinical awareness of iNPH has risen dramatically, and clinical and basic research efforts on iNPH have increased significantly. This third edition of the guidelines was made to share these ideas with the international community and to promote international research on iNPH. The revision of the guidelines was undertaken by a multidisciplinary expert working group of the Japanese Society of Normal Pressure Hydrocephalus in conjunction with the Japanese Ministry of Health, Labour and Welfare research project. This revision proposes a new classification for NPH. The category of iNPH is clearly distinguished from NPH with congenital/developmental and acquired etiologies. Additionally, the essential role of disproportionately enlarged subarachnoid-space hydrocephalus (DESH) in the imaging diagnosis and decision for further management of iNPH is discussed in this edition. We created an algorithm for diagnosis and decision for shunt management. Diagnosis by biomarkers that distinguish prognosis has been also initiated. Therefore, diagnosis and treatment of iNPH have entered a new phase. We hope that this third edition of the guidelines will help patients, their families, and healthcare professionals involved in treating iNPH.

A multi-center, prospective study on the progression rate of asymptomatic ventriculomegaly with features of idiopathic normal pressure hydrocephalus on magnetic resonance imaging to idiopathic normal pressure hydrocephalus.

INTRODUCTION: Our previous community-based study demonstrated that some individuals with AVIM [asymptomatic ventriculomegaly with features of idiopathic normal pressure hydrocephalus (iNPH) on magnetic resonance imaging (MRI)] progressed to iNPH in several years. In this hospital-based study, we investigated the progression rate from AVIM to iNPH and its possible predictors. METHODS: We conducted a prospective study of participants with AVIM from several medical institutions/hospitals in Japan. AVIM is defined as "asymptomatic ventriculomegaly with features of iNPH on MRI"; in the present study, asymptomatic was defined as "0 (no symptoms) or 1 (presence of only subjective, but not objective, symptoms) on the iNPH Grading Scale (iNPH-GS)." We also measured possible predicting factors for AVIM-to-iNPH progression, including age, sex, body weight, blood pressure, diabetes mellitus, dyslipidemia, history of mental disease/head injury/sinusitis/smoking/alcohol-intake, Evans index, and the presence of DESH (disproportionately enlarged subarachnoid-space hydrocephalus) findings on brain MRI, and analyzed these potential predictive values. RESULTS: In 2012, 93 participants with AVIM were registered and enrolled in the study. Of these, 52 participants were able to be tracked for three years (until 2015). Of the 52 participants, 27 (52%) developed iNPH during the follow-up period (11 definite, 6 probable, and 10 possible iNPH), whereas 25 participants remained asymptomatic in 2015. Among the possible predictive factors examined, the baseline scores of iNPH-GS predicted the AVIM-to-iNPH progression. CONCLUSIONS: The multicenter prospective study demonstrated that the progression rate from AVIM to iNPH was ~17% per year, and the baseline scores of iNPH-GS predicted the AVIM-to-iNPH progression.

Normalized power variance of eLORETA at high-convexity area predicts shunt response in idiopathic normal pressure hydrocephalus.

Idiopathic normal pressure hydrocephalus (iNPH) is a neuropsychiatric disease characterized by gait disturbance, cognitive deterioration and urinary incontinence associated with excessive accumulation of cerebrospinal fluid (CSF) in the brain ventricles. These symptoms, in particular gait disturbance, can be potentially improved by shunt operation in the early stage of the disease, and the intervention associates with a worse outcome when performed late during the course of the disease. Despite the variable outcome of shunt operation, noninvasive presurgical prediction methods of shunt response have not been established yet. In the present study, we used normalized power variance (NPV), a sensitive measure of the instability of cortical electrical activity, to analyze cortical electrical activity derived from EEG data using exact-low-resolution-electromagnetic-tomography (eLORETA) in 15 shunt responders and 19 non-responders. We found that shunt responders showed significantly higher NPV values at high-convexity areas in beta frequency band than non-responders. In addition, using this difference, we could discriminate shunt responders from non-responders with leave-one-subject-out cross-validation accuracy of 67.6% (23/34) [positive predictive value of 61.1% (11/18) and negative predictive value of 75.0% (12/16)]. Our findings indicate that eLORETA-NPV can be a useful tool for noninvasive prediction of clinical response to shunt operation in patients with iNPH.

Thalamic pulvinar metabolism, sleep disturbances, and hallucinations in dementia with Lewy bodies: Positron emission tomography and actigraphy study.

OBJECTIVES: Although sleep disturbances are prevalent among patients with dementia with Lewy bodies (DLB), their neural substrates remain unclear. We aimed to clarify the neural substrates of sleep disturbances in patients with DLB. METHODS: We evaluated sleep disturbances, neuropsychiatric symptoms, and brain glucose metabolism in 22 patients with probable DLB using actigraphy, the Neuropsychiatric Inventory (NPI), and 18 F-fluorodeoxyglucose (FDG) positron emission tomography, respectively. Total sleep time (TST) and average activity count per minute (AAC) during sleep were calculated for seven consecutive days via actigraphy. We investigated associations between FDG uptake and the actigraphy parameters using Statistical Parametric Mapping version 12b. Spearman's rank correlation coefficients were used to investigate associations among TST, AAC, and clinical symptoms. The level of statistical significance was set at P < .05. P values were adjusted using the Benjamini-Hochberg method for multiple comparisons. This study was registered with ClinicalTrials.gov (NCT00776347). RESULTS: TST exhibited a significant positive association with FDG uptake in the bilateral orbitofrontal cortex and left thalamus, while AAC exhibited a significant negative association with FDG uptake in the left thalamus and the left parieto-occipital region. FDG uptake in the left pulvinar was associated with both TST and AAC. In addition, TST exhibited a significant negative association with the NPI hallucinations score (r = -0.66, P = .001), while AAC exhibited significant positive associations with the NPI delusions (r = 0.70, P < .001) and hallucinations (r = 0.63, P = .002) scores. CONCLUSIONS: TST and bodily activity during sleep are associated with dysfunction of the left pulvinar and the severity of hallucinations in patients with DLB.

Correlation between regional brain volume and olfactory function in very mild amnestic patients.

BACKGROUND & AIMS: We aimed to determine neural correlates of olfactory detection and identification and analyze associations between cognitive function and olfactory identification or detection in very mild amnestic patients. METHODS: We recruited 70 patients with chief complaints of memory impairment diagnosed as amnestic mild cognitive impairment (MCI) or Alzheimer's disease (AD) with a clinical dementia rating of 0.5. Olfactory detection and identification were assessed using T&T olfactometry. A voxel-wise correlation analysis of gray matter volume and olfactometry scores was performed. We also analyzed correlations between neuropsychological results and olfactometry scores. RESULTS: A significant negative correlation was observed between detection scores and nucleus accumbens and left parahippocampal gyrus volumes and between identification scores and orbitofrontal, right frontal, and right anterior temporal cortex volumes (p < .001). No significant correlation existed between detection and cognitive assessment scores. Identification score was significantly correlated with the Alzheimer's Disease Assessment Scale-Cognitive Part word recall score (r = 0.305, p = .01). CONCLUSIONS: Olfactory detection and identification dysfunction were attributable to impairments in different regions in MCI and very early AD; the former was attributed to the olfactory circuit, while the latter to neocortices. The dysfunction of identification of olfactory information was associated with episodic memory in those patients.

Amyloid ß deposition in subcortical stroke patients and effects of educational achievement: A pilot study.

OBJECTIVE: A direct causal relationship of cerebrovascular risk factors/stroke to amyloid ß (Aß) deposition has yet to be shown. We conducted [11 C] Pittsburgh compound B (PiB)-positron emission tomography (PET) analysis on subacute ischemic stroke patients and healthy controls. We hypothesized that subacute ischemic stroke patients would show focal Aß accumulation in cortical regions, which would increase and extend over time during the chronic phase after stroke onset. METHODS: Patients were recruited 14 to 28 days after acute subcortical ischemic stroke and examined with [11 C]PiB-PET scans. Regional time-activity data were analyzed with the Logan graphical method. Whole brain voxel-based analysis was conducted to compare stroke patients with healthy controls. We also performed longitudinal comparison of patients with successive [11 C]PiB-PET scans 1 year after stroke. RESULTS: Voxel-based analysis revealed a significant increase of [11 C]PiB-BPND of the precuneus/posterior cingulate cortex (PCu/PCC) in stroke patients at the subacute stage. Based on stepwise multiple regression analysis of [11 C]PiB-BP changes during follow-up as the dependent variable, years of education was the best independent correlate. There was a significant negative relationship between changes in [11 C]PiB-BP and years of education. CONCLUSIONS: Our results suggest that processes before and after the onset of ischemic stroke may trigger Aß deposition in the PCu/PCC, whereby amyloid deposition begins at an early stage of Alzheimer's disease (AD). Our findings support the existence of a cooperative association between vascular risk factors/stroke and AD progression. Further, educational achievement had a protective effect against the increase in Aß accumulation.