Cerebral white matter lesions and regional blood flow are associated with reduced cognitive function in early-stage cognitive impairment.

Background: Differences in the extent of cerebral white matter lesions (WML) and regional cerebral blood flow (rCBF) in early-stage cognitive impairment (ESCI) contribute to the prognosis of cognitive decline; however, it is unclear precisely how WML and rCBF affect cognitive decline in ESCI. Objective: We examined the association between WML, rCBF, and cognitive impairment in the ESCI, using path analysis to clarify how these variables affect each other. Methods: Eighty-three patients who consulted our memory clinic regarding memory loss were included in this study based on the Clinical Dementia Rating. Participants underwent the Mini-Mental State Examination (MMSE), brain magnetic resonance imaging (MRI) for voxel-based morphometry analysis, and brain perfusion single-photon emission computed tomography (SPECT) for rCBF evaluation in cortical regions, using 3D stereotactic surface projection (3D-SSP) analysis. Results: Path analysis was performed on the MRI voxel-based morphometry and SPECT 3D-SSP data, showing a significant correlation between both and MMSE scores. In the most suitable model (GFI = 0.957), correlations were observed between lateral ventricular (LV-V) and periventricular WML (PvWML-V) volumes [standardized coefficient (SC) = 0.326, p = 0.005], LV-V and rCBF of the anterior cingulate gyrus (ACG-rCBF; SC = 0.395, p < 0.0001), and ACG-rCBF and PvWML-V (SC = 0.231, p = 0.041). Furthermore, a direct relationship between PvWML-V and MMSE scores was identified (SC = -0.238, p = 0.026). Conclusion: Significant interrelationships were observed among the LV-V, PvWML-V, and ACG-rCBF that directly affected the MMSE score in the ESCI. The mechanisms behind these interactions and the impact of PvWML-V on cognitive function require further investigation.

The relationship between the distinct ratios of benserazide and carbidopa to levodopa and motor complications in Parkinson's disease: A retrospective cohort study.

BACKGROUND: In Japan, only two medications of immediate-release levodopa with distinct ratios of decarboxylase inhibitor (DCI), namely levodopa/benserazide 100/25 mg and levodopa/carbidopa 100/10 mg, are available for the treatment of Parkinson's disease (PD). The relationship between the difference in the DCI to levodopa ratio and the development of motor complications in long-term administration of levodopa is unknown. PURPOSE: We assessed the duration from initiation of levodopa/DCI to the emergence of motor fluctuations in patients with PD treated with levodopa/benserazide and levodopa/carbidopa. METHODS: We retrospectively assessed the disease course, especially the period from the onset of motor symptoms or initiation of levodopa/DCI to the emergence of motor fluctuations, in patients with PD who were initially treated with either levodopa/benserazide (300/75 mg/day) or levodopa/carbidopa (300/30 mg/day). RESULTS: Of the 186 candidates, 52 patients were enrolled. The mean duration to the emergence of motor fluctuations in the levodopa/carbidopa group was significantly longer than that in the levodopa/benserazide group (5.0 ± 1.4 vs 3.1 ± 1.2 years, p < 0.01). The mean duration from onset of motor symptoms to the emergence of motor fluctuations in the levodopa/carbidopa group was also significantly longer than that in the levodopa/benserazide group (6.6 ± 1.6 vs 4.7 ± 1.3 years, p < 0.01). CONCLUSION: Our study suggests that levodopa/carbidopa therapy with a DCI to levodopa ratio of 1:10 may delay the occurrence of motor fluctuations when compared to levodopa/benserazide therapy with that of 1:4. The difference in the blending ratio of levodopa/DCI may influence the disease progression in PD.

White Matter Lesions May Aid in Differentiating Idiopathic Normal Pressure Hydrocephalus and Alzheimer's Disease.

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) is often misdiagnosed as Alzheimer's disease (AD) due to overlapping pathophysiology and similar imaging characteristics, including ventricular enlargement and increased white matter lesions (WMLs). OBJECTIVE: To compare the extent and distribution of WMLs directly between iNPH and AD and examine the association with underlying pathophysiology. METHODS: Twelve patients with iNPH (mean age: 78.08 years; 5 females), 20 with AD (mean age: 75.40 years; 13 females), and 10 normal cognition (NC) participants (mean age: 76.60 years; 7 females) were recruited. The extent and distribution of WMLs and the lateral ventricular volume (LV-V) were evaluated on MRI using voxel-based morphometry analysis. Concentrations of cerebrospinal fluid biomarkers, such as amyloid-ß protein (Aß)42, Aß40, Aß38, and tau species, were also measured. Risk factors for small vessel disease (SVD) were assessed by blood examination and medical records. RESULTS: The periventricular WML volume (PWML-V) and deep WML volume (DWML-V) were significantly larger in iNPH than in AD and NC. The DWML-V was dominant in iNPH, while the PWML-V was dominant in AD and NC. GM-V was significantly smaller in AD than in iNPH and NC. The LV-V positively correlated with WML-V in all participants. There was a significant negative correlation between LV-V and Aß38 in iNPH. Furthermore, there was no significant difference in SVD risk factors between the groups. CONCLUSION: The differences in the extent and distribution of WMLs between iNPH and AD, especially predominance of DWML-V over PWML-V in iNPH, may reflect decreased fluid and Aß clearance.

[Marcel Proust: Birth of Neurology of Memory and Time in "In Search of Lost Time"].

Marcel Proust had interactions with a lot of neurologists through treatments of his asthma. His great work, "In Search of Lost Time", is one of the highest masterpieces in French literature, about which numerous reviews have been published from various angles as well as literature. This work is also important for neurology, as the origin of Proust's idea of creations is related to the neurology of memory and time. Especially, this article focuses on and discusses the Proust and the beginning of neurology of memory and time.

The Eyes Are More Eloquent Than Words: Anticipatory Looking as an Index of Event Memory in Alzheimer's Disease.

Alzheimer's disease (AD) is a disorder in which individuals experience a difficulty in maintaining event memory for when, where, who, and what. However, verbal deficiency, one of the other symptoms of AD, may prevent a precise diagnosis of event memory because existing tests are based on verbal instructions by the tester and verbal response from patient. Therefore, non-verbal methods are essential to evaluate event memory in AD. The present study, using eye tracking, investigated whether AD patients deployed anticipatory looking to target acts related to future events based on previous experience when an identical video was presented to them twice. The results revealed the presence of anticipatory looking, although AD patients were unable to verbally report the content of the video. Our results illustrate that AD patients have a one-time event memory better than previously thought.

Serum BDNF as a Potential Biomarker of Alzheimer's Disease: Verification Through Assessment of Serum, Cerebrospinal Fluid, and Medial Temporal Lobe Atrophy.

There is an urgent need to establish blood biomarkers for Alzheimer's disease (AD). Although it has been speculated that brain-derived neurotrophic factor (BDNF) is associated with AD, whether it can be used as a blood biomarker has yet to be determined. We used serum, cerebrospinal fluid (CSF), and medial temporal lobe atrophy from patients with AD to evaluate the association of BDNF with AD and assess its severity. For the blood analysis, 66 participants [21 normal controls (NCs) with normal cognitive function, 22 patients with mild cognitive impairment (MCI) due to AD, and 23 patients with AD] were included. For the CSF analysis, 30 participants were included. Magnetic resonance imaging, including a voxel-based specific regional analysis system for AD, and a Mini Mental State Examination were performed. Serum levels of BDNF and CSF levels of amyloid-ß42, total tau, and phosphorylated tau were measured using ELISA. Serum BDNF levels were significantly lower in the MCI due to AD group than in the NC group (p = 0.037). Although there was no significant difference in the AD group, there was a downward trend compared to the NC group. Serum BDNF levels were positively correlated with CSF Aß42 levels (r = 0.49, p = 0.005). There was a significant correlation between serum BDNF levels and medial temporal lobe atrophy. Decreased serum BDNF can potentially be used as a biomarker for early AD detection. Early detection of AD with a less invasive blood test is very beneficial, as it allows for intervention before dementia progresses.

Sex Differences in the Relationship of Serum Vitamin B1 and B12 to Dementia Among Memory Clinic Outpatients in Japan.

Dementia and cognitive impairment are considered to be one of the biggest social and medical problems. While there is a definite relationship between vitamin B and cognitive decline, this has yet to be fully assessed with regard to sex differences. Thus, the present study investigated the relationship of vitamin B1 or vitamin B12 with dementia in accordance with the sex in 188 patients who visited the Memory Clinic at Showa University Hospital in Japan from March 2016 to March 2019. Cognitive function was tested by the Japanese version of the Mini-Mental State Examination (MMSE) and Hasegawa Dementia Scale-Revised (HDS-R). Blood tests were performed to measure the vitamin levels. Logistic regression analysis was used to calculate the odds ratio (OR) for dementia and the 95% confidence interval (CI). Compared to the highest vitamin group (third tertile), the lowest vitamin group (first tertile) exhibited a significantly increased OR for dementia defined by MMSE for vitamin B1 (OR:3.73, 95% CI:1.52-9.16) and vitamin B12 (2.97, 1.22-7.28) among women. In contrast, vitamin levels were not significantly associated with dementia determined by MMSE in men. These findings were similar even when dementia was defined by HDS-R. The present study suggests that vitamin B1 plays a role in preventing development of dementia in women. Future longitudinal studies will need to be undertaken in order to examine whether decreasing vitamin levels occur before or after cognitive impairment, and whether maintaining a higher vitamin level can prevent a worsening of cognitive function and the development of dementia.

Stopwatch training improves cognitive functions in patients with Parkinson's disease.

Parkinson's disease (PD) impairs various cognitive functions, including time perception. Dysfunctional time perception in PD is poorly understood, and no study has investigated the rehabilitation of time perception in patients with PD. We aimed to induce the recovery of time perception in PD patients and investigated the potential relationship between recovery and cognitive functions/domains other than time perception. Sixty patients with PD (27 females) and 20 healthy controls (10 females) were recruited. The participants underwent a feedback training protocol for 4 weeks to improve the accuracy of subjective spatial distance or time duration using a ruler or stopwatch, respectively. They participated in three tests at weekly intervals, each comprising 10 types of cognitive tasks and assessments. After duration feedback training for 1 month, performance on the Go/No-go task, Stroop task, and impulsivity assessment improved in patients with PD, while no effect was observed after distance feedback training. Additionally, the effect of training on duration production correlated with extended reaction time and improved accuracy in the Go/No-go and Stroop tasks. These findings suggest that time perception is functionally linked to inhibitory systems. If the feedback training protocol can modulate and maintain time perception, it may improve various cognitive/psychiatric functions in patients with PD. It may also be useful in the treatment of diseases other than PD that cause dysfunctions in temporal processing.

Toxic Amyloid-ß42 Conformer May Accelerate the Onset of Alzheimer's Disease in the Preclinical Stage.

BACKGROUND: Toxic amyloid-ß protein (Aß) conformers play an important role in the progression of Alzheimer's disease (AD). The ratio of toxic conformer to total Aß42 in cerebrospinal fluid (CSF) was significantly high in AD and mild cognitive impairment (MCI) due to AD using an enzyme-linked immunosorbent assay kit with a 24B3 antibody. OBJECTIVE: We compared the toxic Aß42, conformer at different stages of AD to identify its contribution to AD pathogenesis. METHODS: We compared 5 patients with preclinical AD, 11 patients with MCI due to AD, 21 patients with AD, and 5 healthy controls to measure CSF levels of total Aß42, total tau, tau phosphorylated at threonine 181 (p-tau), and toxic Aß conformers. All were classified using the Clinical Dementia Rating. Cognitive function was assessed using the Japanese version of the Mini-Mental State Examination (MMSE-J). RESULTS: Toxic Aß conformer level was insignificant between groups, but its ratio to Aß42 was significantly higher in AD than in preclinical AD (p < 0.05). Toxic Aß42 conformer correlated positively with p-tau (r = 0.67, p < 0.01) and p-tau correlated negatively with MMSE-J (r = -0.38, p < 0.05). CONCLUSION: Toxic Aß conformer triggers tau accumulation leading to neuronal impairment in AD pathogenesis.

Cingulate Island Sign in Single Photon Emission Computed Tomography: Clinical Biomarker Correlations in Lewy Body Disease and Alzheimer's Disease.

We compared 'CIScore' determined by quantitative single photon emission computed tomography studies of the cingulate island sign to cerebrospinal fluid (CSF) biomarkers in Lewy body disease (LBD) and Alzheimer's disease (AD) to assess its usefulness and pathological background. Among the 16 each age-matched LBD and AD patients, the CIScore differed significantly but was not correlated with CSF biomarkers. In LBD, hippocampal atrophy significantly correlated with Clinical Dementia Rating and CSF p-tau and t-tau levels. Our results showed CIS was not related to CSF biomarkers in LBD and high CSF tau levels were related to clinical disease severity and hippocampal atrophy.

Numbsense of shape, texture, and objects after left parietal infarction: A case report.

Numbsense is a phenomenon, wherein patients can correctly respond to somatosensory stimuli at a higher rate than expected by chance, but cannot perceive the same stimuli consciously. Previously, numbsense has been reported in tactile localization of stimuli on the patient's own body. Here, we describe a patient with numbsense that involved touched objects. The patient could not recognize the majority of somatosensory stimuli after left parietal infarction, but could correctly select shape, texture, and object stimuli more frequently than expected by chance.

A case of prosopometamorphopsia caused by infarction of the splenium of the corpus callosum and major forceps.

An adult female complained of enlargement of right eyes in other people. Diffusion-weighted imaging detected an abnormal high-intensity area in the region from the splenium of the corpus callosum to the major forceps on the right side. The patient reported that right eyes appeared larger in size, which suggested prosopometamorphopsia. Adichotic listening test identified left-ear deficit. Acombination of prosopometamorphopsia and left-ear deficit was not identified in the reported patients. Prosopometamorphopsia in most of the reported patients included the eye as did that in our patient. This result suggested the importance of information on the eye in recognizing faces.

Increased Presence of Cerebral Microbleeds Correlates With Ventricular Enlargement and Increased White Matter Hyperintensities in Alzheimer's Disease.

Objective: To investigate whether the number of cerebral microbleeds (CMB) could be a useful indicator to predict glymphatic system dysfunction in Alzheimer's disease (AD) patients, by comparing the degree of cerebral spinal fluid (CSF) and interstitial fluid (ISF) stasis. Methods: Forty probable AD patients were included, with those exhibiting two or more CMB were included in the multiple CMB group (mCMB, n = 21, mean = 11.1), and none or one CMB included in the non-multiple CMB group (nmCMB, n = 19, mean = 0.84). CMB was defined in axial gradient recalled echo (GRE) T2*-weighted images. Evans index (EI) was calculated to measure lateral ventricle enlargement, Voxel-based Specific Regional Analysis System for Alzheimer's Disease (VSRAD) software was used to determine the extent of gray and white matter atrophy, and Fazekas scale (FS) was used to determine white matter hyperintensities (WMH). Results: EI was significantly larger in mCMB than in nmCMB, while the gray and white matter volume was not different between groups. Thus, the difference in lateral ventricle enlargement between AD with and without multiple CMB reflects a combination of the degree of brain atrophy and the extent of CSF stasis. FS was higher in mCMB than in the nmCMB, suggesting the failure of ISF elimination was more severe in mCMB cases. Conclusion: The difference in lateral ventricle enlargement and WMH between AD with or without multiple CMB may reflect a difference in the degree of CSF/ISF stagnation.

Discriminating chorea-acanthocytosis from Huntington's disease with single-case voxel-based morphometry analysis.

BACKGROUND AND PURPOSE: Chorea-acanthocytosis is clinically difficult to distinguish from Huntington's disease because these disorders have similar symptoms and MR imaging findings. We evaluated the usefulness of single-case voxel-based morphometry (VBM) analysis for differentiating the two diseases as well as VBM analysis. MATERIALS AND METHODS: We examined five genetically proven chorea-acanthocytosis patients and 11 Huntington's disease patients to detect differences in the gray and white matter atrophic pattern by using single-case VBM analysis in each patient and their clinical findings. We also evaluated VBM analysis for a group comparison in both disease and control groups. RESULTS: The single-case VBM analysis results demonstrated a gray matter volume loss in caudate nucleus in all 16 patients. A characteristic symmetrical white matter volume loss was detected in globus pallidus, putamen, and thalamus on both sides in all the chorea-acanthocytosis patients, but this pattern of atrophy was not seen in any of the Huntington's disease patients. With the VBM analysis, a significant gray matter volume loss was noted in caudate nucleus on both sides in chorea-acanthocytosis patients compared with Huntington's disease patients, and a more extensive white matter volume loss around the basal ganglia and thalamus was observed in chorea-acanthocytosis patients compared to Huntington's disease patients, consistent with the single-case VBM analysis results. Genetic testing identified two novel pathogenic mutations, exon 1 c.16_22delGTGGTCG and exon 55 c.7736-7739delGAGA in a chorea-acanthocytosis patient. CONCLUSIONS: Single-case VBM analysis may be useful to differentiate chorea-acanthocytosis from Huntington's disease with a focus on white matter atrophy.

Contraction of distance and duration production in autism spectrum disorder.

Autism spectrum disorder (ASD) presents certain hallmark features associated with cognitive and social functions, however, the ability to estimate self-generated distance and duration in individuals with ASD are unclear. We compared the performance of 20 ASD individuals with 20 typical developments (TDs) with respect to two tasks: (1) the drawing of a line of a specified distance (10 or 20 cm) and (2) waiting for a specified time (10 or 20 s). We observed that both the line distances and waiting times were substantially shorter in the ASD group than in the TD group. Furthermore, a trait of "attention to detail," as measured by the Autism-Spectrum Quotient, correlated with some distance and duration productions observed in individuals with ASD. We suggest that attentional functions are related to the contraction of distance and duration in ASD.

The relationship between thyroid function and cerebral blood flow in mild cognitive impairment and Alzheimer's disease.

The thyroid hormones have been reported to be associated with cognitive decline and Alzheimer's disease. The relationship between thyroid function within the normal range and cerebral blood flow in Alzheimer's disease patients has been shown in a recent study. Mild cognitive impairment is often the first stage of Alzheimer's disease; thus, early diagnosis is important. The present study investigated the relationship between thyroid function and regional cerebral blood flow in patients with mild cognitive impairment and Alzheimer's disease. A total of 122 memory clinic outpatients who underwent thyroid function testing and single photon emission computed tomography were divided into mild cognitive impairment, Alzheimer's disease, and Normal groups. Regional cerebral blood flow was calculated using a three-dimensional stereotactic region of interest template in an automated cerebral perfusion single photon emission computed tomography analysis system. Multiple regression analysis adjusted for age and sex was conducted to examine the relationships between thyroid hormones and regional cerebral blood flow. Thyroid stimulating hormone was significantly associated with regional cerebral blood flow in the bilateral temporal, bilateral pericallosal, and bilateral hippocampal regions in the mild cognitive impairment group. In the Alzheimer's disease group, free triiodothyronine was significantly associated with regional cerebral blood flow in the bilateral parietal, right temporal, and bilateral pericallosal regions. The present study showed the association of thyroid stimulating hormone with regional cerebral blood flow in the mild cognitive impairment group and the association of free triiodothyronine with regional cerebral blood flow in the Alzheimer's disease group. These study findings could contribute to the early diagnosis of mild cognitive impairment at general memory clinics and the prevention of subsequent progression to Alzheimer's disease.

High serum high-density lipoprotein-cholesterol is associated with memory function and gyrification of insular and frontal opercular cortex in an elderly memory-clinic population.

The issue of whether serum lipid marker values are cognitively and neurologically significant for elderly individuals attending a memory clinic has been controversial. We investigated the associations of serum lipid markers with the memory function and cortical structure in 52 patients aged ≥75 years who had attended our memory clinic based on their subjective memory complaints. None had a history of medication for hyperlipidemia. The Wechsler Memory Scale-Revised (WMS-R) was administered to all patients for the assessment of their memory function. Serum low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDLC), and triglyceride (TG) were measured for each patient. Surface-based morphometry (SBM) was performed for the calculation of each patient's cortical thickness and gyrification index based on structural MRI data. Our analyses revealed that the serum HDLC level was positively and significantly correlated with the WMS-R subtests of visual paired associates I/II and logical memory I (p < 0.05). The serum TG level was negatively correlated with the logical memory I subtest. The SBM results showed positive correlations between the serum HDLC level and the gyrification indices of the bilateral insular and frontal opercular cortices, and those two gyrification indices were positively correlated with the logical memory I and visual paired associates I/II. These results suggest that in these elderly patients, a high serum HDLC level was associated with not only preserved memory function but also gyrification of the insular and frontal opercular cortex. We conclude that elderly individuals' serum lipid markers should be carefully assessed in memory clinic settings, because serum HDLC may be a biomarker for memory function and cortical structure.

Impaired cognitive modification for estimating time duration in Parkinson's disease.

Parkinson's disease (PD) is associated with various cognitive impairments. However, the nature of cognitive modification in patients with PD remains to be elucidated. In the present study, we examined whether patients with PD could correct and maintain subjective time duration and line length estimation. After training sessions, in which participants repeatedly memorized either a duration or a length, we compared a learning performance in 20 PD patients with 20 healthy controls. In the case of duration in the PD patients, the learned durations immediately returned to baseline of pre-training within a few minutes. However, the patients' ability to learn length estimation remained unimpaired. In contrast, healthy controls were able to retain the learned duration and length estimations. Time compression in PD's internal clock may become entrained to their altered duration estimation even after learning of accurate time duration. These deficits may be associated with disrupting cognitive modification in PD.

The subjective perception of past, present, and future time in patients with Alzheimer's disease: a qualitative study.

BACKGROUND: The relationship between dementia and time perception impairment is unknown. AIM: This study aims to explore subjective perception of the passage of time in patients with Alzheimer's disease (AD). METHODS: We conducted semi-structured interviews with 11 AD patients. Grounded theory, a qualitative research methodology, was used for data analysis. RESULTS: Based on interview transcripts, five categories were designated: {Live according to a private clock}, {The past comes up}, {Move back and forth between the present and the past}, {Cannot imagine the future}, and {Bid farewell to this world as early as tomorrow}. DISCUSSION: Our results suggest that AD patients alternate past and present without complete awareness and cannot imagine a future other than one ending in death.