[Mechanism of action and clinical trial results of Lecanemab (Leqembi® 200†|mg, 500†|mg for Intravenous Infusion), a novel treatment for Alzheimer's disease].

Lecanemab is a humanized monoclonal antibody directed against human soluble amyloid-ß aggregates. It was developed for the treatment of early Alzheimer's disease (mild cognitive impairment or mild dementia stage of Alzheimer's disease). Among the amyloid-ß (Aß) involved in Alzheimer's disease, Lecanemab selectively binds to the highly neurotoxic Aß protofibrils, and is thought to reduce Aß protofibrils and amyloid plaques (Aß plaques) in the brain. The efficacy and safety of Lecanemab in early Alzheimer's disease were investigated in an international Phase II placebo-controlled study (Study 201) and an international Phase III placebo-controlled study (Study 301). Both studies included Japanese subjects. Lecanemab was given accelerated approval in the United States in January 2023, followed by traditional approval in July 2023. In Japan, it was approved for "control of the progression of mild cognitive impairment or mild dementia stage of Alzheimer's disease" in September 2023, and was added to the NHI drug price list in December 2023.

Condensed but liquid-like domain organization of active chromatin regions in living human cells.

In eukaryotes, higher-order chromatin organization is spatiotemporally regulated as domains, for various cellular functions. However, their physical nature in living cells remains unclear (e.g., condensed domains or extended fiber loops; liquid-like or solid-like). Using novel approaches combining genomics, single-nucleosome imaging, and computational modeling, we investigated the physical organization and behavior of early DNA replicated regions in human cells, which correspond to Hi-C contact domains with active chromatin marks. Motion correlation analysis of two neighbor nucleosomes shows that nucleosomes form physically condensed domains with ~150-nm diameters, even in active chromatin regions. The mean-square displacement analysis between two neighbor nucleosomes demonstrates that nucleosomes behave like a liquid in the condensed domain on the ~150 nm/~0.5 s spatiotemporal scale, which facilitates chromatin accessibility. Beyond the micrometers/minutes scale, chromatin seems solid-like, which may contribute to maintaining genome integrity. Our study reveals the viscoelastic principle of the chromatin polymer; chromatin is locally dynamic and reactive but globally stable.

Challenges and opportunities for improving the landscape for Lewy body dementia clinical trials.

Lewy body dementia (LBD), including dementia with Lewy bodies and Parkinson's disease dementia, affects over a million people in the USA and has a substantial impact on patients, caregivers, and society. Symptomatic treatments for LBD, which can include cognitive, neuropsychiatric, autonomic, sleep, and motor features, are limited with only two drugs (cholinesterase inhibitors) currently approved by regulatory agencies for dementia in LBD. Clinical trials represent a top research priority, but there are many challenges in the development and implementation of trials in LBD. To address these issues and advance the field of clinical trials in the LBDs, the Lewy Body Dementia Association formed an Industry Advisory Council (LBDA IAC), in addition to its Research Center of Excellence program. The LBDA IAC comprises a diverse and collaborative group of experts from academic medical centers, pharmaceutical industries, and the patient advocacy foundation. The inaugural LBDA IAC meeting, held in June 2019, aimed to bring together this group, along with representatives from regulatory agencies, to address the topic of optimizing the landscape of LBD clinical trials. This review highlights the formation of the LBDA IAC, current state of LBD clinical trials, and challenges and opportunities in the field regarding trial design, study populations, diagnostic criteria, and biomarker utilization. Current gaps include a lack of standardized clinical assessment tools and evidence-based management strategies for LBD as well as difficulty and controversy in diagnosing LBD. Challenges in LBD clinical trials include the heterogeneity of LBD pathology and symptomatology, limited understanding of the trajectory of LBD cognitive and core features, absence of LBD-specific outcome measures, and lack of established standardized biologic, imaging, or genetic biomarkers that may inform study design. Demands of study participation (e.g., travel, duration, and frequency of study visits) may also pose challenges and impact trial enrollment, retention, and outcomes. There are opportunities to improve the landscape of LBD clinical trials by harmonizing clinical assessments and biomarkers across cohorts and research studies, developing and validating outcome measures in LBD, engaging the patient community to assess research needs and priorities, and incorporating biomarker and genotype profiling in study design.

Long-term intraocular pressure after switching a combination ophthalmic medication of ß-blocker/prostaglandin.

PURPOSE: We examined intraocular pressure (IOP)-reducing effects 12 months after switching timolol maleate/travoprost combination ophthalmic solution in one bottle (TM/TR-COMBI-SOL) to carteolol hydrochloride/latanoprost combination ophthalmic solution in one bottle (CR/LT-COMBI-SOL). CASES: The participants included 25 patients (25 eyes) who could be followed up for 12 months after a switch from TM/TR-COMBI-SOL to CR/LT-COMBI-SOL in Saiseikai Arida Hospital between March 1, 2017, and August 31, 2018. They consisted of patients in whom antiglaucoma eye drop other than TM/TR-COMBI-SOL had not been used (monotherapy group, 12 patients [12 eyes], 12.8 ± 3.0 mmHg) and those in whom antiglaucoma eye drop other than TM/TR-COMBI-SOL had been concomitantly used (multitherapy group, 13 patients [13 eyes], 13.8 ± 2.4 mmHg). We excluded patients in whom drugs for glaucoma were changed or added during the follow-up and those who underwent intraocular surgery. MATERIALS AND METHODS: We retrospectively and statistically examined the IOP before eye drop switching and after 1, 6, and 12 months, using the paired t-test. RESULTS: The IOPs 1 month after eye drop switching in the monotherapy group and multitherapy group were 12.5 ± 3.3 and 13.8 ± 2.5 mmHg, respectively. The values after 6 months were 13.5 ± 3.0 and 11.5 ± 2.7 mmHg, respectively. Those after 12 months were 12.8 ± 2.7 and 11.7 ± 2.5 mmHg, respectively. In the monotherapy group, there was no significant difference during the follow-up period. In the multitherapy group, there were significant decreases in comparison with the preswitching value after 6 and 12 months (P < 0.05, respectively). CONCLUSION: The IOP-reducing effects of CR/LT-COMBI-SOL were similar to those of TM/TR-COMBI-SOL. However, the effects may be enhanced after switching from TM/TR-COMBI-SOL in patients receiving multitherapy.

PHi-C: deciphering Hi-C data into polymer dynamics.

Genomes are spatiotemporally organized within the cell nucleus. Genome-wide chromosome conformation capture (Hi-C) technologies have uncovered the 3D genome organization. Furthermore, live-cell imaging experiments have revealed that genomes are functional in 4D. Although computational modeling methods can convert 2D Hi-C data into population-averaged static 3D genome models, exploring 4D genome nature based on 2D Hi-C data remains lacking. Here, we describe a 4D simulation method, PHi-C (polymer dynamics deciphered from Hi-C data), that depicts 4D genome features from 2D Hi-C data by polymer modeling. PHi-C allows users to interpret 2D Hi-C data as physical interaction parameters within single chromosomes. The physical interaction parameters can then be used in the simulations and analyses to demonstrate dynamic characteristics of genomic loci and chromosomes as observed in live-cell imaging experiments. PHi-C is available at https://github.com/soyashinkai/PHi-C.

A Direct Link between Rényi-Tsallis Entropy and Hölder's Inequality-Yet Another Proof of Rényi-Tsallis Entropy Maximization.

The well-known Hölder's inequality has been recently utilized as an essential tool for solving several optimization problems. However, such an essential role of Hölder's inequality does not seem to have been reported in the context of generalized entropy, including Rényi-Tsallis entropy. Here, we identify a direct link between Rényi-Tsallis entropy and Hölder's inequality. Specifically, we demonstrate yet another elegant proof of the Rényi-Tsallis entropy maximization problem. Especially for the Tsallis entropy maximization problem, only with the equality condition of Hölder's inequality is the q-Gaussian distribution uniquely specified and also proved to be optimal.

Modulation of Corticospinal Excitability Depends on the Pattern of Mechanical Tactile Stimulation.

We investigated the effects of different patterns of mechanical tactile stimulation (MS) on corticospinal excitability by measuring the motor-evoked potential (MEP). This was a single-blind study that included nineteen healthy subjects. MS was applied for 20 min to the right index finger. MS intervention was defined as simple, lateral, rubbing, vertical, or random. Simple intervention stimulated the entire finger pad at the same time. Lateral intervention stimulated with moving between left and right on the finger pad. Rubbing intervention stimulated with moving the stimulus probe, fixed by protrusion pins. Vertical intervention stimulated with moving in the forward and backward directions on the finger pad. Random intervention stimulated to finger pad with either row protrudes. MEPs were measured in the first dorsal interosseous muscle to transcranial magnetic stimulation of the left motor cortex before, immediately after, and 5-20 min after intervention. Following simple intervention, MEP amplitudes were significantly smaller than preintervention, indicating depression of corticospinal excitability. Following lateral, rubbing, and vertical intervention, MEP amplitudes were significantly larger than preintervention, indicating facilitation of corticospinal excitability. The modulation of corticospinal excitability depends on MS patterns. These results contribute to knowledge regarding the use of MS as a neurorehabilitation tool to neurological disorder.

Regulation of primary motor cortex excitability by repetitive passive finger movement frequency.

Somatosensory input induced by passive movement activates primary motor cortex (M1). We applied repetitive passive movement (RPM) of different frequencies to test if modulation of M1 excitability depends on RPM frequency. Twenty-seven healthy subjects participated in this study. Motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) to left M1 were recorded from the right first dorsal interosseous muscle (FDI) to assess corticospinal excitability (experiment 1: n=15), and F-waves were measured from the right FDI as an index of spinal motoneuron excitability (experiment 2: n=15). Passive abduction/adduction of the right index finger was applied for 10min at 0.5, 1.0, 3.0, and 5.0Hz. Both 0.5Hz-RPM and 1.0Hz-RPM decreased MEPs for 2min (p<0.05), and 5.0Hz-RPM decreased MEPs for 15min compared with baseline (p<0.05); however, there was no difference in MEPs after 3.0Hz-RPM. No F-wave changes were observed following any RPM intervention. Based on the results of experiments 1 and 2, we investigated whether RPM modulates cortical inhibitory circuit using the paired-pulse TMS technique (experiment 3: n=12). Short-interval intracortical inhibition (SICI) was measured using paired-pulse TMS (inter-stimulus interval of 3ms) before and after 1.0, 3.0, and 5.0Hz-RPM. Both 1.0 and 5.0Hz-RPM increased SICI compared with baseline (p<0.05). These experiments suggest that M1 excitability decreases after RPM depending on movement frequency, possibly through frequency-dependent enhancement of cortical inhibitory circuit in M1.

Effects of Passive Finger Movement on Cortical Excitability.

This study examined the effects of joint angle and passive movement direction on corticospinal excitability. The subjects were 14 healthy adults from whom consent could be obtained. We performed two experiments. In Experiment 1, we measured motor evoked potential (MEP) amplitude, F-wave and M-wave at 0° and 20° adduction during adduction or abduction movement, in the range of movement from 10° abduction to 30° adduction. In Experiment 2, MEPs were measured at static 0° and 20° adduction during passive adduction from 10° adduction to 30° adduction and static 20° adduction. MEP, F-waves and M-waves were recorded from the right first dorsal interosseous (FDI) muscle. Experiment 1 revealed significantly increased MEP amplitude at 0° during passive adduction compared to static 0° (p < 0.01). No other significant differences in MEP, M-wave and F-wave parameters were observed. In Experiment 2, MEP amplitude was significantly higher at 20° adduction during passive adduction compared with static 0° (p < 0.01). Based on these findings, it appears that fluctuations in MEP amplitude values during passive movement are not influenced by joint angle, but rather it is possible that it is due to intracortical afferent facilitation (AF) dependent on afferent input due to the start of movement and interstimulus interval (ISI) of transcranial magnetic stimulation (TMS).

Presence and Absence of Muscle Contraction Elicited by Peripheral Nerve Electrical Stimulation Differentially Modulate Primary Motor Cortex Excitability.

Modulation of cortical excitability by sensory inputs is a critical component of sensorimotor integration. Sensory afferents, including muscle and joint afferents, to somatosensory cortex (S1) modulate primary motor cortex (M1) excitability, but the effects of muscle and joint afferents specifically activated by muscle contraction are unknown. We compared motor evoked potentials (MEPs) following median nerve stimulation (MNS) above and below the contraction threshold based on the persistence of M-waves. Peripheral nerve electrical stimulation (PES) conditions, including right MNS at the wrist at 110% motor threshold (MT; 110% MNS condition), right MNS at the index finger (sensory digit nerve stimulation [DNS]) with stimulus intensity approximately 110% MNS (DNS condition), and right MNS at the wrist at 90% MT (90% MNS condition) were applied. PES was administered in a 4 s ON and 6 s OFF cycle for 20 min at 30 Hz. In Experiment 1 (n = 15), MEPs were recorded from the right abductor pollicis brevis (APB) before (baseline) and after PES. In Experiment 2 (n = 15), M- and F-waves were recorded from the right APB. Stimulation at 110% MNS at the wrist evoking muscle contraction increased MEP amplitudes after PES compared with those at baseline, whereas DNS at the index finger and 90% MNS at the wrist not evoking muscle contraction decreased MEP amplitudes after PES. M- and F-waves, which reflect spinal cord or muscular and neuromuscular junctions, did not change following PES. These results suggest that muscle contraction and concomitant muscle/joint afferent inputs specifically enhance M1 excitability.

Pretreatment Cognitive Profile Likely to Benefit from Donepezil Treatment in Dementia with Lewy Bodies: Pooled Analyses of Two Randomized Controlled Trials.

BACKGROUND/AIMS: Based on Mini-Mental State Examination (MMSE) subitem scores, in dementia with Lewy bodies (DLB), we aimed to delineate features of cognitive impairment, identify cognitive domains improved by donepezil, and define a pretreatment cognitive profile likely to benefit from donepezil. METHODS: Pooled data were used from two randomized controlled trials of donepezil in DLB (n = 235). Baseline MMSE subitem scores were calculated for all patients. Mean changes in subitem scores at week 12 were compared between the placebo and the active group. Finally, the subgroup identification based on differential effect search (SIDES) method was applied. RESULTS: Baseline subitem scores were relatively low for serial 7's, delayed recall, and copying. Significant improvement by donepezil was found for orientation, serial 7's, repetition, 3-step command, and copying. The subgroup with pretreatment scores of serial 7's = 1, 2, or 3, delayed recall ≥1, and copying = 0 were the best responders. MMSE change in subgroups increased as more of these three conditions were fulfilled. CONCLUSION: Cognitive domains characteristically impaired in DLB are particularly improved by donepezil. The number of fulfilled conditions for serial 7's = 1, 2, or 3, delayed recall ≥1, and copying = 0 (likely to benefit score) may predict the response to donepezil in DLB patients.

Influence of Transcranial Direct Current Stimulation to the Cerebellum on Standing Posture Control.

Damage to the vestibular cerebellum results in dysfunctional standing posture control. Patients with cerebellum dysfunction have a larger sway in the center of gravity while standing compared with healthy subjects. Transcranial direct current stimulation (tDCS) is a noninvasive technique for selectively exciting or inhibiting specific neural structures with potential applications in functional assessment and treatment of neural disorders. However, the specific stimulation parameters for influencing postural control have not been assessed. In this study, we investigated the influence of tDCS when applied over the cerebellum on standing posture control. Sixteen healthy subjects received tDCS (20 min, 2 mA) over the scalp 2 cm below the inion. In Experiment 1, all 16 subjects received tDCS under three stimulus conditions, Sham, Cathodal, and Anodal, in a random order with the second electrode placed on the forehead. In Experiment 2, five subjects received cathodal stimulation only with the second electrode placed over the right buccinator muscle. Center of gravity sway was measured twice for 60 s before and after tDCS in a standing posture with eyes open and legs closed, and average total locus length, locus length per second, rectangular area, and enveloped area were calculated. In Experiment 1, total locus length and locus length per second decreased significantly after cathodal stimulation but not after anodal or sham stimulation, while no tDCS condition influenced rectangular or enveloped areas. In Experiment 2, cathodal tDCS again significantly reduced total locus length and locus length per second but not rectangular and enveloped areas. The effects of tDCS on postural control are polarity-dependent, likely reflecting the selective excitation or inhibition of cerebellar Purkinje cells. Cathodal tDCS to the cerebellum of healthy subjects can alter body sway (velocity).

Increased plasma donepezil concentration improves cognitive function in patients with dementia with Lewy bodies: An exploratory pharmacokinetic/pharmacodynamic analysis in a phase 3 randomized controlled trial.

OBJECTIVE: To investigate whether increasing plasma donepezil concentration further improves cognitive function and neuropsychiatric symptoms without compromising safety in patients with dementia with Lewy bodies (DLB). METHODS: We analyzed data from a 12-week phase 3 trial of donepezil (5 and 10mg/day) in patients with DLB. The contribution of factors affecting plasma donepezil concentration was evaluated using multivariate regression analysis. The relationships between plasma donepezil concentration and efficacy (cognitive function as measured by the Mini-Mental State Examination [MMSE], hallucinations and cognitive fluctuation), or safety (blood pressure, pulse rate, body weight, and parkinsonism as measured by the Unified Parkinson's Disease Rating Scale part III) were assessed by scatterplots and Pearson correlation. RESULTS: The data of 87 patients were used in the analyses. Plasma donepezil concentration increased proportionally with increasing dose from 5 to 10mg/day. The dose (contribution rate: 0.39, p<0.0001) and age (contribution rate: 0.12, p=0.0003) were statistically significant contributing factors affecting plasma donepezil concentration. Plasma donepezil concentration correlated significantly with improvement of MMSE score (p=0.040), but no significant correlations were found with the change in other tested parameters. CONCLUSIONS: Plasma donepezil concentration correlated positively with change in cognitive function without affecting safety, and was affected mainly by dose and to a lesser extent by age. Therefore, for patients in whom safety concerns are not found at donepezil 5mg/day, increasing the dose to 10mg/day to increase plasma concentration is worthwhile to further improve cognitive function.

An Analytical Framework for Studying Small-Number Effects in Catalytic Reaction Networks: A Probability Generating Function Approach to Chemical Master Equations.

Cell activities primarily depend on chemical reactions, especially those mediated by enzymes, and this has led to these activities being modeled as catalytic reaction networks. Although deterministic ordinary differential equations of concentrations (rate equations) have been widely used for modeling purposes in the field of systems biology, it has been pointed out that these catalytic reaction networks may behave in a way that is qualitatively different from such deterministic representation when the number of molecules for certain chemical species in the system is small. Apart from this, representing these phenomena by simple binary (on/off) systems that omit the quantities would also not be feasible. As recent experiments have revealed the existence of rare chemical species in cells, the importance of being able to model potential small-number phenomena is being recognized. However, most preceding studies were based on numerical simulations, and theoretical frameworks to analyze these phenomena have not been sufficiently developed. Motivated by the small-number issue, this work aimed to develop an analytical framework for the chemical master equation describing the distributional behavior of catalytic reaction networks. For simplicity, we considered networks consisting of two-body catalytic reactions. We used the probability generating function method to obtain the steady-state solutions of the chemical master equation without specifying the parameters. We obtained the time evolution equations of the first- and second-order moments of concentrations, and the steady-state analytical solution of the chemical master equation under certain conditions. These results led to the rank conservation law, the connecting state to the winner-takes-all state, and analysis of 2-molecules M-species systems. A possible interpretation of the theoretical conclusion for actual biochemical pathways is also discussed.

Time Course of Macular and Peripapillary Inner Retinal Thickness in Non-arteritic Anterior Ischaemic Optic Neuropathy Using Spectral-Domain Optical Coherence Tomography.

To report a time course of the ganglion cell complex (GCC) and circumpapillary retinal nerve fibre layer (cpRNFL) thicknesses using spectral-domain optical coherence tomography in patients with non-arteritic anterior ischaemic optic neuropathy (NAION), five patients with unilateral NAION were studied (the average age of 66.8 ± 7.8 years old). Forty-one age-matched normal controls were also enrolled. The GCC and cpRNFL thicknesses were measured at the initial visit and at 1, 3, 6, and 12 months using RTVue-100. The GCC thickness and the cpRNFL thickness of the patients were compared with those of the normal controls. The GCC thickness in the NAION patients was 96.49 µm at the initial visit, 84.28 µm at 1 month, 74.26 µm at 3 months, 71.23 µm at 6 months, and 69.51 µm at 12 months. The values at 1, 3, 6, and 12 months were significantly reduced (p < 0.01). The cpRNFL thickness at the initial visit was significantly increased, whereas the values at 6 and 12 months were significantly reduced (p < 0.01). The GCC thickness is more useful for the detection of retinal ganglion cell loss at an early stage than the cpRNFL thickness, because the GCC thickness is unaffected by optic disc swelling at the initial visit, unlike the cpRNFL thickness.

Adequacy of Using Consensus Guidelines for Diagnosis of Dementia with Lewy Bodies in Clinical Trials for Drug Development.

BACKGROUND/AIMS: To evaluate the adequacy of using the consensus diagnostic criteria for dementia with Lewy bodies (DLB) to recruit patients with homogeneous characteristics in future clinical trials, where multiple departments of multinational centres are expected to participate with a long enrolment period, and additionally, to contribute to the possible future criteria revision. METHODS: Using data from 2 trials of donepezil for DLB, conducted 3 years apart, characteristics in patients with probable DLB were analysed and compared between studies and between psychiatric and neurological centres. RESULTS: In 273 patients (phase II: 135, phase III: 138; psychiatric: 73, neurological: 184), clinical characteristics overall were very similar between studies, and between specialty centres, excluding distinctive parkinsonism in the neurological versus psychiatric centres: incidence of parkinsonism (91.8 vs. 71.2%, p < 0.001), Hoehn and Yahr stage (III: 55.0 vs. 21.2%, p < 0.001), and concomitant anti-Parkinson medication (24.5 vs. 11.0%, p = 0.017). Rapid eye movement sleep behaviour disorder, depression, and delusion, suggestive or supportive features, were observed in 35-40%. Additionally, a high prevalence (55.3%) of anxiety was observed. CONCLUSION: Employing the consensus criteria is adequate to enrol homogeneous DLB patients into future clinical trials regardless of the specialty of centres and time. Further discussion could involve adding anxiety to future criteria.

Sectoral analysis of the retinal nerve fiber layer thinning and its association with visual field loss in homonymous hemianopia caused by post-geniculate lesions using spectral-domain optical coherence tomography.

PURPOSE: To report a sectoral analysis of circumpapillary retinal nerve fiber layer (cpRNFL) thinning and its association with visual field loss using spectral-domain optical coherence tomography (SD-OCT) in patients with homonymous hemianopia following acquired post-geniculate visual pathway damage. PATIENTS AND METHODS: Seven patients with homonymous hemianopia due to unilateral acquired post-geniculate visual pathway lesions were studied. The average duration from the onset of brain lesions to the initial visit was 49.8 months. Forty-nine normal control subjects without visual field defects, as confirmed using a Humphrey visual field analyzer, were also enrolled. Measurement of the cpRNFL thickness was performed at the initial visit and 24 months using SD-OCT (RTVue-100® OCT). The cpRNFL thickness was divided into eight sectors (superior temporal: ST, temporal upper: TU, temporal lower: TI, inferior temporal: IT, inferior nasal: IN, nasal lower: NL, nasal upper: NU, superior nasal: SN). The eye on the same side as the occipital lobe lesions was defined as the ipsilateral eye, and the eye on the opposite side was defined as the contralateral eye. RESULTS: The average cpRNFL thickness in the homonymous hemianopic eyes was significantly reduced as compared with that seen in the normal controls, except for the ipsilateral eyes at the initial visit. Four of the eight sectors of the cpRNFL thickness in the homonymous hemianopic eyes were significantly reduced compared with that noted in the normal controls. In the ipsilateral eyes, the cpRNFL thickness in the ST, TU, TL, and IT sectors was significantly reduced at both the initial visit and 24 months. In the contralateral eyes, the cpRNFL thickness in the TU, TL, IT, and SN sectors was significantly reduced at both the initial visit and 24 months. The reduction of the quadrantic cpRNFL thickness significantly correlated with some of the visual field parameters, in accordance with the structure-function relationship. In the contralateral eyes, the T and I quadrant cpRNFL thickness correlated with the mean deviation and hemianopic field total deviation at 24 months. In the ipsilateral eyes, the S, T, and I quadrant cpRNFL thickness correlated with mean deviation. However, there were no correlations between the cpRNFL thickness and visual field parameters at the initial visit. CONCLUSIONS: A reduction of the cpRNFL thickness corresponding to the hemianopic visual field loss due to acquired post-geniculate visual pathway lesions was detected using SD-OCT, and the change was more evident at 24 months than at the initial visit. The latter finding suggests that this change is, at least partially, caused by transsynaptic retrograde degeneration.

Effects of Donepezil on Extrapyramidal Symptoms in Patients with Dementia with Lewy Bodies: A Secondary Pooled Analysis of Two Randomized-Controlled and Two Open-Label Long-Term Extension Studies.

BACKGROUND/AIMS: The aim of this study was to clarify the effects of donepezil on extrapyramidal symptoms in patients with dementia with Lewy bodies (DLB). METHODS: Using pooled datasets from phase 2 and 3, 12-week randomized, placebo-controlled trials (RCT, n = 281) and 52-week open-label long-term extension trials (OLE, n = 241) of donepezil in DLB, the effects of donepezil on the incidence of extrapyramidal adverse events (AEs) and on the Unified Parkinson's Disease Rating Scale (UPDRS) part III were assessed, and potential baseline factors affecting the AEs were explored. RESULTS: The RCT analysis did not show significant differences between the placebo and active (3, 5, and 10 mg donepezil) groups in extrapyramidal AE incidence (3.8 and 6.5%, p = 0.569) and change in the UPDRS (mean ± SD: -0.2 ± 4.3 and -0.6 ± 6.5, p = 0.562). In the OLE analysis (5 and 10 mg donepezil), the incidence did not increase chronologically; all AEs leading to a dose reduction or discontinuation except one were relieved. The UPDRS was unchanged for 52 weeks. An exploratory multivariate logistic regression analysis of the RCTs revealed that donepezil treatment was not a significant factor affecting the AEs. Baseline severity of parkinsonism was a predisposing factor for worsening of parkinsonism without significant interactions between donepezil and baseline severity. CONCLUSION: DLB can safely be treated with donepezil without relevant worsening of extrapyramidal symptoms, but treatment requires careful attention to symptom progression when administered to patients with relatively severe parkinsonism.

Generalized Lyapunov exponent as a unified characterization of dynamical instabilities.

The Lyapunov exponent characterizes an exponential growth rate of the difference of nearby orbits. A positive Lyapunov exponent (exponential dynamical instability) is a manifestation of chaos. Here, we propose the Lyapunov pair, which is based on the generalized Lyapunov exponent, as a unified characterization of nonexponential and exponential dynamical instabilities in one-dimensional maps. Chaos is classified into three different types, i.e., superexponential, exponential, and subexponential chaos. Using one-dimensional maps, we demonstrate superexponential and subexponential chaos and quantify the dynamical instabilities by the Lyapunov pair. In subexponential chaos, we show superweak chaos, which means that the growth of the difference of nearby orbits is slower than a stretched exponential growth. The scaling of the growth is analytically studied by a recently developed theory of a continuous accumulation process, which is related to infinite ergodic theory.

Donepezil for dementia with Lewy bodies: a randomized, placebo-controlled, confirmatory phase III trial.

INTRODUCTION: The efficacy of a cholinesterase inhibitor, donepezil, in patients with dementia with Lewy bodies (DLB) was investigated to confirm the superiority over placebo in the 12-week, double-blind phase of this phase III study. METHODS: Patients with probable DLB (n = 142) were randomly assigned to placebo or to 5 mg or 10 mg of donepezil administered once daily for 12 weeks. The co-primary endpoints were changes in cognitive function assessed using the Mini-Mental State Examination (MMSE) and behavioral and neuropsychiatric symptoms using the Neuropsychiatric Inventory (NPI-2: hallucinations and fluctuations). The superiority of each active group over placebo was determined with simultaneous statistical significance in both endpoints. Safety evaluations included adverse events (AEs) and the unified Parkinson's disease rating scale (UPDRS) part III. RESULTS: The predefined superiority of donepezil to the placebo was not confirmed in either active group in the primary analysis. MMSE score significantly improved compared to placebo in the 10 mg group (10 mg: 2.2 ± 0.4, placebo: 0.6 ± 0.5 (mean ± standard error); P = 0.016). The change in MMSE score in the 5 mg group was not significant (1.4 ± 0.5 (mean ± standard error); P = 0.232). Although NPI-2 improved compared to baseline in the active groups, the differences from placebo were not significant. Most AEs were mild or moderate. Although the incidence of parkinsonism was slightly higher in the 10 mg group, the change in the UPDRS score was minimal and without a significant difference from the placebo group. CONCLUSIONS: The co-primary endpoints were not achieved in this trial. However, significant improvement in MMSE score was demonstrated with 10 mg, but not 5 mg, of donepezil. The evaluation of psychiatric symptoms might be affected by advanced education and instructions given to caregivers. Overall, donepezil was well tolerated in patients with DLB. With careful attention on gastrointestinal or parkinsonian symptoms, patients with DLB can safely benefit from treatment with donepezil. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01278407 (trial registration date: 14 January 2011).