Effect of dual-task interaction combining postural and visual perturbations on cortical activity and postural control ability

Previous studies have suggested cortical involvement in postural control in humans by measuring cortical activities and conducting dual-task paradigms. In dual-task paradigms, task performance deteriorates and can be facilitated in specific dual-task settings. Theoretical frameworks explaining these dual-task interactions have been proposed and debated for decades. Therefore, we investigated postural control performance under different visual conditions using a virtual reality system, simultaneously measuring cortical activities with a functional near-infrared spectroscopy system. Twenty-four healthy participants were included in this study. Postural stability and cortical activities after perturbations were measured under several conditions consisting of postural and visual perturbations. The results showed that concurrent visual and postural perturbations could facilitate cortical activities in the supplementary motor area and superior parietal lobe. Additionally, visual distractors deteriorated postural control ability and cortical activation of the supplementary motor area. These findings supported the theoretical framework of the "Cross talk model", in which concurrent tasks using similar neural domains can facilitate these task performances. Furthermore, it indicated that the cortical resource capacity and domains activated for information processing should be considered in experiments involving dual-task paradigms and training.

Alterations of ATG4A and LC3B in neurons derived from Alzheimer's disease patients

We investigated the alterations in autophagy-related molecules in neurons differentiated from induced pluripotent stem cells obtained from patients with Alzheimer's disease (AD). Consistent with our previous microarray data, ATG4A protein was upregulated in the neurons derived from a familial AD patient with an APP-E693Δ mutation who showed accumulation of intracellular amyloid β peptide (Aβ). This upregulation was reversed by inhibiting Aβ production, suggesting that the intracellular Aβ may be responsible for the upregulation of ATG4A. The LC3B-II/LC3B-I ratio, an index of autophagosome formation, was lower in the neurons derived from the AD patient with APP-E693Δ as well as the neurons derived from other familial and sporadic AD patients. These findings indicate that dysregulation of autophagy-related molecules may accelerate the pathogenesis of AD.

Repurposing bromocriptine for Aβ metabolism in Alzheimer's disease (REBRAnD) study: randomised placebo-controlled double-blind comparative trial and open-label extension trial to investigate the safety and efficacy of bromocriptine in Alzheimer's disease with presenilin 1 (PSEN1) mutations

INTRODUCTION

Alzheimer's disease (AD) is one of the most common causes of dementia. Pathogenic variants in the presenilin 1 (PSEN1) gene are the most frequent cause of early-onset AD. Medications for patients with AD bearing PSEN1 mutation (PSEN1-AD) are limited to symptomatic therapies and no established radical treatments are available. Induced pluripotent stem cell (iPSC)-based drug repurposing identified bromocriptine as a therapeutic candidate for PSEN1-AD. In this study, we used an enrichment strategy with iPSCs to select the study population, and we will investigate the safety and efficacy of an orally administered dose of bromocriptine in patients with PSEN1-AD.

METHODS AND ANALYSIS

This is a multicentre, randomised, placebo-controlled trial. AD patients with PSEN1 mutations and a Mini Mental State Examination-Japanese score of ≤25 will be randomly assigned, at a 2:1 ratio, to the trial drug or placebo group (≥4 patients in TW-012R and ≥2 patients in placebo). This clinical trial consists of a screening period, double-blind phase (9 months) and extension phase (3 months). The double-blind phase for evaluating the efficacy and safety is composed of the low-dose maintenance period (10 mg/day), high-dose maintenance period (22.5 mg/day) and tapering period of the trial drug. Additionally, there is an open-labelled active drug extension period for evaluating long-term safety. Primary outcomes are safety and efficacy in cognitive and psychological function. Also, exploratory investigations for the efficacy of bromocriptine by neurological scores and biomarkers will be conducted.

ETHICS AND DISSEMINATION

The proposed trial is conducted according to the Declaration of Helsinki, and was approved by the Institutional Review Board (K070). The study results are expected to be disseminated at international or national conferences and published in international journals following the peer-review process.

TRIAL REGISTRATION NUMBER

jRCT2041200008, NCT04413344.

Clinical Benefits of Antioxidative Supplement Twendee X for Mild Cognitive Impairment: A Multicenter, Randomized, Double-Blind, and Placebo-Controlled Prospective Interventional Study

Oxidative stress is part of the entire pathological process that underlies the development of Alzheimer's disease (AD), including the mild cognitive impairment (MCI) stage. Twendee X (TwX) is a supplement containing a strong antioxidative mix of eight antioxidants, which has been shown to have a clinical and therapeutic benefit in AD model mice. Here, we conducted a multicenter, randomized, double-blind, and placebo-controlled prospective interventional study to evaluate the efficacy of TwX in mitigating MCI. The primary outcomes were differences in Mini-Mental State Examination (MMSE) and Hasegawa Dementia Scale-revised (HDS-R) scores between baseline and six months for placebo and TwX groups. Seventy-eight subjects with MCI were randomized into placebo (n = 37) and TwX (n = 41) groups. MMSE scores at six months differed significantly between the TwX and placebo groups (p = 0.018), and HDS-R scores for the TwX group exhibited a significant improvement at six months relative to baseline (p = 0.025). The TwX group did not show any change in affective or activities of daily living scores at six months. The present study indicates that strong antioxidative supplement TwX is clinical beneficial for cognitive function in subjects with MCI.

Social problems in daily life of patients with dementia

AIM

Most patients with dementia frequently encounter various problems in their daily lives. Those troubles embarrass both the patients and their families, and cause problems for society. However, there have been few scientific reports on the difficulties in the daily life of patients with dementia. Therefore, we tried to clarify the frequency and characteristics of troubles experienced by patients with dementia.

METHODS

Seven medical centers treating dementia patients in Okayama Prefecture, Japan, participated in this survey. A total of 737 patients were placed in one of the three groups: a dementia group (n = 478), a mild cognitive impairment group (n = 199) and a control group (n = 60). The frequency of 13 difficulties was scored for each patient.

RESULTS

Among normal participants, no person caused these problems once a year or more frequently. "Massive, recurrent buying" and "acts that risk causing a fire" were reported once a year or more for >10% of mild cognitive impairment patients. "Troubles with wealth management" and "troubles with money management" were the most frequent problems of dementia patients.

CONCLUSIONS

Several problems are already sometimes encountered in patients with mild cognitive impairment. It would be useful to know which social difficulties are often seen in dementia patients in order to protect the safety of the patients. It is always difficult to balance respecting the autonomy of dementia patients and ensuring their safely. Geriatr Gerontol Int 2019; 19: 113-118.

A simplified and sensitive method to identify Alzheimer's disease biomarker candidates using patient-derived induced pluripotent stem cells (iPSCs)

We developed a simplified and sensitive method to identify Alzheimer's disease (AD) biomarker candidates by a quantitative and targeted proteomic analysis (combination of liquid chromatography tandem mass spectrometry and multiplexed-multiple reaction monitoring/selected reaction monitoring analysis) of culture media from neurons differentiated from induced pluripotent stem cells (iPSCs) established from AD patients. We found that alpha-1-acid glycoprotein (ORM1) was decreased in the culture media of AD-iPSC-derived neurons, consistent with previous observations for AD patient cerebrospinal fluid, thus validating our new strategy. Moreover, our method is applicable for identifying biomarker candidates for other neurodegenerative disorders using patient-derived iPSCs.

A second pedigree with amyloid-less familial Alzheimer's disease harboring an identical mutation in the amyloid precursor protein gene (E693delta)

A 59-year-old woman developed early-onset, slowly progressive dementia and spastic paraplegia. positron emission tomography (PET) imaging revealed a large reduction in the level of glucose uptake without amyloid deposition in the cerebral cortex. We identified a homozygous microdeletion within the amyloid β (Aβ) coding sequence in the amyloid precursor protein (APP) gene (c.2080_2082delGAA, p.E693del) in three affected siblings and a heterozygous microdeletion in an unaffected sibling. The identical mutation was previously reported in the first Alzheimer's pedigree without amyloid deposits. Furthermore, an increase in high-molecular-weight Aβ-reactive bands was detected in the patient's CSF. Our findings suggest that soluble Aβ-oligomers induce neuronal toxicity, independent of insoluble Aβ fibrils.

Modeling Alzheimer's disease with iPSCs reveals stress phenotypes associated with intracellular Aβ and differential drug responsiveness

Oligomeric forms of amyloid-β peptide (Aβ) are thought to play a pivotal role in the pathogenesis of Alzheimer's disease (AD), but the mechanism involved is still unclear. Here, we generated induced pluripotent stem cells (iPSCs) from familial and sporadic AD patients and differentiated them into neural cells. Aβ oligomers accumulated in iPSC-derived neurons and astrocytes in cells from patients with a familial amyloid precursor protein (APP)-E693Δ mutation and sporadic AD, leading to endoplasmic reticulum (ER) and oxidative stress. The accumulated Aβ oligomers were not proteolytically resistant, and docosahexaenoic acid (DHA) treatment alleviated the stress responses in the AD neural cells. Differential manifestation of ER stress and DHA responsiveness may help explain variable clinical results obtained with the use of DHA treatment and suggests that DHA may in fact be effective for a subset of patients. It also illustrates how patient-specific iPSCs can be useful for analyzing AD pathogenesis and evaluating drugs.

[FTDP-17 presenting amnestic MCI as an initial symptom: case report]

A 46-year-old woman was admitted to our hospital for examination of her amnesia. Psychiatric examinations revealed that her recent memory was moderately disturbed despite well-preserved general cognitive function. Brain MRI and I-IMP SPECT (eZIS) revealed mild brain atrophy and hypoperfusion localized to the hippocampus, superior parietal lobule, and posterior cingulate gyrus. She was diagnosed with amnestic MCI at that time. However, five years later, she developed personality changes, parkinsonism and dementia. Investigation of her family medical history revealed that the patient's two sisters are demented and under the medical care. DNA analysis revealed an intronic mutation IVS10 C>T in the MAPT gene. Although her two sisters also have the same mutation, her elder sister has typical FTD without parkinsonism. Approximately 10% of patients with amnestic MCI develop Alzheimer's disease each year. Thus, amnestic MCI has been usually considered to be an early stage of Alzheimer's disease. Interestingly our patient having a MAPT gene mutation started to develop amnestic MCI as an initial symptom. Therefore because of the diversity in early clinical features of FTDP-17, aggressive DNA analysis is necessary for accurate diagnosis.

Dramatic response of dropped head sign to treatment with steroid in Parkinson's disease: report of three cases

Neck dystonia is the most common cause of dropped head sign in parkinsonism. Isolated neck extensor myopathy, which is a rare condition, can also cause dropped head sign in parkinsonism, but no improvement has been achieved with immunosuppressive therapy. We report three cases of treatable neck extensor myopathy causing dropped head sign in patients with Parkinson's disease. Needle electromyography and magnetic resonance imaging suggested a restrictive active myopathy affecting neck extensor muscles. All cases responded dramatically to steroid therapy. Routine needle electromyography should be performed to explore treatable myopathy in Parkinson's disease.

[Case of chronic progressive encephalo-myelo-radiculo-neuropathy]

A 65-year-old man developed urinary impairment and gait disturbance over a period of four months. On admission, neurological examinations revealed paraplegia, decreased deep tendon reflexes in the extremities, bilateral positive Babinski and Chaddock signs, superficial and deep sensory disturbances and neurogenic bladder. Cerebrospinal fluid examination disclosed a total cell count of 70/mm3, and protein of 76 mg/dl. Nerve conduction studies and somatosensory evoked potential suggested demyelinating neuropathy and myelopathy. Brain MRI revealed irregular-shaped white matter lesions distributed over the bilateral cerebral hemispheres and the brain stem. In addition spinal MRI disclosed long spinal cord lesions disseminated from the higher cervical to the lower thoracic spine. A 1 microm-thick epon-embedded section and teased fiber preparations of a biopsied sural nerve showed segmental demyelination and remyelination. Treatments using intravenous methylprednisolone and IVIg were both effective. The positive responses to immunological treatment, along with the findings, strongly suggested that the demyelinating lesions occurred in both the central and peripheral nervous systems. We regarded this case as one of chronic progression of Encephalo-myelo-radiculo-neuropathy.

[A case of Castleman disease accompanying neuropathy only detected by S-SEP in the tibial nerve]

A 77-year-old woman was admitted with a chief complaint of tingling sensation in the both feet, which gradually developed just after the diagnosis of Castleman disease was made. Neurological examination showed mild weakness in the neck and pelvic girdle muscles, and sensory impairment affecting all modalities in the lower legs. Although these neurological findings suggest a diagnosis of neuropathy, nerve conduction studies (NCS) and F-wave disclosed no abnormalities. However, the short latency somatosensory evoked potential (S-SEP) in the tibial nerve revealed a significant delay in the P15 latency, which is indicative of neuropathy affecting proximal potion of the peripheral nerve. To our knowledge, only a few reports described proximal neuropathy associated with Castleman disease. In our case, the examination of S-SEP was very informative to make a diagnosis of neuropathy.

[Two brothers with very late onset of muscle weakness in X-linked recessive spinal and bulbar muscular atrophy]

Spinal and bulbar muscular atrophy (SBMA) is a motor neuron disease characterized by slowly progressive spinal and bulbar muscular atrophy associated with signs of androgen insensitivity including gynecomastia. This disease becomes prominent clinically in the fourth and fifth decades of life. Mutations of the androgen receptor (AR) gene associated with an expansion of CAG repeats is the cause of this disease. Here we report a unique family case in two brothers with SBMA with very late onset of muscular weakness. Motor functional symptoms in the two brothers developed at the ages of 66 and 78 years. The number of CAG repeats in the AR gene in both patients was 42. According to previous reports, the number of CAG repeats is related to the age at onset of muscular weakness. Our patient's conditions were consistent with this concept as there was a short expansion of 42 CAG repeats linked to the clinical phenotype of very late onset of muscular weakness. However, the issue of whether the number of CAG repeats is related to the age at onset of androgen insensitivity is still controversial. In the younger brother, gynecomastia appeared in his 20's and preceded the development of muscular weakness by about 40 years, whereas the gynecomastia in the older brother was unremarkable throughout his life. Our brother cases, which had the same number of CAG repeats and should share many common genetic factors, exhibited the androgen insensitivity differed. We therefore consider that an expansion of CAG repeats in the AR gene is not necessarily related to the age at onset of androgen insensitivity. In conclusion, the etiologies of muscular weakness and androgen insensitivity in SBMA could be different.

[A case of combined sensation disturbance and clumsiness of the left hand caused by an infarction localized to brodmann areas 1 and 2]

A 70-year-old woman was admitted to our hospital with a complaint of numbness and clumsiness of the left hand. On physical examination 23 days after the onset of cerebral infarction, she showed no apparent muscle weakness. Although her elementary somatosensory function was mostly intact with a minimal joint position sensation disturbance, she showed disturbances in tactile recognition, two-point discrimination, and weight perception. She also had difficulty in discrete finger movement of her left hand, especially when her eyes were closed. Brain MRI disclosed a small infarction localized to Brodmann areas 1 and 2 in the right postcentral gyrus. In the left median nerve short-latency somatosensory evoked potentials (s-SEPs), the N20 potential was normally evoked. This finding also indicated that the area 3b was preserved. The sensory symptoms observed in this patient were compatible with the hierarchical somatosensory processing model in the postcentral gyrus proposed by Iwamura et al, in which the elementary sensation recognized in area 3 is transferred to areas 1 and 2, and then processed to discriminative sensation. The disturbed discrete finger movement in this patient probably resulted from impaired tactile recognition which could be compensated for by visual information.