Clinical presentations and diagnostic application of proposed biomarkers in psychiatric-onset prodromal dementia with Lewy bodies.

Research criteria for the diagnosis of prodromal dementia with Lewy bodies (DLB) include three clinical subtypes: mild cognitive impairment with Lewy bodies (MCI-LB), delirium-onset prodromal DLB, and psychiatric-onset prodromal DLB. Late-onset psychiatric manifestations are at a higher risk of developing dementia, but its relation to prodromal DLB remains unclear. In addition to the risk of severe antipsychotic hypersensitivity reactions, accurate discrimination from non-DLB cases is important due to the potential differences in management and prognosis. This article aims to review a rapidly evolving psychiatric topic and outline clinical pictures of psychiatric-onset prodromal DLB, including the proposed biomarker findings of MCI-LB: polysomnography-confirmed rapid eye movement sleep behaviour disorder, cardiac [123I]metaiodobenzylguanidine scintigraphy, and striatal dopamine transporter imaging. We first reviewed clinical pictures of patients with autopsy-confirmed DLB. Regarding clinical reports, we focused on the patients who predominantly presented with psychiatric manifestations and subsequently developed DLB. Thereafter, we reviewed clinical studies regarding the diagnostic applications of the proposed biomarkers to patients with late-onset psychiatric disorders. Clinical presentations were mainly late-onset depression and psychosis; however, other clinical manifestations were also reported. Psychotropic medications before a DLB diagnosis may cause extrapyramidal signs, and potentially influences the proposed biomarker findings. These risks complicate clinical manifestation interpretation during the management of psychiatric symptoms. Longitudinal follow-up studies with standardised evaluations until conversion to DLB are needed to investigate the temporal trajectories of core features and proposed biomarker findings. In patients with late-onset psychiatric disorders, identification of patients with psychiatric-onset prodromal DLB provides the opportunity to better understanding the distinct prognostic subgroup that is at great risk of incident dementia. Advances in the establishment of direct biomarkers for the detection of pathological α-synuclein may encourage reorganising the phenotypic variability of prodromal DLB.

Stress-impaired reward pathway promotes distinct feeding behavior patterns.

Although dietary behaviors are affected by neuropsychiatric disorders, various environmental conditions can have strong effects as well. We found that mice under multiple stresses, including social isolation, intermittent high-fat diet, and physical restraint, developed feeding behavior patterns characterized by a deviated bait approach (fixated feeding). All the tested stressors affected dopamine release at the nucleus accumbens (NAcc) shell and dopamine normalization reversed the feeding defects. Moreover, inhibition of dopaminergic activity in the ventral tegmental area that projects into the NAcc shell caused similar feeding pattern aberrations. Given that the deviations were not consistently accompanied by changes in the amount consumed or metabolic factors, the alterations in feeding behaviors likely reflect perturbations to a critical stress-associated pathway in the mesolimbic dopamine system. Thus, deviations in feeding behavior patterns that reflect reward system abnormalities can be sensitive biomarkers of psychosocial and physical stress.

Aberrant interaction between FUS and SFPQ in neurons in a wide range of FTLD spectrum diseases.

Fused in sarcoma (FUS) is genetically and clinicopathologically linked to frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). We have previously reported that intranuclear interactions of FUS and splicing factor, proline- and glutamine-rich (SFPQ) contribute to neuronal homeostasis. Disruption of the FUS-SFPQ interaction leads to an increase in the ratio of 4-repeat tau (4R-tau)/3-repeat tau (3R-tau), which manifests in FTLD-like phenotypes in mice. Here, we examined FUS-SFPQ interactions in 142 autopsied individuals with FUS-related ALS/FTLD (ALS/FTLD-FUS), TDP-43-related ALS/FTLD (ALS/FTLD-TDP), progressive supranuclear palsy, corticobasal degeneration, Alzheimer's disease, or Pick's disease as well as controls. Immunofluorescent imaging showed impaired intranuclear co-localization of FUS and SFPQ in neurons of ALS/FTLD-FUS, ALS/FTLD-TDP, progressive supranuclear palsy and corticobasal degeneration cases, but not in Alzheimer's disease or Pick's disease cases. Immunoprecipitation analyses of FUS and SFPQ revealed reduced interactions between the two proteins in ALS/FTLD-TDP and progressive supranuclear palsy cases, but not in those with Alzheimer disease. Furthermore, the ratio of 4R/3R-tau was elevated in cases with ALS/FTLD-TDP and progressive supranuclear palsy, but was largely unaffected in cases with Alzheimer disease. We concluded that impaired interactions between intranuclear FUS and SFPQ and the subsequent increase in the ratio of 4R/3R-tau constitute a common pathogenesis pathway in FTLD spectrum diseases.

Silencing of FUS in the common marmoset (Callithrix jacchus) brain via stereotaxic injection of an adeno-associated virus encoding shRNA.

Fused in sarcoma (FUS) is an RNA binding protein that is involved in frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). To establish the common marmoset (Callithrix jacchus) as a model for FTLD, we generated a stereotaxic injection-based marmoset model of FUS-silencing. We designed shRNAs against the marmoset FUS gene and generated an AAV9 virus encoding the most effective shRNA against FUS (shFUS). The AAV encoding shFUS (AAV-shFUS) was introduced into the frontal cortex of young adult marmosets, whereas AAV encoding a control shRNA was injected into the contralateral side. We obtained approximately 70-80% silencing of FUS following AAV-shFUS injection. Interestingly, FUS-silencing provoked a proliferation of astrocytes and microglias. Since FTLD is characterized by various emotional deficits, it would be helpful to establish a marmoset model of FUS-silencing in various brain tissues for investigating the pathomechanism of higher cognitive and behavioral dysfunction.

Altered Tau Isoform Ratio Caused by Loss of FUS and SFPQ Function Leads to FTLD-like Phenotypes.

Fused in sarcoma (FUS) and splicing factor, proline- and glutamine-rich (SFPQ) are RNA binding proteins that regulate RNA metabolism. We found that alternative splicing of the Mapt gene at exon 10, which generates 4-repeat tau (4R-T) and 3-repeat tau (3R-T), is regulated by interactions between FUS and SFPQ in the nuclei of neurons. Hippocampus-specific FUS- or SFPQ-knockdown mice exhibit frontotemporal lobar degeneration (FTLD)-like behaviors, reduced adult neurogenesis, accumulation of phosphorylated tau, and hippocampal atrophy with neuronal loss through an increased 4R-T/3R-T ratio. Normalization of this increased ratio by 4R-T-specific silencing results in recovery of the normal phenotype. These findings suggest a biological link among FUS/SFPQ, tau isoform alteration, and phenotypic expression, which may function in the early pathomechanism of FTLD.

Active brain changes after initiating fingolimod therapy in multiple sclerosis patients using individual voxel-based analyses for diffusion tensor imaging.

Voxel-based analysis (VBA) of diffusion tensor images (DTI) and voxel-based morphometry (VBM) in patients with multiple sclerosis (MS) can sensitively detect occult tissue damage that underlies pathological changes in the brain. In the present study, both at the start of fingolimod and post-four months clinical remission, we assessed four patients with MS who were evaluated with VBA of DTI, VBM, and fluid-attenuated inversion recovery (FLAIR). DTI images for all four patients showed widespread areas of increased mean diffusivity (MD) and decreased fractional anisotropy (FA) that were beyond the high-intensity signal areas across images. After four months of continuous fingolimod therapy, DTI abnormalities progressed; in particular, MD was significantly increased, while brain volume and high-intensity signals were unchanged. These findings suggest that VBA of DTI (e.g., MD) may help assess MS demyelination as neuroinflammatory conditions, even though clinical manifestations of MS appear to be in complete remission during fingolimod.

Content analysis of medical students' seminars: a unique method of analyzing clinical thinking.

BACKGROUND: The study of communication skills of Asian medical students during structured Problem-based Learning (PBL) seminars represented a unique opportunity to assess their critical thinking development. This study reports the first application of the health education technology, content analysis (CA), to a Japanese web-based seminar (webinar). METHODS: The authors assigned twelve randomly selected medical students from two universities and two clinical instructors to two virtual classrooms for four PBL structured tutoring sessions that were audio-video captured for CA. Both of the instructors were US-trained physicians. This analysis consisted of coding the students' verbal comments into seven types, ranging from trivial to advanced knowledge integration comments that served as a proxy for clinical thinking. RESULTS: The most basic level of verbal simple responses accounted for a majority (85%) of the total students' verbal comments. Only 15% of the students' comments represented more advanced types of critical thinking. The male students responded more than the female students; male students attending University 2 responded more than male students from University 1. The total mean students' verbal response time for the four sessions with the male instructor was 6.9%; total mean students' verbal response time for the four sessions with the female instructor was 19% (p < 0.05). CONCLUSIONS: This report is the first to describe the application of CA to a multi-university real time audio and video PBL medical student clinical training webinar in two Japanese medical schools. These results are preliminary, mostly limited by a small sample size (n = 12) and limited time frame (four sessions). CA technology has the potential to improve clinical thinking for medical students. This report may stimulate improvements for implementation.

[An adult Guillain-Barré syndrome patient with enhancement of anterior roots on spinal MRI and severe radicular pain relieved by intravenous methylprednisolone pulse therapy: A case report].

A 37-year-old man was admitted to our hospital because of progressive abnormal gait and severe pain in the low back and lower extremities, more severe on the right side, especially in his right posterior thigh. The pain appeared one week after he suffered from slight fever and diarrhea. On admission, a neurological examination revealed mild distal weakness of the all extremities and loss of Achilles tendon reflex, associated with positive Lasègue sign. However, sensation was intact except for slightly impaired vibratory sensation on the trunk. An electrophysiological study showed diminished amplitude of compound muscle action potential and loss of F-wave of the posterior tibial nerves. Finding of cerebrospinal fluid was normal at the time of admission, although 12 days later albuminocytologic dissociation was found. Cervical and lumbar magnetic resonance images showed gadolinium enhancement of the anterior nerve roots and the cauda equina, more prominent on the right side, correlating with the prominent side of the patient's leg pain. Because of neurological features, electrophysiological abnormalities and CSF findings, we diagnosed his illness as Guillain-Barré syndrome (GBS) characterized by severe back and leg pain. The character of pain was deep and aching, suggesting myalgic pain caused by the affected anterior roots. A short course high-dose intravenous immunoglobulin (IVIg) therapy was not effective against the radicular pain although minimal improvement of limb weakness occurred. Non-steroidal anti-inflammatory drugs and carbamazepine were unsuccessful for pain relief. Thereafter, intravenous methylprednisolone (IVMP) pulse therapy was introduced. On the day IVMP pulse therapy started, severe radicular pain began to decrease and became gradually milder without any marked effect on the other symptoms and signs of GBS.Moderate to severe pain is a common and early symptom of GBS and requires aggressive treatment. IVMP pulse therapy may be one of treatments for refractory and intolerable pain of GBS.

Effect of tamsulosin on bladder microcirculation in rat model of bladder outlet obstruction using pencil lens charge-coupled device microscopy system.

OBJECTIVE: To determine the effect of tamsulosin hydrochloride on blood flow in the submucosal capillaries of the bladder (SCB) in a rat model of bladder outlet obstruction (BOO) using a pencil lens charge-coupled device microscopy system. MATERIALS AND METHODS: BOO was established in rats by partial ligature of the proximal urethra and was maintained for 2 weeks. Tamsulosin or saline (control) was subcutaneously administered using an osmotic pump for 2 weeks immediately after surgery. The pencil lens charge-coupled device microscopy system was used to visualize the bladder microcirculation and quantitatively assess the blood flow in the SCB by measuring the velocity of the blood flow at the base and dome of the bladder. The blood flow in the SCB of the sham-operated rats, control BOO rats, and tamsulosin-treated BOO rats was compared. RESULTS: The blood flow in the SCB was significantly greater at the base than at the dome of the bladder. The reduction in blood flow through the SCB at the base and dome of the bladder was more significant in the BOO rats than in the sham-operated rats. However, after pretreatment with tamsulosin, the BOO rats showed a significant increase in blood flow through the SCB at the base and dome of the bladder compared with that of the control rats. The pencil lens charge-coupled device microscopy system image showed that the BOO rats had chronic ischemic capillary injury, which was ameliorated by tamsulosin. CONCLUSION: The results of the present study suggest that tamsulosin hydrochloride protects the SCB from ischemic injury after BOO.