Comparison of REM sleep behaviour disorder variables between patients with progressive supranuclear palsy and those with Parkinson's disease

PurposeRapid eye movement (REM) sleep behaviour disorder (RBD) is an important indicator of underlying synucleinopathies. However, the frequency of RBD in tauopathies such as progressive supranuclear palsy (PSP) remains unclear. In this study, we compared RBD-related symptoms and polysomnographic (PSG) findings between patients with PSP and those with Parkinson’s disease (PD).MethodsWe conducted clinical interviews of 20 patients with PSP, 93 patients with PD and their caregivers regarding RBD-related symptoms, and conducted PSG recordings on all the subject patients. We then compared the clinical backgrounds, PSG parameters, and frequency of RBD-related symptoms between the two groups.ResultsPSP patients had more severe symptoms of Parkinsonism and cognitive impairment, and took lower doses of dopaminergic agents compared with PD patients. The PSP group had lower values for both estimated total sleep time and sleep efficiency on PSG compared with the PD group (p = 0.002, p = 0.021, respectively). The PSP group also included a significantly smaller number of patients having REM sleep without atonia (RWA) compared with the PD group (n = 5, 20.0% vs. n = 56, 60.2%, p = 0.003). None of the PSP patients were experiencing RBD-related symptoms at the time of the investigation, while 30 PD patients (32.3%) had RBD-related symptoms.DiscussionThe existence of RWA as well as RBD-related symptoms was less frequent in patients with PSP versus patients with PD. Differences in brain stem pathology and/or disease course between the two disorders might influence this difference.     

Segregated pathways carrying frontally derived top-down signals to visual areas MT and V4 in macaques

The bottom-up processing of visual information is strongly influenced by top-down signals, at least part of which is thought to be conveyed from the frontal cortex through the frontal eye field (FEF) and the lateral intraparietal area (LIP). Here we investigated the architecture of multisynaptic pathways from the frontal cortex to the middle temporal area (MT) of the dorsal visual stream and visual area 4 (V4) of the ventral visual stream in macaques. In the first series of experiments, the retrograde trans-synaptic tracer, rabies virus, was injected into MT or V4. Three days after rabies injections, the second-order (disynaptically connected) neuron labeling appeared in the ventral part of area 46 (area 46v), along with the first-order (monosynaptically connected) neuron labeling in FEF and LIP. In the MT-injection case, second-order neurons were also observed in the supplementary eye field (SEF). In the next series of experiments, double injections of two fluorescent dyes, fast blue and diamidino yellow, were made into MT and V4 to examine whether the frontal inputs are mediated by distinct or common neuronal populations. Virtually no double-labeled neurons were observed in FEF or LIP, indicating that separate neuronal populations mediate the frontal inputs to MT and V4. The present results define that the multisynaptic frontal input to V4 arises primarily from area 46v, whereas the input to MT arises from not only area 46v but also SEF, through distinct FEF and LIP neurons. Segregated pathways from the frontal cortex possibly carry the functionally diverse top-down signals to each visual stream.     

发作期宽频脑电技术精确定位致痫灶

癫痫外科术前评估的目的就是尽可能地找到或无限接近于致痫灶(epileptogenic zone,EZ),然而致病灶却是一个理论上的概念,手术切除的是否为真正的致痫灶,目前还只能靠术后随访患者能否获得完全的临床缓解来予以证实.所以,在癫痫外科的术前评估中我们会尽量用由发作期脑电、发作期SPECT、fMRI和肌电图等手段确定的发作起始区(seizure-onset zone,SOZ)来无限接近致痫灶[1].     

Five‐year efficacy of finasteride in 801 Japanese men with androgenetic alopecia

Finasteride is standard medical treatment for androgenetic alopecia; however, no large studies with 5 years or more of follow up have been performed in Japan. The authors followed Japanese men with androgenetic alopecia treated with finasteride for 5 years to evaluate long‐term treatment efficacy. Of 903 men treated with finasteride (1 mg/day), 801 patients were evaluated over 5 years by modified global photographic assessment. Although the proportion of improvement was high (99.4%), modified global photographic assessment scores after 5 years of treatment were lower in patients with more advanced disease as measured by the modified Norwood–Hamilton scale. After separating patients into “sufficient” and “insufficient” efficacy groups according to the modified global photographic assessment score after 5 years (scores ≥6 and <6, respectively), multivariate analysis showed that independent risk factors of insufficient efficacy were age at start of treatment of 40 years or more (P = 0.021) and classification on the modified Norwood–Hamilton scale (P < 0.001), whereas presence of stress at start of treatment was a negative predictor (P = 0.025). In conclusion, continuous finasteride treatment for 5 years improved androgenetic alopecia with sustained effect among Japanese. Younger age and less advanced disease at start of treatment were the key predictors of higher finasteride efficacy.     

Very high frequency oscillations (over 1000 Hz) in human epilepsy

Objective

High frequency oscillations (HFO) of 100–500 Hz have been reported in epileptic human brain. However, the questions of how fast these oscillations can reach, and which frequency range is clinically important remain unanswered. We recorded interictal and ictal very high frequency oscillations (VHFO) of 1000–2500 Hz by subdural electrodes using 10 kHz sampling rate. We describe the characteristics of VHFO, and discuss their underlying mechanism and clinical significance.

Methods

Five patients with neocortical epilepsy were studied. All patients underwent intracranial EEG monitoring with subdural electrodes. EEG recording with sampling rate of 10 kHz was conducted. Histopathology revealed malformation of cortical development in all cases.

Results

In four of five patients, very high frequency activities of 1000–2500 Hz were detected in highly localized cortical regions (one to four electrodes in individual patient). We named these activities “very high frequency oscillations (VHFO)”. Interictally, VHFO appeared intermittently, and were interrupted by spikes. Sustained VHFO without spikes appeared around the start of seizures.

Conclusions

Both interictal and ictal VHFO can be recorded by subdural electrodes. Compared to HFO previously reported, VHFO have much higher frequency, more restricted distribution, smaller amplitude, and different timing of onset.

Significance

Recording of VHFO may be useful for identifying the epileptogenic zone.     

Pesticides in Water and Sediment from Littoral Area of Lake Biwa

A survey of 29 pesticides was performed for water and sediment from two littoral areas of Lake Biwa in 2007. Two insecticides, 5 fungicides and 13 herbicides in the water and an insecticide, 4 fungicides and 7 herbicides in the sediment were detected from the present survey. Pesticide accumulation potential in the sediment was calculated as “Pesticide concentration ratio” from the results of the survey on water and sediment in Lake Biwa. Correlation was investigated for each of the detected pesticides between sediment ignition loss and pesticide concentration ratio or between sediment particle size and pesticide concentration ratio. The ignition loss correlated well with the pesticide concentration ratio for pyrokiron, simetryn, and isoprothiolane (p < 0.01 to p < 0.001) but did not for molinate, bromobutide and pretilachlor. Further, the <0.025 mm particle size ratio correlated well with the pesticide concentration ratio for pyrokiron, simetryn, flutolanil, isoprothiolane and mefenacet (p < 0.01 to p < 0.001) but did not for bromobutide and pretilachlor. The correlation between <0.025 mm particle size ratio and pesticide concentration ratio had almost the same tendency as that between ignition loss and pesticide concentration ratio, suggesting sediment with higher <0.025 mm particle size ratio had higher weight (%) of ignition loss.     

Use of monoclonal antibodies as an effective strategy for treatment of ciguatera poisoning

Ciguatera is a global food poisoning caused by the consumption of fish that have accumulated sodium channel activator toxins, ciguatoxins. At present, most diagnosed cases of ciguatera are treated with symptomatic and supportive remedies, and no specific therapy has been devised. Here we report that ciguatoxin CTX3C can be effectively neutralized in vitro and in vivo by simultaneous use of two anti-ciguatoxin monoclonal antibodies, providing the first rational approach toward directly preventing and treating ciguatera.     

Dietary catechol causes increased oxidative DNA damage in the livers of mice treated with acetaminophen

We have shown that direct reaction of catechol with nitric oxide (NO) results in generation of reactive oxygen and nitrogen species (RNS) through semiquinone radical formation, leading to oxidative DNA damage in rat forestomach. In the present study, we investigated whether dietary catechol systemically exerts the same effects under NO-rich circumstances, when given before and during induction of inflammatory lesions. Male ICR mice were treated with or without 0.8% catechol in the diet for 2 weeks followed by acetaminophen (APAP) administration at a dose of 300 mg/kg by single i.p. injection. Along with several indicators of APAP-induced hepatitis, 8-hydroxydeoxyguanosine (8-OHdG) levels and immunohistochemistry for 3-nitrotyrosine (NO₂Tyr) in the livers were examined at 1.5, 4 and 24 h after APAP injection. 8-OHdG was significantly increased at 24 h in the co-treatment group, but not with either catechol or APAP alone. Elevation of serum ALT and AST activities, decrease of reduced glutathione levels and histopathological liver changes were observed to the same extents in both APAP-treated groups. In view of the finding of positive hepatocytes for NO₂Tyr prior to generation of 8-OHdG, the process of oxidative DNA damage might involve RNS formation. Precise quantitative analysis of NO₂Tyr by means of liquid chromatography with tandem mass spectrometry (LC-MS/MS) in an additional study with the same experimental protocol confirmed increase of RNS due to the reaction of catechol with NO produced after APAP-induced hepatitis. The overall data imply that antioxidants with a catechol structure can cause oxidative DNA damage under inflammatory conditions.