NESSCA Validation and Responsiveness of Several Rating Scales in Spinocerebellar Ataxia Type 2

Spinocerebellar ataxia type 2 (SCA2), caused by a CAG expansion (CAGexp) at ATXN2, has a complex clinical picture. While validated ataxia scales are available, comprehensive instruments to measure all SCA2 neurological manifestations are required. This study aims to validate the Neurological Examination Score for the assessment of Spinocerebellar Ataxias (NESSCA) to be used in SCA2 and to compare its responsiveness to those obtained with other instruments. NESSCA, SARA, SCAFI, and CCFS scales were applied in symptomatic SCA2 patients. Correlations were done with age at onset, disease duration, CAGexp, and between scales. Responsiveness was estimated by comparing deltas of stable to worse patients after 12 months, according to Patient Global Impression of change, and the area under the curve (AUC) of the Receiver Operating Characteristics curve of scores range. Eighty-eight evaluations (49 patients) were obtained. NESSCA had an even distribution and correlated with disease duration (r = 0.55), SARA (r = 0.63), and CAGexp (rho = 0.32): both explained 44% of NESSCA variance. Deltas (95% CI) after 1 year in stable and worse patients were only significantly different for SARA. NESSCA, SARA, SCAFI, and CCFS AUC were 0.63, 0.81, 0.49, and 0.48, respectively. NESSCA is valid to be used in SCA2. However, the only instrument that presented good responsiveness to change in 1 year was SARA. We suggest that NESSCA can be used as a secondary outcome in future trials in SCA2 due to the burden of neurological disabilities related to disease progression.

Corrigendum: Long-term NMDAR antagonism correlates reduced astrocytic glutamate uptake with anxiety-like phenotype

[This corrects the article on p. 219 in vol. 9, PMID: 26089779.].

Genetic aspects of Huntington's disease in Latin America. A systematic review

We aimed to present a systematic review on Huntington's disease (HD) in Latin America (LA). PubMed and LILACS were searched up to March 2015, reporting confirmed HD cases in LA. Case series, cross-sectional, case-control, and prospective studies were included. From 534 communications, 47 were eligible. Population-based studies were not found; minimal prevalence of 0.5-4/100,000 was estimated for Venezuela and Mexico. Geographical isolates were well characterized in Venezuela and in Peru. CAG repeats at HTT gene varied between 7-33 and 37-112 in normal and expanded alleles, respectively. Intermediate alleles were found in 4-10% of controls. Ages at onset and the expanded CAG repeats correlated with r from - 0.55 to -0.91. While haplotype patterns of Venezuelan and Brazilian chromosomes were similar to those observed in Europeans, haplotypes from Peruvian HD patients did not match the same pattern. The limited number of papers found suggests that HD is poorly diagnosed in LA. Minimal prevalence seemed to be halfway between those of Caucasians and Asians. Range of CAG repeats was similar to those of Europeans. Haplotype studies indicate that majority of HD patients might be of Caucasian descent; an Asian origin for some Peruvian patients was proposed.

Long-term NMDAR antagonism correlates reduced astrocytic glutamate uptake with anxiety-like phenotype

The role of glutamate N-methyl-D-aspartate receptor (NMDAR) hypofunction has been extensively studied in schizophrenia; however, less is known about its role in anxiety disorders. Recently, it was demonstrated that astrocytic GLT-1 blockade leads to an anxiety-like phenotype. Although astrocytes are capable of modulating NMDAR activity through glutamate uptake transporters, the relationship between astrocytic glutamate uptake and the development of an anxiety phenotype remains poorly explored. Here, we aimed to investigative whether long-term antagonism of NMDAR impacts anxiety-related behaviors and astrocytic glutamate uptake. Memantine, an NMDAR antagonist, was administered daily for 24 days to healthy adult CF-1 mice by oral gavage at doses of 5, 10, or 20 mg/kg. The mice were submitted to a sequential battery of behavioral tests (open field, light–dark box and elevated plus-maze tests). We then evaluated glutamate uptake activity and the immunocontents of glutamate transporters in the frontoparietal cortex and hippocampus. Our results demonstrated that long-term administration of memantine induces anxiety-like behavior in mice in the light–dark box and elevated plus-maze paradigms. Additionally, the administration of memantine decreased glutamate uptake activity in both the frontoparietal cortex and hippocampus without altering the immunocontent of either GLT-1 or GLAST. Remarkably, the memantine-induced reduction in glutamate uptake was correlated with enhancement of an anxiety-like phenotype. In conclusion, long-term NMDAR antagonism with memantine induces anxiety-like behavior that is associated with reduced glutamate uptake activity but that is not dependent on GLT-1 or GLAST protein expression. Our study suggests that NMDAR and glutamate uptake hypofunction may contribute to the development of conditions that fall within the category of anxiety disorders.

Clinical Scales Predict Significant Videofluoroscopic Dysphagia in Machado Joseph Disease Patients

Background

Although aspiration is one of the main causes of death in SCA, such as SCA3/Machado Joseph disease (SCA3/MJD), clinical studies on dysphagia are lacking for these diseases. The aims of this study were to characterize dysphagia in SCA3/MJD through videofluoroscopy (VF) of swallowing, correlate VF with disease severity criteria and weight loss, and determine the clinical criteria cutoffs for performing VF in the clinical routine, in order to detect aspiration.

Methods

A cross-sectional study on 34 SCA3/MJD patients was performed. Clinical and molecular data, as well as body mass index (BMI), were obtained. Neurological scales, such as the Scale for the Assessment and Rating of Ataxia (SARA), and the Swallowing Quality of Life (SWAL-QOL) questionnaire were applied. The VF scores, Dysphagia Outcome and Severity Scale (DOSS) and penetration/aspiration scale (PAS), were obtained: Moderate-to-severe scores were grouped as "significant dysphagia."

Results

Overall, 31 of 34 individuals showed abnormal scores at VF. SARA, BMI, and the domain "eating duration" of SWAL-QOL correlated with VF: Their relation to significant dysphagia (DOSS <4 points or PAS >3) was evaluated through receiver operating characteristic curves. A sensitivity of 100% was equivalent to a cutoff of 15 points on SARA score, 23.72 kg/m² on BMI, and 60% on eating duration-SWAL-QOL (P < 0.05).

Conclusion

Significant dysphagia was not related to age at onset, disease duration, or CAG repeat expansion, but with SARA scores, lower BMI, and the domain eating duration of SWAL-QOL. As a guideline for preventing aspiration, we suggest that SARA scores greater than 15 or eating duration-SWAL-QOL lower than 60% should urge VF studies in SCA3/MJD.

The influence of different concentrations of melatonin on the cell surface hydrophobic characteristics of Neisseria meningitidis

The cell surface hydrophobicity of micro-organisms is a characteristic that has been associated with the colonization of mammalian epithelia and with their capacity to induce diseases. Melatonin is a hormone produced by the pineal gland that affects the immune response mechanism. This study investigated, as an expression of the virulence of Neisseria meningitidis, how its hydrophobic characteristics were affected by exposure to increasing concentrations of melatonin. An increase in the cell surface hydrophobicity of N. meningitidis was found at concentrations of 1 mmol l(-1), while lower concentrations of melatonin did not significantly affect this particular cell surface characteristic of the micro-organism. It may be concluded that melatonin clearly influences the cell surface hydrophobicity of N. meningitidis, a circumstance that should be taken into account in future studies to determine whether this hormone plays a role in the variable pathogenicity of the bacteria in different hosts.