Rachelle Dar Santos

Prevention of depressive behaviour in the YAC128 mouse model of Huntington disease by mutation at residue 586 of huntingtin

Huntington disease is a neurodegenerative disorder caused by an expanded CAG repeat in the Huntington disease gene. The symptomatic phase of the disease is defined by the onset of motor symptoms. However, psychiatric disturbances, including depression, are common features of Huntington disease and recent studies indicate that depression can occur long before the manifestation of motor symptoms. The aetiology of depression in Huntington disease is not fully understood and psychosocial factors such as the knowledge of carrying a mutation for an incurable disease or adverse social circumstances may contribute to its presentation. Due to the difficulties in discriminating between social and biological factors as contributors to depression in clinical Huntington disease, we chose to assess whether a model for Huntington disease not subject to environmental stressors, namely the YAC mouse model of Huntington disease, displays a depressive phenotype. Indeed, the YAC transgenic mice recapitulate the early depressive phenotype of Huntington disease as assessed by the Porsolt forced swim test as well as the sucrose intake test as a measure of anhedonia. The YAC model mirrors clinical Huntington disease in that there were no effects of CAG repeat length or disease duration on the depressive phenotype. The depressive phenotype was completely rescued in YAC transgenic animals expressing a variant of mutant huntingtin that is resistant to cleavage at amino acid 586 suggesting that therapies aimed towards inhibition of huntingtin cleavage are also likely to have beneficial effects on this aspect of the disease. In conclusion, our study provides strong support for a primary neurobiological basis for depression in Huntington disease.

Evaluation of longitudinal 12 and 24 month cognitive outcomes in premanifest and early Huntington's disease

Background Deterioration of cognitive functioning is a debilitating symptom in many neurodegenerative diseases, such as Huntingtons disease (HD). To date, there are no effective treatments for the cognitive problems associated with HD. Cognitive assessment outcomes will have a central role in the efforts to develop treatments to delay onset or slow the progression of the disease. The TRACK-HD study was designed to build a rational basis for the selection of cognitive outcomes for HD clinical trials. Methods There were a total of 349 participants, including controls (n=116), premanifest HD (n=117) and early HD (n=116). A standardised cognitive assessment battery (including nine cognitive tests comprising 12 outcome measures) was administered at baseline, and at 12 and 24 months, and consisted of a combination of paper and pencil and computerised tasks selected to be sensitive to cortical-striatal damage or HD. Each cognitive outcome was analysed separately using a generalised least squares regression model. Results are expressed as effect sizes to permit comparisons between tasks. Results 10 of the 12 cognitive outcomes showed evidence of deterioration in the early HD group, relative to controls, over 24 months, with greatest sensitivity in Symbol Digit, Circle Tracing direct and indirect, and Stroop word reading. In contrast, there was very little evidence of deterioration in the premanifest HD group relative to controls. Conclusions The findings describe tests that are sensitive to longitudinal cognitive change in HD and elucidate important considerations for selecting cognitive outcomes for clinical trials of compounds aimed at ameliorating cognitive decline in HD.

The structural involvement of the cingulate cortex in premanifest and early Huntington's disease†‡§

The impact of Huntingtons disease neuropathology on the structure of the cingulate is uncertain, with evidence of both cortical enlargement and atrophy in this structure in early clinical disease. We sought to determine differences in cingulate volume between premanifest Huntingtons disease and early Huntingtons disease groups compared with controls using detailed manual measurements. Thirty controls, 30 subjects with premanifest Huntingtons disease, and 30 subjects with early Huntingtons disease were selected from the Vancouver site of the TRACK‐HD study. Subjects underwent 3 Tesla magnetic resonance imaging and motor, cognitive, and neuropsychiatric assessment. The cingulate was manually delineated and subdivided into rostral, caudal, and posterior segments. Group differences in volume and associations with performance on 4 tasks thought to utilize cingulate function were examined, with adjustment for appropriate covariates. Cingulate volumes were, on average, 1.7 mL smaller in early Huntingtons disease (P = .001) and 0.9 mL smaller in premanifest Huntingtons disease (P = .1) compared with controls. Smaller volumes in subsections of the cingulate were associated with impaired recognition of negative emotions (P = .04), heightened depression (P = .009), and worse visual working memory performance (P = .01). There was no evidence of associations between volume and ability on a performance‐monitoring task. This study disputes previous findings of enlargement of the cingulate cortex in Huntingtons disease and instead suggests that the cingulate undergoes structural degeneration during early Huntingtons disease with directionally consistent, nonsignificant differences seen in premanifest Huntingtons disease. Cingulate atrophy may contribute to deficits in mood, emotional processing, and visual working memory in Huntingtons disease.

A longitudinal study of magnetic resonance spectroscopy Huntington's disease biomarkers

Putaminal metabolites examined using cross‐sectional magnetic resonance spectroscopy (MRS) can distinguish pre‐manifest and early Huntingtons Disease (HD) individuals from controls. An ideal biomarker, however, will demonstrate longitudinal change over short durations. The objective here was to evaluate longitudinal in vivo brain metabolite profiles in HD over 24 months. Eighty‐four participants (30 controls, 25 pre‐manifest HD, 29 early HD) recruited as part of TRACK‐HD were imaged at baseline, 12 months, and 24 months using 3T MRS of left putamen. Automated putaminal volume measurement was performed simultaneously. To quantify partial volume effects, spectroscopy was performed in a second, white matter voxel adjacent to putamen in six subjects. Subjects underwent TRACK‐HD motor assessment. Statistical analyses included linear regression and one‐way analysis of variance (ANOVA). At all time‐points N‐acetyl aspartate and total N‐acetyl aspartate (NAA), neuronal integrity markers, were lower in early HD than in controls. Total NAA was lower in pre‐manifest HD than in controls, whereas the gliosis marker myo‐inositol (MI) was robustly elevated in early HD. Metabolites were stable over 24 months with no longitudinal change. Total NAA was not markedly different in adjacent white matter than putamen, arguing against partial volume confounding effects in cross‐sectional group differences. Total NAA correlations with disease burden score suggest that this metabolite may be useful in identifying neurochemical responses to therapeutic agents. We demonstrate almost consistent group differences in putaminal metabolites in HD‐affected individuals compared with controls over 24 months. Future work establishing spectroscopy as an HD biomarker should include multi‐site assessments in large, pathologically diverse cohorts.

Reliability and Factor Structure of the Short Problem Behaviors Assessment for Huntington’s Disease (PBA-s) in the TRACK-HD and REGISTRY studies

The authors report the inter-rater reliability and factor structure of the Short Problem Behaviors Assessment (PBA-s), a semistructured interview to measure severity and frequency of behavioral problems in Huntingtons disease. Video recordings of 410 PBA-s interviews were rescored by an independent rater, and Cohens kappa calculated to assess inter-rater reliability. The mean kappa was 0.74 for severity and 0.76 for frequency scores, whereas weighted kappa (allowing scores to differ by 1 point) was 0.94 for severity and 0.92 for frequency scores. The results of factor analysis were consistent with previous studies using other measures. The authors conclude that the PBA-s is a reliable measure.

Autism and peripheral hearing loss: A systematic review

OBJECTIVE To systematically review the literature describing the relationship between autism spectrum disorder (ASD) and peripheral hearing loss including literature recommendations for audiological assessment and auditory habilitation in cases where peripheral hearing loss and ASD coexist. DATA SOURCES Published studies indexed in MEDLINE (1948-2011). REVIEW METHODS The search strategy identified 595 potential studies. After a review of the titles, 115 abstracts were reviewed and 39 articles were retrieved and assessed independently by at least two authors for possible inclusion. 22 articles pertained to children with ASD and peripheral hearing loss, hearing assessment in children with ASD, audiological habilitation for children with ASD or hyper-responsiveness in children with ASD. 17 further studies were garnered from the reference section of the 22 papers. RESULTS Controversy exists in the literature regarding prevalence of hearing impairment among individuals with ASD. In cases where ASD and hearing impairment co-exist, diagnosis of one condition often leads to a delay in diagnosing the other. Audiological assessment can be difficult in children with ASD and test-retest reliability of behavioural thresholds can be poor. In cases where hearing impairment exists and hearing aids or cochlear implantation are recommended, devices are often fit with special considerations for the child with ASD. Hyper-responsiveness to auditory stimuli may be displayed by individuals with ASD. Evidence or the suspicion of hyper-responsiveness may be taken into consideration when fitting amplification and planning behavioural intervention. CONCLUSIONS Prevalence rates of hearing impairment among individuals with ASD continue to be debated. At present there is no conclusive evidence that children with ASD are at increased risk of peripheral hearing loss. A complete audiological assessment is recommended in all cases where ASD is suspected so as not to delay the diagnosis of hearing impairment in the event that hearing loss and ASD co-exist. Objective assessment measures should be used to confirm behavioural testing in order to ensure reliability of audiological test results. Fitting of hearing aids or cochlear implantation are not contraindicated when hearing loss is present in children with ASD; however, success with these devices can be variable.

The safety and efficacy of short-term budesonide delivered via mucosal atomization device for chronic rhinosinusitis without nasal polyposis

Budesonide is a potent corticosteroid commonly prescribed for management of inflammation in chronic rhinosinusitis (CRS). The standard for prescribing budesonide is via impregnated nasal saline irrigation (INSI), although recently the mucosal atomization device (MAD) has emerged as a theoretically superior method of distributing medication into the sinuses. The MAD atomizes medication into small droplets and this is thought to enhance absorption and improve bioavailability. However, no studies have shown whether enhanced absorption and improved bioavailability of budesonide via MAD causes adrenal suppression. The objective of this study is to determine whether budesonide via MAD affects the hypothalamic‐pituitary‐adrenal (HPA) axis.

The effect of head position on the distribution of topical nasal medication using the Mucosal Atomization Device: a cadaver study.

The Mucosal Atomization Device (MAD) distributes medication throughout the paranasal sinuses for patients with chronic rhinosinusitis (CRS). Determining the optimal head position is important to ensure maximal delivery of medication to the sinus cavities. The objective of this work was to determine the effect of the lying‐head‐back (LHB) and head‐down and forward (HDF) position, on the distribution of topical nasal medication via MAD in cadaver specimens.

Use of the SNOT-22 and UPSIT to Appropriately Select Pediatric Patients With Cystic Fibrosis Who Should Be Referred to an Otolaryngologist: Cross-sectional Study

IMPORTANCE Sinonasal disease and, specifically, nasal polyps, occur frequently in children with cystic fibrosis (CF). As survival rates have improved, it has become imperative that otolaryngologists become involved in the care of patients with CF to provide appropriate medical and surgical interventions for sinonasal disease. Despite significant variability in the subjective reporting of clinical symptoms, previous work has suggested there may be a relationship between clinical indicators and sinonasal disease in this population. OBJECTIVE To determine whether the 22-item Sino-Nasal Outcome Test (SNOT-22), the University of Pennsylvania Smell Identification Test (UPSIT), and other measures of sinonasal disease could be used to predict the presence of subclinical nasal polyps in children with CF. DESIGN, SETTING, AND PARTICIPANTS This was a cross-sectional study performed from May 2012 through April 2013 at a cystic fibrosis clinic at BC Childrens Hospital in Vancouver, British Columbia, Canada. There were 72 eligible children with CF for this study (with a confirmed diagnosis of CF based on genetic testing; their ages ranged from 6 to 18 years, and they were not actively being treated by an otolaryngologist). Thirty-seven of these patients (23 males, 14 females) consented to participate in this study. Twenty-three declined participation, and 12 could not be contacted. MAIN OUTCOMES AND MEASURES Potential clinical predictors for the presence of subclinical nasal polyps were determined a priori. All 37 recruited participants completed a full study assessment. Nasal endoscopy (the gold standard) was performed to determine the presence of nasal polyps. Potential predictors that were assessed included age, sex, genotype, pancreatic function, SNOT-22 and UPSIT scores, oral culture swab result, and severity of forced expiratory volume in 1 second (FEV(1)). RESULTS A SNOT-22 score of greater than 11 was the only statistically significant predictor of nasal polyps (P = .04). The positive predictive value was 68.1%, the negative predictive value was 66.7%, and the positive likelihood ratio was 1.82. CONCLUSIONS AND RELEVANCE Given that the SNOT-22 is easy to administer and inexpensive, this sinus disease-specific questionnaire seems to be an appropriate tool for routine use by respirologists when assessing patients with CF to help predict subclinical nasal polyps.

The Rhinological Manifestations of Women’s Health

Objective To systematically review the literature and appraise the evidence reporting the effects of women’s health, including pregnancy, postpartum, menstruation, oral contraception, menopause, and hormone replacement therapy, on common rhinological pathologies and nasal physiology. Data Sources Systematic search strategy using MEDLINE (1966-2012) and EMBASE (1980-2012) databases. Review Methods Title review, abstract screening, and then full paper analysis were undertaken by 2 authors independently. Level of evidence was graded according to the Oxford Centre of Evidence Based Medicine 2011 criteria and risk of bias assessment using the Jadad scale for randomized controlled trials and Newcastle-Ottawa Scale for cohort and case-controlled studies. Results Over the 46 years analyzed, the search strategy produced 2904 titles. In total, 314 abstracts were screened, from which 192 full-text articles were evaluated, and 145 research papers met all the criteria for inclusion in the study. Overall, the available evidence was of low quality. Seventy percent of studies (102 of 145) were case reports or case series from which only limited conclusions can be drawn. Only 3% of the included papers (4 of 145) were randomized controlled studies. The remaining data were mainly of a prospective cohort design. Study heterogeneity in design and measured outcomes resulted in data synthesis being limited to a descriptive/exploratory review. Study findings are presented by women’s health category and then by rhinological manifestation with important clinical correlations highlighted. Conclusion Physiological and hormonal changes occurring as a normal part of women’s health have an important influence on rhinological function and disease.