Does attentional dysfunction and thalamic atrophy predict decline in dementia with Lewy bodies?

INTRODUCTION: To evaluate the clinical characteristics of DLB subjects who died within 1 year of assessment compared to those who survived and investigate their patterns of in vivo regional thalamic atrophy using structural MRI. METHODS: Seventy subjects (35 DLB, 35 aged controls) underwent 3 T T1-weighted MR scanning as well as clinical and cognitive assessments, including a computerised assessment of attention. All subjects were contacted after 12 months for reassessment. For both hemispheres, using FSL FIRST, the thalamus was automatically segmented followed by inter-subject vertex-wise analyses involving group comparisons and behavioural correlates. RESULTS: There was significant bilateral atrophy in the ventral-dorsal and pulvinar regions in DLB relative to controls (pcorrected < 0.05). The DLB group was then re-categorised based on 12-month mortality data: DLB-a (n = 26) and DLB-d (n = 9) (a = alive, d = death within 12 months of study assessment). Compared to controls, significant attentional dysfunction and bilateral atrophy of the pulvinar, ventral and dorsal nuclei were observed in DLB-d (pcorrected < 0.05), whereas in DLB-a, atrophy was far less extensive. CONCLUSIONS: Distinct patterns of thalamic atrophy occur in DLB that may relate to the attentional dysfunction and cognitive fluctuations that characterise this disorder. Relative to controls, the extent of attentional impairment and pattern of thalamic degeneration differ in those patients who died within 12 months of assessment, despite having an otherwise similar level of dementia severity. These findings may provide insight into the neurobiological changes underpinning important clinical characteristics and disease heterogeneity.

Predictors of adverse events after parotidectomy: a review of 2919 cases.

OBJECTIVE: There is a current paucity of large-scale, multi-institutional studies that explore the risk factors for major complications following parotidectomy. METHODS: The American College of Surgeons National Surgical Quality Improvement Program participant use file was reviewed to identify all patients who had undergone parotidectomy between 2006 and 2011. Risk factors that predicted adverse events were estimated by using multivariate logistic regression. RESULTS: Of 2919 included patients, 202 patients experienced adverse outcomes within the first 30 days of surgery. These included surgical complications in 76 (2.6%) patients; medical complications in 90 (3.1%) patients; death in 7 (0.2%) patients; and reoperation in 77 (2.6%) patients. Predictors of any complication included disseminated cancer (odds ratio [OR] = 2.28; 95% confidence interval [CI], 1.05-4.95; P = .036) and increasing total relative value units (OR = 1.01; 95% CI, 1.00-1.02; P = .027). Active smoking was a major risk factor for surgical complications (OR = 1.81; 95% CI, 1.08-3.05; P = .025). Dyspnea (OR = 2.93; 95% CI, 1.37-6.27; P = .006) significantly predicted medical complications. CONCLUSION: Although complication rates after parotidectomy are generally low, avoidance of specific and nonspecific postoperative complications still remains an area for improvement. Future outcomes databases should include procedure-specific complications, including facial nerve injury.

Characterizing dementia with Lewy bodies by means of diffusion tensor imaging.

OBJECTIVE: To investigate patterns of in vivo white matter tract change using diffusion tensor imaging (DTI), we conducted a cross-sectional study of dementia with Lewy bodies (DLB) in comparison with Alzheimer disease (AD) and normal aging. METHODS: The study included 106 subjects (35 with DLB, 36 with AD, and 35 elderly controls) who underwent clinical and neuropsychological assessment and diffusion tensor MRI. We used tract-based spatial statistics to investigate patterns of reduced fractional anisotropy (FA) and increased mean diffusivity (MD) across the entire white matter tract skeleton and also investigated correlations with clinical features. RESULTS: Areas of reduced FA in subjects with DLB vs controls were found primarily in parieto-occipital white matter tracts; in AD, the changes were much more diffuse. DLB was also associated with reduced FA in the pons and left thalamus, in comparison with AD. The pattern of MD increase was diffuse in AD and DLB. We found an association between DTI parameters and impaired episodic memory, letter fluency, and severity of motor parkinsonism in DLB. CONCLUSIONS: Despite a similar level of dementia severity, patterns of DTI changes in AD and DLB differed significantly. The selective involvement of the visual association areas and subcortical structures and the significant clinical correlations highlight the potential importance of white matter tract change in the pathogenesis of DLB. DTI may be a useful technique to investigate early and possible preclinical changes in DLB and warrants further investigation.

Factors determining the risk of inadvertent retroviral transduction of male germ cells after in utero gene transfer in sheep.

The possibility of permanent genetic changes to the germline is central to the bioethics of in utero gene therapy (IUGT) because of the concern of inadvertent potentially deleterious alterations to the gene pool. Despite presumed protection of the male germline due to early germ cell (GC) compartmentalization, we reported that GCs within the developing ovine testes are transduced at low levels after retrovirus-mediated IUGT, thus underscoring the need for a thorough understanding of GC development in clinically predictive models to determine the optimal time to perform IUGT and avoid germline modification. In the present studies, we used the fetal sheep model to analyze GCs for phenotype, location, proliferation, and incidence of transduction after IUGT at various fetal ages to learn when during development the nascent germline is likely to be at greatest risk of retrovirus-mediated alteration. Our studies show that although GCs were transduced at all injection ages, the levels of transduction varied by nearly 700-fold as a function of the age at transfer. After remaining largely quiescent as they migrated to/settled within nascent sex cords, GCs began active cycling before cord closure was complete, suggesting this is likely the point at which they would be most susceptible to retroviral transduction.Furthermore, we observed that compartmentalization of GCs continued into early postnatal life, suggesting the male germline may be vulnerable to low-level inadvertent retroviral vector modification throughout fetal life, but that this risk can be minimized by performing IUGT later in gestation.