Neuropsychological outcome following minimal access subtemporal selective amygdalohippocampectomy.

PURPOSE: The present study provides a detailed account of neurocognitive outcome following minimal access subtemporal selective amygdalohippocampectomy (SAH) and establishes rates of neurocognitive decline in the largest sample to date. Use of a subtemporal surgical approach to SAH has been proposed to possibly reduce the risk for postoperative neurocognitive decline since lateral neocortical tissues is not resected and the temporal stem is preserved. The current study extends prior research with subtemporal SAH patients to include not only group level analyses but also analyses based on reliable change data. METHODS: Neurocognitive comparisons are made between 47 patients that underwent subtemporal SAH. Statistical comparisons were made between neurocognitive performance at the group level and with use of reliable change scores. RESULTS: Approximately 75% of patients were seizure free postoperatively. At the group level, there were no significant postoperative changes. For the left SAH patients, reliable change scores demonstrated a decline in approximately one third of patients for memory, verbal intellect, and naming. Right SAH patients showed decline primarily in memory. CONCLUSIONS: These results indicated good seizure control following subtemporal SAH with greatest risk for neurocognitive decline following dominant SAH and best cognitive outcome following non-dominant SAH. Findings demonstrated the importance of reliable change analyses that make individual based comparisons and take into account measurement error. Despite preservation of the lateral neocortical tissue and the temporal stem, subtemporal SAH presents a risk for cognitive decline in a notable portion of patients

The impact of seasonal variability in wildlife populations on the predicted spread of foot and mouth disease

Modeling potential disease spread in wildlife populations is important for predicting, responding to and recovering from a foreign animal disease incursion such as foot and mouth disease (FMD). We conducted a series of simulation experiments to determine how seasonal estimates of the spatial distribution of white-tailed deer impact the predicted magnitude and distribution of potential FMD outbreaks. Outbreaks were simulated in a study area comprising two distinct ecoregions in South Texas, USA, using a susceptible-latent-infectious-resistant geographic automata model (Sirca). Seasonal deer distributions were estimated by spatial autoregressive lag models and the normalized difference vegetation index. Significant (P < 0.0001) differences in both the median predicted number of deer infected and number of herds infected were found both between seasons and between ecoregions. Larger outbreaks occurred in winter within the higher deer-density ecoregion, whereas larger outbreaks occurred in summer and fall within the lower deer-density ecoregion. Results of this simulation study suggest that the outcome of an FMD incursion in a population of wildlife would depend on the density of the population infected and when during the year the incursion occurs. It is likely that such effects would be seen for FMD incursions in other regions and countries, and for other diseases, in cases in which a potential wildlife reservoir exists. Study findings indicate that the design of a mitigation strategy needs to take into account population and seasonal characteristics

Helicobacter pylori, persistent infection burden and structural brain imaging markers

Persistent infections, whether viral, bacterial or parasitic, including Helicobacter pylori infection, have been implicated in non-communicable diseases, including dementia and other neurodegenerative diseases. In this cross-sectional study, data on 635 cognitively normal participants from the UK Biobank study (2006–21, age range: 40–70 years) were used to examine whether H. pylori seropositivity (e.g. presence of antibodies), serointensities of five H. pylori antigens and a measure of total persistent infection burden were associated with selected brain volumetric structural MRI (total, white, grey matter, frontal grey matter (left/right), white matter hyperintensity as percent intracranial volume and bi-lateral sub-cortical volumes) and diffusion-weighted MRI measures (global and tract-specific bi-lateral fractional anisotropy and mean diffusivity), after an average 9–10 years of lag time. Persistent infection burden was calculated as a cumulative score of seropositivity for over 20 different pathogens. Multivariable-adjusted linear regression analyses were conducted, whereby selected potential confounders (all measures) and intracranial volume (sub-cortical volumes) were adjusted, with stratification by Alzheimer’s disease polygenic risk score tertile when exposures were H. pylori antigen serointensities. Type I error was adjusted to 0.007. We report little evidence of an association between H. pylori seropositivity and persistent infection burden with various volumetric outcomes (P &gt; 0.007, from multivariable regression models), unlike previously reported in past research. However, H. pylori antigen serointensities, particularly immunoglobulin G against the vacuolating cytotoxin A, GroEL and outer membrane protein antigens, were associated with poorer tract-specific white matter integrity (P &lt; 0.007), with outer membrane protein serointensity linked to worse outcomes in cognition-related tracts such as the external capsule, the anterior limb of the internal capsule and the cingulum, specifically at low Alzheimer’s disease polygenic risk. Vacuolating cytotoxin A serointensity was associated with greater white matter hyperintensity volume among individuals with mid-level Alzheimer’s disease polygenic risk, while among individuals with the highest Alzheimer’s disease polygenic risk, the urease serointensity was consistently associated with reduced bi-lateral caudate volumes and the vacuolating cytotoxin A serointensity was linked to reduced right putamen volume (P &lt; 0.007). Outer membrane protein and urease were associated with larger sub-cortical volumes (e.g. left putamen and right nucleus accumbens) at middle Alzheimer’s disease polygenic risk levels (P &lt; 0.007). Our results shed light on the relationship between H. pylori seropositivity, H. pylori antigen levels and persistent infection burden with brain volumetric structural measures. These data are important given the links between infectious agents and neurodegenerative diseases, including Alzheimer’s disease, and can be used for the development of drugs and preventive interventions that would reduce the burden of those diseases

Neuropsychological outcome following minimal access subtemporal selective amygdalohippocampectomy.

PURPOSE: The present study provides a detailed account of neurocognitive outcome following minimal access subtemporal selective amygdalohippocampectomy (SAH) and establishes rates of neurocognitive decline in the largest sample to date. Use of a subtemporal surgical approach to SAH has been proposed to possibly reduce the risk for postoperative neurocognitive decline since lateral neocortical tissues is not resected and the temporal stem is preserved. The current study extends prior research with subtemporal SAH patients to include not only group level analyses but also analyses based on reliable change data. METHODS: Neurocognitive comparisons are made between 47 patients that underwent subtemporal SAH. Statistical comparisons were made between neurocognitive performance at the group level and with use of reliable change scores. RESULTS: Approximately 75% of patients were seizure free postoperatively. At the group level, there were no significant postoperative changes. For the left SAH patients, reliable change scores demonstrated a decline in approximately one third of patients for memory, verbal intellect, and naming. Right SAH patients showed decline primarily in memory. CONCLUSIONS: These results indicated good seizure control following subtemporal SAH with greatest risk for neurocognitive decline following dominant SAH and best cognitive outcome following non-dominant SAH. Findings demonstrated the importance of reliable change analyses that make individual based comparisons and take into account measurement error. Despite preservation of the lateral neocortical tissue and the temporal stem, subtemporal SAH presents a risk for cognitive decline in a notable portion of patients

The current status of postconcussion syndrome

PURPOSE OF REVIEW: Concussion produces a brief disruption in mental status and is associated with a variety of physical and cognitive symptoms which typically diminish during the first several days to weeks posttrauma. This review highlights problems in defining and measuring concussion, the mildest form of traumatic brain injury (TBI). Furthermore, the \u27natural\u27 course of recovery correlates of postconcussion syndrome (PCS) and guidelines for clinical management are discussed. RECENT FINDINGS: Traditional measures of TBI severity (e.g. length of loss of consciousness or period of posttraumatic amnesia) do not correlate with persistent concussion symptoms. Abnormal eye movements, cerebrovascular disturbances, extra-axial injuries, alcohol intoxication at time of injury, and presence of an axis I disorder are associated with persistent symptoms. Early management of physical, cognitive, and emotional symptoms following concussion may reduce long-term morbidity. Techniques used to help concussed athletes return to play appear useful when evaluating and treating concussion in nonathletes. SUMMARY: The study of concussion and PCS has increased significantly over the past 10 years, with recent research supporting an underlying biological cause for initial symptomatology. Persistent symptoms may be associated with both neurological and non-neurological variables. Early and serial monitoring and treatment of symptoms appears to result in substantial improvement in the vast majority of concussed patients

Deep white matter volume loss and social reintegration after traumatic brain injury in children

Objective: To explore whether children judged by their parents as showing an excellent or complete social reintegration after pediatric traumatic brain injury have less white matter volume (WMV) loss and better neuropsychological test scores than children who do not achieve this same level of reintegration. Setting: Primary-care hospital/medical center. Participants: Twenty-eight children with post-acute traumatic brain injury evaluated as outpatients. Measures: Parental ratings of overall social reintegration, neuropsychological test performance, and voxel-based morphometry analysis of brain WMV loss. Results: In addition to showing worse neuropsychological test performance, children judged not to make a complete or excellent social reintegration had greater WMV loss, particularly within the corpus callosum. WMV loss in the corpus callosum correlated with the child\u27s Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) Full Scale IQ (ρ = .677, P = .000) and parental ratings of level of social integration (ρ = .415, P = .028). Admitting Glasgow Coma Scale scores, mother\u27s level of education, WISC-IV Processing Speed Index scores, and WMV loss in the region of the corpus callosum significantly contributed to parental ratings of a child\u27s level of social reintegration. Conclusions: Preliminary findings suggested that diffuse WMV loss, particularly in deep brain regions (eg, corpus callosum), may relate to the child\u27s long-term psychosocial outcome as viewed from the parents\u27 perspective. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins

Individual case analysis of processing speed difficulties in children with and without traumatic brain injury

Two studies were conducted to determine the frequency of processing speed difficulties relative to estimates of other problem-solving abilities in children with and without traumatic brain injury (TBI). The two samples consisted of 213 normally functioning school-age children and 65 TBI children and 19 trauma controls. All children were administered the WISC-III/IV Vocabulary, Block Design, and Coding subtests. The frequency of children in each sample having a Coding subtest score of 3 or 4 scale points below the Vocabulary or Block Design score (whichever one was lower) was calculated. Using a 3-point scale difference, the presence of processing speed deficits relative to other cognitive abilities in the school sample was low (5.2%), and was equivalent to that demonstrated by trauma controls (5.3%). However, in the TBI sample, 18 out of 65 TBI patients (27.7%) showed this same pattern. Using a 4-point discrepancy scale, 3.3% of normal children and 16.9% of TBI children showed this pattern. The frequency of this pattern increased with severity of TBI, using two different but related classification systems. These preliminary findings require cross validation in a larger sample before definite conclusions can be reached. © 2007 Psychology Press

Interaction between Helicobacter pylori and latent toxoplasmosis and demographic variables on cognitive function in young to middle-aged adults.

Helicobacter pylori and latent toxoplasmosis are widespread diseases that have been associated with cognitive deficits and Alzheimer's disease. We sought to determine whether interactions between Helicobacter pylori and latent toxoplasmosis, age, race-ethnicity, educational attainment, economic status, and general health predict cognitive function in young and middle-aged adults. To do so, we used multivariable regression and multivariate models to analyze data obtained from the United States' National Health and Nutrition Examination Survey from the Centers for Disease Control and Prevention, which can be weighted to represent the US population. In this sample, we found that 31.6 percent of women and 36.2 percent of men of the overall sample had IgG Antibodies against Helicobacter pylori, although the seroprevalence of Helicobacter pylori varied with sociodemographic variables. There were no main effects for Helicobacter pylori or latent toxoplasmosis for any of the cognitive measures in models adjusting for age, sex, race-ethnicity, educational attainment, economic standing, and self-rated health predicting cognitive function. However, interactions between Helicobacter pylori and race-ethnicity, educational attainment, latent toxoplasmosis in the fully adjusted models predicted cognitive function. People seropositive for both Helicobacter pylori and latent toxoplasmosis - both of which appear to be common in the general population - appear to be more susceptible to cognitive deficits than are people seropositive for either Helicobacter pylori and or latent toxoplasmosis alone, suggesting a synergistic effect between these two infectious diseases on cognition in young to middle-aged adults

Association between Toxoplasma gondii seropositivity and serointensity and brain volume in adults: A cross-sectional study.

The intracellular protozoal parasite Toxoplasma gondii has been associated with worsened cognitive function in animal models and in humans. Despite these associations, the mechanisms by which Toxoplasma gondii might affect cognitive function remain unknown, although Toxoplasma gondii does produce physiologically active intraneuronal cysts and appears to affect dopamine synthesis. Using data from the UK Biobank, we sought to determine whether Toxoplasma gondii is associated with decreased prefrontal, hippocampal, and thalamic gray-matter volumes and with decreased total gray-matter and total white-matter volumes in an adult community-based sample. The results from adjusted multivariable regression modelling showed no associations between Toxoplasma gondii and prefrontal, hippocampal, and thalamic brain gray-matter volumes. In contrast, natural-log transformed antibody levels against the Toxoplasma gondii p22 (b = -3960, 95-percent confidence interval, -6536 to -1383, p < .01) and sag1 (b = -4863, 95-percent confidence interval, -8301 to -1425, p < .01) antigens were associated with smaller total gray-matter volume, as was the mean of natural-log transformed p22 and sag1 titers (b = -6141, 95-percent confidence interval, -9886 to -2397, p < .01). There were no associations between any of the measures of Toxoplasma gondii and total white-matter volume. These findings suggest that Toxoplasma gondii might be associated with decreased total gray-matter in middle-aged and older middle-aged adults in a community-based sample from the United Kingdom

Psychiatric Disease as a Potential Risk Factor for Dementia: A Narrative Review

Neurodegenerative disease is a major global health problem with 150 million people predicted to have dementia by 2050. Genetic factors, environmental factors, demographics, and some diseases have been associated with dementia. In addition to associations between diseases such as hypertension and cerebrovascular disease and dementia, emerging findings associate some psychiatric disorders with incident dementia. Because of the high and increasing global prevalence of dementia and the high worldwide prevalence of psychiatric disorders, the primary objective of this narrative review was to evaluate published findings that evaluate the association between bipolar disorder, depression, anxiety, post-traumatic stress disorder, obsessive–compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorder, schizophrenia and other psychosis syndromes, and personality disorders and personality traits and incident dementia. Here, we highlight findings indicating possible associations between these psychiatric disorders and subsequent dementia and suggest that some psychiatric disorders may be risk factors for incident dementia. Further research, including more large longitudinal studies and additional meta-analyses, however, is needed to better characterize the associations between psychiatric disorders and incident dementia, to identify possible mechanisms for these putative associations, and to identify risk factors within psychiatric disorders that predispose some people with a psychiatric disorder but not others to subsequent dementia. Additional important questions concern how the treatment of psychiatric disorders might affect the risk of incident dementia