Monitoring cerebral blood flow (CBF) during neurosurgery can provide important physiological information for a variety of surgical procedures. CBF measurements are important for assessing whether ...blood flow has returned to presurgical baseline levels and for assessing postsurgical tissue viability. Existing techniques for intraoperative monitoring of CBF based on magnetic resonance imaging are expensive and often impractical, while techniques such as indocyanine green angiography cannot produce quantitative measures of blood flow. Laser speckle contrast imaging (LSCI) is an optical technique that has been widely used to quantitatively image relative CBF in animal models in vivo. In a pilot clinical study, we adapted an existing neurosurgical operating microscope to obtain LSCI images in humans in real time during neurosurgery under baseline conditions and after bipolar cautery. Simultaneously recorded ECG waveforms from the patient were used to develop a filter that helped reduce measurement variabilities due to motion artifacts. Results from this study demonstrate the feasibility of using LSCI to obtain blood flow images during neurosurgeries and its capability to produce full field CBF image maps with excellent spatial resolution in real-time with minimal disruption to the surgical procedure.
The incidence and prevalence of older adults living with HIV infection is increasing. Recent reports of increased neuropathologic and metabolic alterations in older HIV+ samples, including increased ...cortical beta-amyloid, have led some researchers to suggest that aging with HIV may produce a neuropsychological profile akin to that which is observed in “cortical” dementias (e.g., impairment in memory consolidation). To evaluate this possibility, we examined four groups classified by HIV serostatus and age (i.e., younger ≤40 years and older ≥50 years): (1) Younger HIV− (
n
= 24); (2) Younger HIV+ (
n
= 24); (3) Older HIV− (
n
= 20); and (4) Older HIV+ (
n
= 48). Main effects of aging were observed on episodic learning and memory, executive functions, and visuoconstruction, and main effects of HIV were observed on measures of verbal learning and memory. The interaction of age and HIV was observed on a measure of verbal recognition memory, which post hoc analyses showed to be exclusively attributed to the superior performance of the younger HIV seronegative group. Thus, in this sample of older HIV-infected individuals, the combined effects of HIV and aging do not appear to result in a “cortical” pattern of cognitive deficits.
Objective
Examine the associations between smartphone keystroke dynamics and cognitive functioning among persons with multiple sclerosis (MS).
Methods
Sixteen persons with MS with no self-reported ...upper extremity or typing difficulties and 10 healthy controls (HCs) completed six weeks of remote monitoring of their keystroke dynamics (i.e., how they typed on their smartphone keyboards). They also completed a comprehensive neuropsychological assessment and symptom ratings about fatigue, depression, and anxiety at baseline.
Results
A total of 1,335,787 keystrokes were collected, which were part of 30,968 typing sessions. The MS group typed slower (P < .001) and more variably (P = .032) than the HC group. Faster typing speed was associated with better performance on measures of processing speed (P = .016), attention (P = .022), and executive functioning (cognitive flexibility: P = .029; behavioral inhibition: P = .002; verbal fluency: P = .039), as well as less severe impact from fatigue (P < .001) and less severe anxiety symptoms (P = .007). Those with better cognitive functioning and less severe symptoms showed a stronger correlation between the use of backspace and autocorrection events (P < .001).
Conclusion
Typing speed may be sensitive to cognitive functions subserved by the frontal–subcortical brain circuits. Individuals with better cognitive functioning and less severe symptoms may be better at monitoring their typing errors. Keystroke dynamics have the potential to be used as an unobtrusive remote monitoring method for real-life cognitive functioning among persons with MS, which may improve the detection of relapses, evaluate treatment efficacy, and track disability progression.
An emerging literature indicates that HIV infection is associated with deficits in prospective memory (ProM), or the ability to execute a future intention. This literature offers evidence of ...neurobiological dissociability of ProM from other cognitive abilities and its incremental ecological validity as a predictor of poorer everyday functioning outcomes (e.g., medication nonadherence). The present study evaluated the hypothesis that ProM represents a unique cognitive construct in HIV disease. A confirmatory 4-factor structural equation model was tested on data derived from 162 participants with HIV. The model posited that measures of ProM comprise a unique factor, apart from standard clinical tests of retrospective memory, executive functions, and motor skills. The fit of the model was evaluated using the Bollen-Stine bootstrap method and indicated that a 4-factor model with measures of ProM loading on a unique factor fit the data well, and better than a model with a single common factor hypothesized to drive cognitive performance. The results of this study lend further evidence to the dissociability of ProM in HIV infection, are consistent with prior studies in healthy adults, and contribute to a growing literature on the construct validity of ProM in HIV disease.
Abstract
Objective
Estimating premorbid intellectual functioning after brain injury is a critical element of determining cognitive decline. However, little research has been conducted on how Peabody ...Picture Vocabulary Test (PPVT-IV) performs in adults after traumatic brain injury (TBI). Given that PPVT measures receptive vocabulary, it has potential to serve as a hold measure test. The objective was to explore characteristics of PPVT in TBI relative to a commonly used proxy of premorbid function (Wechsler Test of Adult Reading, WTAR).
Method
Sixty-one adults with moderate to severe TBI underwent a comprehensive neuropsychological evaluation and structural neuroimaging. Principal components analyses were used to create cognitive composite scores. Pearson’s correlations were conducted to explore the relationships between PPVT/WTAR standard scores (SS) and neuropathology (white matter integrity as whole brain functional anisotropy FA). The relationships between PPVT/WTAR SSs and cognitive constructs were similarly examined.
Results
PPVT was significantly related to FA (r = 0.34, p = 0.014). However, there was no relationship between WTAR and neuropathology. PPVT was significantly related to age (r = 0.38, p = 0.006), so this variable was controlled for in associated analyses (NB. WTAR was not related to age). PPVT was found to be significantly related to contextualized and noncontextualized memory, attention, executive function, and processing speed (all ps < 0.05). In contrast, WTAR was only significantly related to contextualized memory, attention, and executive function.
Conclusions
PPVT appears to be impacted by neuropathology, indicating that it may not be appropriate as a hold measure after TBI. This may be explained by PPVT’s significant relationship with fluid intelligence domains known to be impacted after neurologic insult.
Abstract
Objective
The role of social support or connectedness on health is profound. While this has been known for some time, recent reports of the role of social activity on mortality, general ...health, cognition, and well-being have suggested that it may play a larger role than the known culprits of poor outcomes (e.g., smoking, diet, exercise). The present study looked at the role of social support among women with multiple sclerosis (MS), specifically whether one felt that they had a friend to confide in.
Methods
One hundred and sixty women with MS completed measures of general health, MS symptomatology, and well-being. Participants also completed the Community Integration Questionnaire in which they were asked if they had a close friend that they could confide in. Thirty (19%) reported that they did not (Confidant -). We compared these women to those that did (Confidant +).
Results
There were no differences between the groups on age, education, relationship status, disease course or duration. The Confidant – group reported worse general, physical, and mental health and greater fatigue, pain, and sleep disturbance (p’s < 0.05). They also reported greater depression and anxiety and worse satisfaction with life and psychological well-being (p’s < 0.001). Consistent with this, they reported lower perceived social support and partner satisfaction (p’s < 0.001).
Conclusion
The simple question of “Do you have a best friend” was a large determinant in individuals’ health and well-being. Findings urge practitioners to inquire about one’ social network and support and assist individuals in assuring greater social connectedness in hopes of maintaining or improving one’s health.
In neurological diseases such as multiple sclerosis (MS), a neuropsychological assessment is often requested to assist clinicians in evaluating the role of cognition in a patient’s level of everyday ...functioning. To be effective in this charge, it is assumed that performance on neuropsychological tests is related to how a person may function in everyday life, and the question is often asked: “Are neuropsychological tests ecologically valid?” In this review, we synthesize the literature that examines the use of neuropsychological tests to assess functioning across a variety of everyday functioning domains in MS (i.e. driving, employment, instrumental activities of daily living (IADLs)). However, we critically examine the usefulness of asking this broad question regarding ecological validity, given the psychometric and conceptual pitfalls it may yield. While many neuropsychological tests may be generally considered “ecologically valid” in MS, it is much more helpful to specify for whom, under what circumstances, and to what degree.
Advances in the treatment of the human immunodeficiency virus (HIV) have dramatically improved survival rates over the past 10 years, but HIV-associated neurocognitive disorders (HAND) remain highly ...prevalent and continue to represent a significant public health problem. This review provides an update on the nature, extent, and diagnosis of HAND. Particular emphasis is placed on critically evaluating research within the realm of cognitive neuropsychology that aims to elucidate the component processes of HAND across the domains of executive functions, motor skills, speeded information processing, episodic memory, attention/working memory, language, and visuoperception. In addition to clarifying the cognitive mechanisms of HAND (e.g., impaired cognitive control), the cognitive neuropsychology approach may enhance the ecological validity of neuroAIDS research and inform the development of much needed novel, targeted cognitive and behavioral therapies.
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