Catherine C. Price

Type and Severity of Cognitive Decline in Older Adults after Noncardiac Surgery

Background:The authors investigated type and severity of cognitive decline in older adults immediately and 3 months after noncardiac surgery. Changes in instrumental activities of daily living were examined relative to type of cognitive decline. Methods:Of the initial 417 older adults enrolled in the study, 337 surgery patients and 60 controls completed baseline, discharge, and/or 3-month postoperative cognitive and instrumental activities of daily living measures. Reliable change methods were used to examine three types of cognitive decline: memory, executive function, and combined executive function/memory. SD cutoffs were used to grade severity of change as mild, moderate or severe. Results:At discharge, 186 (56%) patients experienced cognitive decline, with an equal distribution in type and severity. At 3 months after surgery, 231 patients (75.1%) experienced no cognitive decline, 42 (13.6%) showed only memory decline, 26 (8.4%) showed only executive function decline, and 9 (2.9%) showed decline in both executive and memory domains. Of those with cognitive decline, 36 (46.8%) had mild, 25 (32.5%) had moderate, and 16 (20.8%) had severe decline. The combined group had more severe impairment. Executive function or combined (memory and executive) deficits involved greater levels of functional (i.e., instrumental activities of daily living) impairment. The combined group was less educated than the unimpaired and memory groups. Conclusion:Postsurgical cognitive presentation varies with time of testing. At 3 months after surgery, more older adults experienced memory decline, but only those with executive or combined cognitive decline had functional limitations. The findings have relevance for patients and caregivers. Future research should examine how perioperative factors influence neuronal systems.

Postoperative cognitive disorders

Purpose of reviewThe elderly are the fastest growing segment of the population and undergo 25–30% of all surgical procedures. Postoperative cognitive problems are common in older patients following major surgery. The socioeconomic implications of these cognitive disorders are profound; cognitive decline is associated with a loss of independence, a reduction in the quality of life, and death. This review will focus on the two most common cognitive problems following surgery: postoperative delirium and postoperative cognitive dysfunction (POCD). Recent findingsFor years, preoperative geriatric consultation/screening was the only intervention proven to decrease postoperative delirium. There are, however, several recent publications indicating that preoperative and postoperative pharmacological and medical (hydration, oxygenation) management can reduce postoperative delirium. Spinal anesthesia with minimal propofol sedation has been shown to decrease the incidence of postoperative delirium in hip-fracture patients. Likewise, dexmedetomidine sedation in mechanically ventilated patients in the ICU is associated with less postoperative delirium and shorter ventilator times. Preoperative levels of education and brain function (cognitive reserve) may predict patients at risk for postoperative cognitive problems. Reduced white matter integrity is reported to place patients at a higher risk for both postoperative delirium and POCD. SummaryThe etiology of postoperative cognitive problems is unknown, but there is emerging evidence that decreased preoperative cognitive function contributes to the development of postoperative delirium and POCD. There is growing concern that inhalation anesthetics may be neurotoxic to the aging brain, but there are no human data evaluating this hypothesis to date. Randomized controlled trials evaluating interventions to improve long-term cognitive outcomes in elderly patients are urgently needed.

Stroke After Aortic Valve Surgery Results From a Prospective Cohort

Background— The incidence and impact of clinical stroke and silent radiographic cerebral infarction complicating open surgical aortic valve replacement (AVR) are poorly characterized. Methods and Results— We performed a prospective cohort study of subjects ≥65 years of age who were undergoing AVR for calcific aortic stenosis. Subjects were evaluated by neurologists preoperatively and postoperatively and underwent postoperative magnetic resonance imaging. Over a 4-year period, 196 subjects were enrolled at 2 sites (mean age, 75.8±6.2 years; 36% women; 6% nonwhite). Clinical strokes were detected in 17%, transient ischemic attack in 2%, and in-hospital mortality was 5%. The frequency of stroke in the Society for Thoracic Surgery database in this cohort was 7%. Most strokes were mild; the median National Institutes of Health Stroke Scale was 3 (interquartile range, 1–9). Clinical stroke was associated with increased length of stay (median, 12 versus 10 days; P=0.02). Moderate or severe stroke (National Institutes of Health Stroke Scale ≥10) occurred in 8 (4%) and was strongly associated with in-hospital mortality (38% versus 4%; P=0.005). Of the 109 stroke-free subjects with postoperative magnetic resonance imaging, silent infarct was identified in 59 (54%). Silent infarct was not associated with in-hospital mortality or increased length of stay. Conclusions— Clinical stroke after AVR was more common than reported previously, more than double for this same cohort in the Society for Thoracic Surgery database, and silent cerebral infarctions were detected in more than half of the patients undergoing AVR. Clinical stroke complicating AVR is associated with increased length of stay and mortality.Background— The incidence and impact of clinical stroke and silent radiographic cerebral infarction complicating open surgical aortic valve replacement (AVR) are poorly characterized. Methods and Results— We performed a prospective cohort study of subjects ≥65 years of age who were undergoing AVR for calcific aortic stenosis. Subjects were evaluated by neurologists preoperatively and postoperatively and underwent postoperative magnetic resonance imaging. Over a 4-year period, 196 subjects were enrolled at 2 sites (mean age, 75.8±6.2 years; 36% women; 6% nonwhite). Clinical strokes were detected in 17%, transient ischemic attack in 2%, and in-hospital mortality was 5%. The frequency of stroke in the Society for Thoracic Surgery database in this cohort was 7%. Most strokes were mild; the median National Institutes of Health Stroke Scale was 3 (interquartile range, 1–9). Clinical stroke was associated with increased length of stay (median, 12 versus 10 days; P =0.02). Moderate or severe stroke (National Institutes of Health Stroke Scale ≥10) occurred in 8 (4%) and was strongly associated with in-hospital mortality (38% versus 4%; P =0.005). Of the 109 stroke-free subjects with postoperative magnetic resonance imaging, silent infarct was identified in 59 (54%). Silent infarct was not associated with in-hospital mortality or increased length of stay. Conclusions— Clinical stroke after AVR was more common than reported previously, more than double for this same cohort in the Society for Thoracic Surgery database, and silent cerebral infarctions were detected in more than half of the patients undergoing AVR. Clinical stroke complicating AVR is associated with increased length of stay and mortality. # CLINICAL PERSPECTIVE {#article-title-47}

Effects of STN and GPi Deep Brain Stimulation on Impulse Control Disorders and Dopamine Dysregulation Syndrome

Objective Impulse control disorders (ICDs) and dopamine dysregulation syndrome (DDS) are important behavioral problems that affect a subpopulation of patients with Parkinsons disease (PD) and typically result in markedly diminished quality of life for patients and their caregivers. We aimed to investigate the effects of subthalamic nucleus (STN) and internal globus pallidus (GPi) deep brain stimulation (DBS) on ICD/DDS frequency and dopaminergic medication usage. Methods A retrospective chart review was performed on 159 individuals who underwent unilateral or bilateral PD DBS surgery in either STN or GPi. According to published criteria, pre- and post-operative records were reviewed to categorize patients both pre- and post-operatively as having ICD, DDS, both ICD and DDS, or neither ICD nor DDS. Group differences in patient demographics, clinical presentations, levodopa equivalent dose (LED), and change in diagnosis following unilateral/bilateral by brain target (STN or GPi DBS placement) were examined. Results 28 patients met diagnostic criteria for ICD or DDS pre- or post-operatively. ICD or DDS classification did not differ by GPi or STN target stimulation. There was no change in DDS diagnosis after unilateral or bilateral stimulation. For ICD, diagnosis resolved in 2 of 7 individuals after unilateral or bilateral DBS. Post-operative development of these syndromes was significant; 17 patients developed ICD diagnoses post-operatively with 2 patients with pre-operative ICD developing DDS post-operatively. Conclusions Unilateral or bilateral DBS did not significantly treat DDS or ICD in our sample, even though a few cases of ICD resolved post-operatively. Rather, our study provides preliminary evidence that DDS and ICD diagnoses may emerge following DBS surgery.

Capacity to maintain mental set in dementia.

Two experiments investigating the capacity to sustain mental set in dementia were conducted. Experiment 1 analyzed performance of a non-demented control group (NC), participants with Alzheimers disease (AD) and participants with ischemic vascular dementia (IVD) on the Boston Revision of the Wechsler Memory Scale Mental Control subtest (MC). On simple tasks there were no between-group differences after controlling for time to completion. On complex tasks, NC participants outperformed both dementia groups and AD participants obtained higher accuracy indices than IVD participants. The IVD group produced a disproportionate number of commission errors regardless of task complexity. The AD group tended to produce more omission errors on more difficult measures of mental set. Individual task performance was divided into three sections-first, middle, and last. IVD participants made fewer and fewer correct responses over all three sections, whereas performance of AD participants leveled off by the middle section with no further decline. Experiment 2 compared letter fluency performance among NC, AD and IVD groups, and participants with dementia secondary to idiopathic Parkinsons disease (PD). For all letter cues, IVD and PD participants generated fewer responses than NC and AD participants. However, IVD and PD participants generated a larger proportion of words than AD and NC participants within the first 15 s. As the task progressed, the output of IVD and PD participants dropped precipitously. These findings indicate that failure to maintain mental set is not a diffuse or general cognitive disability. Rather, failure to maintain mental set in dementia may be best understood within the context of predictable and specific within-task time epochs.

Is the N-Back Task a Valid Neuropsychological Measure for Assessing Working Memory?

The n-back is a putative working memory task frequently used in neuroimaging research; however, literature addressing n-back use in clinical neuropsychological evaluation is sparse. We examined convergent validity of the n-back with an established measure of working memory, digit span backward. The relationship between n-back performance and scores on measures of processing speed was also examined, as was the ability of the n-back to detect potential between-groups differences in control and Parkinsons disease (PD) groups. Results revealed no correlation between n-back performance and digit span backward. N-back accuracy significantly correlated with a measure of processing speed (Trail Making Test Part A) at the 2-back load. Relative to controls, PD patients performed less accurately on the n-back and showed a trend toward slower reaction times, but did not differ on any of the neuropsychological measures. Results suggest the n-back is not a pure measure of working memory, but may be able to detect subtle differences in cognitive functioning between PD patients and controls.

Verbal Serial List Learning in Mild Cognitive Impairment: A Profile Analysis of Interference, Forgetting, and Errors

Using cluster analysis Libon et al. (2010) found three verbal serial list-learning profiles involving delay memory test performance in patients with mild cognitive impairment (MCI). Amnesic MCI (aMCI) patients presented with low scores on delay free recall and recognition tests; mixed MCI (mxMCI) patients scored higher on recognition compared to delay free recall tests; and dysexecutive MCI (dMCI) patients generated relatively intact scores on both delay test conditions. The aim of the current research was to further characterize memory impairment in MCI by examining forgetting/savings, interference from a competing word list, intrusion errors/perseverations, intrusion word frequency, and recognition foils in these three statistically determined MCI groups compared to normal control (NC) participants. The aMCI patients exhibited little savings, generated more highly prototypic intrusion errors, and displayed indiscriminate responding to delayed recognition foils. The mxMCI patients exhibited higher saving scores, fewer and less prototypic intrusion errors, and selectively endorsed recognition foils from the interference list. dMCI patients also selectively endorsed recognition foils from the interference list but performed similarly compared to NC participants. These data suggest the existence of distinct memory impairments in MCI and caution against the routine use of a single memory test score to operationally define MCI.

Error analysis of the nine-word California Verbal Learning Test (CVLT-9) among older adults with and without dementia.

The nine-word California Verbal Learning Test (CVLT-9; Libon et al., 1996; Spreen & Strauss, 1998) is a verbal list learning task used to assess declarative memory impairment among dementia patients. The present study sought to investigate the neuro-cognitive mechanisms that underlie the production of intrusions and perseverations on the list A, free recall learning trials, and the false positive responses made on the delayed recognition condition. Patients with probable Alzheimers disease (AD), Ischaemic Vascular Dementia associated with periventricular and deep white matter changes (IVD), and individuals without dementia (NC) were studied. Between-group analyses showed that AD participants produced more initial intrusion errors, and perseverated on those same intrusion errors across list A learning trials than IVD or NC participants. Also, as participants with dementia produced initial free recall intrusion errors, the semantic organization of their responses on the ‘animal’ word list generation task declined (Giovannetti-Carew, Lamar, Cloud, Grossman, & Libon, 1997). On the delayed recognition test condition, within-group analyses revealed that the IVD group endorsed more list B interference foils, than other errors. AD participants endorsed semantically related foils and list B interference foils. In addition, as participants with dementia endorsed more list B interference foils, more perseverations were produced on the Graphical Sequence Test – Dementia Version (Lamar et al., 1997). These results were interpreted within the context of the semantic knowledge, and executive functions deficits that typify AD and IVD, respectively.

Management of the hospitalized patient with Parkinson's disease: current state of the field and need for guidelines.

OBJECTIVE To review the literature and to identify practice gaps in the management of the hospitalized Parkinsons disease (PD) patient. BACKGROUND Patients with PD are admitted to hospitals at higher rates, and frequently have longer hospital stays than the general population. Little is known about outpatient interventions that might reduce the need for hospitalization and also reduce hospital-related complications. METHODS A literature review was performed on PubMed about hospitalization and PD between 1970 and 2010. In addition, in press peer-reviewed papers or published abstracts known to the authors were included. Information was reviewed by a National Parkinson Foundation workgroup and a narrative review article was generated. RESULTS Motor disturbances in PD are believed to be a causal factor in the higher rates of admissions and complications. However, other conditions are commonly recorded as the primary reason for hospitalization including motor complications, reduced mobility, lack of compliance, inappropriate use of neuroleptics, falls, fractures, pneumonia, and other important medical problems. There are many relevant issues related to hospitalization in PD. Medications, dosages and specific dosage schedules are critical. Staff training regarding medications and medication management may help to avoid complications, particularly those related to reduced mobility, and aspiration pneumonia. Treatment of infections and a return to early mobility is also critical to management. CONCLUSIONS Educational programs, recommendations, and guidelines are needed to better train interdisciplinary teams in the management of the PD patient. These initiatives have the potential for both cost savings and improved outcomes from a preventative and a hospital management standpoint.

LEUKOARAIOSIS SEVERITY AND LIST-LEARNING IN DEMENTIA

In patients with dementia, leukoaraiosis (LA) was hypothesized to result in differential patterns of impairment on a verbal serial list-learning test. Using a visual rating scale, 144 dementia patients with ischemic scores <4 were re-categorized as having mild (n = 73), moderate (n = 44), or severe LA (n = 27). Mild LA was predicted to be associated with an amnestic list-learning profile, while severe LA was predicted to be associated with a dysexecutive profile. List-learning performances were standardized to a group of healthy older adults (n = 24). Analyses were conducted on a set of four factors derived from the list-learning paradigm, as well as error scores. Data indicate that LA severity is an important marker for understanding list learning in dementia.