Cognitive Decline in Post-treatment Lyme Disease Syndrome

OBJECTIVE

Patient-reported cognitive complaints are common in those with post-treatment Lyme disease syndrome (PTLDS). Objective evidence of cognitive impairment in this population is variable in part due to methodological variability in existing studies. In this study, we sought to use a systematic approach to characterizing PTLDS based on the most current consensus diagnosis. We further examined PTLDS-related cognitive decline, operationalized as a significant decline in cognitive test performance relative to premorbid cognitive ability.

METHOD

We enrolled a case series of 124 patients with confirmed PTLDS defined by Infectious Diseases Society of America-proposed case definition. Cognitive functioning was evaluated using standardized neuropsychological measures.

RESULTS

The majority (92%) of participants endorsed some level of cognitive difficulty, yet 50% of the sample showed no statistically or clinically significant cognitive decline, 26% of the sample evidenced significant cognitive decline on measures of memory and variably on measures of processing speed, and 24% of the sample were excluded from analyses due to suboptimal test engagement.

CONCLUSIONS

The current findings are consistent with the literature showing that the most robust neurocognitive deficit associated with PTLDS is in verbal memory and with variable decline in processing speed. Compared to population normative comparison standards, PTLDS-related cognitive decline remains mild. Thus, further research is needed to better understand factors related to the magnitude of subjective cognitive complaints as well as objective evidence of mild cognitive decline.

Reducing deep sedation and delirium in acute lung injury patients: a quality improvement project

OBJECTIVE

Deep sedation and delirium are common in the ICU. Mechanically ventilated patients with acute lung injury are at especially high risk for deep sedation, delirium, and associated long-term physical and neuropsychiatric impairments. We undertook an ICU-wide structured quality improvement project to decrease sedation and delirium.

DESIGN

Prospective quality improvement project in comparison with a retrospective acute lung injury control group.

SETTING

Sixteen-bed medical ICU in an academic teaching hospital with pre-existing use of goal-directed sedation with daily interruption of sedative infusions.

PATIENTS

Consecutive acute lung injury patients.

INTERVENTION

A "4Es" framework (engage, educate, execute, evaluate) was used as part of the quality improvement process. A new sedation protocol was created and implemented, which recommends a target Richmond Agitation Sedation Scale score of 0 (alert and calm) and requires failure of intermittent sedative dosing prior to starting continuous infusions. In addition, twice-daily delirium screening using the Confusion Assessment Method for the ICU was introduced into routine practice.

MEASUREMENTS AND MAIN RESULTS

Sedative use and delirium status in acute lung injury patients after implementation of the quality improvement project (n = 82) were compared with a historical control group (n = 120). During the quality improvement vs. control periods, use of narcotic and benzodiazepine infusions were substantially lower (median proportion of medical ICU days per patient: 33% vs. 74%, and 22% vs. 70%, respectively, both p < 0.001). Further, wakefulness increased (median Richmond Agitation Sedation Scale score per patient: -1.5 vs. -4.0, p < 0.001), and days awake and not delirious increased (median proportion of medical ICU days per patient: 19% vs. 0%, p < 0.001).

CONCLUSION

Through a structured quality improvement process, use of sedative infusions can be substantially decreased and days awake without delirium significantly increased, even in severely ill, mechanically ventilated patients with acute lung injury.

The Johns Hopkins Delirium Consortium: a model for collaborating across disciplines and departments for delirium prevention and treatment

Delirium is an important syndrome affecting inpatients in various hospital settings. This article focuses on multidisciplinary and interdepartmental collaboration to advance efforts in delirium clinical care and research. The Johns Hopkins Delirium Consortium, which includes members from the disciplines of nursing, medicine, rehabilitation therapy, psychology, and pharmacy within the departments and divisions of anesthesiology, geriatrics, oncology, orthopedic surgery, psychiatry, critical care medicine, and physical medicine and rehabilitation at the Johns Hopkins Hospital and Johns Hopkins Bayview Medical Center, is one model of such collaboration. This article describes the process involved in developing functional collaboration around delirium and highlights projects, opportunities, and challenges resulting from them.

Executive Control and Learning Pattern on the CVLT

We evaluated a 23 year-old man after recovery from encephalitis. In contrast to the expected pattern of increasingly better acquisition across the 5 learning trials of the California Verbal Learning Test (CVLT-2), he produced a "J-shaped" curve (Trials 1-5: 8,6,6,9,11). Because he also demonstrated excessive levels of proactive interference as well as poor divided attention, we hypothesized that his atypical learning pattern was due to a build-up of proactive interference secondary to executive dyscontrol. Using a large sample of 4462 healthy adult men, we identified four groups exhibiting various learning patterns. We found that a learning pattern similar to this patient (i.e., a drop after trial 1 followed by recovery) was rare (1.1% of the sample). Individuals with this learning pattern demonstrated increased perseverative responses, as well as greater difficulty maintaining cognitive set on the Wisconsin Card Sorting Test, decreased attentional control on the Paced Auditory Serial Addition Test, and greater levels of proactive interference on the CVLT. Taken together, the results of the study suggest that an early drop, followed by a recovery in learning trial performance, is associated with executive dyscontrol.

Acculturation, reading level, and neuropsychological test performance among African American elders

The independent effects of cultural and educational experience on neuropsychological test performance were examined among 503 nondemented African Americans ages 65 and older. Measures of cultural experience (acculturation) and quality of education (reading level) were administered. Reading level was the most influential predictor of cognitive test performance, even after accounting for age, sex, years of education, and acculturation level. Age had small but significant unique effects on most measures, especially word list learning. Years of education had independent effects on measures of verbal abstraction, fluency, and figure matching. More acculturated African Americans obtained higher scores on most measures; however, after accounting for age, years of education, sex, and reading level, the effect of acculturation was diminished. The results suggest that quality of education and cultural experience influence how older African Americans approach neuropsychological tasks; therefore, adjustment for these variables may improve specificity of neuropsychological measures.

Cancellation test performance in African American, Hispanic, and White elderly

Shape and letter cancellation test performance was investigated among large samples of African American, Hispanic, and White non-demented elders. Ethnic minority elders took significantly longer to complete both tasks compared to Whites. An index of task efficiency, which simultaneously measures time and accuracy, suggested that slower time by minority elders was not related to a measurable effort to achieve greater accuracy. The frequency of commission errors was greater in our sample than in previous reports, especially among ethnic minority elders. Although significant differences were observed between the ethnic groups when matched for years of education, equating for literacy level eliminated all performance differences between African Americans and Whites on both cancellation tasks.

Literacy and memory decline among ethnically diverse elders

Literacy may be a more powerful indicator of brain reserve than years of education. Literacy level may be a proxy for native intellectual capacity or life experience that can compensate for brain damage or provide brain reserve. Alternately, the experience of acquiring literacy skills may in itself change the organization of the brain and increase protection against cognitive decline. However, because people with low levels of literacy obtain poor scores on most cognitive measures, only longitudinal studies can elucidate the role of reading ability in reserve. We determined whether literacy skills could predict cognitive change in a sample of 136 English-speaking African American, Caucasian, and Hispanic elders selected from a longitudinal aging study in New York City. According to a physician's independent examination, all participants were nondemented throughout the four longitudinal assessments. Literacy level was assessed using the WRAT-3 reading subtest. After accounting for age at baseline and years of education, GEE analyses showed that elders with low levels of literacy had a steeper decline in both immediate and delayed recall of a word list over time as compared to high literacy elders. Our findings suggest that literacy skills are protective against memory decline among nondemented elders.

Reading level attenuates differences in neuropsychological test performance between African American and White elders

The current study sought to determine if discrepancies in quality of education could explain differences in cognitive test scores between African American and White elders matched on years of education. A comprehensive neuropsychological battery was administered to a sample of African American and non-Hispanic White participants in an epidemiological study of normal aging and dementia in the Northern Manhattan community. All participants were diagnosed as nondemented by a neurologist, and had no history of Parkinson's disease, stroke, mental illness, or head injury. The Reading Recognition subtest from the Wide Range Achievement Test-Version 3 was used as an estimate of quality of education. A MANOVA revealed that African American elders obtained significantly lower scores than Whites on measures of word list learning and memory, figure memory, abstract reasoning, fluency, and visuospatial skill even though the groups were matched on years of education. However, after adjusting the scores for WRAT-3 reading score, the overall effect of race was greatly reduced and racial differences on all tests (except category fluency and a drawing measure) became nonsignificant. These findings suggest that years of education is an inadequate measure of the educational experience among multicultural elders, and that adjusting for quality of education may improve the specificity of certain neuropsychological measures.