The association of chemotherapy-induced peripheral neuropathy with reduced executive function in chemotherapy-treated cancer survivors: A cross-sectional study

INTRODUCTION

Chemotherapy-induced peripheral neuropathy (CIPN) is common and disabling among cancer survivors. Little is known about the association of CIPN with other measures of the nervous system's integrity, such as executive dysfunction. We compared measures of executive function in older chemotherapy-treated cancer survivors with and without CIPN.

MATERIALS AND METHODS

This cross-sectional study enrolled 50 chemotherapy-treated cancer survivors (65.6 ± 11.5 years, 88% female) post-chemotherapy treatment who were previously referred for outpatient rehabilitation at the request of the cancer survivor or a medical provider. Twenty-two participants (44%) had CIPN defined by patient-reported distal paresthesia or numbness, which began with chemotherapy and continued to the time of cognitive testing. Measures of executive function included Trails-B, Stroop, and rapid reaction accuracy (RRA) and were evaluated between cancer survivors with and without CIPN using t-tests. Multivariable models were then used to determine whether CIPN was an independent determinant of the measures of executive function (Trails-B, Stroop Incongruent, and RRA). Models were adjusted for age, sex, history of anxiety, and benzodiazepine use due to their known associations with CIPN and executive function.

RESULTS

Cancer survivors with CIPN (CIPN+) had reduced executive function compared to survivors without CIPN (CIPN-) on Trails-B (CIPN+: 84.9 s ± 44.1 s, CIPN-: 59.1 s ± 22.5 s, p = 0.01), Stroop (CIPN+: 100.6 s ± 38.2 s, CIPN-: 82.1 s ± 17.3 s, p = 0.03), and RRA (CIPN+: 60.3% ± 12.9%, CIPN-: 70.6% ± 15.7%, p = 0.01). There were no differences in cancer stage severity or functional status by patient report or sit-to-stand function. The association between CIPN and reduced executive function was found in multivariable models after adjusting for age, sex, anxiety, and benzodiazepine use for Trails-B (ß:17.9, p = 0.046), Stroop (ß:16.9, p = 0.02), and RRA (ß:-0.072, p = 0.03).

DISCUSSION

In this population, CIPN is associated with reduced executive function in older cancer survivors treated with chemotherapy. Future research is required to further understand this preliminary association, the causality, and the potential risk factors.

Measuring treatment adverse event burden in myasthenia gravis: Single-center prospective evaluation utilizing the Adverse Event Unit (AEU)

INTRODUCTION/AIMS

We developed a patient- and physician-weighted consensus unit called the adverse event unit (AEU) that quantifies and compares adverse event (AE) burden among any group of medications in neurological patients. In this study we evaluated preliminary validity and feasibility of measuring AE burden with the AEU in myasthenia gravis (MG).

METHODS

This is a single-center, prospective, 1-year, observational study of adult MG patients presenting for routine care between April 1, 2021 and March 31, 2022. The MG Activities of Daily Living (MG-ADL), the 15-item MG Quality of Life revised (MG-QOL15r), MG-Composite, and AEU scores were obtained at all visits. A priori primary feasibility metric was AEU completion rate equal to (within 3.8%, one-sided 95% confidence interval [CI]) or better than MG-ADL completion rate. Time to administer AEU and MG-ADL/MG-QOL15r, correlation between AEU total score and MG-QOL15r, and median AEU scores for each MG medication were evaluated.

RESULTS

Fifty-four patients completed 67 study visits; side effects were reported at 75% of the visits. The study met the primary feasibility endpoint; AEU and MG-ADL were recorded at all visits. Times to administer the AEU (median 5 minutes) and MG-ADL/MG-QOL15r were similar. We observed a weak correlation of 0.29 (95% CI 0.03 to 0.51, P = .032) between AEU and MG-QOL15r scores. Non-statistically significant differences in median AEU scores were observed among MG medications.

DISCUSSION

Our data demonstrate preliminary feasibility and validity of using the AEU to measure AE burden in MG. Future studies will compare AE burden among MG treatments and evaluate clinically meaningful AEU scores in MG.

Executive function is associated with balance and falls in older cancer survivors treated with chemotherapy: A cross-sectional study

INTRODUCTION

Balance decrements and increased fall risk in older cancer survivors have been attributed to chemotherapy-induced peripheral neuropathy (CIPN). Cognition is also affected by chemotherapy and may be an additional contributing factor to poor balance through changes in executive functioning. We examined the association of executive function with balance and falls in older cancer survivors who had been treated with chemotherapy.

MATERIALS AND METHODS

Fifty cancer survivors (aged 65.6 ± 11.5 years; 88% female) who were all treated with chemotherapy were included in this cross-sectional study at a tertiary medical center. Executive function was measured by Trails-B, Stroop, and rapid reaction accuracy, a measure emphasizing rapid inhibitory function. Balance was measured by five sit-to-stand time (5STS), repetitions of sit-to-stand in thirty seconds (STS30), and unipedal stance time (UST), which was the primary balance outcome measure. Self-reported falls in the past year were also recorded and was a secondary outcome. Bivariate analyses were conducted between executive function measures and balance variables. Multivariable models were constructed for UST and falls outcomes and included covariates of age and chemotherapy induced peripheral neuropathy status.

RESULTS

Pearson correlations demonstrated significant relationships between two executive function measures (rapid reaction accuracy, Trails-B) and all the balance measures assessed (UST, STS30, and 5STS). Rapid reaction accuracy correlations were stronger than Trails-B. The Stroop measure correlated solely with UST. In multivariable models, rapid reaction accuracy was associated with better UST (standardized regression coefficient: 64.1, p < 0.01), decreased any fall (odds ratio = 0.000901, p = 0.04), and decreased recurrent falls (odds ratio = 0.0000044, p = 0.01). The interaction of CIPN with the inhibitory measures in the prediction of balance was not significant.

DISCUSSION

Measures of executive function were associated with balance, but among the executive function tests, rapid reaction accuracy had the strongest correlations to balance and was independently associated with falls. The findings suggest that executive function should be considered when assessing fall risk and developing interventions intended to reduce fall risk in older chemotherapy-treated cancer survivors.