Cognitive functioning in patients with low-grade glioma: effects of hemispheric tumor location and surgical procedure

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>The authors evaluated the cognitive performance of patients with low-grade glioma (LGG) before and after surgery, and specifically investigated 1) the effects of hemispheric tumor location and 2) the type of surgery (either with or without intraoperative stimulation mapping [ISM]).</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Patients underwent neuropsychological assessment 1 day before (T0) and 3 months after (T3) surgery. ISM targeted motor and/or language functions, but no other cognitive functions. Using 2-way mixed ANOVAs, differences between groups (i.e., for patients with right- vs left-sided lesions and normative controls [NCs], and also for patients operated on with vs without ISM and NCs), effects over time (T0–T3), and interaction effects in cognitive functioning were explored. Individual changes over time were assessed with reliable change indices for each neuropsychological test.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>In total, 77 patients with LGG were included (38 and 39 patients with right- and left-sided lesions, respectively; and 42 patients with and 35 patients without ISM). The majority of patients who were operated on with ISM had left-sided lesions. Patients with right- and left-sided lesions scored significantly lower on 6 and 3 out of 8 tests, respectively, compared to NCs. No significant differences between hemispheric groups were found at T0 or at T3. Patients with left-sided lesions showed significant deterioration of performance on verbal memory and sustained attention over time. Patients who underwent operation with versus without ISM scored significantly lower on 6 and 3 out of 8 tests, respectively, compared to NCs. Patients in the ISM group scored significantly lower on the Stroop test, shifting attention test, and verbal fluency test than patients without ISM. Also, the ISM group showed a significant decline in mean cognitive flexibility and sustained attention performance over time.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>Cognitive impairments were found in patients irrespective of hemispheric tumor location, whereby patients who were operated on with ISM performed slightly worse after surgery than patients without ISM. The authors conclude that there is room for improvement of cognitive functioning in surgically treated patients with LGG. The use of specific tests for higher cognitive functions during surgery may potentially improve functional outcome, but that is to be determined in future studies and balanced against oncological outcome. Implementation of neuropsychological assessments into the clinical management of patients with LGG should be encouraged, to inform and alert patients and clinicians on the status of cognitive functioning.</jats:p></jats:sec>

Neuropsychological Outcomes After Awake Resections of Right Frontal IDH-Mutated Glioma: Insights From a Consecutive Series of 20 Cases.

“…Resection map symptom mapping highlighted the right frontal lobe as being the location most at risk [28]. Such results were further con rmed by studies in 77 low-grade glioma patients, including 27 cases of right frontal location [55]: preoperative impairments in verbal memory, nger tapping, symbol digit coding, cognitive exibility, verbal uency and sustained attention were observed, with further deterioration at three months for sustained attention. Two other recent studies also emphasized the risk regarding inhibition capabilities (as measured by Stroop's task) when operating in the right frontal lobe [50,51].…”

The APOE ε4 allele in relation to pre‐ and postsurgical cognitive functioning of patients with primary brain tumors

“…Further exclusion criteria were: previous intracranial surgery, a recent history (≤2 years) of severe psychiatric or neurologic disorder, other major medical illnesses in the last year (eg, cancer), no basic proficiency in Dutch, and inability to undergo NPA (eg, due to severe visual or motor problems). Patient data described in the current study are partly described in previous studies [10,38,39].…”

Reducing the Cognitive Footprint of Brain Tumor Surgery

“…Such a balance is often referred to as the patient "onco-functional balance." However, while it is well known that not all cortical tissue is functionally eloquent and the brain is generally resistant to a degree of surgical reduction, glioma patients continue to present post-operatively with poor cognitive functioning limiting social interactions and integration back into the workforce (3)(4)(5). If the neurosurgical community is to further consider increasing the extent of resection such as in supramaximal resection, further anatomical and functional information is required to improve our effective navigation of human cerebrum during tumor surgery and to maximize cognitive preservation.…”

“…Anatomical familiarity with specific cortical structures and advancements in multimodal imaging have allowed neurosurgeons to minimize surgically induced neurologic deficits related to major functions including language and motor skills. However, such notions are still often unable to explain the subtle deficits seen in patients with higher-order cognitive functions nor can it explain the heterogeneity in cognitive outcomes with lesions located in traditionally "non-eloquent" tissue (3,(5)(6)(7). One plausible hypothesis suggests that interindividual variability in brain network architecture may explain why certain patients cannot safely tolerate resection of tumor in classically non-eloquent tissue that is based on generalized brain atlases (8).…”