Neurocognitive Changes Associated With Surgical Resection of Left and Right Temporal Lobe Glioma

Abstract

Background: Little is known regarding the neurocognitive impact of temporal lobe tumor resection.

Objective: To clarify subacute surgery-related changes in neurocognitive functioning (NCF) in patients with left (LTL) and right (RTL) temporal lobe glioma.

Methods: Patients with glioma in the LTL (n = 45) or RTL (n = 19) completed comprehensive pre- and postsurgical neuropsychological assessments. NCF was analyzed with 2-way mixed design repeated-measures analysis of variance, with hemisphere (LTL or RTL) as an independent between-subjects factor and pre- and postoperative NCF as a within-subjects factor.

Results: About 60% of patients with LTL glioma and 40% with RTL lesions exhibited significant worsening on at least 1 NCF test. Domains most commonly impacted included verbal memory and executive functioning. Patients with LTL tumor showed greater decline than patients with RTL tumor on verbal memory and confrontation naming tests. Nonetheless, over one-third of patients with RTL lesions also showed verbal memory decline.

Conclusion: In patients with temporal lobe glioma, NCF decline in the subacute postoperative period is common. As expected, patients with LTL tumor show more frequent and severe decline than patients with RTL tumor, particularly on verbally mediated measures. However, a considerable proportion of patients with RTL tumor also exhibit decline across various domains, even those typically associated with left hemisphere structures, such as verbal memory. While patients with RTL lesions may show even greater decline in visuospatial memory, this domain was not assessed. Nonetheless, neuropsychological assessment can identify acquired deficits and help facilitate early intervention in patients with temporal lobe glioma.

FIGURE 1

Temporal lobe segmentation. Abbreviations: A, lateral anterior; P, lateral posterior; M, medial.

FIGURE 2

Pre- to postoperative neurocognitive change by patient group. See Table 3 for sample size descriptions. Error bars represent standard error of the mean. *Significant difference between LTL and RTL groups, P≤.05.

FIGURE 3

Rates of postoperative neurocognitive decline by patient group across measures Severe Decline, z-score change < −3.00; Moderate Decline, z-score change −2.99 to −2.00; Mild Decline, z-score change −1.99 to −1.00. *Significant difference in total decline between LTL and RTL groups, P≤.05.