Decoding the clinical effects of low-grade glioma-induced cortical excitability.
J Neurosurg 2024;
140:18-26. [PMID:
37439490 DOI:
10.3171/2023.5.jns23747]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 05/17/2023] [Indexed: 07/14/2023]
Abstract
OBJECTIVE
Patients with low-grade glioma (LGG) in eloquent regions often present with seizures, and findings on detailed neuropsychological testing are often abnormal. This study evaluated the association between cortical excitability, seizures, and cognitive function in patients with LGG.
METHODS
LGG patients who underwent transcranial magnetic stimulation (TMS) from January 2021 to December 2022 were studied. Cortical excitability was measured using the resting motor thresholds (RMTs) of the upper and lower extremities. Early postoperative seizures served as the seizure endpoint. Neuropsychological assessment was completed prior to surgery contemporaneous with the TMS studies.
RESULTS
A total of 31 patients were analyzed for seizure outcome. Median (interquartile range [IQR]) upper-extremity RMT was 39% (34%-46%) of maximum stimulator output, and the median (IQR) lower-extremity RMT was 69% (51%-79%). Lower-extremity RMT was higher in patients with early postoperative seizures, especially in those with motor region tumors (p = 0.02); however, RMT was not associated with seizures at presentation or long-term seizure control. A total of 26 patients completed neuropsychological assessment. There were significant negative correlations between upper-extremity RMT and psychomotor processing speed (Wechsler Adult Intelligence Scale-Fourth Edition [WAIS-IV] Processing Speed Index r = -0.42, p = 0.031; WAIS-IV Coding r = -0.41, p = 0.036; WAIS-IV Symbol Search r = -0.39, p = 0.048), executive function (Trail Making Test Part B r = -0.41, p = 0.036), and hand dexterity (Grooved Pegboard Test r = -0.50, p = 0.047).
CONCLUSIONS
RMT was positively correlated with early postoperative seizure risk and negatively correlated with psychomotor processing speed, executive function, and hand dexterity. These findings support the theory of local and regional resting oscillatory network dysfunction from a glioma-brain network.
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