Design of a neuropsychological battery for the detection of cognitive deficits in asymptomatic patients with low-grade glioma: a pilot study

Abstract

Objective: Gliomas are a group of CNS neoplasms arising from neuroglial cells with various degrees of aggressiveness. Resection of brain tumors is complex to perform without neurological sequelae due to the diffuse nature of the tumors. This study aimed to design a neuropsychological battery to examine pre surgical cognitive deficits in a case series of patients with LGG and to determine the post-surgical effects after resection.

Participants and Methods: 11 adult patients aged 19-65 years (38 ±DS:15.5) with a diagnosis of LGG without cognitive complaint were evaluated with a selection of specific neuropsychological tests to identify possible baseline cognitive deficits and their evolution after tumor resection. All participants completed a comprehensive neuropsychological evaluation assessing memory, language, attention, executive functions, visuospatial functions, social cognition, praxis, agnosias, functionality, mood, and quality of life. The neuropsychological battery design was based on a systematic review of the literature on surgical interventions in low-grade gliomas.

Results: Despite not reporting subjective cognitive complaints, patients showed deficits in multiple cognitive domains in the pre-surgical evaluation when comparing their performance with normative values adjusted for age, sex, and education. Deficits in executive functions and attention were observed: 36% presented failures in graphomotor speed (TMT A), 27% of subjects presented failures in attentional span (Direct Digit Span), working memory (Inverse Digit Span), and cognitive flexibility (Wisconsin Card Sorting Test) and 9% presented difficulties in processing speed (Trail Making Test A) and inhibitory capacity (Stroop Test). Memory: 18% of the patients showed deficits in immediate logical memory and 9% in delayed memory (Craft Story 21). Likewise, 18% of the patients presented compromise in immediate auditory-verbal learning and 27% in delayed auditory-verbal learning (Rey Auditory-Verbal Test). Language: 18% showed failures in naming (Boston 60) and 9% in comprehension (Token Test). Likewise, 27% of the patients presented difficulties in social cognition (Mind in the Eyes Test). Finally 41% of the patients reported symptoms of depression and/or anxiety in the neuropsychiatric questionnaires.

Conclusions: The results highlight the importance of strategically designed pre-surgical cognitive assessment for the detection and follow-up of cognitive and mood disorders associated with the location of the space-occupying lesion (LOE). The patients assessed in this study will be evaluated three months after surgery to document changes in baseline cognitive symptoms. Furthermore, in patients with lesions in the left hemisphere, an intraoperative evaluation will be performed to minimize subsequent deficits, assessing these functions during surgery and emphasizing language.