51 Optimizing the Mapping out of Neurocognitive Functioning in Glioblastomas in the Era of Intraoperative Mapping in Surgical Resection

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Objective:

Glioblastomas, Grade 4 astrocytomas, comprise about 60% of all astrocytomas and have a median survival rate between 14 and 16 months. The extent of resection impacts the prognosis, with an eloquent balance of preserving the patient's functional status. As preoperative imaging and intraoperative techniques improve to maximize safe operative resection, thorough neuropsychological evaluation can aid in assessing cognitive decline and quality of life pre- and post-treatment. In light of the tumors' progressive nature and potential presence in precarious brain locations, it is imperative that the functional burden of the various presentations of glioblastomas be understood. Given the limited data on cognitive presentations of glioblastomas, we present a case study describing a neuropsychological and neuroradiologic profile of a Grade 4 astrocytoma in a patient with a left temporal glioblastoma.

Participants and Methods:

The patient signed consent for clinical evaluation and research. At the time of evaluation, he was 68 years old with a master's degree and was working at multiple start-up companies. He began noticing subtle cognitive functioning changes approximately two months prior with difficulty understanding information. His challenges progressed to difficulty composing emails, word-finding issues, and some slurring and mispronunciations. He was diagnosed with a brain tumor after an emergency MRI was performed. He participated in a neuropsychological evaluation just prior to surgery. The evaluation included a battery of neuropsychological tests examining attention, processing speed, executive functioning, learning and memory, language functioning, visuospatial functioning, motor functioning, and mood.

Results:

The imaging results revealed a non-enhancing intra-axial mass in the left superior temporal lobe with surrounding edema. Also noted were rare scattered nonspecific T2 hyperintensities. The scores showed variable motor functioning and deficits within attention for complex information, executive functioning abilities (i.e., motor planning and sequencing, phonemic fluency), language functioning, visuospatial functioning, and learning and memory of information relative to his premorbid level of functioning, indicating total brain involvement consistent with imaging findings of edema.

Conclusions:

Taken together, the results of the evaluation and imaging were suggestive of a level of cognitive decline that is more than expected with normal aging. Moreover, there was a lack of evidence representative of a lateralized profile. Notably, the evaluation was conducted before resection surgery, and therefore, the patient continued to experience significant brain edema due to the tumor. Although medication may have contributed to dysfunction, particularly with motor and cognitive slowing, it is not likely that it explained his presentation entirely. As such, the evaluation results were suggestive of neurocognitive dysfunction, which was partially attributable to the tumor and edema displacing neuronal tissue. Given the potential for improvement following tumor resection and secondary decline resulting from recurrence or treatment, it is crucial to have a baseline and the ability to map out higher order functioning, including frontal and temporal lobe functioning. Ultimately, as the field continues to look toward long-term survival for patients with currently lethal brain tumors, the goal is to achieve maximum resection with minimal neurocognitive loss.