Post‐surgical effects on language in patients with presumed low‐grade glioma
Patients with gliomas in a language‐eloquent area of the brain often deteriorate in their language ability immediately after surgery, but have a high degree of recovery during the first months after surgery.3 However, most studies focus on patients with tumours in language‐eloquent cortex undergoing awake surgery. Less is known about the surgical effect on language for patients with tumours outside classical language areas in the left or right hemisphere (LH, RH). Satoer et al10 found that patients with a tumour in language‐eloquent areas, and patients with a tumour in non‐language‐eloquent areas had comparable results both before and after surgery. Furthermore, Yordanova et al11 found an early post‐operative worsening of language function in patients with tumours in non‐eloquent areas in the LH. Studies investigating language deficits in patients with a tumour in the right hemisphere are scarce, but lexical retrieval difficulties have been reported.12
Several studies also stress the need for sensitive measurements of language function.12 Aphasia test batteries designed to detect aphasia after strokes are often used for assessments4 but tumour patients can have milder impairments and greater variability than stroke patients.14 In contrary, high‐level language (HLL) includes more complex language abilities demanding extensive language and cognitive processing,16 such as understanding metaphors and drawing conclusions about something that is not stated explicitly. Consequently, HLL testing is more sensitive and perhaps more suitable for this patient population, but have not been studied.
Our overall aim was to investigate language outcome following tumour surgery in a consecutive series of patients with presumed LGG, using sensitive tests of language ability including tests of HLL. This was done by investigating: (1) preoperative language ability in patients with LGG in either LH or RH with a relevant reference group; (2) language ability in patients with LGG directly after surgery and at 3‐month follow‐up compared to their preoperative testing; and (3) the influence of tumour location on language impairment in individual patients before and after surgery.