Box 1.

Tumor location and other relevant factors related to cognitive performance prior to and/or following treatment

Relevant factors	Relevant findings	Study
Tumor location	No sign differences in cognitive status between lateralization groups prior to and following surgery	Tucha [4]
	Sign differences in changes over time between lateralization groups, mainly on attentional functions. Left-sided (n = 22) MGM improved sign on flexibility and shifting. Right-sided (n = 21) MGM improved sign on variety of attentional functions
	Sign effect of frontal MGM on pre-operative and post-operative cognitive status. Prior to surgery; falx cerebri (n = 14) performed sign better on figural fluency than frontobasal (n = 19) and convexity (n = 17) MGM. Following surgery; frontobasal (n = 19) and falx cerebri (n = 14) MGM performed sign better on divided attention and figural memory than convexity (n = 17) MGM
	Sign differences between localization groups for various cognitive domains. Convexity (n = 17) MGM: only improvement on flexibility and shifting (attentional/executive functions), frontobasal (n = 19) MGM: improvement on a broader range of attentional/executive functions after surgery. Pts with falx cerebri (n = 14) MGM improved on various cognitive domains
	No sign differences in cognitive status between lateralization groups prior to and following surgery	Meskal [20]
	No sign associations between tumor lateralization and cognitive improvement over time
	No sign differences in pre-operative or post-operative cognitive functioning based on tumor localization, except for complex attention: sign better performance for infratentorial (n = 7) as opposed to supratentorial (n = 61) tumors
	No sign associations between tumor localization (skull base, convexity, and convexity/falx) and cognitive improvement over time
	Cognitive function normalized in right-sided (n = 17) MGM following surgery. Left-sided (n = 17) MGM did not normalize or improve	Yoshii [7]
	No statistical tests were conducted in this study: no clear conclusions can be drawn
	No reports on specific localization or lateralization effects on cognitive functioning	Koizumi [19]
	Based on data in a table; 3 pts with very low scores (<10) on MMSE before surgery, suffered from convexity (n = 4) MGM. These pts improved substantially after surgery, but still had the lowest scores on MMSE (≤ 23), compared with other localization groups
	No clear associations of memory functions with localization before FSRT (no data reported)	Steinvorth [27]
	No clear lateralization effects before and after FSRT
	Pts with left-sided (n = 37) MGM performed sign worse on verbal memory compared to right-sided (n = 25) MGM	Dijkstra [5]
	Lower cognitive performance in skull-base (n = 24) MGM on verbal memory, information processing, and psychomotor speed compared to convexity (n = 28) MGM. Not clear as to whether theses analyses were done in smaller subgroups of the study sample
Epilepsy	Sign negative correlation between epilepsy burden and executive functioning, primarily due to AEDs use, not to epileptic seizures	Dijkstra [5]
	Sign impaired cognitive functioning also in pts who did not use AEDs (n = 66) compared with HC
	Comparable HRQoL in pts to that in HC	Waagemans [2]
	HRQoL worse in pts with cognitive deficits and pts who use AEDs, irrespective of seizure control
Mood	No sign correlation between anxiety and cognitive domains, negative correlation between depression and 6/7 cognitive domains prior to surgery (n = 60 out of 68)	Meskal [20]
	Negative correlation between anxiety and attention, negative correlation between depression, memory and attention following surgery (n = 52 out of 62)
	Sign improvement toward a positive mood from baseline (no data reported) up to 6 weeks after follow-up of FSRT	Steinvorth [27]
	No correlations were investigated
Quality of life	RTx+ pts lower HRQoL than RTx- pts	Van Nieuwenhuizen [8]
	No sign differences in HRQoL between RTx- pts and HC. After correction for duration of disease, no sign differences in HRQoL between both MGM groups
	No comparisons were made for HRQoL between RTx+ pts and HC
	No sign differences between pts and HC on 7/8 HRQoL scales	Waagemans [2]
	Impaired executive functioning had a direct negative relationship with other cognitive domains (information processing, verbal memory, psychomotor speed, and attention), and an indirect negative relationship with HRQoL
Other factors	IZM-SPECT images showed recovered binding potential of IZM following surgery	Koizumi [19]

AEDs anti-epileptic drugs, FSRT fractioned stereotactic radiotherapy, HC healthy controls, HRQoL health-related quality of life, IZM-SPECT ¹³³I-iomazenil (IMZ) single-photon emission computed tomography (SPECT) imaging. MGM meningioma, MMSE mini-mental state examination, Pts patients, RTx radiotherapy. Sign significant