Introduction
Methodology (systematic review)
Inclusion criteria
Search strategy
Study selection process
Results
Study | Patient group | Control group | Treatment | NP tests/domains | Timing of assessment(s) | Definition of CI | Statistics | Relevant results prior to treatment | Relevant results following treatment |
---|---|---|---|---|---|---|---|---|---|
Tucha [4] | 54 ST frontal MGM Grade1 = NR M age = 57.8 (SD = 1.5) M vol = 79.3 cm (SD = 11.3) | 54 matched HC M age = 57.9 (SD = 1.5) | Surgical removal | VerM, VisM, Att, EF, VC | 2–3 days before surgery, 4–9 months after surgery | None | Non parametric tests, Ipsative scores2, Spearman rank corr | Sign lower mean raw scores, longer reaction times, or higher error rates on measures of WM, Att, and EF | Sign lower mean raw scores, longer reaction times, or higher error rates on Att and EF. Sign improvements on measures of (immediate recall) VisM and Att |
Tucha [10] | 33 ST MGM Grade = NR M age = 72.8 (SEM = 0.9) M vol = NR 7 tumors diameter ≤ 4 cm 26 tumors diameter > 4 cm | 20 HC M age = 73.1 (SEM = 1.0) | Surgical removal | Same as in [4] | Before surgery, 3–6 months after surgery | None | (Non) parametric tests | Sign lower mean raw scores, longer reaction times, or higher error rates on measures of WM, (short-term) VisM, Att, and EF | Sign improvements on measures of (short-term) VisM and Att. Comparable post-op cogn status to cogn functioning of elderly HC, except for WM |
Meskal [20] | 68 ST and IT MGM Grade I M age = 55.7 (range = 36–74) M vol = NR Maximum diameter = 4.38 cm | Norms based on healthy American population [22] (N = 1,069) | Surgical removal | Mem, PsyMo, RT, Att, CogFlex, ProcSp, EF (computer tests) | 1 day before surgery, 3 months after surgery | Standard scores ≥1.5–2 SD below norm | T-tests, Mc Nemar’s tests, Pearson product-moment corr | Sign lower standard scores on all cogn domains. 47/68 pts (69 %) low or very low on 1 or more cogn domains | Sign improved mean standard scores for all cogn domains, except PsyMo and RT. Sign lower mean standard scores for all cogn domains. 27/62 pts (47 %) low or very low on 1 or more cogn domains |
Yoshii [7] | 34 MGM Grade = NR Right-sided: M age = 64 (SD = NR) Left-sided: M age = 59 (SD = NR) M vol = NR 83 glioma | Normative healthy population values from manual (reference: could not be retrieved) | Surgical removal | 3MS test | Before surgery and/or within 1 month after surgery | Subnormal cogn function = 3 MS score <85 | NR | Subnormal cogn function. No differences in cogn function between left-sided and right-sided MGM | Normalization only in right-sided group, not in left-sided group |
Koizumi [19] | 10 ST MGM Grade I: (n = 9), grade II: (n = 1) M age = 68.1 (SD = 13.1) M vol = 89.1 ml (SD = 51.8) | Normative healthy population values (reference: NR) | Surgical removal | MMSE IZM-SPECT | Within 4 weeks before surgery, 3 months after surgery | MMSE score ≤23 | NR for MMSE data, T-tests for IZM-SPECT data | Mean MMSE scores = 19.9 (SD = 11.4), ranging from 2 to 30 | Sign improvement of cogn function, mean MMSE score = 26.5 (SD = 3.8) |
Van Niewenhuizen [6] | 21 untreated MGM, wait-and-scan approach Grade I M age = 63.4 (SD = 13.5) M vol = 6.3ml (SD = 6.5) | 21 normative matched (age, gender, education) HC from MAAS [26] (N = 2,000), M age = 62.4 (SD = 12.9) | None | VerM, WM, Att, EF, PsyMo, InfPro | Once | Z-scores ≥1.5 SD below norm | Mann-Whitney U-tests, Kendall’s Tau | Sign lower mean Z-scores on WM and PsyMo, sign better mean Z-scores on VerM | NAp |
Steinvorth [27] | 40 ST MGM Grade = NR M age = 55 (SD = 14) M vol = NR 1 total resection: (n = 16), 1 partial resection: (n = 8), ≥ 2 resections: (n = 6), no resection: (n = 10) | Normative healthy population values from manuals | FSRT | VerM, VisM, Att, IQ | 1 day before FSRT, within 24 hrs after first fraction, at end of FSRT, 6 weeks, 6 and 12 months after FSRT | None | (Non) parametric tests | Sign lower mean pct scores on Att/InfPro | After first fraction: transient decline in Mem and improvements in Att. During further follow-up: no deteriorations, but further improvements in Mem and Att |
Van Niewenhuizen [8] | 36 ST MGM Grade I 18 RTx+: surgery and RTx M age = 63.3 (SD = 10.6) M vol = 39.4 ml (SD = 43.5) 18 RTx-: surgery only M age = 62.6 (SD = 11.8) M vol = 23.5 ml (SD = 19.3) | 18 normative matched (age, gender, education) HC from MAAS [26] (N = 2,000) M age = NR | Surgical removal with (RTx+) /without (RTx-) adjuvant RTx | Mem, Att, EF, Perc | ≥1 year after surgery | None | Chi-square tests, T-tests | NAp | No sign differences in mean standard scores on all cogn domains between RTx- and RTx+. Sign lower mean standard scores on all cogn domains in RTx-. No comparisons were made for cogn functioning between RTx+ group and HC |
Krupp [9] | 91 ST MGM Grade I M age = 56 (SD = 10) M vol = NR | Normative healthy population values from manuals | Surgical removal | Tests of Att, IQ | 10–18.5 months after surgery | None | T-tests, Chi-square tests, ANOVA, Spearman rank corr, Regression analyses | NAp | Negative corr between age and Att in pts > 55 yrs, as well as with IQ factors verbal knowledge, technical ability, and word fluency |
Dijkstra [5] | 89 ST MGM Grade I M age = 58.6 (SD = 12.1) M vol = 46.1 ml (SD = 51.8) | 89 normative matched (age, gender, education) HC from MAAS [26] (N = 2,000) M age = 58.3 (SD = 13.3) | Surgical removal with (n = 22)/ without adjuvant RTx (n = 67) | VerM, WM, Att, EF, PsyMo, InfPro | ≥1 year after surgery | Z-scores ≥1.5 SD below HC mean | T-tests, Multiple regression analyses | NAp | Sign lower mean Z-scores on all domains, except for Att |
Waagemans [2] | 89 ST MGM Grade I M age = 58.4 (SD = 13.2) M vol = 46.1 ml (SD = 51.8) | 89 normative matched (age, gender, education) HC from MAAS [26] (N = 2,000) M age = 58.3 (SD = 13.3) | Surgical removal with (n = 22)/without adjuvant RTx (n = 67) | Same as in [5] | ≥1 year after surgery | Z-scores ≥1.5 SD below HC mean | T-tests, Multiple regression analyses | NAp | Same population as in [5]. Similar findings on cogn functioning as in [5] |
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] |