Table 3.
Results of included studies
| Reference | Outcome measure | Measure of effect | Results in exposed group v controls (where applicable) | Result |
|---|---|---|---|---|
| Porterw1 | Psychometric | Group comparison* | Better scores in 2/12 tests v controls | P<0.05 |
| Porterw2 | Psychometric | Group comparison* | Deterioration in finger tapping dominant hand (1/12 tests) | P<0.01 |
| Zetterbergw3 | CSF biomarkers | Group comparison* | Increase in 3/6 CSF biomarkers v controls and baseline (at rest) | P=0.04/0.001 |
| Moriartyw4 | Psychometric | Group comparison† | Improvement in 1/5 tests v controls and baseline | P<0.05 |
| Stewartw5 | Psychometric | Odds ratio, contingency analysis | No differences in contingency or odds of abnormality with exposure | Not significant |
| Stewartw5 | EEG | Odds ratio, contingency analysis | No differences in contingency or odds of abnormality with exposure | Not significant |
| Stewartw5 | Brain evoked potentials | Odds ratio, contingency analysis | No differences in contingency or odds of abnormality with exposure | Not significant |
| Butlerw6 | Psychometric | Group comparison* | Improvements in 10/12 tests from baseline | P<0.01-0.001 |
| Haglundw7 | MRI | Group comparison†, contingency analysis | Small numbers of abnormalities in boxers and controls | Not stated |
| Haglundw7 | CT | Group comparison†, contingency analysis | CSP in 2/47 boxers v 4/50 controls, no group differences | Not stated |
| Braynew8 | Creatine kinase BB | Group comparison†, correlation | Significantly increased levels v controls and with exposure | P<0.01, P=0.05 |
| Masterw9 | Psychometric | Group comparison* | Significant changes v controls in 5/8 tests used | P<0.001-0.047 |
| Heilbronnerw10 | Psychometric | Multivariate analysis | Significant changes, both positive (motor) and negative (memory) | P<0.0001-0.004 |
| Kempw11 | Psychometric | Group comparison† | Significant difference v controls in 4/5 tests | P<0.05 |
| Kempw11 | SPECT | Contingency analysis | 14/34 boxers v 5/34 controls abnormal | P<0.02 |
| Mureliusw12 | Psychometric | Group comparison† | No significant difference except finger tapping (dominant hand). | P<0.001 |
| Haglundw13 | Platelet monoamine oxidase | Group comparison * | No difference between exposed group and controls | Not significant |
| Haglundw13 | Neurological | Contingency analysis | 1/47 boxers v 3/50 controls abnormal | Not significant |
| Haglundw14 | EEG | Contingency analysis | No differences in contingencies of abnormalities | Not significant |
| Haglundw14 | Brain evoked potentials | Group comparison† | No significant difference between exposed group and controls | Not significant |
| Levinw15 | Psychometric | Multivariate analysis | Exposed group moved closer to control group results | P=0.10-0.89 |
| Levinw15 | MRI | NA | No abnormalities found in boxers (MRI not performed in controls) | NA |
| Brooksw16 | Psychometric | Group comparison* | No evidence of neuropsychological abnormalities in boxers | Not significant |
| Thomassenw17 | Psychometric | Multivariate analysis | No significant differences except finger tapping (dominant hand). | P<0.01 |
| Thomassenw17 | EEG | Multivariate analysis | No significant difference between exposed and control group | Not significant |
| Thomassenw17 | Neurological | Contingency analysis | “Sparse discrete” findings in boxers and controls | Not significant |
| Holzgrafew18 | MRI | Contingency analysis | 0/13 abnormal before and after exposure | Not significant |
| Jedlinskiw19 | Psychometric | Contingency analysis, correlation | 11/60 abnormal v 0/30 controls, correlation with increasing bouts | Not stated, r=0.50 |
| Jedlinskiw19 | EEG | Contingency analysis, correlation | 24/60 abnormal v 2/30 controls, correlation with increasing bouts | Not stated, r=0.50 |
| Jedlinskiw19 | Neurological | Contingency analysis, correlation | 33/60 abnormal v 3/30 controls, correlation with increasing bouts | Not stated |
| Rodriguezw20 | Regional cerebral blood flow | NA | No abnormalities | NA |
| McLatchiew21 | Psychometric | Group comparison* | 9/16 abnormal, significant differences v controls in 3/10 tests | P<0.05 |
| McLatchiew21 | CT | Correlation | 1/20 abnormal in exposed group (dilated ventricles) | Not significant |
| McLatchiew21 | EEG | Correlation | 8/20 abnormal (various) correlating with increasing number of fights | P<0.05 |
| McLatchiew21 | Neurological | Correlation | 7/20 abnormal correlating with increasing number of fights | P<0.05 |
| Rossw22 | CT | NA | 7/13 abnormal (not specified) | NA |
| Rossw22 | EEG | NA | 4/8 abnormal | NA |
| Rossw22 | Neurological | NA | 1/8 abnormal | NA |
| Jordanw23 | MRI | NA | 1/4 abnormal (congenital or post-traumatic cyst of hippocampus) | NA |
| Jordanw23 | CT | NA | 1/4 abnormal (congenital or post-traumatic cyst of hippocampus) | NA |
| Legwoldw24 | Neurological | NA | 68 concussions/7000 bouts, none resulting in neurological dysfunction | NA |
| Jordanw25 | MRI | NA | 0/9 abnormal | NA |
| Jordanw25 | Neurological | NA | 0/9 abnormal | NA |
| Cassonw26 | Psychometric | NA | 2/5 abnormal as defined by “impairment index” | NA |
| Cassonw26 | CT | NA | 1/5 abnormal (generalised cerebral atrophy) | NA |
| Cassonw26 | EEG | NA | 1/4 abnormal | NA |
| Cassonw26 | Neurological | NA | 1/5 abnormal (mild “organic mental syndrome,” right Babinsky) | NA |
| Kastew27 | Psychometric | NA | 0/8 abnormal | NA |
| Kastew27 | CT | NA | 1/8 abnormal | NA |
| Kastew27 | EEG | NA | 4/7 abnormal | NA |
| Kastew27 | Brain evoked potentials | NA | 1/7 abnormal | NA |
| Kastew27 | Neurological | NA | 0/8 abnormal | NA |
| Corsellisw28 | Histological | NA | 0/3 abnormal | NA |
| Beaussartw29 | EEG | Contingency analysis | 0/123 abnormal (before v after bout) | Not significant |
| Szymusikw30 | Neurological | NA | 6/60 abnormal (“boxer's encephalopathy”) | NA |
| Moriyasuw31 | EEG | NA | 2/10 abnormal (“slightly slow patterns”) | NA |
| Nesarajahw32 | EEG | Not stated | 30/50 abnormal v 6/75 controls | Not stated |
| Beaussartw33 | EEG | Not stated | 25/52 rhythm and slow posterior waves | Not stated |
| Blonsteinw34 | EEG | NA | 0/29 abnormal | NA |
| Blonsteinw34 | Neurological | NA | 0/29 abnormal | NA |
| Pampusw35 | EEG | NA | 11/26 abnormal after 3 bouts v 34/116 before any bouts | Not stated |
| Pampusw35 | Neurological | NA | 42/175 abnormal | NA |
| Blonsteinw36 | EEG | NA | 4/24 abnormal after bout but returned to normal rapidly | NA |
NA=not applicable; CSF=cerebrospinal fluid; CSP=cavum septum pellucidum; CT=computed tomography; EEG=electroencephalography; MRI=magnetic resonance imaging; SPECT=single photon emission computerised tomography.
*t tests (or equivalent non-parametric tests).
†Analysis of variance.