Examining for Cavum Septum Pellucidum and Ventricular Enlargement in Retired Elite-Level Rugby League Players

Enlarged cavum septum pellucidum as a neuroimaging signature of head impact exposure

Cavum septum pellucidum (CSP) is commonly observed upon neuroimaging examination in individuals exposed to repetitive head impacts (RHI) and post-mortem in cases with chronic traumatic encephalopathy. Consequently, CSP has been proposed as a potential biomarker for RHI-related neurodegeneration, yet prevalence estimates of CSP across other neurodegenerative diseases and its clinical implications are largely unknown. We assessed CSP prevalence and clinical correlates in individuals with RHI exposure, a history of traumatic brain injury (TBI), a neurodegenerative disease (i.e. Alzheimer's disease or frontotemporal dementia) and normal cognition. The primary group of interest, i.e. individuals exposed to RHI in contact sports or military service (n = 65; mean exposure 21.58 years), was compared against age- and sex-matched participants with TBI (n = 57; number of TBI range: 1-5) and non-exposed participants of the Amsterdam Dementia Cohort (Alzheimer's disease, n = 30; frontotemporal dementia, n = 24; normal cognition, n = 27). Structural 3D brain MRI scans were visually rated for CSP grade (ranging 0-4) by two raters blinded to the clinical information. A CSP of at least Grade 2 was considered enlarged/abnormal. Inter-rater reliability was assessed with Cohens' weighted Kappa (κ). We investigated whether prevalence of enlarged CSP differed between groups and assessed associations with neuropsychological outcomes (verbal memory, processing speed, mental flexibility and semantic fluency), neuropsychiatric symptoms (neuropsychiatric inventory), ventricular enlargement as measured with Evan's index and MRI volumes of composite regions (limbic, temporal-meta regions and the whole brain). Inter-rater reliability was substantial [κ = 0.734 (95% confidence interval 0.67-0.80)]. An enlarged CSP was more often observed in the RHI group (44.6%) compared with individuals with Alzheimer's disease [13.3%, odds ratio (OR) = 5.24 (1.79-19.26)], frontotemporal dementia [16.7%, OR = 4.03 (1.35-15.02)] and normal cognition [18.5%, OR = 3.54 (1.27-11.62)], all P FDR < 0.05, but not compared with the TBI group [29.8%, OR = 1.90 (0.90-4.06), P FDR  = 0.094]. In those with RHI, enlarged CSP was associated with lower outcomes on verbal memory learning (η² = 0.09, P FDR = 0.023) and recall (η² = 0.08, P FDR = 0.030). For TBI, enlarged CSP was associated with lower performance on verbal memory learning; however, this lost significance after multiple comparison correction (η² = 0.014, P FDR = 0.09). Enlarged CSP was not associated with the composite MRI volumes, ventricular enlargement or neuropsychiatric symptoms. In summary, enlarged CSP was more prevalent in RHI-exposed individuals compared with individuals with a neurodegenerative disease or normal cognition, but not compared with TBI, and was associated with lower verbal memory performance in the RHI group. Our study highlights enlarged CSP as a potential consequence of long-term head impact exposure and, to a lesser extent, TBI, rather than a general consequence of neurodegeneration.

Chronic traumatic encephalopathy: State-of-the-science update and narrative review

OBJECTIVE

The long-recognized association of brain injury with increased risk of dementia has undergone significant refinement and more detailed study in recent decades. Chronic traumatic encephalopathy (CTE) is a specific neurodegenerative tauopathy related to prior exposure to repetitive head impacts (RHI). We aim to contextualize CTE within a historical perspective and among emerging data which highlights the scientific and conceptual evolution of CTE-related research in parallel with the broader field of neurodegenerative disease and dementia.

METHODS

We provide a narrative state-of-the-science update on CTE neuropathology, clinical manifestations, biomarkers, different types and patterns of head impact exposure relevant for CTE, and the complicated influence of neurodegenerative co-pathology on symptoms.

CONCLUSIONS

Now almost 20 years since the initial case report of CTE in a former American football player, the field of CTE continues evolving with increasing clarity but also several ongoing controversies. Our understanding of CTE neuropathology outpaces that of disease-specific clinical correlates or the development of in-vivo biomarkers. Diagnostic criteria for symptoms attributable to CTE are still being validated, but leveraging increasingly available biomarkers for other conditions like Alzheimer's disease may be helpful for informing the CTE differential diagnosis. As diagnostic refinement efforts advance, clinicians should provide care and/or referrals to providers best suited to treat an individual patient's clinical symptoms, many of which have evidence-based behavioral treatment options that are etiologically agnostic. Several ongoing research initiatives and the gradual accrual of gold standard clinico-pathological data will pay dividends for advancing the many existing gaps in the field of CTE.

Long-term neurobehavioral and neuroimaging outcomes in athletes with prior concussion(s) and head impact exposure

Objective: The long-term health of former athletes with a history of multiple concussions and/or repetitive head impact (RHI) exposure has been of growing interest among the public. The true proportion of dementia cases attributable to neurotrauma and the neurobehavioral profile/sequelae of multiple concussion and RHI exposure among athletes has been difficult to determine. Methods: Across three exposure paradigms (i.e. group comparisons of athletes vs. controls, number of prior concussions, and level of RHI exposure), this review characterizes the prevalence of neurodegenerative/neurological disease, changes in cognitive and psychiatric function, and alterations on neuroimaging. We highlight sources of variability across studies and provide suggested directions for future investigations. Results: The most robust finding reported in the literature suggests a higher level of symptom endorsement (general, psychiatric, and cognitive) among those with a greater history of sport-related concussion from adolescence to older adulthood. Pathological processes (e.g. atrophy, tau deposition, and hypometabolism) may be more likely to occur within select regions (frontal and temporal cortices) and structures (thalamus and hippocampus). However, studies examining concussion(s) and RHI exposure with imaging outcomes have yet to identify consistent associations or evidence of a dose-response relationship or a threshold at which associations are observed. Discussion: Studies have not observed a simple dose-response relationship between multiple concussions and/or RHI exposure with cognitive, psychiatric, or in vivo neurobiological outcomes, particularly at lower levels of play. The relationship between prior concussion and RHI exposure with long-term outcomes in former athletes is complex and likely influenced by -several non-injury-related factors.

Cavum Septum Pellucidum in Former American Football Players: Findings From the DIAGNOSE CTE Research Project

Background and Objectives

Exposure to repetitive head impacts (RHI) is linked to the development of chronic traumatic encephalopathy (CTE), which can only be diagnosed at post-mortem. The presence of a cavum septum pellucidum (CSP) is a common finding in post-mortem studies of confirmed CTE and in neuroimaging studies of individuals exposed to RHI. This study examines CSP in living former American football players, investigating its association with RHI exposure, traumatic encephalopathy syndrome (TES) diagnosis, and provisional levels of certainty for CTE pathology.

Methods

Data from the DIAGNOSE CTE Research Project were used to compare the presence and ratio of CSP in former American football players (n = 175), consisting of former college (n = 58) and former professional players (n = 117), and asymptomatic unexposed controls without RHI exposure (n = 55). We further evaluated potential associations between CSP measures and cumulative head impact index (CHII) measures (frequency, linear acceleration, and rotational force), a TES diagnosis (yes/no), and a provisional level of certainty for CTE pathology (suggestive, possible, and probable).

Results

Former American football players exhibited a higher CSP presence and ratio than unexposed asymptomatic controls. Among player subgroups, professional players showed a greater CSP ratio than former college players and unexposed asymptomatic controls. Among all football players, CHII rotational forces correlated with an increased CSP ratio. No significant associations were found between CSP measures and diagnosis of TES or provisional levels of certainty for CTE pathology.

Discussion

This study confirms previous findings, highlighting a greater prevalence of CSP and a greater CSP ratio in former American football players compared with unexposed asymptomatic controls. In addition, former professional players showed a greater CSP ratio than college players. Moreover, the relationship between estimates of CHII rotational forces and CSP measures suggests that cumulative frequency and strength of rotational forces experienced in football are associated with CSP. However, CSP does not directly correlate with TES diagnosis or provisional levels of certainty for CTE, indicating that it may be a consequence of RHI associated with rotational forces. Further research, especially longitudinal studies, is needed for confirmation and to explore changes over time.

Linking Type and Extent of Head Trauma to Cavum Septum Pellucidum in Older Adults With and Without Alzheimer Disease and Related Dementias

BACKGROUND AND OBJECTIVES

Cavum septum pellucidum (CSP) is a common but nonspecific MRI finding in individuals with prior head trauma. The type and extent of head trauma related to CSP, CSP features specific to head trauma, and the impact of brain atrophy on CSP are unknown. We evaluated CSP cross-sectionally and longitudinally in healthy and clinically impaired older adults who underwent detailed lifetime head trauma characterization.

METHODS

This is an observational cohort study of University of California, San Francisco Memory and Aging Center participants (healthy controls [HCs], those with Alzheimer disease or related dementias [ADRDs], subset with traumatic encephalopathy syndrome [TES]). We characterized traumatic brain injury (TBI) and repetitive head impacts (RHI) through contact/collision sports. Study groups were no RHI/TBI, prior TBI only, prior RHI only, and prior RHI + TBI. We additionally looked within TBI (1, 2, or 3+) and RHI (1-4, 5-10, and 11+ years). All underwent baseline MRI, and 67% completed a second MRI (median follow-up = 5.4 years). CSP measures included grade (0-4) and length (millimeters). Groups were compared on likelihood of CSP (logistic regression, odds ratios [ORs]) and whether CSP length discriminated groups (area under the curve [AUC]).

RESULTS

Our sample included 266 participants (N = 160 HCs, N = 106 with ADRD or TES; age 66.8 ± 8.2 years, 45.3% female). Overall, 123 (49.8%) participants had no RHI/TBI, 52 (21.1%) had TBI only, 41 (16.6%) had RHI only, 31 (12.6%) had RHI + TBI, and 20 were classified as those with TES (7.5%). Compared with no RHI/TBI, RHI + TBI (OR 3.11 [1.23-7.88]) and TES (OR 11.6 [2.46-54.8]) had greater odds of CSP. Approximately 5-10 years (OR 2.96 [1.13-7.77]) and 11+ years of RHI (OR 3.14 [1.06-9.31]) had higher odds of CSP. CSP length modestly discriminated participants with 5-10 years (AUC 0.63 [0.51-0.75]) and 11+ years of prior RHI (AUC 0.69 [0.55-0.84]) from no RHI/TBI (cut point = 6 mm). Strongest effects were noted in analyses of American football participation. Longitudinally, CSP grade was unchanged in 165 (91.7%), and length was unchanged in 171 (95.5%) participants.

DISCUSSION

Among older adults with and without neurodegenerative disease, risk of CSP is driven more by duration (years) of RHI, especially American football, than number of TBI. CSP length (≥6 mm) is relatively specific to individuals who have had substantial prior RHI. Neurodegenerative disease and progressive atrophy do not clearly influence development or worsening of CSP.

Health conditions among retired elite rugby players: a scoping review

The aim of this scoping review was to present an overview of the existing epidemiological evidence in retired male and female elite rugby players regarding the prevalence rates of musculoskeletal, cardiovascular, neurocognitive, psychological and gynaecological health conditions. A systematic search was carried out across MEDLINE (via PubMed), SPORTDiscus (via EBSCOhost), PsycINFO (via EBSCOhost) and EMBASE for musculoskeletal (eg, osteoarthritis), cardiovascular (eg, hypertension), neurocognitive (eg, dementia) and psychological health (eg, disordered eating, alcohol misuse) conditions in retired elite male and female rugby players and gynaecological health conditions (menorrhagia) in retired female rugby players. Primary research studies describing the prevalence rates of health conditions in retired elite male and female rugby players written in English, Dutch or French and with full text available online were included. Five hundred and seventy-three citations were originally identified and 16 studies were ultimately included in our review. No studies on health conditions in retired elite female rugby players were found. Four individual studies showed there was a significant higher prevalence rate of osteoarthritis in retired elite male rugby players compared with control groups. Various neurocognitive health conditions were investigated and showed, among others, a prevalence rate of 57% for mild cognitive disorder. The prevalence of self-reported depression and hazardous alcohol use in retired elite male rugby players was significantly higher than in control groups matched for age and education. Our review found relatively high prevalence rates of musculoskeletal health conditions such as osteoarthritis and psychological health conditions such as depression and hazardous alcohol use in retired elite male rugby players. More research needs to be conducted to understand better the health conditions of retired elite rugby players, especially among retired elite female players.

Examining later-in-life health risks associated with sport-related concussion and repetitive head impacts: a systematic review of case-control and cohort studies

OBJECTIVE

Concern exists about possible problems with later-in-life brain health, such as cognitive impairment, mental health problems and neurological diseases, in former athletes. We examined the future risk for adverse health effects associated with sport-related concussion, or exposure to repetitive head impacts, in former athletes.

DESIGN

Systematic review.

DATA SOURCES

Search of MEDLINE, Embase, Cochrane, CINAHL Plus and SPORTDiscus in October 2019 and updated in March 2022.

ELIGIBILITY CRITERIA

Studies measuring future risk (cohort studies) or approximating that risk (case-control studies).

RESULTS

Ten studies of former amateur athletes and 18 studies of former professional athletes were included. No postmortem neuropathology studies or neuroimaging studies met criteria for inclusion. Depression was examined in five studies in former amateur athletes, none identifying an increased risk. Nine studies examined suicidality or suicide as a manner of death, and none found an association with increased risk. Some studies comparing professional athletes with the general population reported associations between sports participation and dementia or amyotrophic lateral sclerosis (ALS) as a cause of death. Most did not control for potential confounding factors (eg, genetic, demographic, health-related or environmental), were ecological in design and had high risk of bias.

CONCLUSION

Evidence does not support an increased risk of mental health or neurological diseases in former amateur athletes with exposure to repetitive head impacts. Some studies in former professional athletes suggest an increased risk of neurological disorders such as ALS and dementia; these findings need to be confirmed in higher quality studies with better control of confounding factors.

PROSPERO REGISTRATION NUMBER

CRD42022159486.

Severe CTE and TDP-43 pathology in a former professional soccer player with dementia: a clinicopathological case report and review of the literature

In the last decades, numerous post-mortem case series have documented chronic traumatic encephalopathy (CTE) in former contact-sport athletes, though reports of CTE pathology in former soccer players are scarce. This study presents a clinicopathological case of a former professional soccer player with young-onset dementia. The patient experienced early onset progressive cognitive decline and developed dementia in his mid-50 s, after playing soccer for 12 years at a professional level. While the clinical picture mimicked Alzheimer's disease, amyloid PET imaging did not provide evidence of elevated beta-amyloid plaque density. After he died in his mid-60 s, brain autopsy showed severe phosphorylated tau (p-tau) abnormalities fulfilling the neuropathological criteria for high-stage CTE, as well as astrocytic and oligodendroglial tau pathology in terms of tufted astrocytes, thorn-shaped astrocytes, and coiled bodies. Additionally, there were TAR DNA-binding protein 43 (TDP-43) positive cytoplasmic inclusions in the frontal lobe and hippocampus, and Amyloid Precursor Protein (APP) positivity in the axons of the white matter. A systematic review of the literature revealed only 13 other soccer players with postmortem diagnosis of CTE. Our report illustrates the complex clinicopathological correlation of CTE and the need for disease-specific biomarkers.