By Nitin K. Sethi, MD
Associate Professor of Neurology, Weill Cornell Medical College; Director, Weill Cornell Concussion and Brain Injury Center
Dr. Sethi reports no financial relationships relevant to this field of study.
SYNOPSIS: A cohort study assessing participants from the Professional Fighters Brain Health Study found that the presence of cavum septum pellucidum and cavum vergae is associated with lower regional brain volumes and lower cognitive performance.
SOURCE: Lee JK, Wu J, Bullen J, et al. Association of cavum septum pellucidum and cavum vergae with cognition, mood, and brain volumes in professional fighters. JAMA Neurol 2020;77:35-42.
Professional boxing and mixed martial arts are popular sports with high risk for both acute and chronic traumatic brain injury (TBI). Acute catastrophic neurological injuries include subdural hematoma, epidural hematoma, subarachnoid hemorrhage, intracranial hemorrhage, and second-impact syndrome. Structural brain imaging may aid in identifying a combatant more likely to express late-life neuropsychologic sequelae of brain injury, such as chronic traumatic encephalopathy (CTE), dementia pugilistica, chronic post-concussion syndrome, post-traumatic dementia, post-traumatic cognitive impairment, post-traumatic parkinsonism, and chronic post-traumatic headache.
Investigators at the Cleveland Clinic studied participants from the Professional Fighters Brain Health Study, an ongoing observational cohort study of active and retired professional fighters and healthy age-matched controls. They enrolled 476 fighters (440 men, 36 women; mean [SD] age, 30.0 [8.2] years [range, 18-72 years]) and 63 control participants (57 men, six women; mean [SD] age, 30.8 [9.6] years [range, 18-58 years]) in the study. All participants underwent brain imaging on a Siemens Verio 3-T magnetic resonance imaging (MRI) scanner. The investigators were blinded to whether the images belonged to a fighter or a control participant and assessed the presence of cavum septum pellucidum (CSP) and cavum vergae (CV) and measured their total combined length (CSPV length).
Additional information regarding study participants was obtained using the Patient Health Questionnaire Depression Scale, the Barratt Impulsiveness Scale, and the Epworth Sleepiness Scale. Cognition in the clinical realms of verbal memory, processing speed, psychomotor speed, and reaction time were assessed using raw scores from the computerized CNS Vital Signs test. Volumes of various brain structures of interest (supratentorium, thalamus, corpus callosum, caudate, putamen, hippocampus, and amygdala) were measured via MRI. Compared to fighters without CV, fighters with CV had significantly lower mean psychomotor speed and lower mean volumes in the supratentorium and other brain structures. Longer CSPV length was associated with lower processing speed, lower psychomotor speed, and lower brain volumes in the supratentorium and other structures, suggesting that the presence of CSP and CV is associated with lower regional brain volumes and cognitive performance in fighters exposed to repetitive head trauma.
COMMENTARY
Currently there are no reliable blood/cerebrospinal fluid or structural imaging biomarkers for chronic TBI and its reported link with late-life neuropsychologic sequelae, such as CTE, dementia pugilistica, chronic post-concussion syndrome, post-traumatic dementia, post-traumatic cognitive impairment, mood and behavioral changes, post-traumatic parkinsonism, and chronic post-traumatic headache.
Incidentally, the association of CSP and boxers first was noted by Spillane.1 Fenestrated CSP commonly is seen on neuroimaging and neuropathological studies carried out in boxers, and its significance in these athletes has long been debated. The mechanism of cavum formation in combat sports athletes is unclear. Repeated head blows may cause repeated sudden rises in intraventricular pressure, causing rupture of the septal leaves or strain the dorsal septal attachment due to repeated movements of the corpus callosum on the tethered fornix.2 Jordan et al reported computed tomography (CT) scan findings in 388 active professional boxers. CT was normal in 93% and showed “borderline” atrophy in 6%. Boxers with CSP were more likely to have cerebral atrophy.3
Either a CT or MRI of the brain currently is included in the process of registering for a license to compete in combat sports in some jurisdictions in the United States and around the world. The presence of an isolated CSP or CV does not preclude the combatant from taking part in his or her sport. The demonstration of serial enlargement of a CSP on neuroimaging studies should raise concern for late-life neuropsychologic sequelae, such as CTE, post-traumatic cognitive impairment, and mood and behavioral changes.
REFERENCES
- Spillane JD. Five boxers. Br Med J 1962;2: 1205-1210.
- McCrory P. Cavum septi pellucidi – A reason to ban boxers? Br J Sports Med 2002;36:157-161.
- Jordan BD, Jahre C, Hauser WA, et al. CT of 338 active professional boxers. Radiology 1992;185:509-512.
