2002 06 01 British Journal of Sports Medicine - Vol 36 No 3 - McCrory

Magazine Overview

This issue of BJSM (British Journal of Sports Medicine) features two main articles: an editorial titled "Of UFOs and other thoughts" and a research article titled "Cavum septi pellucidi - a reason to ban boxers?"

Of UFOs and Other Thoughts

This editorial by P McCrory begins with a lighthearted reflection on airport experiences and the need for survival guides, referencing the "Worst Case Survival Handbook." The author humorously touches upon instructions for foiling alien abductions, noting a survey suggesting many Americans have experienced such events. The article then shifts to a more serious discussion about drug testing in sports, particularly in light of a poll indicating a high prevalence of illegal drug use among young Britons. McCrory questions the current approach to testing athletes for non-ergogenic social drugs, suggesting a need for common sense and a balanced perspective on maintaining a "level playing field."

Cavum septi pellucidi - a reason to ban boxers?

This comprehensive article by P McCrory delves into the association between a cavum septum pellucidum (CSP) and chronic brain injury in boxers, specifically dementia pugilistica or chronic traumatic encephalopathy (CTE).

Anatomy

The septum pellucidum is described as a thin membrane separating the lateral ventricles. A cavum septum pellucidum is a persistent separation of its two leaves, which can communicate with the ventricular system if ruptured or fenestrated. The septum's role is not fully established but may be involved in limbic functions.

Incidence of Cavum Septi Pellucidi

The incidence of CSP in the general population is not well-documented. Studies on adult brains have reported varying percentages, from 3% to 60%, depending on the methodology (neuropathology vs. neuroradiology). Imaging studies show a wide range, from 0.7% to 37%.

Neuropathological Studies

Limited studies on ex-boxers have noted CSP. One study of six boxers found CSP in all, with fenestrations in three. It was speculated that septal abnormalities might be secondary to enlarged ventricles.

The most significant neuropathological study cited is by Corsellis et al., who examined 15 ex-boxers with extensive boxing histories. They identified several features of CTE, including abnormalities of the septum pellucidum, cerebellar scarring, and substantia nigra degeneration. In this study, a cavum was noted in 12 out of 13 brains, often fenestrated, with detachment of the fornix. The authors speculated that repeated head blows strain the dorsal septal attachment, leading to fenestrations and enlargement.

Radiological Studies

Early studies using pneumoencephalography noted CSP in boxers. Spillane first reported it in retired boxers, noting it in two out of five cases. Subsequent studies by Mawdsley and Ferguson, and Isherwood et al., using pneumoencephalography, found CSP in eight out of 16 boxers with cortical atrophy.

Computed tomography (CT) studies have shown varying results. Harvey and Davis reported CSP in a young boxer with chronic traumatic encephalography. Jordan et al.'s large study of 388 active professional boxers found normal CT scans in 93%, with 6% showing borderline atrophy. Boxers with CSP (14%) were more likely to have cerebral atrophy.

Magnetic resonance imaging (MRI) studies have also yielded mixed results. Some studies found no abnormal MRI findings in amateur boxers, while others emphasized MRI's superiority over CT for detecting subtle abnormalities. No clear relation between boxing exposure and radiological findings was consistently noted.

Magnetic resonance spectroscopy has shown reduced N-acetylaspartate in ex-boxers with parkinsonism, potentially indicating neuronal loss. One of three boxers studied had CSP.

Radionucleotide studies measuring cerebral blood flow have shown reductions in some boxers, but no correlation was found between these abnormalities and neuropsychological tests or the number of bouts fought.

Changes in Cavum Septum Pellucidum on Serial Imaging

An early study using pneumoencephalography noted variations in the size and structure of the cavum septum pellucidum. A study of serial CT scans in active boxers found progressive brain injury in some, including progressive cortical atrophy, in those with CSP.

Conclusions

The presence of an isolated cavum septum pellucidum is common and usually incidental, with no clear evidence linking it to clinical abnormalities or boxing exposure. However, a fenestrated cavum septum pellucidum, particularly when associated with other neuropathological findings, may be suggestive of dementia pugilistica. Current neuroimaging techniques have not consistently detected early signs of chronic brain damage in boxers, and more sophisticated imaging protocols and prospective studies are needed.

Recurring Themes and Editorial Stance

The issue touches on themes of sports-related injuries and their long-term neurological consequences, particularly in boxing. It also briefly addresses the broader issue of drug use and testing in sports. The editorial stance appears to be one of critical inquiry, questioning established practices and advocating for common sense and further research, especially in the context of athlete safety and the interpretation of medical findings.