AAN2017: neurotrauma and sports neurology

Written by Hannah Wilson, General Manager, The Drake Foundation

In this Sunday afternoon session at the American Academy of Neurology Annual Meeting (22-28 April, Boston, MA, USA), eight abstracts on traumatic brain injury (TBI) were presented with discussion particularly focusing on sports injury, some of which we highlight below.

First up, Massachusetts local Dr Jesse Mez from Boston University (MA, USA) presented on APOE 4 as a risk factor for CTE severity. In his group’s work, APOE 4 status was ascertained in 85 autopsy-confirmed CTE cases in former American football players. APOE 4 was found to be significantly associated with increased CTE stage, an association that was strengthened in cases of lower exposure to football. These data add to evidence for APOE 4 as a risk factor for CTE severity. When opened up to discussion, general consensus in the room was that although APOE 4 testing is commercially available at a low price point there is not yet sufficient evidence to support allele testing to inform sports participation decision-making.

Dr Jianhua Qiu from Harvard Medical School (MA, USA) presented new data on tau phosphorylation after mild TBI and the effectiveness of genetic strategies targeting tau. Using a mouse model of repetitive mild TBI, it was observed that tau hyperphosphorylation was related to impaired functional outcomes following repetitive mild TBI. Qiu therefore concluded that this may be a potential therapeutic target for investigation.

Also presented by Qiu in this session was a mouse study investigating environmental enrichment as a method to improve outcomes following repetitive mild TBI. The group observed that mice randomized to environmental enrichment displayed improved memory in addition to decreased anxiety and impulsivity. Increases in amyloid precursor protein were also mitigated, suggesting an effect on synaptic changes. These findings support the need for clinical trials of environmental enrichment strategies for those exposed to repetitive mild TBI, a point that was echoed during the discussion with one commenter highlighting the major environmental changes experienced by retiring sports professionals as an area for consideration.

Moving the session towards a sporting focus, Samuel Frank from Beth Israel Deaconess Medical Center (MA, USA) presented data from a study of 95 retired American football players. Compared with same-age controls, former players exhibited statistically significant deficits in motor function, although motor test performances were deemed relatively normal and unrelated to head impact exposure. These findings differ from those in former boxers, a point that led to discussion in the room regarding mechanism of injury and its influence on later-life symptoms.

Presenting the only abstract of this session with an imaging focus, Nikos Gorgoraptis (Imperial College London, UK) shared data from 17 TBI patients alongside 10 controls who had undergone [18F]AV-1451 PET MRI and neuropsychological testing. This imaging identified increased tau binding several years following injury in some TBI patients versus controls. This tau positivity was associated with relative hippocampus atrophy and reduced memory performance, suggesting its utility as a marker of long-term TBI-related effects.

Also presented in this session were abstracts covering disruption to the dopamine system following TBI, characterisation of measures used in the Cleveland Clinic Concussion application plus white matter tract integrity in patients with post-concussion syndrome.

This session was rounded off by an open discussion led by Francis Conidi (Florida Center for Headache and Sports Neurology, FL, USA). With much of the work presented still in early stages emphasis was on the need for further study and validation.

You can find more content from the AAN Annual Meeting here.