For the last month, I thought I had found the only two documented cases of Female CTE, but thanks to a tip by the NFL Objectors I learned of 13 additional cases of possible Female CTE from the October 2015 paper, Histological evidence of chronic traumatic encephalopathy in a large series of neurodegenerative diseases. These 13 women were from a study of brains from the Queen Square Brain Bank for Neurological Studies in London and thus I have named them the Queen Square 13.

Histological evidence of chronic traumatic encephalopathy in a large series of neurodegenerative diseases

Helen Ling1 · Janice L. Holton1 · Karen Shaw1 · Karen Davey1 · Tammaryn Lashley1 · Tamas Revesz1

Received: 3 September 2015 / Revised: 8 October 2015 / Accepted: 11 October 2015 © Springer-Verlag Berlin Heidelberg 2015

I emailed with the paper's lead author, Dr. Helen Ling, to learn more about the women who were found to have CTE in this study and summarized our exchanges below.

Katherine: Dr. Ling, how many cases of Female CTE did you find in your study?

Dr. Ling: In our study, we found 13 cases of Female CTE and 19 of Male CTE (Total of 32 positive CTE cases, all with early stages of pathology) among 268 screened cases with neurodegenerative diseases and healthy controls.

Katherine: Do you know how many female to male brains were in the original 268?

Dr. Ling: I am sorry I will not be able to provide these figures for you. The 268 screened cases were the most recent consecutive cases that reached the Queen Square Brain Bank and they were not selected according to gender. Therefore, the gender distribution would have been even and I am sure of the 268 cases, at least 100 cases were female.

Katherine: Can you tell me more about the cases of Queen Square 13?

Dr. Ling: These 13 cases have mild focal histological evidence of CTE. From retrospective review of the case notes and telephone interview of the next-of-kin, it seems that they did not have any clinical symptoms related to CTE. This group of cases were obtained from those with neurodegenerative diseases such as Parkinson's disease and related conditions and some were healthy elderly individuals (included as controls). Most had history of different types of head injury.

Ann McKee's paper in 2013 showed that up to a third of autopsied confirmed cases had concomitant histological findings of other neurodegenerative disorders such as Alzheimer's disease changes. That was also our experience that a proportion of CTE cases may have other pathologies in the brain.

Katherine: Can you review the individual case histories not included in your paper and tell me more about the individual women’s risk factors?

Dr. Ling: Here is the additional data from our series:

1. There are 32 positive CTE cases (male: female = 19: 13) among 268 screened cases with neurodegenerative diseases and healthy controls

2. ‘Positive CTE’ in these cases means focal scattered histological changes compatible with early CTE pathology

3. Among the 13 female, their other pathological diagnoses are: Multiple system atrophy (1), Parkinson’s disease (1), healthy elderly (4), corticobasal degeneration (1), progressive supranuclear palsy (6)

4. Mean age of death of the 13 female with positive CTE: 84 years

5. Potential risk factors and related info of the 13 female with positive CTE: excessive alcohol (2), suicide attempt (1), risk sports (2 – gymnastic, cycling, horse riding), falls and related traumatic brain injury in old age (11), fractures resulted from falls (8), motor accident (2), domestic abuse (1). Some cases have more than 1 of these factors.

Katherine: Why do you think there have been so few cases of Female CTE reported in scientific papers and the press?

Dr. Ling: I think the small number of female with CTE is mainly due to sampling bias in that most brain donors with a history of repetitive traumatic brain injury happened to be male and there are more male athletes in high risk sports. Whether genetic factor of the female gender plays a protective role is not known.

Katherine: Could you look at new study, Chronic traumatic encephalopathy pathology in a neurodegenerative disorders brain bank, and tell me what you think about what can be concluded about gender and female CTE?

Chronic traumatic encephalopathy pathology in a neurodegenerative disorders brain bank

Kevin F. Bieniek1,2 · Owen A. Ross1 · Kerry A. Cormier3 · Ronald L. Walton1 · Alexandra Soto‐Ortolaza1 · Amelia E. Johnston4 · Pamela DeSaro4 · Kevin B. Boylan4 · Neill R. Graff‐Radford4 · Zbigniew K. Wszolek4 · Rosa Rademakers1 · Bradley F. Boeve5 · Ann C. McKee3,6 · Dennis W. Dickson1

Received: 28 September 2015 / Revised: 23 October 2015 / Accepted: 25 October 2015 / Published online: 30 October 2015 © Springer-Verlag Berlin Heidelberg 2015

Dr. Ling: In this paper, they looked at all cases with history of risk sports in men and checked if there was CTE pathology in the brains. The finding was: 32% male athletes had CTE pathology. Women were excluded from the screening so no female athletes were included. Non-female athletes were also screened for CTE as control subjects but 0% had CTE.

Katherine: I am most grateful to Dr. Ling and the time she made to answer my many questions and really expand our limited knowledge of Female CTE.

Dr Helen Ling, PhD, BMedSc, BMBS, MSc, FRCP(T), MRCP(UK)

Senior Clinical Research Associate

Dr Helen Ling completed her medical training at the University of Nottingham, UK. After her Neurology training, she joined the Reta Lila Weston Institute and Queen Square Brain Bank for Neurological Studies, Institute of Neurology, University College London, UK since 2008 and was awarded a PhD in neuroscience research in 2014. Dr Ling’s main research interests include clinical and pathological features of progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and chronic traumatic encephalopathy (CTE). Dr Ling is currently funded by the CBD Solution Grant to study the pathological staging of CBD.