Investigation of relationship between neurological assessment and neurofilament light (NFL) in the cerebrospinal fluid (CSF).

NFL in the cerebrospinal fluid has been analyzed in the same cohort of boxers and the results are previously published [9]. After a boxing bout, cerebrospinal fluid was collected at two occasions, first 1–6 days (test A) after bout and then after a rest period of at least 14 days (test B). 23 of 30 boxers had elevated concentrations of the axonal injury biomarker NFL at test A. At follow up, 4 of the boxers were lost, 12 of 26 (46%) boxers still hade elevated concentrations and these had significantly lesser performance on Trail Making A (p = 0.041) and Simple Reaction Time (p = 0.042) compared to the other boxers.

1

ROCF: Rey Osterrieth Complex Figure Test.

2

Vocabulary: 35 words were presented and for each word 0,1 or 2 points were assigned.

3

COWAT (Controlled Word Association Test): Participants were asked to generate as many words as possible that begin with the given letters F, A and S. Sixty seconds were allowed for each letter. One point per word was received.

4

Digit Span: Participants were presented with series of numbers, starting with three (for example 3–4–8). There were two series in each level and in total seven levels. The task was to immediately repeat the numbers back. When doing this successfully, the participants were given a longer serie of numbers.

5

Listening Span: A mixed lists of digits and letters were read aloud to the participants and they were asked to recall this list in correct numeric and alphabetic order.

6

Trail Making: In trail A the participant is instructed to trace a line that connects circled numbers in consecutive order. In trail B the task is to trace a line by alternating circled numbers and circled letters in consecutive order. Time is measured in seconds(s).

7

Reaction time: a) Simple reaction time: Participants were instructed to respond as quickly as possible whenever the circle appeared on the screen. Complex reaction time: Required participants to respond with right hand to the circle and left hand to the triangle. Difference = Complex−Simple reaction time.

8

Finger Tapping. In total five trials with 15 s rests between the trials. The participants were asked to press the space board with their index finger on the computer keyboard as many times as possible for 15 s, alternating dominate and non-dominant hand. The mean value was calculated.

9

Proportional values (range 0.04–0.96). The number of words in the auditory and visual conditions was 30 respectively. The correct recognition hit rates (HR) are presented.