Francesca Galiano
02/03/2023 - Last update 12/04/2023

Jayme D. Mancini, Nicole Angelo, Reem Abu-Sbaih, Patricia Kooyman, Sheldon Yao | Year 2022

Concussion-related visual memory and reaction time impairment in college athletes improved after osteopathic manipulative medicine: a randomized clinical trial



Type of study:

Randomized controlled trial

Date of publication of the study’:



Purpose of the study

  • Objective: to evaluate the effects of OMT on neurological changes due to concussion
  • Measured outcomes:
    • primary: evaluation of post-concussion cognitive alterations through Immediate Post-Concussion Assessment and Cognitive Testing (imPACT) and King-Devick test (KD)
    • secondary: evaluation of adverse effects due to OMT


  • Number: 25 people (7 female and 18 male, mean age 20 years)
    • symptoms reported: headache, amnesia, visual impairment, nausea, dizziness, balance and sleep disorders, photophobia, phonophobia, confusion, lethargy, tinnitus
    • 5 participants (3 women and 2 men) did not report neurological changes after the concussion
  • Criteria of inclusion: college athletes, aged 18 to 50, with a clinical diagnosis of concussion issued by a family doctor or neurologist in the previous two weeks.
  • Criteria of exclusion: diagnosis of any emergency conditions, current or previous neurodegeneration or spinal cord injury, inability to complete the evaluations required by the study, absolute contraindications to the OMT (including skull fractures, intracranial bleeding, cervical fractures, dissections, stroke), concussion-related loss of consciousness for more than 2 minutes, seizures, treatment-resistant vomiting, pregnancy, paralysis (self-reported or witnessed), lack of neurological changes resulting from concussion.
  • Groups of study: 2 groups obtained by randomization
    Group 1: OMT, 11 people (3 female and 8 male)
    Group 2: concussion management education, 9 people (3 female and 6 male)

Interventions and evaluations

  • Assessment of cognitive alterations through imPACT and KD at the first visit, at the second visit, 72 hours later, and at the third visit (3-4 days later)
    • the tests evaluated: visual memory, verbal memory, visuo-motor processing speed, reaction time, impulse control and symptom severity;
    • at the first visit was given the imPACT assessment made at the beginning of the athletic season (pre-sport), which served as a baseline to detect the presence of cognitive changes emerged after the concussion.
  • At the first consultation, assessment of the medical history.
  • Evaluation of OMT’s adverse effects.
  • 2 30-minute sessions of OMT or concussion management education at the first and second visit (72 hours later).
  • OMT: customized treatment
    • overall structural evaluation (cervical, thoracic, lumbar and sacral tract; head, thorax, pelvis, diaphragm and limbs; thorough evaluation of the skull and cranial rhythmic impulse) to detect possible somatic dysfunctions.
    • treatment intended to alleviate perceived somatic dysfunctions through cranial OMM, face decompression, balanced ligamentous tension, muscle energy techniques, facilitated positional release, articulatory, high-velocity low-amplitude, and counterstrain
    • treatment directed to the improvement of blood circulation and lymphatic, glynophatic and venous drainage


  • Symptoms’ analysis: the main alterations according to the imPACT testing were decrease in verbal memory, visual memory, processing speed and increase in reaction time, as well as obviously a greater amount of symptoms compared to the pre-season assessment. It was also found, especially in men, an increase in the score related to impulse control, indicating a greater number of errors in the test, score that was correlated with the need to sleep more than usual.
  • Primary outcomes: Generally, neurological changes improved in both groups. The OMT group showed greater improvement in visual memory in men and women, impulse control, and reaction time in men, while the education group showed better verbal memory recovery in women.

However, after the first session, the group with OMT showed an improvement in visual memory and in symptoms, and their severity, in both women and men and an improvement of the reaction time only in men. After the second session, the OMT group showed improvements in men regarding verbal memory, visual memory, processing speed, reaction time and number of symptoms. The effect size was great for visual memory and average for reaction time and processing speed. The group with education showed an improvement in verbal memory and reaction time in men, and in the number of symptoms and their severity in both women and men.

After the first session, the KD test showed an improvement in the OMT group for both women and men, and an improvement after the second session for men, while the group with education showed improvement in men at the first session and improvement in women at the second session.

  • Adverse events: Participants reported no adverse effects.


The OMT has been shown to improve acute neurological alterations caused by an episode of concussion from sports activity. In particular, visual memory and reaction time were the functions most favorably affected by the OMT in the recovery.

Improvements in other functions are less clear, also because of some participamts dropping out, which reduced even more the already small sample. In this regard, it is interesting the improvement in ‘verbal memory’ through the intervention of education, and it would interesting to look better into the improved values in the ‘speed of processing’ compared to baseline, an improvement also obtained in group 2.

However, OMT proved to be better than rest, as recommended by the guidelines, and showed no adverse effects. Most likely, the OMT resolved the mechanical stresses at both bone and connective level and improved the drainage of the waste of nervous metabolism through the glymphatic system or the nervous sinuses. Potentially, OMT may have helped restore the function of the nerves involved in the visual function and in the saccharide eye movements.

A limitation of the study is the lack of KD-test data previews to the sports season, which limits the interpretation of the data obtained with the test. In addition, the sample analyzed was small to carry out statistically strong analyses, and the long-term consequences of the concussion were not investigated, but only primary acute symptoms. Consequently, we cannot know whether the OMT, acting on the drainage of inflammatory products and on the resolution of tensions, can also have long-term effects.

Future studies will have to exploit Sham treatments (fictitious), evaluate biological markers for concussion and social placebo effects, as well as female hormone levels as they are able to act on the symptoms of concussion. All this can allow a better understanding of the usefulness of OMT and help define a more targeted and customized treatment.

The review of Osteopedia

By Marco Chiera

Strengths: interesting introduction on physiopathology, and also cellular, that can help to define the most suitable interventions; calculation of the sample size (how many people to recruit) based on previous studies; interesting the use of the Reliable Change Index, method designed to understand if a change is important from a clinical point of view (and not only numerical); effect sizes have been calculated, which may be useful for future studies; although briefly, some advice has been given for the realization of future studies.

Limits: lack of a summary table of the characteristics of the participants; it has not been explained what was meant by adverse effects due to OMT and how they would be measured; part of the results could have been presented more clearly.
To control the placebo effect a sham treatment would have been appropriate, if not necessary, as a comparison, instead of the education intervantion alone (in order to mask the OMT and because many studies shows that even the touch has therapeutic and placebo effects).
Despite the calculation of the sample size, the patients analysed were less than the necessary number, indicating that recruitment should have been better organised. Consequently, the results are difficult to generalise.

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