Warning for athletes – Brain injury is not an isolated incident, but a systemic disorder!

When an athlete—professional or amateur—suffers a hard blow to the head, for example, from a football header, a boxing match, a hockey stick, a handball to the forehead, karate training, or even a kick or a head-on collision with a horse, a complex and disruptive cascade of events is initiated in the brain almost immediately. What at first glance appears to be "just a blow" or "mild concussion" can actually be the beginning of a long-term neurophysiological problem.

What happens immediately after a brain trauma?

1. Microstructural damage and disruption of brain impulses: The impact causes micro-tears in axons and neurons at the cellular level. This disrupts electrical conduction between brain areas, which can immediately impair cognitive functions such as concentration, memory, and coordination. This so-called axonal damage is often not visible on standard imaging.

2. Fluid retention (edema) and intracranial pressure: The trauma causes swelling (edema), which increases the pressure within the skull. This increased pressure can compress healthy brain structures and disrupt blood flow.

3. Neuroinflammatory responses: Within minutes, the immune system initiates an inflammatory response in the brain. Glial cells—normally protective—become overactive and can damage healthy brain cells. This inflammation contributes to long-term fatigue, irritability, and impaired stress regulation.

4. Neurotransmitter imbalance: Crucial brain chemicals such as dopamine, serotonin, and acetylcholine are disrupted in their production and absorption. This leads to mood swings, feelings of depression, anxiety, and even behavioral changes.

5. Reduced cognitive reserve: Repeated trauma increases the risk of chronic post-traumatic stress disorders (such as PCS or CTE). One impact increases the susceptibility to the next: the brain "remembers" damage, and each subsequent blow becomes more severe.

Recent case: a young talent from the Dutch premier league

In August 2025, a young talent from the Dutch premier league was seen at the Functional Neurology Institute (FNI) in Lisse. He had sustained two head injuries during matches since March of that year. Despite intensive support at the club, he continued to suffer from persistent headaches, visual disturbances, reduced focus, and cognitive fatigue. Extensive diagnostic testing at our institute revealed clear neurocognitive dysregulation – disturbances that can persist for a long time without targeted treatment and seriously impact his athletic and social future.

Why this message?

At the Functional Neurology Institute (FNI), we see athletes every week – often young, motivated, and seemingly recovered – with persistent symptoms that are only recognized as neurological injuries months later. More specialized medical care, however well-intentioned, often lacks sufficient knowledge of functional brain damage in sports trauma. This leads to underdiagnosis and delayed treatment.

An athlete who sustains a brain injury isn't experiencing a "minor injury"—but rather an acute disruption of one of the most complex biological systems: the brain.

Our call:

Take brain injury seriously. Not just upon loss of consciousness, but upon any impact with symptoms such as:
– headache
– blurred vision
– difficulty concentrating
– nausea
– emotional instability
– sudden fatigue

Sport safely. Recognize the signs. Demand specialized care. Because one missed diagnosis can have lifelong consequences.

FNI – Functional Neurology Institute Research partner of MMU, Radboud University Medical Center, and Amsterdam UMC