Reconsidering Concussion - October 2025
Concussion is no longer “mild”—it’s a brain network disorder hiding in plain sight.
Having evolved in modern paradigms from outdated wartime triage scales to the 2024 Delphi Consensus and 2025 CMS reclassification, medicine is finally catching up to what patients have long known: recovery isn’t always simple.
The next frontier isn’t rest—it’s precision: decoding biomarkers, evaluating brain networks, and compassionate holistic care.
Reconsidering Concussion: From Acute Injury to Chronic Condition
MBBN Research | Direct from the Desk of Dr. Drew | October 2025
Drew Thodeson, MD
Concussion has long occupied an uncertain space in medicine. It is often considered too mild to be catastrophic, yet there are countless individuals who suffer with unexplained debilitating symptoms. For decades, concussion was defined by what it wasn’t: not a brain bleed, not a skull fracture, not something you could “see” on a scan. Indeed, in the current paradigm, medical professionals call it mild traumatic brain injury (mTBI), but the word mild does not accurately convey the severity concussion has on many individuals lives. Mild implies recovery should be rapid, predictable, and uncomplicated. For many, this is simply not the case. For purposes of this brief communication, I will use the term concussion and mTBI as synonyms which are interchangeable.
A Brief History of How We Got Here
It seems to me that the early definitions of concussion were shaped less by neuroscience and more by necessity. In wartime and sports, people needed a way to triage injuries. The Glasgow Coma Scale became a practical shorthand: if a patient could open their eyes, follow commands, and answer questions, the injury was labeled “mild.” But this simplicity came at a cost—it ignored the subtle, persistent disturbances in attention, mood, and energy that often followed.
Over the last two decades, as athletes, veterans, and children began sharing stories of lingering symptoms—fatigue, headache, cognitive fog—our collective understanding of concussion evolved. Neuroimaging caught up, revealing that even so-called “mild” injuries can alter white matter tracts, glial signaling, and network connectivity. The conversation expanded from when will you be cleared? to how do we help you heal?
The 2024 Delphi Consensus
In 2024, the American Congress of Rehabilitative Medicine published a consensus statement regarding the current state of the diagnosis of mTBI. This research group recognized concussion as more than a transient physiologic event—it’s a disorder of brain network function that can persist beyond the initial impact. The criteria emphasized three essential domains:
Mechanism – A biomechanical force transmitted to the brain.
Immediate or delayed symptoms – Not limited to loss of consciousness.
Functional impairment – Measurable disruption in cognition, emotion, or motor coordination.
This framework has acknowledged that symptoms lasting beyond 30 days represent a chronic form of concussion, not simply a prolonged recovery.
The 2025 CMS Decision: A Policy Shift
In early 2025, the Centers for Medicare and Medicaid Services (CMS) formally recognized chronic concussion as a distinct, reimbursable diagnostic category. This may sound bureaucratic, but it’s a major milestone. For families, it means validation. For clinicians, it means there is a scaffolding on which longitudinal care plans can be built. This has effectively paved the way for multidisciplinary rehabilitation and coverage for therapies once denied as “non-essential,” but there will still be an uphill battle.
Why This Matters
I see concussion not just as a mechanical injury, but as another brain network disorder—a dysfunction caused by a disconnection of the brain, body, and mind. This disconnection may be transient but can be longstanding and cause significant disruption. With the right support many people recover but we must also recognize that some people do not recover or have prolonged symptoms. These tend to be our most vulnerable friends – veterans; people with co-occurring brain network disorders such as ADHD, depression, PTSD, and others; and our children. These individuals need compassionate and neuroscience-guided management approached with the same seriousness we reserve for other chronic health conditions.
Where We Go Next
The next frontier is precision diagnostics, neurotherapeutics and facilitated recovery. This will undoubtedly take a team approach. Through combining evolving blood biomarkers, neurophysiology, neuroimaging, and neuropsychometric data we will continue to identify who is at risk for prolonged symptoms and discover why. I believe the field is moving toward a new language. Concussion is not an acute event, but rather a trigger which cascades into a brain network disorder which has specific propagating, potentiating, and alleviating factors. Like many brain network disorders, concussions change over time and can shift in symptomatology. That evolution historically has been met with skepticism by the clinician which has led to mistrust and victim shaming. It is time to move forward within our current paradigm towards the truth of concussion as a brain network disorder.
As we continue to learn together, I feel that some things are solid and universal. I have found, time after time, that validating people with brain network disorders and listening to their experiences is a therapeutic act which has human value. When I am able to take time and listen, and give a name to what someone is experiencing, only then can we, together, make healing possible.
References (selected):
McCrory P. et al. (2024). Delphi Consensus Diagnostic Criteria for Concussion and mTBI. Journal of Neurotrauma.
Centers for Medicare and Medicaid Services (2025). Decision Memo for Chronic Mild Traumatic Brain Injury Classification.
