By Dr. Robert L. Janda, MA, DC

A study published last month in the American Journal of Public Health tracked academic performance in high-school and college student-athletes after sports-related injuries. The instrument was an academic-dysfunction questionnaire scored from 0 to 174. One week after injury, students with extremity injuries scored an average of 48. Concussed students scored 68 — a 40 percent worse score on a measure of how hard it was to read, follow lectures, retain material, and complete assignments. Most students stabilized within a month. Students with a history of multiple concussions did not.

The conventional response to that result is the protocol most schools and sports programs already use: a few days of cognitive rest, gradual return to learning, gradual return to play, neuropsychological testing to confirm recovery.

The more useful question is the one the AJPH study points at without quite naming: which systems are we measuring, and which are we missing? The thinking systems — attention, working memory, reaction time on a screen — do recover within a month for most adolescents. The systems that don’t show up on the standard concussion battery may not recover at all, if no one is looking for them.

What conventional concussion protocols measure (and miss)

The standard sideline test is a brief cognitive screen — memory of a few words, simple math, reaction time. The post-injury workup adds a longer neuropsychological panel and a graded return-to-activity protocol. Both are useful. Both measure mainly cortical function — the parts of the brain that handle higher-order thinking.

A concussion is rarely a cortex-only event. The impact rotates the head; the brain accelerates and decelerates inside the skull; the brainstem, the cerebellum, the vestibular apparatus in the inner ear, and the cervical spine all take load. Those are the systems that govern balance, eye-tracking, postural control, autonomic regulation — and they are also the systems that, when disrupted, produce the symptoms patients describe as “I just don’t feel like myself” months after the cognitive test comes back clean.

The cerebellum, the vestibular system, and the cranial layer

The cerebellum is sometimes called the “little brain.” It’s the dense, tightly folded structure at the back of the skull that handles motor coordination, posture, eye-movement timing, and a surprising amount of the cognitive precision we don’t think of as cerebellar — keeping your place in a sentence, tracking a moving object smoothly, knowing where your hands are in space. After a concussion, the cerebellum is one of the first systems to show subtle, persistent dysfunction. Standard imaging usually shows nothing.

The vestibular system — the inner-ear apparatus that tells the brain which way is up — almost always takes a hit in any impact strong enough to concuss. A patient who reports being “off” weeks after a concussion, or whose headaches start in the back of the head and creep forward, or whose reading endurance has dropped from forty minutes to ten, is usually showing me a vestibular-cerebellar pattern. Standard cognitive tests do not catch it.

The cranial layer is the third often-missed system. The bones of the skull are not perfectly fused; they articulate, slightly, at the sutures. Practitioners trained in craniosacral and related work can palpate subtle restrictions in cranial mobility that, in my experience, correlate strongly with the post-concussion “stuck” feeling patients describe.

Hidden dysfunction after concussion

The Hidden Dysfunction chain — stressor → dysfunction → compensation → symptom → diagnosis — runs particularly fast after a head impact. The stressor is the hit. The acute dysfunction is what the ER measures and clears. The compensation is everything the brain and the body do to keep the patient functional in the weeks that follow — postural changes, eye-movement workarounds, autonomic shifts (see Issue 10 on vagal tone) — and the symptoms that show up months later are diagnosed as anxiety, attention deficit, migraine, vertigo, or “post-concussive syndrome” without anyone working back up the chain to the actual cerebellar-vestibular-cranial dysfunction that started it.

This is why “cleared to play” so often is not the same as “recovered.” The clearing test measures the cortex. The damage is, often, somewhere else.

Who this is for

This piece is for the parent of a teenage athlete who took a hit weeks or months ago and “isn’t quite right yet.” For the adult who had a car accident or a sports injury years ago and quietly believes their attention or balance was permanently changed by it. For the patient whose cognitive testing came back normal but who still gets nauseated reading in the car, can’t tolerate fluorescent lights, has lost confidence on stairs, or has the kind of headache that lives behind one specific eye.

A standard concussion protocol is doing what it was designed to do. It was not designed to find what I’m describing here. The systems involved need a different kind of evaluation — vestibular, cerebellar, cranial, cervical, autonomic — and they respond, often dramatically, to the right kind of hands-on work even years after the injury.

Call the office for an intake. We’ll find out together which system is still carrying the hit.

— Dr. Robert L. Janda, MA, DC