The old advice was a dark room and complete rest until symptoms stopped. That is no longer the standard, and prolonged inactivity is now understood to slow recovery in many patients. What replaced it is targeted: identify which systems are affected, and treat those.
Treatment follows the findings
A patient whose headaches are driven by an oculomotor problem, one whose dizziness is vestibular, one whose picture is dominated by disrupted sleep, and one whose headache is actually coming from the upper neck are four different clinical problems sharing a diagnosis label. Sorting them is the point of the assessment.
- Vestibular and oculomotor rehabilitation — the best-supported intervention where dysfunction is found on examination, and the reason we test for it deliberately
- Graded return to activity — progressive, symptom-guided reintroduction of physical and cognitive load rather than open-ended rest
- Sleep and headache management — usually the highest-yield early targets, because both amplify every other symptom
- Interventional treatment of neck-origin headache where a diagnostic block identifies it — see occipital neuralgia vs concussion
Metabolic health as part of brain recovery
Recovery from a brain injury is metabolically expensive. The injured brain has increased energy demand at exactly the moment its ability to meet that demand is disrupted, and a patient whose baseline metabolic function is already impaired starts that process at a disadvantage.
This is not a peripheral concern in the population we actually see. Insulin resistance, type 2 diabetes, obesity, obstructive sleep apnoea and vascular disease are common in adults injured in crashes and falls — and are routinely excluded from the concussion trials the entire field is built on, which recruit young, healthy athletes.
So when a 54-year-old with poorly controlled diabetes and untreated sleep apnoea does not recover on the timeline drawn from college football players, the honest reading is not that the patient is exaggerating. It is that the evidence base never included them. We assess and treat the metabolic terrain alongside the injury rather than treating it as somebody else’s problem.
Sleep
Sleep is where a great deal of concussion recovery either happens or fails to. Disrupted sleep is both a symptom of the injury and an independent driver of headache, cognitive difficulty and mood — and insomnia is one of the features that independently predicts persistent symptoms. Treating it early is not symptomatic tinkering; it removes an amplifier sitting underneath everything else.
Where sleep-disordered breathing is present it is investigated, because no amount of vestibular rehabilitation compensates for a brain that is intermittently hypoxic all night.
Pain psychology and Acceptance and Commitment Therapy
Persistent post-concussive symptoms reliably produce a second problem on top of the first: fear of the activities that provoke symptoms. Avoidance is a rational short-term response and a poor long-term strategy, because the deconditioning and withdrawal it causes make the underlying problem harder to treat.
This is measurable. In a prospective cohort of adults working at the time of their mild TBI, persistent or increasing fear-avoidance behaviour was associated with significantly greater odds of still being off work 6–9 months later — independent of the injury itself.
Acceptance and Commitment Therapy (ACT) is directed at exactly this. Rather than trying to argue someone out of their symptoms, it works on psychological flexibility — reducing avoidance, clarifying what the person actually wants their life to contain, and rebuilding activity in that direction while symptoms are still present. It is delivered in-house here rather than referred out, which keeps it integrated with the physical rehabilitation instead of running on a separate track.
To be clear about what this is not: offering ACT is not a statement that the symptoms are psychological. The vestibular injury is real and gets treated as such. ACT addresses the avoidance spiral that a real injury sets off.
Snell DL, et al. Fear avoidance and return to work after mild traumatic brain injury. Brain Inj. 2023;37(6):541–550. doi:10.1080/02699052.2023.2180663
Nutrition and the injured brain
If the core problem in the first days is an energy supply-and-demand mismatch, then fuelling matters more than it usually gets credit for. The practical points are unglamorous and worth stating plainly:
- Do not under-eat during recovery. The injured brain’s glucose demand is elevated. Skipping meals because you feel nauseated or foggy withdraws fuel exactly when demand is highest.
- Hydration — dehydration worsens headache and cognitive symptoms independently, and is common in people who have stopped their normal routine.
- Alcohol — disrupts sleep architecture and lowers seizure threshold; the case for avoiding it during recovery is straightforward.
- Omega-3 fatty acids, magnesium and creatine appear repeatedly in the concussion nutrition literature with plausible mechanisms and mostly preclinical or small-trial human support. Reasonable, low-risk, not established treatment.
The honest framing is that nutrition supports the conditions for recovery rather than driving it. Anyone selling a supplement protocol as concussion treatment is ahead of the evidence.
Sleep support without benzodiazepines — glycine and GABA
Sleep is one of the highest-value targets in concussion recovery, and insomnia is one of the features that independently predicts persistent symptoms. So the clinical question is not whether to treat sleep. It is what to treat it with.
The default answer in most settings is a benzodiazepine or a related sedative-hypnotic. In a brain-injured patient that is a poor trade, and this is the reasoning behind our approach.
Why not a benzodiazepine — they block learning
The usual objections to benzodiazepines are sedation, falls and dependence. All real, and all beside the main point in this population. Benzodiazepines impair the formation of new memories. In a patient whose central complaint is that their memory and concentration are not what they were, that is not a side effect to be weighed — it is the injury being prescribed for a second time.
This is not a fringe concern or a matter of dose. Across the class, benzodiazepines produce dose- and concentration-dependent amnesia, and the amnestic effect is characterised as impairment of information acquisition, impairment of consolidation and storage, or both. Anterograde amnesia — the failure to lay down memories going forward — is so reliably produced that it is used in research as a model of hippocampal cognitive dysfunction. The drug is a standard way of inducing, experimentally, the deficit the patient came in with.
Greenblatt DJ. Pharmacology of benzodiazepine hypnotics. J Clin Psychiatry. 1992;53(Suppl):7–13. · Venault P, et al. Benzodiazepine impairs and beta-carboline enhances performance in learning and memory tasks. Nature. 1986;321(6073):864–866. doi:10.1038/321864a0 · Vandesquille M, et al. J Psychopharmacol. 2012;26(6):845–856. doi:10.1177/0269881111416692
And they remove the window where memory is consolidated
The damage is done twice, by two separate routes, and the second is easy to miss.
Memory is not filed at the moment of learning. It is consolidated during sleep — specifically during slow-wave sleep, and specifically for the hippocampus-dependent declarative memories that concussion patients complain about. In a landmark experiment, cueing newly learned material with an odour during slow-wave sleep improved retention of declarative memories, with functional imaging showing hippocampal activation in response. The same cue during REM sleep or during wakefulness did nothing, and procedural memories — which do not depend on the hippocampus — were unaffected.
Now recall what long-term benzodiazepine use does to sleep architecture: a marked depression of slow-wave activity, with reduced delta power during NREM sleep and a sharply reduced cyclic alternating pattern.
So the drug given to help a concussed patient sleep impairs encoding while they are awake, and then suppresses the sleep stage in which whatever did get encoded would have been consolidated. Both hits land on the same hippocampus-dependent system, which is the system already injured. The patient sleeps more and remembers less, and the memory complaint that brought them in gets worse while being treated.
Rasch B, Büchel C, Gais S, Born J. Odor cues during slow-wave sleep prompt declarative memory consolidation. Science. 2007;315(5817):1426–1429. doi:10.1126/science.1138581 · Manconi M, et al. Sleep architecture in insomniacs with severe benzodiazepine abuse. Clin Neurophysiol. 2017;128(6):875–881. doi:10.1016/j.clinph.2017.03.009 — note this studied long-term high-dose use, not ordinary short-term prescribing.
There is a final turn of the screw. Among the features that independently predict who develops persistent post-concussive symptoms, retrograde amnesia carries the highest odds ratio of any symptom measured — and difficulty concentrating is close behind. The patients most likely to be handed a sedative-hypnotic for poor sleep are disproportionately the ones whose memory is already the problem, and who have the most to lose from a drug that works on exactly that system. See the long-term effects of concussion.
Sedation, unsteadiness, fall risk and dependence are all still true, and in a patient already at risk of a second head injury from a fall they matter. But the reason we reach for something else first is the learning.
Glycine: a thermoregulatory route into sleep, not a sedative
Glycine taken before bed has been reported to improve subjective sleep quality in people with insomniac tendencies. The mechanism is the interesting part, because it is not sedation.
Oral glycine raises plasma and cerebrospinal fluid glycine, increases cutaneous blood flow and lowers core body temperature — and a falling core temperature is a normal precondition for sleep onset, which is maintained through the night. In rodents, glycine shortened the latency to non-REM sleep, and the effect was localised to NMDA receptors in the suprachiasmatic nucleus: ablating the SCN abolished both the sleep-promoting and the hypothermic effect entirely.
So glycine works by nudging the body’s own sleep-onset machinery rather than by suppressing the central nervous system. That difference is the whole point — it does not trade slow-wave sleep away to get unconsciousness.
Bannai M, Kawai N. New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. J Pharmacol Sci. 2012;118(2):145–148. doi:10.1254/jphs.11r04fm · Kawai N, et al. The sleep-promoting and hypothermic effects of glycine are mediated by NMDA receptors in the suprachiasmatic nucleus. Neuropsychopharmacology. 2015;40(6):1405–1416. doi:10.1038/npp.2014.326
GABA: the inhibitory neurotransmitter, working through the gut
GABA is the brain’s major inhibitory neurotransmitter — the signal that damps excitatory activity down. After a concussion, in which a flood of the excitatory neurotransmitter glutamate is a defining early event, restoring inhibitory tone is a coherent thing to want.
The standard objection to oral GABA is that it crosses the blood–brain barrier poorly. That objection is fair, and it is also why the relevant site of action is the gut.
GABA turns out to be a live currency in the gut microbial ecosystem rather than an inert passenger. In work published in Nature Microbiology, one gut bacterium could not be grown in culture at all until GABA was supplied — GABA was the only tested nutrient that supported its growth. Bacteroides species were found to produce large quantities of GABA, genome-scale modelling identified many genera that produce or consume it, and stool from healthy people showed GABA-producing pathways actively expressed by Bacteroides, Parabacteroides and Escherichia. In patients with major depressive disorder, the relative abundance of faecal Bacteroides was negatively correlated with brain signatures associated with depression.
That is the route we are working with: GABA participating in the gut ecosystem, and the gut–brain axis carrying the consequences — not a pill of GABA travelling to the brain and acting there directly. Anyone who tells you oral GABA sedates you the way a benzodiazepine does is describing a pharmacology that does not happen.
Strandwitz P, et al. GABA-modulating bacteria of the human gut microbiota. Nat Microbiol. 2019;4(3):396–403. doi:10.1038/s41564-018-0307-3
The route is gut → vagus nerve → brain
The missing link between “GABA is active in the gut” and “this affects how you sleep” is the vagus nerve — the main neural cable of the parasympathetic nervous system and the principal channel through which the gut talks to the brain.
The cleanest demonstration is a study in which mice fed Lactobacillus rhamnosus showed region-specific changes in brain GABA receptor expression, along with reduced stress-induced corticosterone and less anxiety- and depression-related behaviour. The decisive part of the experiment came next: none of those neurochemical or behavioural effects appeared in vagotomised mice. Cutting the vagus abolished them entirely, identifying the nerve as the communication pathway between gut bacteria and the brain.
That is the whole mechanism in one experiment. Bacteria in the gut, GABA as the signalling currency between them, the vagus carrying the message, and measurable change in the brain’s own inhibitory receptors at the far end — without any requirement that swallowed GABA reach the brain itself.
Bravo JA, Forsythe P, Chew MV, Escaravage E, Savignac HM, Dinan TG, Bienenstock J, Cryan JF. Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proc Natl Acad Sci USA. 2011;108(38):16050–16055. doi:10.1073/pnas.1102999108
The inhibitory side of the nervous system is substantially a gut story. The neurotransmitters that quiet things down and the parasympathetic “rest and digest” state they support are not confined to the brain — they are produced, consumed and signalled from the gut, and relayed upward. Sleep is a parasympathetic activity. Getting into it is not a matter of overriding the nervous system with a sedative but of letting the system that induces it work.
This matters after a concussion specifically, because autonomic disturbance is part of the injury — which is why exercise intolerance, poor temperature regulation and a racing pulse on standing are such common complaints. We will be careful here, though. Heart rate variability has been studied as a marker of that disturbance and the findings are openly conflicting, with the interpretation of its low-frequency component still debated. Autonomic involvement after concussion is real; HRV is not a settled diagnostic for it, and we do not present it as one.
Bishop SA, Dech RT, Guzik P, Neary JP. Heart rate variability and implication for sport concussion. Clin Physiol Funct Imaging. 2018;38(5):733–742. doi:10.1111/cpf.12487
Where this honestly sits
We would rather be precise than impressive:
- There is no randomised trial of glycine or GABA as a treatment for concussion. The reasoning is indirect: sleep drives recovery, these support sleep, therefore they support recovery. That is a chain of inference, not a trial result.
- The human glycine data are small and rest on subjective sleep measures; the detailed mechanism comes from rodent work.
- The GABA–microbiome–vagus work is mechanistic — the decisive vagotomy experiment is in mice, and the human microbiome findings are associative. Neither is an intervention study in brain injury.
- What is solid is that sleep matters here, that these carry low risk, and that the alternative they displace — sedative-hypnotics in a cognitively impaired, fall-prone patient — carries real and documented harm.
They are adjuncts to sleep hygiene, treatment of headache and mood, and investigation of sleep-disordered breathing — not a substitute for any of those.
Other adjunctive approaches
- Transcranial magnetic stimulation (TMS) — non-invasive brain stimulation, studied for persistent post-concussive symptoms with encouraging but not definitive results
- Virtual reality rehabilitation — an effective way to deliver graded vestibular and cognitive work, rather than a distinct treatment in itself
- Whole body vibration therapy — mechanical stimulation used adjunctively; emerging, drawn from musculoskeletal and neurological rehabilitation
- Thermal therapies — controlled cooling and sauna-based heat exposure have both been studied in recovery contexts; mechanistically plausible, early evidence
A word about the trial populations
Most of what is known about concussion recovery comes from studies of young athletes: healthy, monitored, and rapidly identified. Those studies systematically exclude older adults, people with prior head injury, and people with diabetes, obesity, sleep apnoea or vascular disease. Those exclusions describe a large share of the people who actually arrive at a concussion clinic after a crash or a fall at work.
When the evidence base does not cover a patient, the honest response is to say so and treat what the examination shows — not to apply a return-to-play timeline built on college athletes and call it settled.
Common questions
Is rest still the treatment?
Not as it used to be prescribed. Brief relative rest in the first day or two, then a graded, symptom-guided return to physical and cognitive activity. Prolonged inactivity is now understood to slow recovery in many patients and to feed the avoidance cycle that predicts staying off work.
Why would a concussion clinic care about my diabetes or sleep apnoea?
Because recovery is metabolically expensive and both conditions impair it. They are also excluded from most concussion research, which is a large part of why patients who have them do not follow the published timelines and get told their symptoms must be something else.
Does offering therapy mean you think my symptoms are psychological?
No. The vestibular, oculomotor and headache problems are physical and get treated as such. ACT addresses the avoidance and deconditioning that a real injury sets off — a pattern that independently predicts still being off work 6–9 months later.
Do supplements help concussion recovery?
The gut-brain rationale is real and the trial evidence specific to concussion is early and thin. Glycine has better-supported evidence for sleep quality than for brain injury recovery. We use these as low-risk adjuncts and we do not present them as established treatment.