A concussion is a mild traumatic brain injury (mTBI) caused by a bump, blow, or jolt to the head that creates chemical and metabolic changes within brain cells. Historically, medical advice strictly prohibited sleeping. Modern understanding has reversed this guidance. Rest, which includes sleep, is generally safe and beneficial for recovery after a concussion, provided the individual has been medically assessed for more severe injuries.
The Origin of the “Stay Awake” Mandate
The traditional advice to keep a person with a head injury awake stemmed from a fear of missing a life-threatening complication, established long before modern neuroimaging technology was widely available. Doctors were concerned about an undetected, worsening intracranial hemorrhage (bleeding and swelling within the skull).
A growing hematoma, or blood clot, increases pressure on the brain, leading to a rapid decline in neurological function. If a patient was asleep, caregivers could not perform frequent neurological checks to monitor this dangerous progression. They feared that a patient who was sleeping could slip into a coma or even die without the caregiver noticing the changes in consciousness.
Without the ability to quickly perform a computed tomography (CT) scan to rule out bleeding, constant observation was the only method for monitoring. The inability to wake someone, unequal pupil size, or worsening confusion are signs of high intracranial pressure that require immediate intervention. The old advice prioritized monitoring for acute complications over the body’s need for rest.
How Sleep Aids Concussion Recovery
The modern view recognizes that once severe complications have been ruled out, sleep is necessary for healing. Sleep is an active period of repair for the injured brain. The brain needs metabolic rest after a concussion because the injury triggers a temporary energy crisis in the brain cells.
During sleep, the brain’s overall activity decreases, which helps restore the energy balance disrupted by the injury. The injured tissue requires less energy, allowing it to recover from the initial metabolic shock. Deep sleep cycles are beneficial for neural plasticity, involving the brain’s ability to reorganize itself and form new connections.
A specialized waste-clearance system, the glymphatic system, becomes significantly more active during sleep. This system flushes out metabolic waste products and toxins that accumulate after an injury. The enhanced flow of cerebrospinal fluid helps clear substances that can impede recovery.
The quality and duration of sleep are crucial, as sleep disturbances often slow down recovery. People who experience poor sleep quality in the acute phase often take longer to resolve their overall symptoms. Allowing a stable person to sleep supports the brain’s natural mechanisms for healing and detoxification.
Warning Signs Requiring Immediate Medical Care
While sleep is generally recommended, it is crucial for a caregiver to monitor for specific “red flag” symptoms that indicate a serious underlying problem and require immediate emergency medical attention. These signs suggest a potentially worsening condition, such as increased brain swelling or a persistent bleed.
Immediate medical care is required if the patient exhibits any of the following:
- A headache that progressively worsens and does not go away, or a headache that becomes severe.
- Repeated or forceful vomiting, especially more than once.
- Seizures or convulsions after the initial injury.
- Any significant change in consciousness or awareness, including increasing confusion or slurred speech.
- An inability to be roused from sleep.
- Anisocoria, where one pupil is noticeably larger than the other, which can indicate dangerous pressure on the brain.
- Loss of coordination, weakness or numbness in the limbs.
- Clear fluid or blood draining from the ears or nose.