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Second Impact Syndrome
Overview
Second Impact Syndrome (SIS) is a rare but severe neurological condition that may occur when an individual sustains a second concussion before the symptoms of an earlier head injury have fully resolved. The result can be rapid and dangerous swelling of the brain.
At The Royal Buckinghamshire Hospital, we specialise in complex neurological rehabilitation. Our inpatient team supports adults recovering from brain injuries, including complications caused by repeat concussion or delayed recovery from head trauma.
What Is Second Impact Syndrome?
SIS develops when a second head injury occurs before the brain has healed from a previous concussion. Even a relatively mild second impact can trigger a catastrophic loss of blood flow regulation in the brain, leading to:
- Cerebral oedema (brain swelling)
- Raised intracranial pressure
- Loss of consciousness
- Seizures or collapse
Though rare, SIS can result in long-term neurological impairment or death if not treated urgently. Prevention and awareness are essential.
What Increases the Risk?
While most common in younger athletes, SIS can affect adults—especially those returning to high-risk activity before they have fully recovered from an initial concussion. Risk factors include:
- Resuming physical activity or contact sport too soon
- Under-reporting of concussion symptoms
- Lack of medical clearance before returning to work or sport
- A history of multiple concussions
- Incomplete recovery or undiagnosed post-concussion syndrome
Patients with previous traumatic brain injury (TBI) or prolonged post-concussive symptoms may also be more vulnerable to neurological complications after subsequent impacts.
Warning Signs and Symptoms
SIS develops rapidly after a second injury, often within minutes. Symptoms may include:
- Sudden loss of consciousness
- Rapid deterioration in alertness or breathing
- Seizures or convulsions
- Pupil abnormalities
- Coma
This is considered a medical emergency, requiring urgent intervention. Survivors may be left with long-term cognitive, physical, or behavioural difficulties.
How We Help at The Royal Buckinghamshire Hospital
At our specialist hospital, we support adults who have experienced neurological complications following brain injury or concussion, including those recovering from repeated trauma.
Our inpatient neurorehabilitation includes:
Neurological Assessment & Care Planning
- Consultant-led evaluation of brain injury history
- Risk factor monitoring and structured therapy planning
- Coordination with imaging and referring teams where appropriate
Physiotherapy & Occupational Therapy
- Support with movement, strength, and balance
- Relearning functional tasks and routines
- Fatigue and energy management following brain injury
Speech & Language Therapy
- Communication support for speech or cognitive difficulties
- Rehabilitation of language or processing impairments
Neuropsychology
- Support for memory, concentration, and emotional regulation
- Coping strategies for adjustment and post-concussive symptoms
- Insight into behavioural changes and personality shifts post-injury
Specialist Nursing
- 24/7 inpatient support
- Medication management and neurological monitoring
- Patient and family education about post-injury care
Who We Support
We care for adults (18+) who:
- Have experienced post-concussion complications
- Are recovering from repeat head injuries or Second Impact Syndrome
- Require a structured, consultant-led rehabilitation programme
- Need help with regaining independence and preventing long-term disability
To enquire about rehabilitation following a brain injury, please call 01296 678800 or get in touch with our team.
Why Choose The Royal Buckinghamshire Hospital?
- One of the UK’s leading providers of inpatient neurorehabilitation
- Multidisciplinary team experienced in complex brain injury recovery
- Individualised therapy plans delivered 7 days a week
- Calm, focused environment designed for neurological recovery
- Collaborative approach to discharge planning and onward care
8 August 2025