Overview
Definition:
Abusive Head Trauma (AHT) is a serious form of inflicted traumatic brain injury, most commonly seen in infants and young children, resulting from violent shaking, impact, or a combination of both
It is a leading cause of death and severe disability in pediatric victims of physical abuse.
Epidemiology:
AHT affects predominantly children under 2 years of age, with a peak incidence between 3 to 8 months
The incidence is estimated to be between 13 to 40 cases per 100,000 children per year in developed countries
data from India may vary but remains a significant concern
It is a diagnosis of exclusion and requires a high index of suspicion.
Clinical Significance:
AHT is a medical emergency and a forensic challenge
Timely recognition and diagnosis are critical for the child's survival and long-term outcome, as well as for legal and child protection interventions
Failure to diagnose can lead to preventable death or severe neurological sequelae.
Clinical Presentation
Symptoms:
Varying degrees of lethargy and irritability
Poor feeding
Vomiting
Seizures or apnea
Absence of crying
Difficulty breathing
Fever
Signs of poor head control
Change in consciousness level.
Signs:
Subtle findings may include retinal hemorrhages (vitreous and preretinal are classic), ecchymoses in unusual locations, fractures (especially metaphyseal or rib fractures), neurological deficits such as altered mental status, cranial nerve palsies, or pupillary abnormalities
Signs of external trauma may be absent.
Diagnostic Criteria:
There are no specific diagnostic criteria that rely solely on symptoms or signs
Diagnosis is made based on a combination of clinical suspicion, exclusion of accidental causes, characteristic imaging findings (especially intracranial and skeletal), and often, the presence of retinal hemorrhages.
Diagnostic Approach
History Taking:
Obtain a detailed history from all caregivers, noting any discrepancies or inconsistencies
Inquire about the child's symptoms, recent falls, or any trauma
Be alert to vague or conflicting accounts of injury
Ask about the child's baseline behavior and feeding patterns
Obtain birth history and developmental milestones.
Physical Examination:
Perform a thorough head-to-toe examination, paying close attention to the head, neck, eyes (fundoscopy for retinal hemorrhages), chest, abdomen, and extremities
Document all injuries precisely, noting size, shape, color, and location
Assess neurological status meticulously, including level of consciousness, pupillary response, and motor function.
Investigations:
Initial imaging: Head CT scan is the modality of choice for acute intracranial injury, detecting subdural and subarachnoid hemorrhages, contusions, and edema
Skeletal survey: Radiographs of the entire skeleton to detect fractures, especially metaphyseal (bucket-handle) fractures, rib fractures, and fractures of the skull and spine
Fundoscopy: Essential to identify retinal hemorrhages
Follow-up imaging: MRI of the brain is superior for detecting diffuse axonal injury, posterior fossa lesions, and chronic changes
Other investigations: Complete blood count, coagulation profile, electrolytes, glucose, toxicology screen if indicated.
Differential Diagnosis:
Accidental head trauma (falls from low height, birth injuries), metabolic disorders (e.g., vitamin D deficiency rickets), bleeding disorders (e.g., hemophilia, von Willebrand disease), osteogenesis imperfecta, severe sepsis, meningitis, accidental choking, prolonged vomiting leading to subdural effusion.
Imaging Protocol
Initial Imaging:
Head CT scan (non-contrast, axial and coronal views) is the first-line investigation for suspected AHT
It should include the entire brain and cranial vault
A plain radiograph of the cervical spine should also be considered.
Skeletal Survey:
A complete skeletal survey is mandatory in all suspected cases of AHT
This includes X-rays of the skull, cervical spine, chest (anterior-posterior and lateral), abdomen, pelvis, and all four limbs
Specific views for metaphyseal fractures (e.g., oblique views of long bones) are crucial.
Advanced Imaging:
MRI of the brain is indicated for suspected diffuse axonal injury, subacute or chronic subdural hematomas, posterior fossa lesions, or when CT findings are equivocal
MRI can also assess for associated brainstem or cervical spine injuries
MRI is more sensitive for detecting smaller contusions, edema, and subtle injuries.
Interpretation Priorities:
Prioritize identification of subdural hematomas (SDH) of varying ages, subarachnoid hemorrhage (SAH), cerebral contusions, diffuse axonal injury (DAI), and retinal hemorrhages
Look for classic signs like bilateral, layered SDH, posterior SAH, and characteristic metaphyseal fractures
Rule out common accidental causes by carefully evaluating the mechanism of injury described and correlating it with the imaging findings.
Management
Initial Management:
Immediate stabilization of airway, breathing, and circulation (ABCs)
Manage seizures promptly with anticonvulsants (e.g., diazepam, lorazepam)
Control intracranial pressure (ICP) if elevated using osmotic therapy (mannitol, hypertonic saline) and hyperventilation if necessary
Surgical intervention may be required for evacuation of large hematomas causing mass effect.
Medical Management:
Supportive care is paramount
Mechanical ventilation if respiratory compromise
Fluid and electrolyte balance management
Nutritional support via nasogastric or parenteral routes
Avoid sedatives that may mask neurological deterioration
Strict monitoring of vital signs, neurological status, and ICP if monitored.
Surgical Management:
Surgical evacuation of subdural hematomas is indicated if there is significant mass effect, neurological deterioration, or midline shift
Neuroendoscopic techniques may be used for smaller or loculated hematomas
Treatment of associated injuries such as skull fractures or epidural hematomas is also guided by clinical presentation and imaging.
Supportive Care:
Close neurological monitoring in an ICU setting
Pain and agitation management
Prevention of complications like pressure sores, deep vein thrombosis, and infections
Long-term rehabilitation services including physical therapy, occupational therapy, and speech therapy
Psychological support for the child and affected family members.
Complications
Early Complications:
Increased intracranial pressure (ICP), herniation, seizures, hydrocephalus, cerebral edema, stroke, respiratory compromise, cardiac arrest, disseminated intravascular coagulation (DIC), rhabdomyolysis, and failure to thrive.
Late Complications:
Developmental delay, intellectual disability, learning disabilities, behavioral problems, visual impairments (including blindness), hearing loss, motor deficits (e.g., cerebral palsy), epilepsy, and chronic pain syndromes.
Prevention Strategies:
Primary prevention involves public education campaigns about safe infant handling, the dangers of shaking, and non-violent coping strategies for parental stress
Secondary prevention relies on early identification of at-risk families and intervention programs
Tertiary prevention focuses on minimizing injury severity and long-term sequelae through prompt diagnosis and management.
Prognosis
Factors Affecting Prognosis:
Severity of the initial injury (e.g., Glasgow Coma Scale score, presence of diffuse axonal injury), age of the child, extent and location of intracranial and retinal hemorrhages, presence of associated injuries (e.g., fractures), and timeliness and adequacy of medical and surgical management
Aggressive management and supportive care are crucial.
Outcomes:
The prognosis for AHT is highly variable
Approximately 20-30% of children die from their injuries
Survivors often experience significant long-term neurodevelopmental disabilities
A good outcome is associated with less severe initial injury and prompt, effective treatment
Early and accurate diagnosis is key to improving outcomes.
Follow Up:
Children who survive AHT require lifelong multidisciplinary follow-up
This includes regular pediatric, neurological, ophthalmological, audiological, and developmental assessments
Educational support and therapeutic interventions are essential for maximizing functional abilities and quality of life
Social services and child protection agencies often remain involved.
Key Points
Exam Focus:
The classic AHT triad includes subdural hematoma, retinal hemorrhages, and encephalopathy (often with seizures or altered mental status)
However, not all three are always present
Skeletal surveys are critical for detecting occult fractures, especially metaphyseal fractures.
Clinical Pearls:
Always maintain a high index of suspicion in infants presenting with unexplained neurological symptoms, vomiting, or irritability, especially when the history is vague or inconsistent
Fundoscopic examination is crucial, and the absence of external signs does not rule out AHT
Correlate imaging findings with the purported mechanism of injury.
Common Mistakes:
Attributing injuries to accidental causes without rigorous exclusion
Inadequate or incomplete imaging studies (e.g., missing skeletal survey or inadequate brain CT)
Failure to perform a fundoscopic examination
Delay in diagnosis leading to poorer outcomes
Misinterpreting findings in the context of medical conditions that can mimic trauma (e.g., bleeding disorders).