Shaken Baby Syndrome (SBS): Symptoms, Causes & Prevention

Shaken Baby Syndrome (SBS), also called Abusive Head Trauma (AHT), is a severe brain injury resulting from violently shaking an infant or young child. The brain rotates within the skull, tearing blood vessels and nerve fibers, causing bleeding, bruising, and swelling. SBS is a leading cause of child abuse death and permanent disability.

Symptoms (May Appear Immediately or Hours/Days Later)

• Lethargy, excessive sleepiness, or extreme irritability
• Vomiting (without diarrhea or fever)
• Difficulty breathing, irregular breathing, or apnea
• Seizures
• Poor feeding, sucking, or swallowing
• Unequal pupil size, inability to focus eyes, or eye rolling
• Bruising on face, head, neck, chest, or arms
• Bulging fontanelle (soft spot)
• Decreased muscle tone (floppiness) or rigidity
• Coma or unconsciousness

Causes & Mechanism

Violent shaking (even for a few seconds) causes the infant's heavy head to whip back and forth. The brain lags behind the skull movement, stretching and tearing bridging veins (causing subdural hematomas) and shearing nerve axons (diffuse axonal impact). Impact against a surface (even soft) worsens injury. Normal play (bouncing on knee, tossing in air, jogging with baby) does NOT cause SBS.

Risk Factors

• Caregiver stress, fatigue, depression, or lack of support
• Unrealistic expectations of infant behavior
• History of violence or abuse in caregiver's past
• Substance abuse
• Infant prematurity, colic, or special needs (increased crying)
• Social isolation, financial stress, domestic violence

Long-Term Consequences

• Death (25% of diagnosed cases)
• Cerebral palsy
• Intellectual and developmental disabilities
• Seizure disorders
• Vision loss or blindness
• Hearing loss
• Learning disabilities, behavioral problems
• Paralysis or motor deficits

Prevention

• NEVER shake a baby. No exceptions.
• If frustrated by crying: put baby safely in crib, walk away, breathe, call a friend/family member/crisis line.
• Educate all caregivers (grandparents, babysitters, partners) about SBS.
• Learn soothing techniques: swaddling, white noise, rocking, pacifier, walk/stroller ride.
• Screen for postpartum depression and caregiver stress.

If you suspect SBS, call 911 immediately. Early intervention saves lives and reduces disability.