By: Megha Singh

Abusive head trauma (AHT) is an injury to a child’s brain as a result of child abuse. AHT is also called shaken baby syndrome (or SBS), inflicted traumatic brain injury, shaken impact syndrome, or whiplash shake syndrome. SBS usually occurs when a parent or other caregiver vigorously shakes a child or strikes the child’s head against a surface. The average victim of SBS is between three and eight months old, and SBS is usually seen in children younger than age two.

SBS is a form of AHT. SBS or AHT injuries may result in death or permanent neurologic disability of the child. Cerebral Palsy, seizures, cognitive impairment, and various forms of disabilities are also consequences of SBS.

Why is Shaking a Baby Dangerous?

Babies have weak neck muscles which are not strong enough to support their disproportional large heads. When an infant or young child is violently shaken, the brain bounces back and forth within the skull, bruising or destroying brain tissue, tearing blood vessels and often causing retinal bleeding.

Contested Science

            Many SBS/AHT injuries are “silent injuries.” Therefore, in AHT cases, doubts have been raised about doctors’ ability to conclusively diagnose SBS. Doctors have been able to tell when a baby has been shaken based on a triad of a signature pattern, including subdural hematoma, retinal hemorrhages, and brain swelling.  Subdural hematoma is the bleeding between the brain and the skull. Retinal hemorrhage is the bleeding at the back of the eyes, and brain swelling is caused by lack of oxygen. Doctors who support this diagnosis say that this triad has been validated by years of clinical observation, research, and confessions from caregivers.

But some biomechanical studies have challenged the notion that a person can shake a baby with the force needed to cause the pattern of internal symptoms without also causing a serious damage to the baby’s neck, or other injuries. Other studies state that underlying conditions, such as bleeding disorders, could lead to injuries similar to SBS injuries. On the other hand, some doctors have denied that there is any significant disagreement over the science.

Regardless of the different views and studies, there is a general consensus about the diagnosis of AHT in infants. Major national and international professional medical societies have consistently confirmed the validity of the AHT diagnosis, its classic features and its severity.

Legal Challenges

AHT cases involve many challenges when presenting complex medical information to a jury. To effectively cross-examine defense experts and communicate information to the jury, it is essential for prosecutors to have a basic understanding of the medical issues likely to be raised by the defense. Here are some of the issues likely to be raised by defense experts in AHT cases.

Defense attorneys may claim that the evidence that children can sustain brain injuries from having been shaken is too unreliable to be admitted in court. However, every jurisdiction that has considered the issue holds that AHT evidence is admissible under Daubert, Frye, or state-specific admissibility tests.

Defense experts may cite a study by Duhaime as proof that a person cannot shake a baby hard enough to produce subdural hematoma. On the other hand, the results from the Cory and Jones study invalidate this theory because Duhaime’s experiment used dummies with necks that did not mechanically resemble an infant’s neck.

Defense experts will often testify that violent shaking would injure an infant’s neck prior to injuring the brain. The defense relies upon a biomechanical study by Faris Bandak that has been heavily criticized. To counter such an argument, the prosecutor can point out that studies such as Brennan’s confirmed fatal victims of AHT did not have neck injuries.

Furthermore, defense may claim that short falls commonly produce the types of fatal cranial injuries seen in AHT cases. However, Dr. Chadwick found that the risk of a short fall causing fatal injuries in infants is less than one in a million.

The defense witness may testify that the child experienced a “lucid interval” which means that a child sustained a head injury, improved, and then suffered a loss or reduction of consciousness at another point in time. However, there is no evidence of infants having lucid intervals after non-contact head injuries that lead to death. Also, acceleration-deceleration brain injuries leading to death are immediately symptomatic and without a lucid interval. This is an overview of some of the issues raised by defense and ways in which prosecution can overcome defense expert testimony in AHT cases.

Never Shake a baby!

Shaking generally occurs when a frustrated caregiver becomes overwhelmed with an inconsolable crying baby. Thus, it is extremely important to make parents and caregivers of a baby aware about the dangers of shaking and to create awareness about SBS.