The Shaken Baby Syndrome

A Multidisciplinary Approach

Vincent J. Palusci, Stephen Lazoritz

• Publisher: Routledge
• Year: 2002
• ISBN:
  9781136748028
• Edition: 1
• Topic: Médecine
• Subtopic: Prestation de soins de santé

Diagnose and treat shaken baby syndrome with advice from experts in the field! When an angry adult shakes a baby, the child may suffer brain damage, broken ribs, deafness, mental retardation, cerebral palsy, coma, or death. Often there are personal, ethical, and legal consequences as well for everyone involved. The Shaken Baby Syndrome: A

Chapter One

Overview of Shaken Baby Syndrome

William Brooks
Laura Weathers

SUMMARY. An overview of the problem of the Shaken Infant Syndrome and the impact it has on society, as well as the great importance of the use of a multidisciplinary approach to the problem, and a general overview of what, exactly, Shaken Infant Syndrome is. This chapter will be of general interest to all readers. [Article copies available for a fee from The Haworth Document Delivery Service: 1-800-342-9678. E-mail address: <[email protected]> Website: <http://www.HaworthPress.com> © 2001 by The Haworth Press, Inc. All rights reserved.]

KEYWORDS. Shaken Baby Syndrome, diagnosis, prognosis, prevention

Introduction

The most common cause of traumatic death in infants under one year of age is head injury (American Academy of Pediatrics, 1993; Coody, Brown, Montgomery, Flynn, & Yetman, 1994). Since Caffey (1974) first described “whiplash shaken infant syndrome,” injuries from severe shaking have gained attention as a cause of significant morbidity and mortality. Shaken Baby Syndrome (SBS) is now a widely recognized diagnosis in the medical literature.

The medical components of Shaken Baby Syndrome include retinal hemorrhage, subdural or subarachnoid hemorrhage and associated fractures with a paucity of external physical findings. It is this absence of external signs of abuse, which makes the early diagnosis of SBS so difficult. In this chapter, we will provide an overview of SBS and discuss the importance of recognition and prevention of the syndrome.

Incidence

The incidence of SBS is difficult to ascertain. Because the perpetrator is reluctant to provide an accurate history, most children with the constellation of injuries seen in SBS and without obvious external trauma are initially “presumed” to have been shaken (Hadley, Sonntag, Rekate, & Murphy, 1989; Ludwig & Warman, 1984; Spaide, 1987). Some infants with less serious forms of shaking may not have significant immediate sequelae from the shaking event, and the diagnosis can be missed (Caffey, 1974; Jenny, 1999).

Most victims of SBS are less than six months of age (AAP, 1993; Chiocca, 1995; Riffenburgh & Sathyavagiswaran, 1991; Swenson & Levitt, 1997). Some studies show more male than female victims (Riffenburgh & Sathyavagiswaran, 1991; Starling, Holden, & Jenny, 1995). While there appears to be a predominance of Caucasian and African-American children with fewer Latino and Asian infants injured, SBS has been shown to affect all racial, ethnic and socio-economic groups (Riffenburgh & Sathyavagiswaran, 1991).

Risk Factors

There are several risk factors that are important to recognize as potential crisis situations in which SBS may occur. Parents who are likely to abuse their children are often described as having reversed nurturing needs. They are looking to be nurtured by their infants, and when this does not happen, abuse can occur (AAP, 1993; Coody et al., 1994; Chiocca, 1995; Spaide, Swengel, Scharre, & Mein, 1990; Swenson & Levitt, 1997). Environmental stressors such as emotional or financial problems, illness, or lack of support at home can increase the likelihood of abuse (AAP, 1993; Coody et al., 1994; Chiocca, 1995).

Some children may possess factors, which contribute to their own abuse. Children with colic can cry most of the day, increasing stress and frustration and leading to abuse. Children born prematurely or with handicaps may cause frustration because they do not reach developmental milestones as quickly as their parents think they should, and may require more care (AAP, 1993; Coody et al., 1994).

People who have admitted to shaking a child usually state that they were not trying to harm the infant but wanted to “make the baby stop crying” (Swenson & Levitt, 1997). Others admit to shaking the infant during “vigorous play” which is later found to be inconsistent with the severity of injury. Starling et al. (1995) found that fathers and boyfriends were the most common abusers, accounting for over half the cases reviewed. Baby-sitters were involved in over 20% of cases.

Mechanisms of Injury

Infants are thought to be more susceptible to whiplash shaking injuries that older children and adults because of several factors. Their relatively large head supported by weak neck muscles increases their head movement during shaking. Their unmyelinated brain, soft sutures, open fontanelles, and relatively increased cerebrospinal fluid result in a brain that is more vulnerable to injury (Alexander, Crabbe, Sato, Smith, & Bennett, 1990; Caffey, 1974; Chiocca, 1995; Hadley et al., 1989; Ludwig & Warman, 1984; Nashelsky & Dix, 1995; Spaide et al., 1987;). The cerebral bridging veins are more easily stretched or lacerated with excessive acceleration, deceleration and rotation of the brain. This tearing of the bridging veins can lead to subdural hemorrhage (AAP, 1993; Coody et al., 1994; Spaide et al., 1990).

Various types of ocular injury have been recognized in SBS, including retinal and vitreal hemorrhages and retinal folds and retinoschesis. Several mechanisms have been suggested for these injuries, including consequences of increased intracranial pressure, increased ocular pressure, rapid brain acceleration/deceleration and direct trauma to the retina from being struck by vitreous moving within the eye during shaking or retraction upon the retina by the vitreous pulling away from the retina during shaking (Coody et al., 1994; Lambert, Johnson, & Hoyt, 1986; Ludwig & Warman, 1984; Ober, 1980; Spaide, 1987; Matthews & Das, 1996).

There has been vast disagreement regarding whether the mechanism of vigorously shaking an infant alone, as Caffey described, produces sufficient force to result in the significant intracranial injuries found in SBS. Duhaime et al. (1987) used laboratory and animal models and found that some form of impact was necessary in at least the most severe cases of SBS, stating: “Although shaking may, in fact, be part of the process, it is more likely that infants suffer blunt impact” (p. 414). Alexander et al. (1990) suggest, “shaking, in and of itself, is sufficient to cause serious intracranial injury or death” (p. 726). Irrespective of the presence of impact, SBS injuries occur because of severe acceleration/deceleration and remain a significant cause of morbidity and mortality.

Clinical Presentation

The clinical presentation of the infant of SBS can be very non-specific, hindering a timely diagnosis. The paucity of external signs of trauma can be misleading. Because of the head injuries present, the child may present in a coma, with a bulging fontanelle or with more subtle signs such as vomiting, irritability, seizures, poor feeding or failure to thrive. Children may be misdiagnosed as having meningitis, and a lumbar puncture is performed. Bloody spinal fluid can mistakenly be thought to be related to a spinal tap rather than a sign of subarahnoid bleeding because of a “normal” head CT; lumbar puncture is more sensitive than CT in identifying small SDH/SAH (Coody et al., 1994; Ludwig & Warman, 1984; Spaide et al., 1990).

The classic finding of retinal hemorrhage may be missed if the diagnosis is not made early. Small flame-shaped retinal hemorrhages resolve in only a few days and may no longer be present by the time the suspicion of abuse is raised. Some would argue that retinal hemorrhages were pre-existing as the result of birth trauma. In fact, 14-40% of newborns sustain retinal hemorrhages at birth (Budenz, Farber, Mirchandani, Park, & Rorke, 1994; Caffey, 1974), but these are usually resolved in several days and certainly within two weeks. After the initial neonatal period, any finding of retinal hemorrhage should suggest abusive head trauma unless another obvious traumatic or anatomic reason is apparent.

The victim of SBS may have bruising over the upper extremities, neck or the chest where the child was held and shaken (Coody et al., 1994). However, bruising is more the exception than the rule. Traction lesions of the periostium or old or new fractures of the large bones may also be present (AAP, 1993; Caffey, 1974).

The amount of time from injury to the onset of symptoms is also not completely understood. The absence of an accurate history from the caretakers complicates the clinical picture. It appears that some patients become significantly symptomatic immediately with severe injury, whereas others with less severe injury are less symptomatic (Nashelsky & Dix, 1995). It is theorized that these more insidious cases may have sustained mild initial shaking with subsequent severe shaking causing more visible symptoms to develop. This remains a point of controversy and topic for further research.

Diagnosis

The diagnosis of brain injury in SBS has become easier to make with the wide availability of the computed tomography (CT) scan. CT has become the method of choice for initial imaging of patients with suspected brain injury because it readily identifies lesions requiring operative intervention (AAP, 1993). Sometimes, several CT scans are necessary to show the full evolution of brain injury, particularly if the patient deteriorates.

Magnetic Resonance Imaging (MRI) has shown to detect 50% more subdural hemorrhages than CT scan and detect smaller injuries missed by CT (Spaide, 1987). However, the cost and availability of MRI makes it more useful as a second study in the diagnosis and evolution of brain injury.

An ophthalmologist or other physician trained in detecting retinal hemorrhages should examine the eyes as early as possible after the diagnosis of SBS is suspected. RH has been found in 75-90% of cases of SBS when searched for early in its course (AAP, 1993).

While external signs may be minimal, that is one of the hallmarks of SBS. When bruises are present, they should be carefully documented. A bulging fontanelle was shown to be present in 55% of infants with subdural hematoma when reviewed by Ludwig and Warman (1984). The physician must closely review the non-specific signs and symptoms, which may be present and the risk factors in the caretakers in addition to the history provided to make the diagnosis.

Prognosis

The victims of SBS suffer significant morbidity and mortality. Ludwig and Warman (1984) showed a 15% mortality rate and a 50% morbidity rate in their review of 20 cases. Permanent brain damage, hydrocephalus, developmental delay, blindness, deafness, paralysis and mental retardation have been noted in SBS victims (AAP, 1993; Coody et al., 1994; Spaide et al., 1990). Brown and Minns (1993) noted 10 deaths and 10 cases of mental retardation in 30 SBS victims. Caffey (1974) suggested that milder forms of SBS might present with mental retardation and developmental delay upon reaching school age.

Recognition and Prevention

The recognition of child abuse in our society is often difficult; this is especially true with victims of SBS. The diagnosis of shaken baby syndrome re quires a high index of suspicion. The clinical manifestations are non-specific, external signs are sometimes lacking, and the history is often inconsistent or non-existent. A missed diagnosis could be life threatening for the child. Early recognition is paramount to institute treatment in a timely manner in order to decrease the high mortality and morbidity. Although the medical literature is becoming abundant with information about SBS, many pediatricians and health professionals lack the knowledge, willingness or ability to make the diagnosis.

Even more concerning is the lack of SBS knowledge by the general public. Recent high profile cases such as the “nanny” case in Massachusetts document this lack of information, sometimes by judges, juries and even the medical profession. Despite campaigns to educate the public about the dangers of shaking a child, awareness remains low, with many teenagers and adults still unaware about SBS. With poor neurologic outcomes in many cases, it is obvious that prevention is key. Many confessed perpetrators believed that shaking an infant for discipline or during vigorous play could not harm the child in such a devastating way. Continued work in public and professional education will be necessary to help combat these false assumptions.

References

Alexander, R., Crabbe, L., Sato, Y., Smith, W., & Bennett, T. (1990). Incidence of impact trauma with cranial injuries ascribed to shaking. American Journal of Diseases in Children, 144, 724-726.

American Academy of Pediatrics (AAP). (1993). Committee on child abuse and neglect. Shaken baby syndrome: Inflicted cerebral trauma. Pediatrics, 92, 872-875.

Brown, J.K., & Minns, R.A. (1993). Nonaccidental head injury, with particular reference to whiplash shaking injury and medico-legal aspects. Developmental Medicine and Child Neurology, 35, 849-869.

Budenz, D.L., Farber, M.G., Mirchandani, H.G., Park, H., Rorke, L.B. (1994). Ocular and optic nerve hemorrhages in abused infants with intracranial injuries. Ophthalmology, 101, 559-565.

Caffey, J. (1974). The Whiplash Shaken Baby Syndrome: A manual shaking by the extremities with whiplash-induced intracranial and intraocular bleeding, linked with residual permanent brain damage and mental retardation. Pediatrics, 54, 396-403.

Chiocca, E.M. (1995). Shaken Baby Syndrome: A nursing perspective. Pediatric Nursing, 27, 33-38.

Coody, D., Brown, M., Montgomery, D., Flynn, A., Yetman, R. (1994). Shaken Baby Syndrome: Identification and prevention for nurse practitioners. Journal of Pediatric Health Care, 24, 536-540.

Duhaime, A.C., Gennarelli, T.A., Thibault, L.E., Bruce, D.A., Marguiles, S.S., & Wiser, R. (1987). The Shaken Baby Syndrome: A clinical, pathological and biochemical study. Journal of Neurosurgery, 66, 409-415.

Hadley, M.N., Sonntag, V.K., Rekate, H.L., & Murphy, A. (1989). The infant whiplash-shaken injury syndrome: A clinical and pathological study. Neurosurgery, 24, 536-540.

Lambert, S.R., Johnson, T.E., & Hoyt, C.S. (1986). Optic nerve sheath and retinal hemorrhages associated with the shaken baby syndrome. Archives of Ophthalmology, 104, 1509-1512.

Ludwig, S., & Warman, M. (1984). Shaken Baby Syndrome: A review of 20 cases. Annals of Emergency Medicine, 13, 104-107.

Matthews, G.P., & Das, A. (1996). Dense vitreous hemorrhages predict poor visual and neurological prognosis in infants with shaken baby syndrome. Journal of Pediatric Ophthalmology and Strabismus, 33, 260-265.

Nashelsky, M.B., & Dix, J.D. (1995). The time interval between lethal infant shaking and onset of symptoms:...