Shaken Baby Syndrome I Blumenthal
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732 Postgrad Med J: first published as 10.1136/pmj.78.926.732 on 1 December 2002. Downloaded from REVIEW Shaken baby syndrome I Blumenthal ............................................................................................................................. Postgrad Med J 2002;78:732–735 Shaken baby syndrome is the most common cause of shaking as a technique for stopping the child death or serious neurological injury resulting from child crying.7 Such individuals are most frequently male, fathers, boyfriends, and babysitters.89 abuse. It is specific to infancy, when children have unique anatomic features. Subdural and retinal haemorrhages are markers of shaking injury. An PATHOPHYSIOLOGY American radiologist, John Caffey, coined the name The forces needed for a head injury are transla- tional or rotational. Translational forces produce whiplash shaken infant syndrome in 1974. It was, linear movement of the brain. Such forces occur however, a British neurosurgeon, Guthkelch who first during falls and at worst cause a skull fracture, described shaking as the cause of subdural but are usually relatively benign. Rotational forces, which occur during shaking, cause the haemorrhage in infants. Impact was later thought to brain to turn on its central axis or at the play a major part in the causation of brain damage. attachment to the brainstem. Movement of the Recently improved neuropathology and imaging brain within the subdural space causes stretching and tearing of the bridging veins, which extend techniques have established the cause of brain injury as from the cortex to the dural venous sinus. The loss hypoxic ischaemic encephalopathy. Diffusion weighted of blood, typically 2–15 ml, into the subdural 7 magnetic resonance imaging is the most sensitive and space is not of itself harmful. It provides firm evidence of shaking in the absence of a history of specific method of confirming a shaking injury. Families severe accidental head trauma. of children with subdural haemorrhages should be When an infant is violently shaken the conse- thoroughly investigated by social welfare agencies. quent traumatic axonal damage has in the past been described in clinicopathological terms as .......................................................................... diffuse axonal injury or axonal shearing.710Most infants with shaking injury have some clinical, 11 n 1860 Tardieu reported thickening of blood on radiological, or pathological evidence of impact. the surface of the brain in Parisian children who Experimental evidence in both primates and dolls 1 Iwere the victims of child abuse. In 1946 John also resolved that the force generated by shaking http://pmj.bmj.com/ Caffey, a paediatric radiologist, reported long bone alone would be insufficient to cause diffuse 12–14 fractures in six infants with subdural axonal injury in infants. For these reasons the haematomas.2 A history of injury was lacking and name originally coined by Caffey, whiplash shaken the cause remained unexplained. Nowadays such a infant syndrome, has been deemed by some to be an scenario would seem incredible, but the phenom- inappropriate description of the injury enon of child abuse had received little recognition mechanism.15 They would regard shaking impact at that time. This changed after Kempe et al syndrome as a name more in keeping with the way highlighted the plight of abused children in their the injury is caused.11 16 on September 30, 2021 by guest. Protected copyright. landmark paper in 1962.3 In 1971 Guthkelch, a In the past decade new information has been neurosurgeon, reported subdural haematoma as a gleaned from the use of β-amyloid precursor pro- feature of the “battered child syndrome” and postu- tein, the most reliable marker of axonal damage. lated that the brain injury was caused by shaking.4 It has now become possible to distinguish He wrote that the “relatively large head and puny neck between hypoxic and traumatic axonal injury.17 muscles” render the infant particularly vulnerable The presence of β-amyloid precursor protein indi- to whiplash injury. Guthkelch also noted that a cates survival of at least 2–3 hours, a point of “good shaking” was felt by British parents to be medicolegal significance. Contemporaneous with socially more acceptable and less dangerous than a improved methods in neuropathology, imaging blow to the head or elsewhere. It is difficult to esti- techniques in the last decade have advanced and ....................... mate how frequently infants in Britain are shaken. now also enable the distinction between hypoxic The incidence of those that come to serious harm and traumatic brain damage to be made.18 19 These Correspondence to: Dr Ivan Blumenthal, Royal can, however, be identified. In two recent British advances have established that with violent shak- 17 Oldham Hospital, surveys the annual incidence of inflicted subdural ing the initial brain injury is caused by hypoxia. Rochdale Road, Oldham haemorrhage was 21.0 and 24.6 per 100 000 This in turn causes cerebral oedema and raised OL1 2JH, UK; children under 1 year.56 Most children were aged intracranial pressure.20 Further neurological dam- ivan.blumenthal@ norford.fsbusiness.co.uk less than 6 months. age or death ensue as a consequence of ischaemia Children are usually shaken in response to pro- resulting from a fall in cerebral perfusion Submitted 10 September longed inconsolable crying. In a fit of rage the pressure. The difference between accidental 2002 child may also be thrown down. The perpetrator is (traumatic) and shaking (hypoxic) injury is well Accepted 21 22 14 October 2002 generally of limited patience and experience in depicted in the difference in outcome. In the ....................... handling a child. Some have admitted using context of the new information that shaking is www.postgradmedj.com Shaken baby syndrome 733 Postgrad Med J: first published as 10.1136/pmj.78.926.732 on 1 December 2002. Downloaded from primarily a hypoxic ischaemic injury, the importance of orrhages, which may be unilateral or bilateral, confirm the impact becomes irrelevant. Shown in fig 1 is the sequence of diagnosis of inflicted injury.34 Eye haemorrhage without sub- events causing brain injury. dural haemorrhage has not been reported, probably because a The initial cause of the hypoxia is respiratory difficulty. lesser force is needed to inflict subdural haemorrhage.35 The Apnoea and breathing problems have been commonly severity of head trauma correlates with the extent of eye observed in infants who have been shaken.23 24 Necropsies on haemorrhage.35 The first change is intraretinal haemorrhage such infants reveal brainstem damage. This damage is unique and subhyaloid haemorrhage, which is followed by retinal to infancy, when there is a big head with poor neck muscle detachment and finally choroidal and vitreous tone. The pivotal movement of the head during shaking causes haemorrhage.35 Haemorrhage at the periphery (ora serrata) is a stretch injury at the craniocervical junction.25 26 The younger most frequent, but not easily visualised. Most haemorrhage is the infant the greater the risk of injury. In very premature seen at the posterior pole and can involve one or more layers of infants vigorous physiotherapy without head support can the retina.34–36 The cause of retinal haemorrhage is not clear. To induce histological brain changes of shaking injury identical and fro oscillation of the lens and vitreous causing traction to that in older infants.27 28 In infants, unlike older children, injury where the vitreous is most firmly attached to the retina the base of the skull is smooth and the unmyelinated brain is is one theory, the other being haemorrhage arising from back soft, resulting in a different pattern of injury. Contusions, pressure on the central retinal vein caused by elevated intrac- superficial foci of haemorrhagic necrosis, which characteristi- ranial or intrathoracic pressure.36 cally affect the base of the brain and areas underlying skull Neonatal haemorrhage is common and may be a source of fractures, are seldom observed. Infants also frequently have a confusion. Such haemorrhage usually disappears by eight subarachnoid haemorrhage, which like subdural haemor- days but can persist as long as three months.34 It is not possi- rhage is small and of little clinical significance.17 ble to date retinal haemorrhage by appearance. At necropsy, however, the presence of haemosiderin indicates that the CLINICAL SIGNS haemorrhage is more than three days old.34 With the possible There is a wide spectrum of clinical signs.11 29 The mildest are exception of whooping cough, coughing or vomiting do not non-specific so that injury may never be detected; the most induce retinal haemorrhage. Neither do cardiopulmonary severe being the shocked, unconscious, convulsing child. resuscitation or convulsions.37 38 Non-traumatic causes of reti- Immediately after the incident the child will always be nal haemorrhage include coagulation and haematological dis- obviously unwell, even to the most inexperienced carer. The orders, vasculopathies, and cranial malformations. They can non-specific signs that may persist for days or weeks are poor also be caused by meningitis, intracranial hypertension, and feeding, vomiting, lethargy, and irritability. These signs are some rare metabolic disorders.34 36 39 It should be noted that a often minimised by doctors and may be attributed to viral ill- head injury itself can cause a coagulation abnormality.40 ness, feeding problems, or colic.30 In some, the signs