Subdural haemorrhage, retinal bleeding and hypoxaemic encephalopathy have long been considered a diagnostic clinical triad for the so-called shaken baby syndrome (SBS). The classical triad, however, has been challenged in the recent past by the so-called 'unified hypothesis' by Geddes and colleagues  with subsequent implications in court rulings in suspected cases of SBS.
Judicial and scientific dilemma
The unified hypothesis by Geddes suggested an alternative cause for SBS injuries that did not involve significant shaking. The Geddes theory led to the speculation that subdural and retinal haemorrhage was not caused by traumatic shearing of subdural and retinal veins but by a combination of cerebral hypoxia, raised intracranial pressure and raised arterial and central venous pressure. The publication of this theory was met with scepticism by many forensic and paediatric pathologists but was enthusiastically embraced by defence attorneys. This dilemma resulted in the UK with several appeals against prior convictions of murder/manslaughter because of alleged traumatic shaking of young children. The forensic community awaited with great interest the ruling of the Court of Appeal in London on 21 July 2005.
Court ruling of 21 July 2005
Four cases of alleged SBS were brought to the Court of Appeal in London. Two convictions were upheld, one conviction was dismissed and one conviction was reduced from murder to manslaughter. In their written judgement their Lordships clearly stated: 'In our judgment, it follows that the unified hypothesis can no longer be regarded as a credible or alternative cause of the triad of injuries'. The Crown Prosecution Service made a press release that 'Today's judgement sends a clear signal validating the CPS in prosecuting Shaken Baby Syndrome cases. The Geddes theory will no longer be used by the defence.'
Diagnosing SBS is a very complex and delicate matter. The mere presence of the classic triad does not automatically or necessarily lead to a diagnosis of nonaccidental head injury or a conclusion of unlawful killing. Diagnosis of (intentional) SBS must be based on the combination of: medical elements, elements from police inquiry, and forensic and crime scene elements. Physicians, particularly those working at the medicolegal interface (such as emergency physicians), should realise that medical observations may play a pivotal role in the diagnosis of SBS. As important is the realisation that, despite alternative hypothesis in medical literature, the classical triad of symptoms (subdural haemorrhage, retinal bleeding, hypoxaemic encephalopathy) is still valid as diagnostic for SBS according to recent (UK) court ruling.