Tuesday, 25 January 2011

SBS: Dr Squier and Dr Cohen expert opinions

The case of Re S [2009] EWHC 2115 involved the examination of the death of a child. Mrs Justice King’s judgment has recently been published and is of considerable importance in cases involving issues of death, non-accidental head injury and shaken baby syndrome.

 John Tughan, 4 Paper Buildings

Historically, the classic features of non-accidental head injury were said to be encephalopathy, subdural haemorrhage and retinal haemorrhage.  Encephalopathy is disorder or dysfunction of the brain.  The subdural space within the brain lies above the arachnoid membrane and below the dura.  Bleeding into that area, which is not really a space at all in normal life, is the haemorrhage.  Establishing the presence of the triad involves medical experts from a number of different disciplines interpreting signs within the brain and surrounding tissue.  Those signs can range from the radiological imaging of the brain to the post mortem findings of the pathologist down to the microscopic findings from the tissues of the brain and spinal cord undertaken by a neuropathologist.  Often this process of putting the various strands of evidence together in order to achieve a conclusion is likened to the pieces of a jigsaw puzzle slotting into place.  The clinical history of the people involved with the care of the allegedly injured child is also a part of that puzzle and, for a court attempting to draw conclusions from the medical information, a vitally important part of it.

For some years conventional medical opinion was that the presence of the triad of injuries was diagnostic of non-accidental head injury.

However, practitioners in this area will remember that the controversy included the publication by Dr Geddes of her three papers on the subject leading up to her unified hypothesis or “Geddes III”.  The unified hypothesis of Geddes III challenged the importance of the triad of injuries as a diagnostic tool for evaluating the cause of injuries to a child.  At the core of the unifying hypothesis was the proposition that the triad of injuries could be caused by severe hypoxia (lack of oxygen in the tissues) which in turn led to brain swelling.  In turn, the swelling of the brain combined with raised intracranial pressure and could produce both subdural and retinal haemorrhages.  Accordingly, it was asserted that any incidents of apnoea (cessation of breathing) could set in motion a cascade of events leading to the triad of injuries.  The fundamental importance of this will readily be seen to be not only the questioning of the validity of the triad as a diagnostic tool but also the fact that apnoea has many different causes, trauma or abuse being only one of them.

The Court of Appeal considered these issues in R v Harris, Rock, Cherry and Faulder [2005] EWCA Crim 1980.  The decision of the Court of Appeal was that:
(1) It was not possible to find that the triad had been proved as a fact, rather than as a mere hypothesis.  While the triad of injuries was a strong pointer to non-accidental injury on its own, it was not possible to find that it must automatically and necessarily lead to a diagnosis of non-accidental injury.  All the circumstances, including the clinical picture, must be taken into account.  It was for the judge, or jury, to resolve the disputes as to issues of fact on all the available evidence in the case.

(2)  It was not possible to make any finding on the issue of the degree of force needed to cause serious injuries, other than to refer to some general propositions.  Common sense suggested that the more severe the injury the more probable it was that it would have been caused by greater force than mere ‘rough handling’.  Evidence showed that there were cases in which a small degree of force or a minor fall had caused very severe injuries, but if something less than rough handling commonly caused such injuries, the hospitals would be full of such cases; cases of serious injuries caused by very minor force such as might occur in normal handling or rough handling were likely to be rare or even extremely rare.  Although the younger the child, the more vulnerable the child was likely to be, it was not possible to conclude that age was necessarily a factor in deciding whether injuries were caused by a strong force or a minimal degree of force or impact. The balance of the evidence was that, although an infant’s skull was more pliable than that of an older child, the internal organs and vessels were as robust as those of an older child.  The vulnerability of an infant arose from the fact that its head was generally larger in proportion to its body than that of an older child and its neck muscles were weaker and not as well developed.

(3)    The type and extent of retinal haemorrhage and its place in the constellations of symptoms would be a matter for the court to evaluate in each individual case, but there was force in the evidence that caution should be exercised before a diagnosis of non-accidental injury was made in the absence of retinal haemorrhage, whereas in cases of injuries alleged to be caused by an impact or impacts, the evidence suggested that retinal haemorrhages were not a prerequisite.

(4)    Developments in scientific thinking should not be kept from the court simply because they remained at the status of hypothesis, but, obviously, it was of the first importance that the true status of the expert’s evidence was frankly indicated to the court.

(5)    In cases involving allegations of child abuse the judge should be prepared to give directions in respect of expert evidence, taking into account the guidance on the obligations of an expert witness given by Cresswell J in ‘The Ikarian Reefer’ [1993] 2 Lloyd’s Rep 68 and the guidance given by Wall J in Re AB (Child Abuse: Expert Witnesses) [1995] 1 FLR 181. If this guidance were borne in mind and the directions made were clear and adhered to, it ought to be possible to narrow the areas of dispute before trial and limit the volume of expert evidence under consideration.
The Court of Appeal heard evidence and that included the evidence of Dr Geddes.  One of the points made against Geddes III by clinicians in this area was that, if Geddes III was correct, the hospitals would be full of children who presented with the triad of injuries and that this was simply not the case.  Dr Geddes herself accepted that the unified hypothesis did not seek to show that the triad was inconsistent with non-accidental head injury only that it was not diagnostic.  When asked about the hypothesis, Dr Geddes volunteered that she might not have the theory quite right and that it was never advanced with a view to being proved in court but rather as a means to stimulate debate.

For a time it seemed as though R v Harris might have resolved these controversial issues.

Re S [2009] EWHC 2115 was a case involving the death of a child following collapse.  The central issue in the case was what caused that collapse.  The local authority asserted that there was a single primary event which fitted with a traumatic shake or shake/impact which led to the classic triad of injuries.  The mother put forward a number of possible alternatives.

Mrs Justice King heard the evidence of a large number of experts, many of whom were involved in the Harris case.  In particular the court had to deal with the evidence of Dr Waney Squier, consultant neuropathologist, and Dr Marta Cohen, consultant paediatric histopathologist.  Both of these experts continue to subscribe to Geddes III and consider themselves to be building on the work of that hypothesis.  The court recorded that both Dr Squier and Dr Cohen were against the mainstream of current thinking and the analysis in R v Harris.  In this, the court was echoing the view of Hedley J in F & L v A Local Authority [2009] EWCA 140 insofar as Dr Squier was concerned.  To illustrate the point of the mainstream of medical thinking Mrs Justice King read into her judgment the comment of Dr Al-Sarraj, consultant neuropathologist, that
“…there are 40-44 neuropathologists in the country of whom a maximum of 10 or 12 are forensic neuropathologists.  To his knowledge, the only neuropathologist in the UK believing that hypoxia can cause subdural haemorrhages is Dr Waney Squier.  In addition, he said there are two or three other people who share her opinion who are working in different, but related, specialities, of whom Dr Cohen and Dr Scheimberg (Dr Cohen’s co-author) are presumably two.  Dr Al-Sarraj said:
“They come in all the defence cases, so you do not realise that they are in such a minority.”
The court was asked to make findings about the approach of Dr Squier and Dr Cohen in three particular areas, those being the use of research material, their willingness to defer to experts in another field and the confining of their opinion to their own expertise and the importance of factual accuracy.

The court was critical of both experts in each of those three areas.  The criticisms included the conclusion that both, for different reasons, had been “disingenuous” in their citing of research material, “significantly out of their respective areas of expertise” and misleading in the factual errors made.  The court concluded 
“…In considering the evidence of Dr Cohen and Dr Squier, I remind myself that four years have passed since Dr Geddes accepted that her unified hypothesis could no longer credibly be put forward.  Dr Cohen and Dr Squier regard themselves as having built on her work.  I remind myself also that the next generation of experts and scientific research may, as Butler-Sloss P. said:
“Throw light into corners that were then dark and that the hypothesis of Dr Geddes may yet be proven to be in all, or in part, correct.” 
…Dr Squier and Dr Cohen, I find with regret, have each fallen into that category of expert identified by Butler-Sloss P. in Re U [2004] EWCA Civ 567, namely the expert who has developed a scientific prejudice.  As a consequence, I accept the submission of the Local Authority that Dr Squier has permitted her convictions to lead her analysis.”

John Tughan
4 Paper Buildings

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