The defendants' medical evidence
71 The hospital called Dr Michael Fearnside, a specialist neurosurgeon, to give evidence about various aspects of the case. The decerebrate event was described by him as "transient" and he disagreed with Dr Fitzgerald's opinion that damage had been caused by it, because "Ms Fletcher's clinical parameters returned to the pre-episode levels". A great deal of Dr Fearnside's evidence was focused on the significance of the decerebration event, I take it to demonstrate firstly that its significance is a matter of real medical controversy, which in turn is relevant to a consideration of whether the available evidence - in this case only documentary evidence from the hospital records - is sufficient to enable the medical question posed by its occurrence to be fairly tried. Dr Fearnside said that decerebration "signifies a serious malfunction of the brain, an interruption of the pathways of the brain at the level of the upper portion of the brainstem" and in slightly different language, explained its occurrence as arising from greatly increased intercranial pressure forcing the lower part of the brain down onto and through the tentorium. However, he pointed out that there was a secondary mechanism that caused the rise of intercranial pressure which in turn caused the transient period of decerebration, "and that is that, where patients have raised intercranial pressure, waves of further increases of intercranial pressure can occur, which are self-limiting and explain the phenomenon that Mrs Fletcher exhibited at that time". These, called "A" waves, are generally self-limiting and of short duration. Dr Fearnside also pointed out that decerebration can be fatal if it is sustained. He thought that Ms Fletcher had an intercranial pressure wave which increased the intercranial pressure which, in turn, caused her to lose consciousness. The fact that she recovered consciousness supported this scenario rather than a sustained increase in intercranial pressure. Dr Fearnside also thought that other symptoms were, at least, ambiguous. Thus he was minded to discount the significance of Ms Fletcher's drowsiness which may well have been caused by having taken codeine and being intensively observed during the night which of itself interrupts a sleep pattern although he did not suggest that the symptom, together with the other matters, should have been ignored.
72 So far as Dr Lamond's report of the CT scan was concerned, Dr Fearnside agreed that, if he considered that there was a risk that artefacts on the film in the area of the posterior fossa might have obscured the presence of something as serious as a tumour, he would, as an experienced and appropriately qualified radiologist, perform the CT scan again.
73 Dr Fearnside said -
"The diagnosis of aqueductal stenosis was always very difficult on the early scanners and to a degree it was an inference from the … [appearance of] the enlarged ventricles above the obstruction and the normal ventricle below the obstruction, but it was not until MRI scanning became available that that diagnosis could be refined. And this was the reason that many neurosurgeons would have preferred to ensure that that was so, that it was a benign aqueductal stenosis by doing a ventriculogram because aqueductal stenosis can also be caused by a tumour within the brainstem and that would be more obvious in the ventriculogram than in the CT scans in 1982. So, while one could be reasonably certain, one couldn't be absolutely certain, and obviously the treatment would be different."
74 Dr Fearnside was taken to the admission note made by Dr Caldwell and agreed that it was comprehensive. He also agreed that there were clear indications of a serious symptom complex, particularly having regard to the history of eight drop attacks a day, falling to the floor with complete weakness of arms and legs, morning nausea and vomiting, and, from the neurological examination, that she was mildly dysarthric and that examination of the fundi showed bilateral papilloedema.
75 It seems clear enough from the notes that the treatment plan was that, on the Tuesday Ms Fletcher was to go to the operating theatre for a burr hole to be made, and on the afternoon of that day there would be an isotope study (to document a patent subarachnoid space) and then two days later, on the Thursday "definitive surgery" which could theoretically be either a ventriculostomy or a shunt, though the former procedure was selected. It is pointed out on behalf of Ms Fletcher that this plan was made before the CT scan had been obtained and it is contended, as I understand it, that it follows that the question whether another cause of the aqueductal stenosis such as a tumour was in fact not being considered since, if it were thought to be necessary to exclude it or subdural bleeding the plan would have been expressed to be conditional on further investigation. (At the same time, as I have pointed out, Dr Lamond considered that he was being asked to look for a tumour.)
76 So far as the notes go, it seems clear that the plan, working towards a ventriculostomy, made no provision for any earlier drainage to relieve pressure and symptoms immediately. Dr Fearnside, however, said -
"The problem I have with that is that no diagnosis had been made when she was admitted to Prince Alfred Hospital other than that she had symptoms consistent with raised intercranial pressure …. She didn't have a CT scan at Orange … The differential diagnosis was a cerebral tumour. I cannot imagine that this treatment plan would have been developed without the knowledge of the CT scan because the treatment, had it been a cerebral tumour, which it might have been or hydrocephalus, which it was, would be quite different. A third ventriculostomy wouldn't be treatment for a tumour of the cerebral hemispheres, for example, which this still could have been."
77 Dr Fearnside agreed that the elements of the plan shown in the notes, strongly suggest that "this is a treatment plan for hydrocephalus, not a brain tumour" and that this decision could not reasonably have been made in his opinion until the CT scan had been obtained. It is clear that the CT scan had been ordered by Dr Johnson when Ms Fletcher was first admitted to the emergency department on 23 September at about 12.30 pm. She was seen by Dr Caldwell later on the same day and the treatment plan, which is apparently in Dr Caldwell's writing, made on the same day, though precisely when, is not stated. The CT scan report is dated 23 September, so the same day. It is therefore, I think, at least reasonably likely that the plan was not made until after the scan had been considered. However, Dr Fearnside's view appears to be that, on the assumption that it was available, the scan excluded the likelihood of a tumour because otherwise the plan would not have been unqualified. In other words, if the CT scan did not give a clear answer to the question whether there was a tumour or other cause of the aqueductal stenosis, the plan to proceed nevertheless to a ventriculostomy was unreasonable. In this respect, his evidence favours the application.
78 This reasoning, however, depends upon assuming that, had there been a qualification depending on what the scan revealed, it would have been noted by Dr Caldwell. On the face of it, it seems unlikely that such an important qualification would not have been noted but it is not difficult to imagine circumstances in which such a note might have been overlooked, particularly because the definitive surgery proposed was to occur in three days' time. Dr Gordon, the consultant neurologist, had transferred Ms Fletcher from the Orange Base Hospital to Royal Prince Alfred Hospital because he thought "there was strong evidence that she had a frontal tumour". I simply do not accept that the possibility of a tumour would have been immediately discounted either by Dr Caldwell or by Dr Besser. Indeed, the nursing note of 10.30 pm when Ms Fletcher was admitted to the ward stated that she was admitted "with ? cerebral tumour". Dr Gordon thought that Ms Fletcher had evidence of raised intercranial pressure and, in view of the symptoms and physical signs, that it was most likely she had a parasagittal frontal lobe tumour or alternatively a posterior fossa lesion with hydrocephalus, with the former being more likely.
79 One therefore is left with two unlikely scenarios which depend upon the assumption (which I think is highly probable to be the fact) that it was important to exclude the differential diagnosis: the first is that the need to definitely exclude the possibility of a brain tumour was overlooked; and the second is that no note was made of the need to exclude the possibility before making a plan for a ventriculostomy. It seems to me that the probabilities markedly favour the likelihood that there is simply an omission from the notes. I would draw this conclusion from the logic of the events themselves but it is reinforced by the point that, at the time the note was made, the phrase "definitive surgery" did not necessarily mean (though, according to Dr Fearnside it strongly suggested) that the surgery was directed to hydrocephalus not a brain tumour. Certainly, the plan did not involve any immediate drainage. So far as the note of the plan is concerned, it may well have simply been an initial plan proposed by Dr Caldwell and not a final plan agreed on with Dr Besser. If that is so, it might explain why, when Ms Fletcher was seen the following morning by both Dr Caldwell and Dr Besser, only the first two parts of the plan are confirmed and there is no reference to the proposed surgery. Although a burr hole suggested, as Dr Fearnside said, the probability of performing a ventriculogram it could also be done for the purpose of drainage. Dr Fearnside agreed that the ventriculogram was at the time the best diagnostic tool available for excluding a tumour. If drainage was instituted when Ms Fletcher first attended the hospital, that would have prevented the undertaking of a ventriculogram. The drainage would progressively decrease the ventricles and although it is possible to inject contrast material down the ventricular catheter, this is not technically satisfactory. Depending how rapidly the ventricles would return to a normal size, a further ventricular puncture would be difficult, though not impossible. A ventriculogram is generally performed when the ventricles are enlarged preparatory to performing a definitive procedure such as a shunt or a ventriculostomy. Accordingly, the two reasons for performing a ventriculogram, to confirm the diagnosis of aqueductal stenosis (i.e. to exclude a tumour) and to visualise a third ventricle for the purpose of a ventriculostomy would have been precluded had there been an immediate drainage of CSF.
80 Dr Fearnside's opinion was that the plan could only have been made (or, at, least definitely determined) when Dr Besser had effectively excluded the diagnosis of a tumour or other lesion. On 24 September, namely the day after the plan was noted, a case history noted an examination of Ms Fletcher by Dr Besser and Dr Caldwell. The notes stated that the first two steps proposed in the plan were to be undertaken. There can be little doubt that the CT scan was by that time available. There is no note that suggested the need to consider whether Ms Fletcher was suffering from a brain tumour or, for that matter, a subdural haematoma. It appeared to follow that, if Dr Besser had been troubled by the possibility that the CT scan might not have excluded a tumour, by the time the plan was confirmed, this possibility had been excluded. Dr Fearnside agreed with this, with the qualification, "that he may have been concerned, and it is not in the notes anywhere, of an intrinsic tumour of the brainstem which can cause secondary aqueductal stenosis which may not be identified on the CT scan in 1982 and he was hoping to reassure himself with a ventriculogram that that was not so".
81 Dr Fearnside thought it was important to differentiate the particular part of the posterior fossa relevant to the possibility of a tumour. There were two main parts of the brain at this point, one in the cerebellar hemispheres, which, had a tumour been present there, would have been obvious in the CT scan in 1982. The other component is the brainstem and it is this area which is rather more difficult to image for a number of reasons, principally reflection from adjacent bone and in 1982 CT scans were not particularly accurate at picking up tumours within the brainstem. The fourth ventricle and the aqueduct lie within the brainstem. In 1982, aqueduct stenosis was one of the more difficult areas to absolutely diagnose. This was a reason that ventriculography was used.
82 Both Dr Fearnside and Dr Besser placed some emphasis on the desirability, if not the necessity, to discuss difficult or complicated conditions with senior colleagues. Dr Fearnside accepted that, for a neurosurgeon like Dr Besser, he would have thought it unnecessary that he would have needed to discuss with a senior colleague so basic a procedure as inserting a drain to relieve intercranial pressure to alleviate symptoms caused by a build-up of CFS but this view, I think, concerned the procedure itself, not the need to consider whether a lesion had been excluded.
83 A part of the observations to which Dr Fitzgerald refers as indicating the need for immediate drainage were references in the cerebral observation chart to sluggish pupil reactivity. Dr Fearnside commented that such observations are highly subjective. He said that raised intercranial pressure with some sort of neurological disorder in the brain affecting pupil reflexivity can be examined by shining a light in the eye and comparing the constriction of the pupil with a normal reaction. In the nature of things, as I understand Dr Fearnside's evidence, this is a very subjective observation and, I would infer, one that should be looked at with some caution.
84 Dr Fearnside also pointed out that it was necessary to be cautious about drawing inferences from pupillary reactivity to light, mentioning a number of independent variables which made this so. Dr Fearnside thought that not much weight could be placed on sluggishness or pupillary reactivity: what is important is whether the pupils react or not, and whether the pupils are equal or not, these being the two indicative observations which would raise concerns about raised intercranial pressure. The doctor pointed out that although it is true there were several observations of unequal pupils, yet they normalised. He said that if there were a structural lesion causing pupillary inequality it would not normalise but remain abnormal. Looking at the other observations, that is that she was spontaneously moving, talking and communicating, she was oriented and was gripping a hand, taken as a whole, there would seem to be no other indicators suggesting an overall deterioration in her neurological condition. The pupillary inequality was problematic but it normalised and such inequality can vary because of the position of ambient light. On the other hand, Dr Fearnside thought that these symptoms could not be dismissed; it would be necessary for the specialist to examine the patient him or herself. He made the observation that, had the pupillary signs stated in the notes been significant he would have expected a deterioration in her level of consciousness but the column in the notes dealing with that question does not indicate that this occurred except during the decerebration event.
85 Dr Besser flatly disagreed with Dr Fitzgerald's evidence that a brain tumour capable of causing Ms Fletcher's symptoms could have been so large as to have been obvious on a CT scan such as that taken in 1982 of Ms Fletcher. Dr Besser said that such tumours are not always large or obvious on CT scans and that, in particular, the presence of bone artefact in the posterior fossa can make tumours hard to identify or exclude. This was a common problem with CT scans around that time. By way of elaboration, the doctor pointed out that -
"… This patient came along with symptoms and signs of raised intercranial pressure. The CAT scan showed that the ventricles were very, very dilated and yet we have a head circumference which is in the normal range, so this means the patient wasn't born with ongoing hydrocephalus … Now, the classical diagnosis of hydrocephalus by a radiologist as due to aqueduct stenosis is that the lateral ventricles and the third ventricles are dilated out of proportion to the size of the fourth ventricle which is small. If the fourth ventricle is not seen at all [as the report said] this is a bit of red flag in the context of this patient … [The report] says there is artefact in pituitary fossa. It mentions that there may be abnormality of the brainstem. Now these are things which need to be taken into account before you treat a patient with hydrocephalus."
86 It was pointed out to Dr Besser that his earlier affidavits of 2006 had not referred to the need to consider the question of the presence of a subdural haematoma or a tumour before instituting drainage and that availability of the CT film was necessary to support, if not establish, this explanation. Dr Besser said that, at the earlier time he was attempting to recall, as best he could, the circumstances and the fact was that he was unable to do so. As I understand it, the elaboration of this point by reference to the need to exclude the differential diagnoses is a hypothesis on his part, since he has no actual recollection. It seems to me, having looked at those earlier affidavits, that Dr Besser's explanation is a credible one. However, he did propose in those affidavits a reason for not draining immediately, namely that Ms Fletcher's symptoms were chronic rather than acute and might not have called for the immediate surgical intervention as proposed by Dr Fitzgerald. Dr Besser's explanation was that he was not thinking about all the possible reasons why he would not have put in a drain. In a patient who had a chronic disease that he felt did not need urgent drainage, that would be a sufficient reason for not undertaking that procedure.
87 Dr Besser agreed that the notes of 23 and 24 September show that he had decided upon a plan involving the performance of a ventriculogram on 28 September but says that he nevertheless would have needed to satisfy himself that there was no posterior fossa lesion present before actually performing the ventriculogram. Although this qualification is not mentioned on the notes, I do not think that this fact could justify the inference that Dr Besser's reconstruction of his reasoning is wrong. Since I accept that it was of vital importance to exclude the possibility of a tumour, I think it is most unlikely that it would have been overlooked by Dr Besser. The point really being made on Ms Fletcher's behalf is, I think, that this risk had been excluded by the scan and, accordingly, further delay in drainage could not be explained as a matter of appropriate medical practice. This argument depends upon accepting Dr Fitzgerald's opinion that any potentially dangerous lesion must have been so large as to be unmistakably demonstrated by the CT film and that it could not have been mistaken for an artefact, so that when Dr Besser saw the film on 23 September (as he thinks almost certain) or 24 September (which is certain) there was no longer a reason for not undertaking immediate drainage.
88 Dr Besser agreed that, reading the symptoms recorded by Dr Caldwell, they demonstrate that whilst some of the patient's symptoms historically were essentially chronic or longstanding, they were associated with more severe and significant symptoms of some recency. Dr Besser said that obviously he had concluded at that time that Ms Fletcher required treatment within a few days but not immediately.
89 There are some apparent inconsistencies in the neurological notes. Thus, the patient is shown as having fixed pupils but nevertheless awake and orientated which cannot occur although there is also a note that pupils are very sluggish which may or may not be a correction of the reference to fixed pupils. Other references to very sluggish pupils are made on at least three occasions but, again, as Dr Besser points out, she is shown as orientated. Dr Besser pointed out that although discrepancy between the reactivity of the pupils is consistent with the effects of raised intercranial pressure, there are other explanations. One is that there can be poorly reactive or even non-reactive pupils in patients who have pressure on the tectal plate, that is the upper part of the brainstem, and as it happens in this case the ventriculogram explains that because there was demonstrated a dilated supra-pineal recess, which is the back part of the third ventricle and that impinges on the tectal plate, which is an explanation here for those symptoms. The doctor's volunteering of this possible explanation for the otherwise apparently inconsistent observations redounds, I rather think, to his credit since it is clearly advantageous to him to rely on the suggestion that the apparent discrepancy of observations shows that they were not altogether reliable. He did, however, point out that there were two occasions of inequality of the pupils, an observation which, as I gather, was likely to represent some lack of experience by the nurse because there was no reason that he could see why Ms Fletcher should have inequality of the pupils. Dr Besser put it down to the fact that Ms Fletcher was not in the neurosurgery ward where nurses would be likely to be more experienced in making observations of this kind. There were, however, more than two entries - there were four. Dr Besser agreed that the observation should be taken note of but he thought that inequality of the pupils in a patient who is alert and orientated may be somewhat spurious. Also, he thought that inequality of the pupils in a patient with hydrocephalus is not relevant.
90 So far as the decerebration event is concerned, Dr Besser commented that it appeared to have been transient, possibly caused by (temporarily) raised intercranial pressure and the ventriculogram on the following day confirmed hydrocephalus due to aqueduct stenosis and did not show any other acute problem. Given the history in all likelihood it was intercranial pressure but this was not the only explanation. He does not now recall whether he was told of it, as I have mentioned, but having been told of it other causes such as epilepsy might have been possible though they were, in effect, subsequently excluded. However, as Dr Besser fairly pointed out, there are a great number of other symptoms that at all events indicated raised intercranial pressure. Furthermore, by the time of the decerebrate event the CT scan had been taken and there is no question that that disclosed a condition which would have led to raised intercranial pressure. Dr Besser was asked about the continued drowsiness after the event of decerebration as consistent with residual problems. He did not agree. He said that patho-physiologically the event is an effect of the brainstem and once it recovers and the patient regains consciousness, there is no ongoing effect from what has happened to the brainstem. Continued drowsiness may have been caused by what also caused the decerebration of course. However, Dr Besser agreed that sustained drowsiness after a decerebrate event is a matter of concern.
91 There was a great deal of further cross-examination of both Dr Besser and Dr Fearnside about other matters disclosed in the records, in particular the neurological observations. It is sufficient for me to observe that this evidence disclosed a quite complicated medical picture requiring assessment of a variety of interrelated matters. Although Dr Fitzgerald's opinion is, I think, that these matters were really far more simple - at least to an experienced neurologist - than is suggested by this evidence, on a careful reading of his evidence (including, of course, his affidavits) my opinion that this was a complicated and difficult case requiring careful diagnosis and far from obvious judgments is reinforced. After all, the case sought to be made by Ms Fletcher is whether drainage should have been instituted at a time significantly before the ventriculogram was performed, a timeframe of but five days. I do not accept that the clinical picture is so clearly demonstrated on the documents (which is all, in substance, that we have) as is contended on Ms Fletcher's behalf.