Neuropsychological disturbances and cerebral blood flow in bipolar disorder

Abstract

during the emergence of an alter-child 'personality' were associated with symmetrical activity increases in left and right temporal lobes, whereas left temporal asymmetric increases occurred when the patient was in her 'adult' state.Our data converge with five other independent investigations using SPECT, EEG and MRI regarding an association between presenting symptoms of DID and temporal lobe functioning. Such a reliable association should not be taken lightly and requires explanation. Certainly these results are not surprising considering the connections between the temporal lobe and the limbic system (e.g. the amygdale, involving the processing of emotional responses and the hippocampus, vital to memory storage and retrieval). One theoretical explanation is that of 'paradoxical functional facilitation'. That is, a reduction of left temporal activity accompanied by a loss of semantic knowledge and increased visual revivifying of early life experiences may have occurred in the childhood enactment [1].Nevertheless, neuroscientists and practitioners blithely attribute symptoms of DID to antecedent traumatic events, albeit this connection has never been corroborated; they also accept the patient's self-report of child abuse without any type of corroborating evidence and fail to confirm the existence of DID symptoms prior to psychotherapy, an important consideration given possible iatrogenic aetiology of DID. In short, the patient in this case study may have displayed iatrogenic symptoms or may simply have been a very good actress [2]. In addition, the current findings are consonant with a number of competing explanations that involve temporal lobe functioning: seizures, transcendental beliefs, false memory, and other forms of suggestibility. References 1. Miller BL, Boone K, Cummings FL, Read SL, Mishkin G.Functional correlates of musical and visual ability in frontotemporal dementia. We write to raise a number of questions regarding this study [1]. There is a paucity of data on the acquisition methodology of the cerebral perfusion studies. As 99m Tc HMPAO is an unstable agent, what was the level of quality assurance on the radiopharmaceutical prior to injection? Were these patients injected with eyes patched and ears plugged? If this was not done, it would make calculations of occipital and temporal uptake difficult to interpret. What type of camera were the studies acquired on and with what type of collimation? Such patients are difficult to image as they rarely comply with lying still for the duration of the study. How was this achieved and were images routinely checked for patient motion? Was this performed on MRI studies for each patient and then transferred to coregistered 99m Tc HMPAO images? What was the variability of count statistics in the regions of interest? How reproducible were regions of interest and the counting statistics for these regions of interest as ascribed or interpreted by each nuclear medicine observer?One of the problems with the use of 99m Tc HMPAO in assessment of cerebral blood flow i...