Catherine Loveday

Neuropsychological profile of young adults with spina bifida with or without hydrocephalus

Objectives: To determine the relative impact of hydrocephalus and spinal dysraphism in young adults on intellectual and cognitive functioning. Sub-groups of patients with congenital hydrocephalus and/or spina bifida were assessed between 1995 and 2003. The entry criteria were that individuals should have (i) intact global function, (ii) average verbal intelligence (or above), and (iii) should not have clinical depression. There were three sub-groups: patients with hydrocephalus and spina bifida, patients with hydrocephalus without spina bifida, and patients with spina bifida without hydrocephalus. Methods: Patients were neuropsychologically assessed as part of their normal clinical assessment during their annual medical review. Each individual completed a screening battery assessing global functioning, verbal intelligence, and mood. In addition they completed additional tests including measures of emotional intelligence, memory, attention, and executive function. Results were analysed to compare the performance of the patient sub-groups and to compare them to a healthy control group. Results: Patients with hydrocephalus (with or without spina bifida) were significantly impaired on the vast majority of all test scores as compared to patients with spina bifida and healthy controls. They were particularly poor on measures assessing executive function. By contrast for patients with spina bifida with no associated hydrocephalus, the significant majority of all test scores fell within the average range or above. Conclusions: The neuropsychological profile of patients with hydrocephalus is one of relative impairment and this is so whether or not spina bifida is present. In spina bifida alone, in the absence of hydrocephalus, cognitive function is relatively spared.

Diurnal patterns of salivary cortisol across the adolescent period in healthy females

When examining the diurnal profile of the hormone cortisol in children and adolescents developmental issues are particularly relevant. Previous findings regarding relationships between cortisol secretory activity and reproductive (pubertal) maturation lack clarity and may reflect methodological inconsistencies between studies. This study examined the diurnal cortisol profile across female adolescence, with a particular focus on an obvious and unique marker of development: menarche. In a cross-sectional design, 61 healthy female adolescents aged 9-18 years (mean age 13.89 years, S.D.+/-2.72) collected eight saliva samples per day on two consecutive weekdays. Samples were collected at awakening, 15, 30 and 45min and 3, 6, 9 and 12h post-awakening in order to capture both the cortisol awakening response (CAR) and the subsequent period of decline. Demographic information was recorded and participants also completed the Spielberger State-Trait Anxiety Inventory. Patterns of cortisol secretion exhibited good intra-individual stability across the two sampling days. Participants evidenced a robust diurnal pattern, with cortisol levels peaking approximately 30-45min post-awakening (the CAR) and steadily declining concentrations over the remainder of the day. Differences according to developmental status (in terms of whether or not participants had experienced first menses: menarche) were observed in the time of peak secretion of the CAR, and these distinct patterns could not be accounted for by group differences in demographic, situational or psychological characteristics measured in this study. This effect for the CAR was associated with the onset of menarche alone, unlike cortisol levels over the remainder of the day. For those who had undergone menarche, were older and of greater BMI, cortisol levels remained higher over the day. There was a significant difference in cortisol concentrations at 6h post-awakening between pre- and post-menarche groups. Again, these differences in daytime cortisol secretory activity could not be attributed to situational or psychological factors. Establishing patterns of cortisol secretion in healthy female adolescents provides an important baseline from which to investigate hypothalamic-pituitary-adrenal (HPA) physiology, measured via salivary cortisol, in adolescent populations with known or suspected psychopathology.

The neuropsychology of normal pressure hydrocephalus (NPH).

Normal pressure hydrocephalus (NPH) accounts for one of the few known forms of reversible dementia. Varied aetiology and clinical presentation contribute to difficulties with early or differential diagnoses, and delayed surgical treatment may be less efficacious. Clinical neuropsychology provides a means of determining a cognitive profile for NPH, assisting in differential diagnosis, tracking the disorders progression and assessing the efficacy of treatment. This article will review possible applications of clinical neuropsychology and propose a clinical assessment protocol for NPH.

The diurnal cortisol cycle and cognitive performance in the healthy old.

Associations between cognitive performance and cortisol have variously been reported for measures of both cortisol level and change, and for some domains of cognitive functioning more than others. In this study, associations between cortisol secretion measures and cognitive performance were examined in 50 healthy older people (mean age 74 years; 34 F /16 M). Participants provided 16 accurately timed saliva samples over 2 consecutive days to determine diurnal profiles of cortisol secretion. Overall cognitive performance (OCP) was measured as the principal component of a comprehensive battery of cognitive tests. Across a 30 year age range, there was a strong inverse correlation between age and OCP. Age and poorer OCP were also associated with an attenuated cortisol awakening response (CAR), defined as the rise from 0-30 min after awakening, and a subsequent less steep fall in cortisol level over the rest of the day. Partialling analyses, suggested that the correlation between fall in cortisol over the day and OCP was independent of age. Both older age and less cortisol change were particularly related to poorer performance on tests of declarative memory and executive functioning. Our conclusions are that during the short post-awakening period, an exception exists to the generally pertaining association between higher levels of cortisol and poorer cognitive performance. Consequentially dynamic measures reflecting the rise (CAR) and fall from the post-awakening peak may be particularly salient in helping to explain links between cortisol and cognitive performance. Finally our pattern of results across different cognitive tests suggests an association between cortisol and those domains of cognitive functioning which depend crucially on the integrity of the hippocampus and pre-frontal cortex.

Anxious attachment style and salivary cortisol dysregulation in healthy female children and adolescents

BACKGROUND Attachment style has been linked with basal cortisol secretion in healthy adult women. We investigated whether dysregulation in basal cortisol secretion may be evident in younger healthy females. METHODS Sixty healthy females aged 9-18 years (mean 14.16, SD ± 2.63 years) participated in the Attachment Style Interview (ASI). Eight saliva samples, synchronised to awakening, were collected per day on two consecutive weekdays to examine the cortisol awakening response (CAR) and the subsequent diurnal decline. RESULTS Participants exhibiting an anxious attachment style had higher cortisol levels on awakening, in contrast to those who were securely attached. The anxious insecure group also showed an attenuated CAR compared to all other participants. Attachment style groups did not differ in cortisol secretion over the remainder of the day. CONCLUSIONS These findings indicate that the same pattern of cortisol dysregulation associated with disorder in adulthood manifests as a function of anxious (but not avoidant) insecure attachment style in females during healthy childhood and adolescence.

Remembering, imagining, false memories & personal meanings

The Self-Memory System encompasses the working self, autobiographical memory and episodic memory. Specific autobiographical memories are patterns of activation over knowledge structures in autobiographical and episodic memory brought about by the activating effect of cues. The working self can elaborate cues based on the knowledge they initially activate and so control the construction of memories of the past and the future. It is proposed that such construction takes place in the remembering-imagining system - a window of highly accessible recent memories and simulations of near future events. How this malfunctions in various disorders is considered as are the implication of what we term the modern view of human memory for notions of memory accuracy. We show how all memories are to some degree false and that the main role of memories lies in generating personal meanings.

FMRI/ERP of musical syntax: comparison of melodies and unstructured note sequences

To date, the neural correlates of musical syntax processing have been investigated mainly by means of paradigms in which isolated chords are made incongruent with the harmonic context. Here, we present results obtained contrasting unfamiliar one-part piano melodies with unstructured note sequences, comparable in pitch and rhythm but devoid of any syntactic structure. This paradigm indexes a superset of the cognitive functions involved in processing of harmonic rules. Using functional magnetic resonance imaging, differential activation of a bilateral cortical network comprising the inferior frontal gyrus, superior temporal gyrus and premotor cortex was found. Using event-related potentials, the N2 evoked by each note in melodies was found to have longer latency and a more frontal distribution than that evoked in unstructured sequences.

Functional MRI/Event-related potential study of sensory consonance and dissonance in musicians and nonmusicians

Pleasurability of individual chords, known as sensory consonance, is widely regarded as physiologically determined and has been shown to be associated with differential activity in the auditory cortex and in several other regions. Here, we present results obtained contrasting isolated four-note chords classified as consonant or dissonant in tonal music. Using event-related functional MRI, consonant chords were found to elicit a larger haemodynamic response in the inferior and middle frontal gyri, premotor cortex and inferior parietal lobule. The effect was right lateralized for nonmusicians and less asymmetric for musicians. Using event-related potentials, the degree of sensory consonance was found to modulate the amplitude of the P1 in both groups and of the N2 in musicians only.

Using SenseCam with an amnesic patient: accessing inaccessible everyday memories.

Forgetting is a normal and everyday occurrence that may sometimes reflect a complete loss of the mnemonic record or a failure to encode it in the first place. However, on many occasions with the help of cues we can eventually or suddenly recall a memory that seemed to be lost, thus highlighting the probability that many instances of “forgetting” may in fact reflect inaccessibility rather than true loss. We report here on our amnesic patient CR who presents an extreme example of this normal everyday forgetting. For 4 weeks, CR recorded regular personal autobiographical events both on a SenseCam (henceforth SC) and in a written diary form. Subjective and objective aspects of recall were measured each weekend both without any cues and then with either a SC or diary cue. We show that the SC enabled CR to recall significantly more detailed episodic memories than reading the diary and importantly we observed that the qualitative nature of these memories was different. We comment on the considerable potential of SC for therapeutic purposes.

The cortisol awakening response is related to executive function in older age

Changes in the cortisol awakening response (CAR) have been reportedly associated with older age and may reflect changes in cognitive performance. However methodological issues around adherence, in regard to careful timing of the CAR, suggest caution in drawing firm conclusions. More investigation is also needed regarding which cognitive domains may be most relevant. Executive Function (EF) is linked strongly to functioning of the frontal cortex, itself linked to cortisol secretion via regulation of the Hypothalamic Adrenocortical Axis. In this study, cortisol profiles, cognitive performance and adherence were carefully assessed in a sample of 50 older participants, aged 60-91 years (mean=74 years). Key aspects of EF were assessed using Form B of the standard Trail-making Test controlling for time taken to complete the simpler Trail-A form of the test. Strong associations between CAR profiles and EF were evident. Cortisol measures significantly predictive of superior EF-related performance in a regression analysis were: earlier peaking and greater magnitude of the CAR. Together these measures explained fully a quarter of all the variance in test performance (R(2)=0.25; F=7.90; df=2,47; p<.001). Cognitive tests of declarative memory, often linked to hippocampal functioning, were not associated with CAR profiles. We conclude that in a population of healthy older adults aspects of the CAR may be strongly, and perhaps with some degree of specificity, associated with that domain of cognitive functioning, EF, which seems to depend crucially on the integrity of frontal cortex circuitry.