Angela Costello

The role of rostral prefrontal cortex in prospective memory: A voxel-based lesion study

Highlights ► Prospective memory (PM) is a key cognitive component required in multitasking. ► This lesion study examines the critical regions for event- and time-based PM ► We show that the right rostral prefrontal cortex is necessary for time-based PM. ► Distinct prefrontal regions are associated with deficits in event- and time-based PM. ► The PM deficit of rostral patients might explain their deficit in multitasking situations.

The Early Effects of Radiotherapy on Intellectual and Cognitive Functioning in Patients with Frontal Brain Tumours: The Use of a New Neuropsychological Methodology

Investigations of the effects of radiation on neuropsychological functions have revealed variable outcomes, ranging from no effect to severe cognitive impairment. However, many of the previous studies have relied on retrospective data or have been limited by methodological problems. In this study, prospective neuropsychological assessments were compared at baseline (after surgery and before radiotherapy) and within 4 months of completion of radiotherapy (except one case), to examine early-delayed effects of radiation on intellectual and cognitive functioning. Sixteen adult patients with either low- or high-grade brain tumours, 15 of whom were treated with radiotherapy, were compared with 8 control participants with nonmalignant brain tumours whom did not undergo radiotherapy. All participants had lesions situated mainly in the frontal lobes. All groups of patients had evidence of intellectual and cognitive impairment at baseline. The low- and high-grade brain tumour groups showed a differential pattern of performance following radiotherapy, with the low-grade tumour groups performance being more competent on all of the five main neuropsychological measures. Their pattern of improvement was very similar to that of the nonmalignant brain tumour group who had not undergone radiotherapy. The present study provides some preliminary information about the neuropsychological deficits associated with primary brain tumours, their severity, and the relationship between neuropsychological functioning and brain tumours and radiotherapy.

Cognitive predictors of cognitive change following bilateral subthalamic nucleus deep brain stimulation in Parkinson’s disease

The beneficial effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN) for the motor symptoms in advanced Parkinsons disease (PD) are well established. Early in PD, mild cognitive impairment is present in a proportion of patients. Hence, it can also be present in PD patients considered for DBS. The potential impact of even a modest decline post-surgically is a concern because it could result in impaired cognitive function. Therefore, attempts to determine which pre-operative cognitive measures predict post-operative cognitive change warrant further attention. We report our findings in a cohort of 30 routinely operated non-demented patients who underwent detailed neuropsychological assessments on average 7.1 months before and 9.4 months after STN DBS. We report the individual and group differences pre- and post-DBS. Stepwise regression analysis was used to analyse the best cognitive predictors of post-operative cognitive changes. We describe our data in relation to published normative data. Post-STN DBS, the immediate story recall component of verbal memory was the most affected cognitive function showing a significant decline in its group mean with a large effect size. The best predictors for this change were pre-surgical list learning and Full Scale Intelligence Quotient. These results suggest that non-demented patients, with even mild impairments in both general intellectual functions and list learning, may be at greater risk of decline in other aspects of verbal memory after STN DBS. Pre-existing mild executive dysfunction was not influenced post-operatively. These findings may help selection and consent for STN DBS.

Pathological crying after subthalamic nucleus stimulation

Department of Clinical Neuroscience, Institute of Psychiatry, King’s College London, United Kingdom Department of Psychological Medicine, King’s College Hospital, South London and Maudsley National Health Service Foundation Trust, London, United Kingdom Department of Psychiatry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand Department of Neurology, King’s College Hospital National Health Service Foundation Trust, London, United Kingdom Department of Cognitive Neuropsychiatry, Institute of Psychiatry, London, United Kingdom Department of Neurosurgery, King’s College Hospital National Health Service Foundation Trust, London, United Kingdom Department of Neuropsychology, King’s College Hospital National Health Service Foundation Trust, London, United Kingdom

Verbal Memory Decline following DBS for Parkinson’s Disease: Structural Volumetric MRI Relationships

Background Parkinson’s disease is a chronic degenerative movement disorder. The mainstay of treatment is medical. In certain patients Deep Brain Stimulation (DBS) may be offered. However, DBS has been associated with post-operative neuropsychology changes, especially in verbal memory. Objectives Firstly, to determine if pre-surgical thalamic and hippocampal volumes were related to verbal memory changes following DBS. Secondly, to determine if clinical factors such as age, duration of symptoms or motor severity (UPDRS Part III score) were related to verbal memory changes. Methods A consecutive group of 40 patients undergoing bilateral Subthalamic Nucleus (STN)-DBS for PD were selected. Brain MRI data was acquired, pre-processed and structural volumetric data was extracted using FSL. Verbal memory test scores for pre- and post-STN-DBS surgery were recorded. Linear regression was used to investigate the relationship between score change and structural volumetric data. Results A significant relationship was demonstrated between change in List Learning test score and thalamic (left, p = 0.02) and hippocampal (left, p = 0.02 and right p = 0.03) volumes. Duration of symptoms was also associated with List Learning score change (p = 0.02 to 0.03). Conclusion Verbal memory score changes appear to have a relationship to pre-surgical MRI structural volumetric data. The findings of this study provide a basis for further research into the use of pre-surgical MRI to counsel PD patients regarding post-surgical verbal memory changes.