Rivastigmine: the advantages of dual inhibition of acetylcholinesterase and butyrylcholinesterase and its role in subcortical vascular dementia and Parkinson’s disease dementia Nagaendran Kandiah,1,2 Ming-Chyi Pai,3,4 Vorapun Senanarong,5 Irene Looi,6,7 Encarnita Ampil,8 Kyung Won Park,9 Ananda Krishna Karanam,10 Stephen Christopher11 1Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, 2Duke-NUS, Graduate Medical School, Singapore; 3Division of Behavioral Neurology, Department of Neurology, 4Alzheimer’s Disease Research Center, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan City, Taiwan; 5Division of Neurology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand; 6Clinical Research Centre, 7Department of Medicine, Hospital Seberang Jaya, Penang, Malaysia; 8Department of Neurology and Psychiatry, Faculty of Medicine and Surgery, University of Santo Tomas, Manila, Philippines; 9Department of Neurology and Cognitive Disorders and Dementia Center, Institute of Convergence Bio-Health, Dong-A University College of Medicine, Busan, Republic of Korea; 10Novartis Healthcare Private Limited, Hyderabad, India; 11Novartis (Singapore) Pte. Ltd., Singapore Several studies have demonstrated clinical benefits of sustained cholinesterase inhibition with rivastigmine in Alzheimer’s disease (AD) and Parkinson’s disease dementia (PDD). Unlike donepezil and galantamine that selectively inhibit acetylcholinesterase (AChE; EC 3.1.1.7), rivastigmine is a unique cholinesterase inhibitor with both AChE and butyrylcholinesterase (BuChE; EC 3.1.1.8) inhibitory activity. Rivastigmine is also available as transdermal patch that has been approved by the US Food and Drug Administration for the treatment of mild, moderate, and severe AD as well as mild-to-moderate PDD. In this review, we explore the role of BuChE inhibition in addition to AChE inhibition with rivastigmine in the outcomes of cognition, global function, behavioral symptoms, and activities of daily living. Additionally, we review the evidence supporting the use of dual AChE-BuChE inhibitory activity of rivastigmine as a therapeutic strategy in the treatment of neurological disorders, with a focus on the role of rivastigmine in subcortical dementias such as vascular dementia (VaD) and PDD. Toward this objective, we performed a literature search in PubMed and Ovid with limits to articles published in the English language before June 2016. The available evidence from the literature suggests that the dual inhibition of AChE and BuChE may afford additional therapeutic potential of rivastigmine in subcortical dementias (subcortical VaD and PDD) with benefits on cognition and behavioral symptoms. Rivastigmine was found to specifically benefit executive dysfunction frequently observed in subcortical dementias; however, large randomized clinical studies are warranted to support these observations. Keywords: acetylcholinesterase, BuChE genotype, butyrylcholinesterase, Parkinson’s disease dementia, rivastigmine, subcortical vascular dementia

Background: The Ginkgo biloba special extract, EGb 761^® has been widely used in the treatment of neuropsychiatric disorders, including Alzheimer’s disease (AD).Methods: To guide clinical practice in the Asian region, the Asian Clinical Expert Group on Neurocognitive Disorders compiled evidence‐based consensus recommendations regarding the use of EGb 761^® in neurocognitive disorders with/without cerebrovascular disease.Results: Key randomized trials and robust meta‐analyses have demonstrated significant improvement in cognitive function, neuropsychiatric symptoms, activities of daily living (ADL) and quality of life with EGb 761^®versus placebo in patients with mild‐to‐moderate dementia. In those with mild cognitive impairment (MCI), EGb 761^® has also demonstrated significant symptomatic improvement versus placebo. World Federation of Societies of Biological Psychiatry guidelines list EGb 761^® with the same strength of evidence as acetylcholinesterase inhibitors and N‐methyl‐D‐aspartate (NMDA) antagonists e.g. memantine (Grade 3 recommendation; Level B evidence). Only EGb 761^® had Level B evidence in improving cognition, behaviour, and ADL in both AD and vascular dementia patients. Safety analyses show EGb 761^® to have a positive risk‐benefit profile. While concerns have been raised regarding a possible increased bleeding risk, several randomized trials and two meta‐analyses have not supported this association.Conclusions: The Expert Group foresee an important role for EGb 761^®, used alone or as an add‐on therapy, in the treatment of MCI and dementias, particularly when patients do not derive benefit from acetylcholinesterase inhibitors or NMDA antagonists. EGb 761^® should be used in alignment with local clinical practice guidelines.

Hippocampal atrophy has been associated with mild cognitive impairment (MCI) in Parkinson's disease (PD). However, literature on how hippocampal atrophy affects the pathophysiology of cognitive impairment in PD has been limited. Previous studies assessed the hippocampus as an entire entity instead of their individual subregions. We studied the progression of cognitive status in PD subjects over 18 in relation to hippocampal subfields atrophy. 65 PD subjects were included. Using the MDS task force criteria, PD subjects were classified as either having no cognitive impairment (PD-NCI) or PD-MCI. We extended the study by investigating the hippocampal subfields atrophy patterns in those who converted from PD-NCI to PD-MCI (PD-converters) compared to those who remained cognitively stable (PD-stable) over 18 months. Freesurfer 6.0 was used to perform the automated segmentation of the hippocampus into thirteen subregions. PD-MCI showed lower baseline volumes in the left fimbria, right CA1, and right HATA; and lower global cognition scores compared to PD-NCI. Baseline right CA1 was also correlated with baseline attention. Over 18 months, decline in volumes of CA2-3 and episodic memory were also seen in PD-converters compared to PD-stable. Baseline volumes of GC-DG, right CA4, left parasubiculum, and left HATA were predictive of the conversion from PD-NCI to PD-MCI. The findings from this study add to the anatomical knowledge of hippocampal subregions in PD, allowing us to understand the unique functional contribution of each subfield. Structural changes in the hippocampus subfields could be early biomarkers to detect cognitive impairment in PD.

Team-based learning (TBL), a new active learning method, has not been reported for neurology education. We aimed to determine if TBL was more effective than passive learning (PL) in improving knowledge outcomes in two key neurology topics - neurological localization and neurological emergencies.