Alzheimer Disease: Sergeant JA

van Dijk KR, Scherder EJ, Scheltens P, Sergeant JA. · Department of Clinical Neuropsychology, Vrije Universiteit, Amsterdam, The Netherlands. · Rev Neurosci. · Pubmed #12405228 No free full text.

Abstract: An extensive search through nine electronic bibliographic databases (PubMed, Cochrane Library, Web of Science, ERIC, PsychINFO, Psyndex, Cinahl, Biological Abstracts, Rehabdata) was performed in order to review the effects of Transcutaneous Electrical Nerve Stimulation (TENS) on non-pain related cognitive and behavioural functioning. Eight studies were identified on neglect due to stroke, six studies on Alzheimer's disease (AD), one study on aging, and two studies on coma due to traumatic brain injury. The results of the various studies revealed that TENS has a variety of effects. These consist of enhancement of somatosensory functioning, visuo-spatial abilities and postural control in neglect, improved memory, affective behaviour and rest-activity rhythm in AD and acceleration of awakening in coma. Effectiveness of TENS is discussed in relation to various stimulation parameters: duration, frequency, pulse width and intensity. It is argued that arousal may underlie the beneficial influence of TENS in various conditions. Finally, suggestions are offered for future research.

van Dijk KR, Scheltens P, Luijpen MW, Sergeant JA, Scherder EJ. · Department of Clinical Neuropsychology, Vrije Universiteit, Amsterdam, The Netherlands. · Dement Geriatr Cogn Disord. · Pubmed #15802911 No free full text.

Abstract: In a number of studies, peripheral electrical nerve stimulation has been applied to Alzheimer's disease (AD) patients who lived in a nursing home. Improvements were observed in memory, verbal fluency, affective behavior, activities of daily living and on the rest-activity rhythm and pupillary light reflex. The aim of the present, randomized, placebo-controlled, parallel-group clinical trial was to examine the effects of electrical stimulation on cognition and behavior in AD patients who still live at home. Repeated measures analyses of variance revealed no effects of the intervention in the verum group (n = 32) compared with the placebo group (n = 30) on any of the cognitive and behavioral outcome measures. However, the majority of the patients and the caregivers evaluated the treatment procedure positively, and applying the daily treatment at home caused minimal burden. The lack of treatment effects calls for reconsideration of electrical stimulation as a symptomatic treatment in AD.

Scherder EJ, Deijen JB, Vreeswijk SH, Sergeant JA, Swaab DF. · Department of Clinical Neuropsychology, Vrije Universiteit, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands. · Behav Brain Res. · Pubmed #11796166 No free full text.

Abstract: In one study, behavioral disorders of patients with vascular dementia reacted positively to cranial electrostimulation (CES). In the present study, it was examined whether CES could improve cognition and (affective) behavior in patients with probable Alzheimer's disease (AD). Eighteen AD patients, divided into an experimental and a placebo group, were treated for 30 min per day, 5 days a week, for 6 weeks. No improvements in cognition and (affective) behavior were found after CES.

Van Dijk KR, Luijpen MW, Van Someren EJ, Sergeant JA, Scheltens P, Scherder EJ. · Department of Neurocognition, Faculty of Psychology, Maastricht University, Maastricht, The Netherlands. · J Sleep Res. · Pubmed #17118098 No free full text.

Abstract: Rest-activity rhythm disruption is a prominent clinical feature of Alzheimer's disease (AD). The origin of the altered rest-activity rhythm is believed to be degeneration of the suprachiasmatic nucleus (SCN). In accordance with the 'use it or lose it' hypothesis of Swaab [Neurobiol Aging 1991, 12: 317-324] stimulation of the SCN may prevent age-related loss of neurons and might reactivate nerve cells that are inactive but not lost. Previous studies with relatively small sample sizes have demonstrated positive effects of peripheral electrical nerve stimulation on the rest-activity rhythm in AD patients. The present randomized, placebo-controlled, parallel-group study was meant to replicate prior findings of electrical stimulation in AD in a substantially larger group of AD patients. The experimental group (n = 31) received peripheral electrical nerve stimulation and the placebo group (n = 31) received sham stimulation. Effects of the intervention on the rest-activity rhythm were assessed by using wrist-worn actigraphs. Near-significant findings on the rest-activity rhythm partially support the hypothesis that neuronal stimulation enhances the rest-activity rhythm in AD patients. Interestingly, post-hoc analyses revealed significant treatment effects in a group of patients who were not using acetylcholinesterase inhibitors concomitantly. We conclude that more research is needed before firm general conclusions about the effectiveness of electrical stimulation as a symptomatic treatment in AD can be drawn. In addition, the present post-hoc findings indicate that future studies on non-pharmacological interventions should take medication use into account.

Luijpen MW, Swaab DF, Sergeant JA, van Dijk KR, Scherder EJ. · Department of Clinical Neuropsychology, Vrije Universiteit, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands. · Behav Brain Res. · Pubmed #15698902 No free full text.

Abstract: In previous studies, transcutaneous electrical nerve stimulation (TENS) was shown to have a positive effect on memory in Alzheimer's disease (AD) patients. Moreover, the reported effects appeared to be more beneficial in early stages of Alzheimer's disease compared to later stage intervention. Based on this stage-dependency, the present study examined the effects of TENS on memory in a preclinical stage of AD, i.e. in subjects with mild cognitive impairment (MCI). Our results suggest that TENS did not improve memory in a MCI population. Mechanisms that might underlie the absence of positive effects of the TENS treatment in a MCI population are discussed.