Parkinson Disease: Rezak M

Kessler A, Rezak M. · Department of Neurology, Emory Univeristy School of Medicine, Atlanta, Georgia, USA. · Dis Mon. · Pubmed #17586329 No free full text.

This publication has no abstract.

Rezak M. · Northwestern University, Feinberg School of Medicine, Movement Disorders Program, Evanston Northwestern Healthcare, Evanston and Glenbrook Hospitals, Evanston and Glenview, Illinois, USA. · Dis Mon. · Pubmed #17586328 No free full text.

Abstract: Treatment options for Parkinson's disease have greatly expanded in recent years. Pharmacological treatments, such as levodopa, dopamine receptor agonists, anticholinergic medications, monoamine oxidase B inhibitors, and the catechol-O-methyl transferase inhibitors, remain the mainstay of therapeutic intervention and are reviewed. Additionally, the traditional and new roles for amantadine are explained. Despite the great efficacy of levodopa, "levodopa-sparing strategies" in early Parkinson's disease are emphasized in order to delay the development of difficult-to-manage motor fluctuations and dyskinesias.

Novak KE, Nenonene EK, Bernstein LP, Vergenz S, Medalle G, Prager JM, Eller TW, Cozzens JW, Rezak M. · Department of Neurology, at Evanston Northwestern Healthcare, Evanston, Illinois, USA. · Mov Disord. · Pubmed #16721751 No free full text.

Abstract: Deep brain stimulation is generally a safe and effective method of alleviating motor impairment in advanced-stage Parkinson's disease patients. However, adverse events of surgery have been noted, such as hemorrhage, infection, seizures, and device failure. In this report, we describe 2 cases of the unusual adverse event of ischemia associated with subthalamic nucleus stimulator implantation. We present the intraoperative neurological symptoms, microelectrode recording data, imaging findings, and other correlated events. In the first case, the clinical effects of ischemia were evident intraoperatively and coincided with silence during microelectrode recording from the ischemic region. In the second case, the timing of the ischemic event could not be determined precisely but also was associated with a difficult mapping. Subcortical ischemia may be an underrecognized event that confounds neurophysiological mapping of deep brain structures and affects clinical outcomes.

Demakis GJ, Mercury MG, Sweet JJ, Rezak M, Eller T, Vergenz S. · Department of Psychology, University of North Carolina at Charlotte, Charlotte, NC 28223-0001, USA. · Clin Neuropsychol. · Pubmed #14704883 No free full text.

Abstract: This study examined qualitative aspects of phonemic and semantic fluency before and after unilateral pallidotomy in patients with intractable Parkinson's Disease (PD). Specifically, clustering (number of similar words generated sequentially) and switching (number of changes or switches from one cluster to another) were evaluated for both fluency tasks. Twenty-five PD patients participated and were grouped according to whether they improved or declined on each of the fluency measures after surgery. Decliners evidenced decreased switching, but not clustering, suggesting difficulties with set-shifting and cognitive flexibility rather than a diminished semantic store of information or retrieval difficulties. Though consistent with hypotheses about difficulties with executive processing after pallidotomy, a series of correlational analyses with composite measures of neuropsychological functioning (attention, language, executive processing, and memory) suggest caution in interpreting these findings. In these analyses, clustering was not meaningfully related to any of the composites whereas switching was significantly and positively related to the composites; this pattern emerged, for the most part, on both fluency measures before and after surgery. Switching, but not clustering, was also significantly and positively correlated with total words generated on both semantic and phonemic fluency. Switching changes across time were also related to DRS changes post-pallidotomy. These correlational analyses challenge the specificity of the switching variable and, more broadly, the validity of these qualitative measures of verbal fluency.

Demakis GJ, Mercury MG, Sweet JJ, Rezak M, Eller T, Vergenz S. · Elmhurst College, Elmhurst, IL 60126, USA. · J Clin Exp Neuropsychol. · Pubmed #12187448 No free full text.

Abstract: This study examined the short-term motor and cognitive sequelae of unilateral posterolateral pallidotomy for patients with intractable Parkinson's Disease (PD). Unique to this study was the inclusion of electronic motor steadiness instrumentation among pre- and postsurgical assessment procedures. Fifteen PD patients underwent right-sided surgery and 10 underwent left-sided surgery; patients were evaluated 1 month presurgery and approximately 3 months postsurgery. Motorically, there were no significant changes in grooved pegboard or maze-drawing performances, but patients evidenced significantly improved steadiness, particularly in the hand contralateral to the side of surgery. Cognitively, there were no significant decrements on postsurgery composite variables comprised of well-known tests of attention, executive functioning, delayed memory or recognition memory; these findings were similar for patients with either left- or right-sided surgery. There was, however, a significant change in language abilities among a subset of patients. This change was evident in the decline in verbal fluency in PD patients who underwent left-sided pallidotomy, a finding that has consistently emerged in pallidotomy outcome studies. This decline is discussed in terms of evidence that suggests that the basal ganglia consist of several separate, but parallel circuits, some of which are important for cognition.