Parkinson Disease: Haq I

Rodriguez RL, Fernandez HH, Haq I, Okun MS. · Department of Neurology, University of Florida Movement Disorders Center, McKnight Brain Institute, Gainesville, Florida, USA. · Neurologist. · Pubmed #17848865 No free full text.

Abstract: BACKGROUND: Deep brain stimulation (DBS) has emerged as an important treatment for medication refractory movement and neuropsychiatric disorders. General neurologists and even general practitioners may be called upon to screen potential candidates for DBS. The patient selection process plays an important role in this procedure. REVIEW SUMMARY: In this article, we discuss "pearls" for the clinician who may be called upon to identify appropriate candidates for DBS. Additionally, we will discuss the important points that should be considered when referring patients for surgical intervention. CONCLUSION: Diagnosis, response to levodopa, cognitive status, psychiatric status, access to care, and patient expectations are all essential elements of the patient selection process for DBS. These areas must be adequately addressed prior to any surgical procedure.

Halkias IA, Haq I, Huang Z, Fernandez HH. · Department of Neurology, University of Florida, Gainesville, Florida 32608, USA. · Drugs Aging. · Pubmed #17432922 No free full text.

Abstract: Levodopa is available in three forms: immediate-release, orally disintegrating and sustained-release tablets. Levodopa is metabolised in the gastrointestinal tract, kidney and liver by aromatic acid dopa decarboxylase using pyridoxine as a cofactor. Approximately 70-80% of the dose is eliminated in the urine. Central conversion of levodopa to dopamine likely occurs at surviving dopaminergic terminals and at serotonergic and adrenergic nerve terminals that contain decarboxylase. Dopamine is metabolised by catechol-O-methyltransferase and monoamine oxidase. The major metabolites of dopamine are homovanillic acid and dihydroxyphenylacetic acid.Levodopa remains the most efficacious pharmacological treatment for the symptoms of Parkinson's disease (PD). Results of current levodopa trials suggest that treatment with levodopa at the onset of disease provides superior motor and functional control compared with dopamine receptor agonists. Moreover, levodopa is generally better tolerated with a lower incidence of gastrointestinal and neuropsychiatric adverse effects. The debate over the role of levodopa in the treatment of PD is fuelled by the results of in vitro studies that show generation of free radicals by levodopa and its toxic effects on cell cultures. Levodopa has also consistently been shown to produce motor fluctuations (in particular dyskinesias) sooner than has been observed in PD patients, especially younger patients, given dopamine agonists initially. However, the cumulative body of knowledge thus far does not show definitive evidence that levodopa is neurotoxic to parkinsonian patients.In older PD patients with lesser risk of motor fluctuations, levodopa may be used initially, and perhaps solely, in demented PD patients and those at higher risk of developing neuropsychiatric adverse effects. In young parkinsonian patients with mild motor dysfunction, use of levodopa may be delayed or the dosage minimised. However, because of levodopa's superior efficacy, when a rapid and sustained symptomatic improvement is required because of significant motor disability, levodopa may be used as the first-line agent regardless of age.

Drago V, Foster PS, Okun MS, Haq I, Sudhyadhom A, Skidmore FM, Heilman KM. · Department of Neurology, University of Florida, College of Medicine, Gainesville, FL 32610-0236, USA. · J Neurol Sci. · Pubmed #18945449 No free full text.

Abstract: BACKGROUND: Deep brain stimulation (DBS) is a treatment for patients with Parkinson's disease (PD) who are not adequately controlled with medications. An artist reported changes in her artistic creativity and art appreciation when treated with left DBS. We sought to study her artistic productions and her appreciation of art while both "on" and "off" left DBS. METHODS: A 69-year-old right-handed woman with an approximate 20-year history of PD was referred to us for management of a left subthalamic region nucleus (STN) DBS placed at another institution 4 years prior. In Experiment 1 we had her rate several dimensions (Evocative Impact, Aesthetics, Novelty, Technique, Closure and Representation) of another artist's paintings. In Experiment 2, we tested her with the Abbreviated Torrance Test (of creativity) for Adults (ATTA). During testing the patient remained on her dopaminergic medication, but was tested on and off left DBS. RESULTS: On the judgment task while "on" left DBS, versus "off" DBS, there were significant reductions in her appreciation of artistic Closure and Technique. When "off" DBS her ATTA creativity index was above average, but when switched "on" her creativity index was below average. CONCLUSIONS: These results suggest the possibility that left ventral STN/SNR DBS reduces creativity as well as appreciation of art. The reason for these alterations is not known, but might be related to enhanced activation of the left hemisphere and reciprocal deactivation of the right hemisphere which mediates both visuospatial skills and global attention, both of which are important in artistic creativity and appreciation.