Levodopa slows prosaccades and improves antisaccades: an eye movement study in Parkinson's disease.

BACKGROUND: The integrity of frontal systems responsible for voluntary control and their interaction with subcortical regions involved in reflexive responses were studied in patients with Parkinson's disease (PD). Previous studies have shown that patients with PD have impaired executive function, including deficits in attention, motor planning and decision making. METHODS: Executive function was measured through eye movements: reflexive (stimulus driven) prosaccades and voluntary (internally guided) antisaccades. Patients with advanced idiopathic PD, off and on their optimal levodopa therapy, were tested on a prosaccade and an antisaccade task and compared with matched controls. RESULTS: Levodopa significantly increased response time for reflexive prosaccades and reduced error rate for voluntary antisaccades. CONCLUSIONS: Consistent with our proposed model, patients with PD in the medicated state are better able to plan and execute voluntary eye movements. These findings suggest levodopa improves function of the voluntary frontostriatal system, which is deficient in PD.

Multiple sclerosis in Jordan: A clinical and epidemiological study.

OBJECTIVES: To characterize the clinical, demographic and epidemiological features of multiple sclerosis (MS) in Jordan. METHODS: Data for consecutive Jordanian patients, fulfilling the McDonald criteria for clinically definite and clinically probable MS, during the time period 2004-2005 were collected and analyzed in the three major referral centers for MS in Jordan. RESULTS: We identified a total of 224 patients (165 females, 87%; 59 males, 13%). The mean (+/-SD) age of onset was 29.3 (+/-9.6) years, and mean (+/-SD) duration of illness was 3.9 (+/-9.3) years. The prevalence of MS in the city of Amman was 39/100,000. The prevalence of MS in Irbid, north Jordan, was 38/100,000. The most frequent presentation was weakness (30.8%), followed by optic neuritis (20.1%), sensory impairment (19.6%), and ataxia (14.3%). A relapsing remitting pattern was identified in 90.2% of patients, the rest being primary and secondary progressive, and one patient had a progressive relapsing course. Family history of MS was found in 9.4% of the cases. About 60% of the patients were using interferon beta. The degree of physical disability was determined using the Expanded Disability Status Scale (EDSS). Younger age of onset, shorter duration of illness, a relapsing remitting pattern, and use of interferon were identified as statistically significant predictors of less disability. CONCLUSION: Jordan is a medium-high risk country for MS, with prevalence higher than what has previously been reported, possibly representing an increase in incidence. Clinical and demographic characteristics are similar to most reports worldwide.