L-dopa in the treatment of post-surgical Parkinson patients

Transient resolution of bilateral tremor after unilateral thalamotomy, associated with focal injury of the corpus callosum: case report

We present a patient with Parkinson's disease whose bilateral tremor transiently resolved after a unilateral left ventrolateral thalamotomy. The transient resolution of the bilateral tremor was associated with a focal thalamic lesion and a second lesion in the corpus callosum. The mechanism of this phenomenon may be related to temporary disruption of descending bilateral corticostriate projections by the callosal lesion.

Alterations in cognitive performance and affect-arousal state during fluctuations in motor function in Parkinson's disease

Sixteen patients with idiopathic Parkinson's disease were selected who were all showing severe fluctuations in motor function ("on-off" phenomenon). Measures of cognitive function and of subjective affect/arousal state were taken on two occasions, once when "on" and once when "off". Twenty-five matched normal controls were also assessed on the same measures. Results revealed, on the average, a drop in cognitive function plus an adverse swing in affect/arousal state, in the patient group in the "off" condition, compared to the levels when "on". Analysis of the data suggested that the main factor associated with cognitive function when "off" was not the severity of disability but the level of affect/arousal. The fluctuations in cognitive function found tended to be mild relative to the severe changes in motor ability, and were present in only a proportion of patients.

The long-term results of stereotaxic surgery and L-dopa therapy in patients with Parkinson's disease. A 10-year follow-up study

Sixty patients with Parkinson's disease underwent sterotaxic surgery in Edinburgh between 1965 and 1967, and were examined every 2 years for a total follow-up period of 10 years. Although stereotaxic surgery had been extremely effective in treating tremor and rigidity, the other manifestations of Parkinson's disease were noted to progressively affect more patients at each follow-up examination. L-dopa therapy was instituted in 36 patients after 1968. The effect of L-dopa on bradykinesia was remarkable, but the long-term benefit on the other manifestations of Parkinson's disease was negligible. Furthermore in most cases L-dopa became progressively ineffective for bradykinesia after 3 to 5 years. L-dopa-induced tremor and involuntary movements were less frequently noted in limbs contralateral to the side of a previous stereotaxic procedure. It was concluded that in patients presenting with tremor and rigidity as the major problem in their parkinsonian syndrome, the most effective form of palliative therapy is stereotaxic surgery, and that L-dopa should be reserved for the management of bradykinesia.

Increase in fine motor control in Parkinson patients following levodopa

25 Parkinson patients and 31 controls, matched for age and verbal IQ, were tested on a handwriting task prior to receiving levodopa. 14 of the original 25 patients and 22 of the original 31 controls were also tested on maze-tracing ability prior to levodopa treatment. The Parkinson patients were retested on the same tests after being on levodopa for at least 2 1/2 mo.; the controls were retested after a comparable time interval. Parkinson patients demonstrated improvement in tasks measuring fine motor control and speed. The control groups did not show improvement on either task.

Levodopa's awakening effect on patients with Parkinsonism

The effects of levodopa on tests measuring auditory and visual perception, auditory, and visual short-term memory, verbal learning, and on attention and concentration were studied in 29 patients with Parkinsonism. Thirty-two control subjects matched with the Parkinsonism patients on age, educational level, and verbal IQ were administered the same tests to control for practice effects. Significant improvement occurred for the Parkinsonism patients in verbal learning (an intermediate memory test) and in auditory perception. These improvements were unrelated to changes in anticholinergic medications, increases in alertness or concentration, lessening of depression, or improved motor ability or control. There was no test evidence of levodopa improving visual perception, short-term auditory or visual memory, alertness or concentration. Thus, there is no objective test evidence for levodopa producing a generalized awakening or an alerting effect in Parkinsonism patients who are intellectually alert and well-orientated. Interpretation of the test findings suggests a specific awakening effect, that of improvement in intermediate memory but not in short-term memory. Overall, the Parkinsonism group scored below the control group on all tests, suggesting that cognitive impairment accompanies Parkinson's disease even in patients who are intellectually intact and well oriented.