Atlas template images for nonhuman primate neuroimaging: baboon and macaque.
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Animals↗
Biomedical subjects
Joel S Perlmutter
Publications and source records attributed to Joel S Perlmutter.
Functional changes in brain activity during acquisition and practice of movement sequences.
In the present study, brain activations were measured using positron emission tomography (PET) over the course of practice. Fourteen right-handed participants were scanned during six 1-min periods of practice tracing a cut-out maze design with their eyes closed. Practice-related decreases were found in the right premotor and posterior parietal cortex and left cerebellum, increases in the supplementary motor area (SMA) and primary motor cortex. The decrease in right premotor activity and the increase in SMA was significantly correlated with a decrease in the number of stops, implying involvement in learning and storing the movement sequence. The significant correlation between decreases in errors and left cerebellar and right posterior parietal activity suggests a role in accuracy. Involvement of the primary motor cortex in motor execution is suggested by the correlation of increased activation and movement speed. These results suggest that different neural structures (involving a premotor-parietal-cerebellar circuit) play a role in a sequential maze learning task.
Adult↗
Dysfunction of dopaminergic pathways in dystonia.
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Animals↗
Rapid intravenous loading of levodopa for human research: clinical results.
Levodopa has several advantages as a pharmacological challenge agent for human neuroscience research. Exogenous levodopa changes striatal neuronal activity and increases extracellular dopamine concentrations, and with adequate inhibition of peripheral metabolism levodopa does not change mean cerebral blood flow. For neuroimaging studies of Parkinson disease (PD) and Tourette syndrome, we sought to rapidly produce a biologically relevant steady-state levodopa concentration and then maintain that concentration for at least an hour. We also wished to minimize side effects, even in individuals without prior levodopa treatment. We designed a two-stage intravenous infusion protocol based on published levodopa pharmacokinetic data. We report results of 125 infusions in 106 subjects, including healthy volunteers, PD patients, and people with chronic tics. At higher doses (target steady-state levodopa concentrations of 2,169 and 1,200 ng/ml), treatment-naive volunteers had unacceptably frequent side effects. The final infusion protocol, with a target steady-state concentration of 600 ng/ml, was well-tolerated (mild nausea in 11% of subjects was the only side effect occurring significantly more than in single-blind saline infusions), produced the desired plasma levodopa concentration (612+/-187 ng/ml, mean+/-S.D.), and produced statistically significant antiparkinsonian benefit (16% mean reduction in a standard rating of parkinsonian motor signs, P<0.0005).
Adult↗
Blind men and blinking elephants.
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Basal Ganglia↗
Asymmetric regional cerebral blood flow in sedated baboons measured by positron emission tomography (PET).
The analysis of structural brain asymmetry has been a focal point in anthropological theories of human brain evolution and the development of lateralized behaviors. While physiological brain asymmetries have been documented for humans and animals presenting with pathological conditions or under certain activation tasks, published studies on baseline asymmetries in healthy individuals have produced conflicting results. We tested for the presence of cerebral blood flow asymmetries in 7 healthy, sedated baboons using positron emission tomography, a method of in vivo autoradiography. Five of the 7 baboons exhibited hemispheric asymmetries in which left-sided flow was significantly greater than right-sided flow. Furthermore, the degree of asymmetry in 8 of 24 brain regions was found to be significantly correlated with age; older individuals exhibited a higher degree of asymmetry than younger individuals. Cerebral blood flow itself was uncorrelated with age, and differences between males and females were not significant.
Age Factors↗
Botulinum toxin B reduces sialorrhea in parkinsonism.
We report on our open-label experience with botulinum toxin B for the treatment of severe sialorrhea associated with parkinsonism. Nine adult patients with parkinsonism and medically intractable sialorrhea were treated with botulinum toxin B (1,000 units into each parotid gland using superficial landmarks). After treatment, patients experienced a 61% mean subjective improvement and a 42% mean reduction of quantitative saliva production. There were no adverse effects seen in any subjects. Mean peak benefit from injections lasted 14 weeks. We conclude that denervation of salivary glands with botulinum toxin B produces excellent reduction of excessive salivation associated with parkinsonism.
Aged↗
Different effects of unilateral versus bilateral subthalamic nucleus stimulation on walking and reaching in Parkinson's disease.
The purpose of this study was to determine the effects of unilateral versus bilateral subthalamic nucleus (STN) stimulation on quantitative measures of walking and reaching in Parkinson's disease (PD). We used kinematic measures and the Unified Parkinson's Disease Rating Scale (UPDRS) motor subscale (subscale III) to evaluate the movement of 6 people with PD who had bilateral STN stimulators implanted for at least 6 months and withheld their anti-parkinson medication for at least 8 hours. Subjects were studied with both stimulators off, one on, and both on. Kinematic data were collected as subjects walked, reached to a target, and were rated using the UPDRS motor subscale. STN stimulation improved walking speed and stride length, with the greatest benefit from bilateral stimulation. Reaching speed was improved by unilateral STN stimulation alone, with no additive effect of bilateral stimulation. UPDRS motor subscale ratings paralleled the kinematic findings. STN stimulation did not restore PD subjects' movements to the level of age-matched controls. Overall, these results provide further evidence that the basal ganglia pathways involved in control of walking and reaching may be distinct. We speculate that basal ganglia may influence walking through bilateral pedunculopontine projections and reaching through ipsilateral thalamocortical projections. Our findings also suggest that maximal improvement of walking requires bilateral rather than unilateral STN stimulation.
Adult↗
Effects of pallidotomy and levodopa on walking and reaching movements in Parkinson's disease.
We examined the effects of levodopa and unilateral pallidotomy on quantitative measures of walking and reaching in Parkinson's disease (PD). We also compared quantitative measures of movement with standard clinical rating scales. We used kinematic measures and the Unified Parkinson's Disease Rating Scale (UPDRS) motor subscale (subscale III) to evaluate the movement of 10 people with PD. Subjects were tested after withholding PD medications for at least 8 hours and again 30 to 45 minutes after taking the first morning dose of levodopa. They were studied in this manner before unilateral pallidotomy and then 3.5 to 10 months after surgery. The UPDRS motor subscale was performed in each state. Kinematic data were collected as subjects reached to a target and walked. The UPDRS motor subscale ratings were similar to those reported in the literature: pallidotomy improved the overall motor score and the contralateral bradykinesia + rigidity score, but not the gait + posture score. In contrast, kinematic measures demonstrated that levodopa and pallidotomy had different effects on walking and reaching speed. Both treatments improved walking speed, and the effect was additive. Levodopa improved reaching speed before pallidotomy but did not improve it as much after pallidotomy. Additionally, pallidotomy had inconsistent effects on reaching; some subjects were faster and others were slower. The subjects who initially reached more slowly improved after pallidotomy; the subjects who initially reached more normally (faster) worsened after pallidotomy. On the basis of our results, we speculate that basal ganglia output pathways that control walking and reaching may be distinct, such that bilateral projections to the pedunculopontine area influence walking, whereas ipsilateral thalamocortical projections influence reaching.
Aged↗
A possible substrate for dopamine-related changes in mood and behavior: prefrontal and limbic effects of a D3-preferring dopamine agonist.
Dopamine can induce fascinating, complex human behavioral states, including disinhibition, euphoria, or elaborate stereotypies, whereas dopamine deficiency can cause anxiety or sadness. Limited data suggest that these phenomena may involve dysfunction of orbital frontal cortex, cingulate cortex, or ventral striatum. The dopamine D3 receptor (D3R) has an anatomic distribution that suggests it could mediate these effects, but almost no data directly demonstrate the regional functional effects of D3R activation. We used quantitative positron emission tomography (PET), [15O]water, and the D3-preferring dopamine agonist pramipexole to identify D3-mediated regional cerebral blood flow (rCBF) responses in living primates. We studied seven normal baboons ventilated with 70% nitrous oxide, and analyzed results voxelwise in a common atlas space. At clinically relevant doses, pramipexole produced statistically robust decreases in rCBF in bilateral orbitofrontal cortex, thalamus, operculum, posterior and anterior (subgenual) cingulate cortex, and insula (in decreasing order of significance). Cortical areas related to movement were relatively unaffected, and rCBF did not change in cerebellum or visual cortex. The dose-response curve and duration of pramipexole's effects suggest that these rCBF responses indicate functional effects of a D3-preferring agonist. A D2-preferring agonist studied under the same conditions produced a quantitatively different pattern of responses. We conclude that a dopamine D3 receptor agonist preferentially affects brain activity in prefrontal and limbic cortex, and speculate that dopamine's effects on these regions via D3Rs may mediate some of the known psychiatric complications of dopamine deficiency or excess.
Animals↗
Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline.
BACKGROUND: Parkinson disease (PD) is a degenerative neurological disorder for which no treatment has been shown to slow the progression. OBJECTIVE: To determine whether a range of dosages of coenzyme Q10 is safe and well tolerated and could slow the functional decline in PD. DESIGN: Multicenter, randomized, parallel-group, placebo-controlled, double-blind, dosage-ranging trial. SETTING: Academic movement disorders clinics. PATIENTS: Eighty subjects with early PD who did not require treatment for their disability. INTERVENTIONS: Random assignment to placebo or coenzyme Q10 at dosages of 300, 600, or 1200 mg/d. MAIN OUTCOME MEASURE: The subjects underwent evaluation with the Unified Parkinson Disease Rating Scale (UPDRS) at the screening, baseline, and 1-, 4-, 8-, 12-, and 16-month visits. They were followed up for 16 months or until disability requiring treatment with levodopa had developed. The primary response variable was the change in the total score on the UPDRS from baseline to the last visit. RESULTS: The adjusted mean total UPDRS changes were +11.99 for the placebo group, +8.81 for the 300-mg/d group, +10.82 for the 600-mg/d group, and +6.69 for the 1200-mg/d group. The P value for the primary analysis, a test for a linear trend between the dosage and the mean change in the total UPDRS score, was.09, which met our prespecified criteria for a positive trend for the trial. A prespecified, secondary analysis was the comparison of each treatment group with the placebo group, and the difference between the 1200-mg/d and placebo groups was significant (P =.04). CONCLUSIONS: Coenzyme Q10 was safe and well tolerated at dosages of up to 1200 mg/d. Less disability developed in subjects assigned to coenzyme Q10 than in those assigned to placebo, and the benefit was greatest in subjects receiving the highest dosage. Coenzyme Q10 appears to slow the progressive deterioration of function in PD, but these results need to be confirmed in a larger study.
Administration, Oral↗
Secondary nonresponsiveness to new bulk botulinum toxin A (BCB2024).
We report on a patient with cranio-cervical dystonia injected with the new, lower protein formulation of botulinum toxin A who developed secondary resistance to this toxin. Subsequent injections with botulinum toxin B provided substantial reduction of blepharospasm. This is the first reported case of secondary resistance to the new preparation of botulinum toxin A.
Blepharospasm↗
Parkinson's disease and apolipoprotein E: possible association with dementia but not age at onset.
Idiopathic Parkinson's disease (PD) is an age-dependent, neurodegenerative condition frequently associated with dementia. Although it is predominantly a sporadic disease, 20-30% of cases are familial, suggesting a complex mode of inheritance. Apolipoprotein E (APOE) allele epsilon4 has been associated with familial and sporadic late-onset senile dementia of the Alzheimer's type. To investigate the role of this gene in the development of dementia associated with PD and age at onset of PD, we evaluated the frequency of APOE gene polymorphism in a sample of PD patients with (n=118) and without (n=167) a family history, as well as matched normal controls (n=96). The PD sample was categorized according to age at onset and presence or absence of dementia. Kaplan-Meier survival analysis was used to plot genotype-specific age at onset distribution curves. Allele frequencies of APOE in PD patients with and without a family history and normal controls were not significantly different. APOE genotypes were also similar between the groups. However, the frequencies of epsilon4 allele and epsilon4/- genotype in the PD group with dementia were more than twofold higher than in normal controls, and the differences were statistically significant. There were no differences in the allele and genotype frequencies of the APOE gene between PD groups with different age at onset. The familial PD had significantly earlier age at onset than sporadic PD (Log-rank test, P=0.027). The age at onset distribution curves for different genotype groups were similar, and their differences were not statistically significant (P=0.38). After the Bonferroni's correction for multiple tests, the positive results are not significant at the P<0.05 level. We conclude that APOE does not play an important role in susceptibility to PD or age at onset of PD, but may play a role in dementia associated with PD in our sample.
Adult↗
Clinical features and comorbidity of mood fluctuations in Parkinson's disease.
Parkinson's disease (PD) patients commonly develop fluctuations in their motor responses to levodopa within several years of initiation of treatment; some also develop nonmotor fluctuations. The authors performed a case-control study comparing the frequency of comorbid symptoms in 70 PD patients who experienced clinically apparent mood changes during their motor "on" or "off" states with two control groups with no mood fluctuations. Mood fluctuators had significantly younger age at onset and longer disease duration and were significantly more likely to have dementia, psychosis, clinical depression, and motor complications. This association remained after removing effects of age and disease duration.
Adult↗