The effect of COVID-19 lockdowns on exercise and the role of online exercise in Australians with multiple sclerosis.

INTRODUCTION: Regular exercise is beneficial for people with Multiple Sclerosis (MS), regardless of disability level. The previously reported differential effect of COVID-19-related lockdowns on exercise levels in this population remains unexplained. We examined effects of lockdowns on exercise in Australians with MS according to disability levels, lockdown severity and health technology use. METHODS: A cross-sectional survey of people with MS in Australia (22 April-23 September 2021) collected demographic and clinical information as well as exercise patterns before and during lockdowns. Mann-Whitney was used to compare ordinal data and Likelihood Ratio to compare dichotomous data. RESULTS: 151 people completed the survey. 72.2% had mild disability and 25.2% moderate disability. Extended lockdowns were associated with significantly decreased sedentary behaviour (31.5% to 25.9%) but also with decreased exercise frequency in frequent exercisers (≥3 times/week; 53.7% to 22.2%). The latter occurred significantly more in those with mild disability (-22.7%) than with moderate disability (-3.5%). More people with mild disability walked for exercise pre-pandemic (LR 8.6, p=.004) and during lockdowns (LR 6.6, p=.010). Walking during lockdowns was positively associated with working from home. People with moderate disability were more likely to engage in home exercise both pre-pandemic (LR 5.5, p=.019) and during lockdown (LR 5.2, p=.023). Engagement in home exercise rose for both groups during lockdowns and was facilitated by on-line exercise classes. CONCLUSION: Lockdowns differentially affected exercise patterns according to disability level. The proportion of people achieving exercise recommendations decreased more in those with mild but not moderate disability. Incidental physical activity was disproportionately impacted in people with moderate disability.

Implementing education: Personal communication with a healthcare professional is a critical step to address vaccine hesitancy for people with multiple sclerosis.

BACKGROUND: People with Multiple Sclerosis (PwMS) were first able to access COVID-19 vaccines in Australia from March 2021, when vaccine hesitancy in the general population was high (14-43%). High uptake of vaccination is important globally and critical to protect this vulnerable population. We conducted an on-line survey to examine factors influencing COVID-19 vaccination willingness among PwMS in Australia. METHODS: 149 PwMS living in Australia completed the on-line survey (April-September 2021) examining demographic, environmental and clinical factors with respect to vaccine willingness, including attitudes towards COVID-19 illness and vaccines. Additional items explored the influence of different information sources on vaccination decisions. Continuous and ordinal data were compared using the Mann-Whitney U test. All tests were two-tailed, with alpha set at 0.5. RESULTS: A majority of the respondents were female (87.2%) with relapsing-remitting MS (77.5%) treated by a neurologist (94.0%). A majority were on high efficacy disease-modifying therapies (DMTs) (64.9%), while 19.9% were on no DMTs. About one third of respondents (32.9%) had had two doses, 20.8% had received their first dose, and 22.1% were unvaccinated, while 24.2% of responses were missing. When asked about vaccine intentions, 60.6% of the unvaccinated indicated they were likely to extremely likely to get vaccinated, while 15.2% were very unlikely or extremely unlikely to do so and 24.2% were undecided. Unvaccinated people were significantly more concerned about vaccine side effects (mean 5.3 versus 3.1/10; p < .001). Only 53.3% of people on DMTs were vaccinated, compared to 75% of those who were not. People on ocrelizumab therapy (n = 35) had a lower vaccination rate (39%) than those on other medications (n = 86, 59%). Vaccine willingness in the unvaccinated was most highly correlated with knowledge regarding the vaccine (rs2=.709), agreement with the statement that COVID-19 vaccination is "too new for me to be confident about getting vaccinated" (rs2= -.709), anticipation of regret due to side effects of vaccination (rs2= -.642), and lack of knowledge regarding interactions between COVID-19 vaccines and DMTs (rs2= -.570). Almost two thirds had read MS-specific information about COVID-19 vaccinations and found it easy to understand (67.6%) and applicable to their situation (53.6%). However, less than half (47.8%) reported the information helped them make a personal vaccination decision. Over two-thirds (64.9%) had discussed vaccinations with their healthcare professional and 31.1% had not. Those who had not, were significantly more uninformed about the interactions of the vaccine with MS medications (mean 3.9 versus 2.9/10; p = .044) and significantly lower intention of vaccine uptake than those who had (mean 5.8 versus 7.9/10; p = .009). CONCLUSION: Our study highlights that vaccination efforts should be delivered by healthcare professionals, focus on educating those who are managed with DMTs, and include individual recommendations related to specific DMTs, how the vaccines work, expectations regarding potential side-effects, potential exacerbation of MS symptoms, likelihood of recovery from any exacerbation, and the relative risks of side effects versus COVID-19 infection. Specific recommendations are provided.

The Effect of the ENJOY Seniors Exercise Park Physical Activity Program on Falls in Older People in the Community: A Prospective Pre-Post Study Design.

BACKGROUND: The ENJOY project (Exercise interveNtion outdoor proJect in the cOmmunitY for older people) is a community-based research project actively promoting physical activity engagement through the delivery of an exercise program using outdoor multimodal exercise equipment. This study investigated the impact of the physical activity program on falls in older people. METHOD: This study was a multi-site prospective study with a pre-post intervention design and 12-month follow up. Eighty older people with increased falls risk underwent a 12-week supervised outdoors exercise program followed by a 6-month maintenance phase. The proportion of fallers and falls incidence were compared between the preceding and the prospective years. RESULTS: A sample of 54 (age 72.4±7.3, 79.6% women) was available for the 12 months analysis (due to COVID19 lockdowns, data of 19 participants were excluded and 4 dropped out). Number of fallers (from 51.8% to 31.4%, p=0.03) and falls incidence (from 42 to 29 falls, p<0.01) were significantly reduced at the 12-months follow up. CONCLUSION: The ENJOY Seniors Exercise Park program integrates outdoor multimodal exercise stations including specific exercises designed to challenge dynamic balance during functional daily movements. The outcomes provide preliminary evidence for the potential positive impact of the ENJOY Seniors Exercise Park in reducing falls for older people.

Does early exercise attenuate muscle atrophy or bone loss after spinal cord injury?

OBJECTIVES: To systematically identify and assess the evidence on the efficacy of exercise initiated early after traumatic spinal cord injury (SCI). METHODS: A comprehensive search (Any-2014) of eleven databases identified studies evaluating exercise interventions initiated within 12 weeks after SCI on muscle and bone loss in paralyzed limbs and comparing with standard care or immobilization. Two reviewers assessed methodological quality. One reviewer extracted data and critiqued results according to the Spinal Cord Injury Rehabilitation Evidence body of evidence framework. RESULTS: A total of 2811 titles were screened. Eleven studies were included: five randomized controlled trials, four cohort studies and two within-subject control studies. All provided level II evidence with a moderate risk of bias. Two studies found significant positive effects of high-load FES-resisted stance on physiological measures of muscle. Three reported positive effects of 3 months of Functional Electrical Stimulation (FES) on muscle size. Two studies found positive effects of 6-month body-weight supported treadmill training or FES on trabecular bone using pQCT. CONCLUSION: We found consistent evidence of positive effects of early exercise on muscle, possibly related to load intensity of the protocol. However, the heterogeneity of interventions and outcomes makes this determination speculative. Evidence for the effectiveness of early exercise on bone is scant and confined to measures of trabecular bone mineral density via pQCT. Transparent reporting of methods and variability of data, combined with standardization of valid and sensitive measures of muscle atrophy and bone loss, could facilitate future meta-analysis on this topic.

Severity of depression and anxiety are predictors of response to antidepressant treatment in Parkinson's disease.

BACKGROUND: Antidepressants have appeared to be more effective than placebo treatment in treating depressive syndromes in patients with Parkinson's disease (PD). OBJECTIVE: To identify factors that predict improvement in depressive symptoms during antidepressant treatment in depressed PD patients. METHODS: A secondary analysis was performed on the dataset of the Randomized Placebo-controlled Study of Antidepressants in PD (SAD-PD), in which 76 patients received active treatment with either paroxetine or venlafaxine extended release (XR), and 39 patients received placebo treatment. Backward stepwise regression analyses were conducted with change in 24-item Hamilton Depression Rating Scale (HAMD-24) score between assessments at baseline and week 12 as the main outcome measure, and sex, age, baseline HAMD-24 score, Unified Parkinson's Disease Rating Scale section III (UPDRS-III) score, Mini-Mental State Examination (MMSE), and the Clinical Anxiety Scale (CAS) as independent variables. RESULTS: In both the active treatment and placebo groups, higher baseline HAMD-24 score and lower UPDRS-III score were associated with greater reduction in HAMD-24 score. Higher anxiety scores predicted less response in the active treatment group. Higher MMSE scores predicted greater response only in the placebo-treated group. Sex and age were no predictors of response. CONCLUSIONS: Higher pre-treatment depression scores and lower pre-treatment anxiety scores are the two most important predictors for improvement during antidepressant treatment in depressed PD patients, which is in line with those found in treatment studies of depressed non-PD patients. Furthermore, our results indicate the requirement for different or more intensive treatment for depressed PD patients with more severe anxiety symptoms.

A randomized, double-blind, placebo-controlled trial of antidepressants in Parkinson disease.

OBJECTIVE: To evaluate the efficacy and safety of a selective serotonin reuptake inhibitor (SSRI) and a serotonin and norepinephrine reuptake inhibitor (SNRI) in the treatment of depression in Parkinson disease (PD). METHODS: A total of 115 subjects with PD were enrolled at 20 sites. Subjects were randomized to receive an SSRI (paroxetine; n = 42), an SNRI (venlafaxine extended release [XR]; n = 34), or placebo (n = 39). Subjects met DSM-IV criteria for a depressive disorder, or operationally defined subsyndromal depression, and scored >12 on the first 17 items of the Hamilton Rating Scale for Depression (HAM-D). Subjects were followed for 12 weeks (6-week dosage adjustment, 6-week maintenance). Maximum daily dosages were 40 mg for paroxetine and 225 mg for venlafaxine XR. The primary outcome measure was change in the HAM-D score from baseline to week 12. RESULTS: Treatment effects (relative to placebo), expressed as mean 12-week reductions in HAM-D score, were 6.2 points (97.5% confidence interval [CI] 2.2 to 10.3, p = 0.0007) in the paroxetine group and 4.2 points (97.5% CI 0.1 to 8.4, p = 0.02) in the venlafaxine XR group. No treatment effects were seen on motor function. CONCLUSIONS: Both paroxetine and venlafaxine XR significantly improved depression in subjects with PD. Both medications were generally safe and well tolerated and did not worsen motor function. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that paroxetine and venlafaxine XR are effective in treating depression in patients with PD.

Naturalistic evaluation of entacapone in patients with signs and symptoms of L-dopa wearing-off .

OBJECTIVE: To evaluate the effectiveness of entacapone in the management of levodopa wearing-off in Parkinson's disease (PD) in a naturalistic, real-life setting. RESEARCH DESIGN AND METHODS: This prospective, open-label, observational study included patients with idiopathic PD. Patients were eligible for inclusion if they had been taking 3-5 doses of levodopa per day for ≥2 months and had shown signs of levodopa wearing-off for ≥1 month. Subjects received entacapone (recommended dose: 1 × 200 mg tablet with each levodopa dose) for 28 days. Patients were asked to complete a wearing-off questionnaire and the eight-question Parkinson's Disease Questionnaire Quality of Life assessment (PDQ-8). Activities of daily living (both in the on and off states) were assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) part II. Clinical Global Impression (CGI) of severity of PD-related symptoms was assessed using a modified CGI tool. Patient global assessment of severity of PD symptoms was also obtained. RESULTS: A total of 341 patients were enrolled by 68 physicians across Canada. At Day 28, 56.9% of the subjects indicated improvement compared to baseline on the modified CGI of change (CGI-C); 21.4% reported no change. Improvements were also observed on the UPDRS II and the PDQ-8. Benefit from entacapone appeared to be relatively uniform across subgroups (e.g., number of daily levodopa doses, use of other anti-PD medications). STUDY LIMITATIONS: The results of this study may be biased due to factors inherent in open-label, community-based trials (e.g., compliance). This is, however, reflective of everyday clinical practice. CONCLUSIONS: In this naturalistic, real-life study, the addition of entacapone to levodopa therapy provided benefits in quality of life and activities of daily living for a substantial proportion of PD patients experiencing wearing-off.

Neural substrates of cognitive skill learning in Parkinson's disease.

While cognitive skill learning is normally acquired implicitly through frontostriatal circuitry in healthy individuals, neuroimaging studies suggest that patients with Parkinson's disease (PD) do so by activating alternate, intact brain areas associated with explicit memory processing. To further test this hypothesis, 10 patients with PD and 12 healthy controls were tested on a modified, learning version of the Tower of London task while undergoing positron emission tomography at four different time points over the course of learning. Despite having less accurate problem solving abilities than controls, PD patients were able to acquire the skill learning task. However, as compared to controls, they maintained higher levels of cerebral blood flow activity in the dorsolateral prefrontal cortex and hippocampus and showed an increase in activity in the frontopolar cortex and posterior cingulate over the course of learning. These findings reflect a shift to the explicit memory system in PD patients, enabling them to learn this cognitive skill, which is normally acquired by control subjects using implicit learning strategies and frontostriatal circuitry.

REM sleep behavior disorder predicts cognitive impairment in Parkinson disease without dementia.

OBJECTIVE: To assess the relationship between the presence of REM sleep behavior disorder (RBD) and the cognitive profile of nondemented patients with Parkinson disease (PD). BACKGROUND: Cognitive impairment is an important nonmotor symptom in PD. Waking EEG slowing in nondemented PD has been related to the presence of RBD, a parasomnia affecting brainstem structures and frequently reported in PD. For this reason, RBD may be associated with cognitive impairment in PD. METHODS: Thirty-four patients with PD (18 patients with polysomnographic-confirmed RBD and 16 patients without RBD) and 25 healthy control subjects matched for age and educational level underwent sleep laboratory recordings and a comprehensive neuropsychological assessment. RESULTS: Patients with PD and concomitant RBD showed significantly poorer performance on standardized tests measuring episodic verbal memory, executive functions, as well as visuospatial and visuoperceptual processing compared to both patients with PD without RBD and control subjects. Patients with PD without RBD had no detectable cognitive impairment compared to controls. CONCLUSIONS: This study shows that cognitive impairment in nondemented patients with Parkinson disease (PD) is closely related to the presence of REM sleep behavior disorder, a sleep disturbance that was not controlled for in previous studies assessing cognitive deficits in PD.

LRRK2 screening in a Canadian Parkinson's disease cohort.

BACKGROUND: Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) have become the most common known cause for developing Parkinson's disease. The frequency of mutations described in the literature varies widely depending on the population studied with most reports focusing only on screening for the most common G2019S mutation in exon 41. METHODS: In this study seven exons (19, 24, 25, 31, 35, 38, and 41) in LRRK2 where mutations have been reported were screened in 230 unselected Parkinson's disease patients using denaturing high-performance liquid chromatography. RESULTS: The sequencing of samples with heteroduplex profiles revealed five novel and two known intronic sequence variants. In our cohort, we were unable to detect any of the known mutations in these exons or identify novel mutations within the LRRK2 gene. CONCLUSIONS: Therefore, despite the availability of diagnostic LRRK2 genetic testing it is unlikely to yield a positive result in this population.

Neurobehavioral functioning after cessation of manganese exposure: a follow-up after 14 years.

BACKGROUND: Little is known on the long-term course of early manganese (Mn) neurotoxic effects. Mn alloy workers were examined in a follow-up study 14 years after exposure ceased at a Canadian facility. METHODS: The same battery of neurofunctional tests used in the initial examination in 1990 was administered to 77 Mn-workers and 81 referents in 2004. RESULTS: Manganese-workers had poorer scores compared to referents both in the initial and follow-up examinations for several motor tasks of the Luria Motor Scale. At follow-up, older Mn-workers (>45 years at cessation of exposure) had poorer scores than referents for tests of cognitive flexibility. Cumulated exposure was associated with poorer test scores for certain neuromotor and cognitive tests and on a mood scale. Differences on certain tests observed at initial examination were not present at follow-up. CONCLUSIONS: Manganese exposure was associated with persistent deficits for certain neuromotor functions, cognitive flexibility, and adVerse mood states, while recovery occurred for other functions.

Neurofilament M gene in a French-Canadian population with Parkinson's disease.

BACKGROUND: Recently, a single base pair substitution (G1747A) mutation of the neurofilament M (NF-M) gene was reported in a French-Canadian patient with early onset Parkinson's disease (PD). Three unaffected siblings were found to be heterozygotes for the NF-M Gly336Ser mutation but, to date, no other affected PD individuals have been found with a similar mutation. No other individuals with Parkinson's disease and of similar ethnic background have been screened for this mutation. METHODS: We screened 102 French-Canadian patients with definite PD and 45 French-Canadian controls for this substitution in the NF-M gene using a PCR-restriction enzyme digestion method. RESULTS: None of the patients or controls carried this mutation. CONCLUSION: Our results would indicate that this mutation is not common even in a PD population of similar ethnic background and suggest this change represents a rare variant. However, these results do not exclude the possibility that other mutations in this gene could be present.

Association between waking EEG slowing and REM sleep behavior disorder in PD without dementia.

OBJECTIVE: To compare nondemented patients with Parkinson's disease (PD) with and without REM sleep behavior disorder (RBD) to healthy controls on quantitative EEG characteristics for both wakefulness and REM sleep. METHODS: Fifteen patients with PD (7 patients with polysomnographic-confirmed RBD [PD-RBD] and 8 patients without RBD [PD-NRBD]) and 15 healthy control subjects were studied. Each subject underwent a quantitative EEG analysis of both wakefulness and REM sleep. RESULTS: During wakefulness, patients with PD-RBD showed a higher theta power in frontal, parietal, temporal, and occipital regions in comparison to patients with PD-NRBD and control subjects. Moreover, a slowing of the dominant occipital frequency was observed only in patients with PD-RBD (p < 0.02). Patients with PD-NRBD did not present any slowing of the EEG. No between-group difference in quantitative REM sleep EEG was observed. CONCLUSIONS: This study demonstrates that the EEG slowing reported during wakefulness in nondemented patients with PD is strongly related to the presence of RBD.

REM sleep behavior disorder and REM sleep without atonia in Parkinson's disease.

OBJECTIVE: To determine the frequency of REM sleep behavior disorder (RBD) among patients with PD using both history and polysomnography (PSG) recordings and to further study REM sleep muscle atonia in PD. BACKGROUND: The reported occurrence of RBD in PD varies from 15 to 47%. However, no study has estimated the frequency of RBD using PSG recordings or analyzed in detail the characteristics of REM sleep muscle atonia in a large group of unselected patients with PD. METHODS: Consecutive patients with PD (n = 33) and healthy control subjects (n = 16) were studied. Each subject underwent a structured clinical interview and PSG recording. REM sleep was scored using a method that allows the scoring of REM sleep without atonia. RESULTS: One third of patients with PD met the diagnostic criteria of RBD based on PSG recordings. Only one half of these cases would have been detected by history. Nineteen (58%) of 33 patients with PD but only 1 of 16 control subjects had REM sleep without atonia. Of these 19 patients with PD, 8 (42%) did not present with behavioral manifestations of RBD, and their cases may represent preclinical forms of RBD associated with PD. Moreover, the percentage of time spent with muscle atonia during REM sleep was lower among patients with PD than among healthy control subjects (60.1% vs 93.2%; p = 0.003). CONCLUSIONS: RBD and REM sleep without atonia are frequent in PD as shown by PSG recordings.

Cerebrolysin in Alzheimer's disease: a randomized, double-blind, placebo-controlled trial with a neurotrophic agent.

UNLABELLED: Cerebrolysin (Cere) is a compound with neurotrophic activity. It has been shown to be effective in the treatment of Alzheimer's disease (AD) in earlier trials. In this multicenter, randomized, double-blind, placebo-controlled, parallel-group study, patients were injected intravenously with placebo or 30 mL Cere five days per week for four weeks. Effects on cognition and global function were evaluated with the Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) and the Clinicians Interview-based Impression of Change with Caregiver Input scale (CIBIC+) 4, 12, 24 weeks after the beginning of the injections. 192 patients were enrolled, 95 were randomized to placebo, and 97 to Cere. At baseline, there was a significant difference between groups for age, age of onset of dementia, and the number of patients with hallucinations. At week 12 there was a significant difference on the CIBIC+ (p = 0.033) in favor of Cere. The number of CIBIC+ responders (score < or = 4), was significantly higher (p = 0.007), with 68 (76%) in the Cere group and 51 (57%) in the placebo group. Trends were noted in the Disability Assessment in Dementia scale and the Cornell Depression Scale. Adverse events were recorded in 73% of placebo and 64% of Cere patients. Most common adverse events were headaches, dizziness, weight loss and anxiety. CONCLUSIONS: Cere treatment was well tolerated and resulted in significant improvements in the global score two months after the end of active treatment.

Differential memory impairment in dementia with Lewy bodies and Alzheimer's disease.

This study was conducted in order to elucidate the functioning of the Central Executive System of Working Memory (WM) and to clarify the status of other cognitive functions in Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Fourteen DLB, 22 AD, and 23 control subjects were assessed with the dual task paradigm and other cognitive tests. When compared with controls, DLB subjects performed more poorly in concurrent conditions on semantic WM tasks, and AD subjects performed more poorly on the spatial WM task. The DLB subjects had an inferior verbal span and AD subjects, an inferior recall on the CVLT. These data suggest relative impairments of verbal and semantic WM in DLB and relative impairments of spatial WM and verbal episodic memory in AD.

The relationship between physiological tremor and the performance of rapid alternating movements in healthy elderly subjects.

The power distribution in the frequency spectrum of tremor is known to vary among individuals and its median power frequency declines with ageing. The purpose of the present study was to determine whether a reduction of the central component of physiological tremor would correlate with a reduction of motor performance. Then, the power distribution in the frequency spectrum of tremor from limb extremities might serve as an index of neural drive in healthy elderly subjects. Rest tremor, postural tremor from the finger, and pronation-supination at the wrist were recorded in 102 healthy nuns living in a convent (mean of 72+/-12 years). Results reveal that several elderly subjects possessed a power distribution of tremor very similar to that of much younger subjects (mean 27 years+/-3 SD), showing a preponderance of power within the 7.6- to 12.5-Hz band. Duration of pronation-supination cycles of these elderly subjects was, however, similar to that of other elderly subjects who had a preponderance of power within the 3.6- to 7.5-Hz band. Consequently, healthy elderly subjects who possessed a predominance of power within higher frequencies were not at an advantage over other healthy elderly subjects when performing a pronation-supination task. The age of subjects was, however, a better predictor or motor performance. In conclusion, the present findings suggest that, under normal physiological conditions, a reduction of the central component of physiological tremor does not induce a reduction of motor performance. Consequently, tremor recorded at limb extremities cannot be used as an index of neural drive.

Evidence that ventrolateral thalamotomy may eliminate the supraspinal component of both pathological and physiological tremors.

Ventrolateral (VL) thalamotomy produced a marked reduction of oscillations related to the supraspinal components of Parkinson's disease tremor (4-7 Hz) and physiological tremor (8-12 Hz). Finger tremor was examined in nine patients undergoing unilateral VL thalamotomy and in nine age-matched controls. In comparison to the preoperative state, the relative percentage of power within the 7.6-12.5 Hz band did not increase after the surgical procedure. Furthermore, the amount of absolute power within the 7.6-12.5 Hz band was much lower for post-surgical patients in comparison to matched controls when periods of tremor having equal amplitudes were compared. These results suggest that VL thalamotomy interrupts a common circuit involved in the supraspinal component of both physiological and pathological tremors. We provide evidence that the thalamus may be involved in circuits generating physiological tremor in humans.

Manganese neurotoxicity, a continuum of dysfunction: results from a community based study.

Excessive manganese (Mn) has been associated with neurobehavioral deficits and neurological and/or neuropsychiatric illness, but the level at which this metal can cause adverse neurotoxic effects, particularly with long-term exposure, is still unknown. The objective of the present study was to assess nervous system functions in residents exposed to manganese from a variety of environmental sources. A random stratified sampling procedure was used to select participants; persons with a history of workplace exposure to Mn and other neurotoxic substances were excluded. A self-administered questionnaire provided data on socio-demographic variables. Blood samples were analyzed for total manganese (MnB), lead, mercury and serum iron. Nervous system assessment included computer and hand-administered neurobehavioral tests, computerized neuromotor tests, sensory evaluation and a neurological examination. The present analyses include 273 persons (151 women and 122 men); MnB range: 2.5 micrograms/L-15.9 micrograms/L (median: 7.3 micrograms/L). Multivariate analyses were used and neuro-outcomes were examined with respect to MnB, taking into account potential confounders and covariables. Results were grouped according to neurofunctional areas and MANOVA analyses revealed that higher MnB (7.5 micrograms/L) was significantly associated with changes in coordinated upper limb movements (Wilks' lambda = 0.92; p = 0.04) and poorer learning and recall (men: Wilks' lambda = 0.77; p = 0.002; women: Wilks' lambda = 0.86; p = 0.04). Further analyses revealed that with increasing log MnB (Simple regression: p < 0.05) performance on a pointing task was poorer, frequency dispersion of hand-arm tremor decreased, while harmonic index increased, and the velocity of a pronation/supination arm movement was slower. An Mn-age interaction was observed for certain motor tasks, with the poorest performance observed among those _50 y and in the higher MnB category. Differences between genders suggest that men may be at greater risk than women, although effects were also observed in women. These findings are consistent with the hypothesis that Mn neurotoxicity can be viewed on a continuum of dysfunction, with early, subtle changes at lower exposure levels.