Charcot: Past and present

Jean-Martin Charcot (1825-1893) was the preeminent neurologist of the nineteenth century. Several of his major contributions remain fully relevant to contemporary neurology, and this essay highlights three areas of particular importance to the modern neurologist: the anatomo-clinical method that Charcot developed as the anchor of neurological study; the integration of new scientific discoveries from other fields as a core strategy for neurological advancement; and the role of heredity as the fundamental etiological focus to the understanding of the pathogenesis of primary neurological disorders. Further, Charcot left a strong tradition of visual skills as the core requirement for accurate neurological diagnosis and emphasized scientific humility in the face of difficult diseases. In spite of vast advances in neuroscience over the 20th and 21st centuries, the challenges faced by Charcot remain largely the same for the contemporary neurologist, and the lessons provided by Charcot retain their power and significance today.

Charcot, hysteria, and simulated disorders

Jean-Martin Charcot (1825-1893) was the 19th-century's premier international neurologist. One of his areas of focused interest was the neurologic disorder, hysteria, a condition with distinctive neurologic signs, but no established structural lesions identified at autopsy. Charcot considered hysteria as a physiologic disorder that affected specific neuroanatomic areas of the brain comparable to the same areas that were damaged by structural neurologic disorders provoking the same or similar signs. He considered hysteria primarily a hereditary disorder, but environmental factors including physical and emotional stress served as provoking factors. Charcot drew the strict distinction between hysteria and consciously simulated neurologic disorders, although he was keenly aware that the two disorders could occur in the same patients or be difficult to distinguish at times. He developed specific experimental techniques to separate hysteria from simulation. His studies of hysteria and simulation offer a basis for studies of functional neurologic disorders applicable to the 21st century.

Relationship between the MDS-UPDRS domains and the health-related quality of life of Parkinson's disease patients

BACKGROUND AND PURPOSE

The Movement Disorder Society sponsored version of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) is a comprehensive instrument for assessing Parkinson's disease (PD). The present study was aimed at determining the relationships between MDS-UPDRS components and health-related quality of life (HRQoL) evaluations in PD patients.

METHODS

An international, multicenter, cross-sectional study was carried out of 435 PD patients assessed with the MDS-UPDRS, Hoehn and Yahr (HY), Clinical Impression Severity for PD, EQ-5D and PD Questionnaire - eight items (PDQ-8). Spearman's rank correlation coefficients, exploratory factor analysis and multiple linear regression models (dependent variables EQ-5D and PDQ-8) were performed.

RESULTS

The participants' age was 66.71 ± 10.32 years (51.5% men). PD duration was 8.52 ± 6.14, and median HY was 2 (range 1-5). The correlation between the EQ-5D index and the MDS-UPDRS ranged from -0.46 (Part IV) to -0.72 (Part II) and for the PDQ-8 index from 0.47 (Part III) to 0.74 (Part II). In multiple regression models with the MDS-UPDRS domains as independent variables, the main determinant for both the EQ-5D index and the PDQ-8 was Part II followed by Part I. After factorial grouping of the cardinal PD manifestations embedded in the MDS-UPDRS Parts III and IV for inclusion into multiple regression models, a factor formed by M-EDL, nM-EDL and fluctuations was the main determinant for both the EQ-5D and PDQ-8 indexes.

CONCLUSIONS

The MDS-UPDRS component most tightly related with the HRQoL measures was a combination of motor and non-motor experiences of daily living.

Continuous in-home monitoring of essential tremor

BACKGROUND

Essential tremor (ET) is typically measured in the clinic with subjective tremor rating scales which require the presence of a clinician for scoring and are not appropriate for measuring severity throughout the day. Motion sensors can accurately rate tremor severity during a set of predefined tasks in a laboratory.

METHODS

We evaluated the ability of motion sensors to quantify tremor during unconstrained activities at home. 20 ET subjects wore a wireless sensor continuously for up to 10 h daily on two days and completed hourly standardized tremor assessments involving pre-defined tasks. Mathematical models were used to predict tremor rating scores from the sensor data.

RESULTS

At home tremor scores from hourly standardized assessments correlated with at home tremor scores estimated during unconstrained activities immediately following the standardized assessments. The hourly standardized assessments did not significantly fluctuate throughout the day, while fluctuations in the continuous assessments tended to follow changes in voluntary activity level. Both types of tremor ratings (standardized and continuous) showed high day-to-day test-retest reliability with intraclass correlation coefficients ranging from 0.67 to 0.90 for continuous ratings and 0.77 to 0.95 for standardized ratings.

CONCLUSIONS

Results demonstrate the feasibility of continuous monitoring of tremor severity at home, which should provide clinicians with a measure of the temporal pattern of tremor in the context of daily life and serve as a useful tool for the evaluation of novel anti-tremor medications in clinical trials.

Assessing the non-motor symptoms of Parkinson's disease: MDS-UPDRS and NMS Scale

BACKGROUND AND PURPOSE

Although Parkinson's disease (PD) is characterized by typical motor manifestations, non-motor symptoms (NMS) are an outstanding part of the disease. At present, several specific instruments for assessment of NMS are available. The objective of our study was to determine the performance of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS): Part I - Non-Motor Aspects of Experiences of Daily Living (nM-EDL) compared with the Non-Motor Symptoms Scale (NMSS).

METHODS

To this purpose, 434 consecutive patients with PD were included in an international, observational, cross-sectional study. The association between scores of both scales was determined by the Spearman rank correlation coefficient. Equations for transformation of total score of a scale to the other were constructed from weighted regression models and both, transformed and observed score, contrasted by means of the Lin's Concordance Correlation Coefficient (LCCC) and Bland-Altman plot.

RESULTS

As a whole, the prevalence of the NMS according to each scale was quite similar, and most of the correlations between their corresponding components were high (r(S) > 0.60). The total score correlation of the MDS-UPDRS Part I with the NMSS was high (r(S) = 0.81). Concerning the transformed scores, estimated scores only partially approach the observed ones (sharing about 60-64% of the variance) because residual variance increased with increasing magnitudes of the scores, i.e. the most severe patients (Bland-Altman plot; LCCC < 0.60 for severe patients).

CONCLUSIONS

(i) MDS-UPDRS Part I (nM-EDL) and NMSS showed a strong convergent validity; (ii) however, transformed scores using the equations from weighted regression models showed that for patients with the most severe NMS they are not concordant.

Historical underpinnings of the term essential tremor in the late 19th century

BACKGROUND

The term essential tremor has been in regular use since the second half of the 20th century. To modern neurologists, the word "essential" may seem cryptic. The historical underpinnings of this term have not been examined.

OBJECTIVES

To bring to attention early medical reports using the term essential tremor and examine the characteristics of the disorder that contributed to the proposed use of the term.

METHODS

Review of 19th and early 20th century medical literature on essential tremor.

RESULTS

The term tremore semplice essenziale (simple essential tremor) was first used by Burresi (Italy, 1874) to describe an 18-year-old man with severe, isolated action tremor. Several years later, Maragliano (Italy, 1879), Nagy (Austria, 1890), and Raymond (France, 1892) described similar cases and proposed the terms tremore essenziale congenito (essential congenital tremor), essentieller Tremor (essential tremor), and tremblement essentiel héréditaire (hereditary essential tremor) to define the illness. Mirroring contemporaneous views of constitutional and inherited disease, the key ingredients of the disorder were viewed as the constant presence of tremor in the absence of other neurologic signs and its heritable nature. By the early 20th century, the term began to appear in the medical literature with greater frequency.

CONCLUSIONS

Toward the end of the 19th century, several clinicians attempted to provide a nosologic separation for a tremor diathesis that was often familial and occurred in isolation of other neurologic signs. This disorder, which was termed essential tremor, was later recognized as one of the most common neurologic disorders.

FMR1 CGG repeat length predicts motor dysfunction in premutation carriers

BACKGROUND

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a recently described, underrecognized neurodegenerative disorder of aging fragile X mental retardation 1 (FMR1) premutation carriers, particularly men. Core motor features are action tremor, gait ataxia, and parkinsonism. Carriers have expanded CGG repeats (55 to 200); larger expansions cause fragile X syndrome, the most common heritable cause of mental retardation and autism. This study determines whether CGG repeat length correlates with severity and type of motor dysfunction in premutation carriers.

METHODS

Persons aged >or=50 years with a family history of fragile X syndrome underwent structured videotaping. Movement disorder neurologists, blinded to carrier status, scored the tapes using modified standardized rating scales. CGG repeat length analyses for women incorporated the activation ratio, which measures the percentage of normal active chromosome X alleles.

RESULTS

Male carriers (n = 54) had significantly worse total motor scores, especially in tremor and ataxia, than age-matched male noncarriers (n = 51). There was a trend toward a difference between women carriers (n = 82) and noncarriers (n = 39). In men, increasing CGG repeat correlated with greater impairment in all motor signs. In women, when activation ratio was considered, increasing CGG correlated with greater ataxia.

CONCLUSIONS

CGG repeat size is significantly associated with overall motor impairment in premutation carriers. Whereas this association is most pronounced for men and covers overall motor impairment-tremor, ataxia, and parkinsonism-the association exists for ataxia among women carriers. This is the first report of a significant correlation between the premutation status and a motor feature of fragile X-associated tremor/ataxia syndrome in women.

DLB and PDD boundary issues: Diagnosis, treatment, molecular pathology, and biomarkers

For more than a decade, researchers have refined criteria for the diagnosis of dementia with Lewy bodies (DLB) and at the same time have recognized that cognitive impairment and dementia occur commonly in patients with Parkinson disease (PD). This article addresses the relationship between DLB, PD, and PD with dementia (PDD). The authors agreed to endorse "Lewy body disorders" as the umbrella term for PD, PDD, and DLB, to promote the continued practical use of these three clinical terms, and to encourage efforts at drug discovery that target the mechanisms of neurodegeneration shared by these disorders of alpha-synuclein metabolism. We concluded that the differing temporal sequence of symptoms and clinical features of PDD and DLB justify distinguishing these disorders. However, a single Lewy body disorder model was deemed more useful for studying disease pathogenesis because abnormal neuronal alpha-synuclein inclusions are the defining pathologic process common to both PDD and DLB. There was consensus that improved understanding of the pathobiology of alpha-synuclein should be a major focus of efforts to develop new disease-modifying therapies for these disorders. The group agreed on four important priorities: 1) continued communication between experts who specialize in PDD or DLB; 2) initiation of prospective validation studies with autopsy confirmation of DLB and PDD; 3) development of practical biomarkers for alpha-synuclein pathologies; 4) accelerated efforts to find more effective treatments for these diseases.

Safety of rasagiline in elderly patients with Parkinson disease

The authors examined age effects on adverse events from two randomized, controlled trials of rasagiline, comparing younger (younger than 70 years) and older (70 years and older) subjects. Older patients were more prone to serious adverse effects than younger patients, but there was no statistical interaction between age and rasagiline exposure. This absence of an age-rasagiline interaction suggests that rasagiline does not require special safety precautions for elderly subjects with Parkinson disease.

What's new? Clinical progression and staging of Parkinson's disease

Several new advances facilitate current understanding of the progression of Parkinson's disease. The application of statistical modeling techniques has helped to estimate rates of clinical decline in the context of symptomatic interventions. These approaches may allow a new means for testing neuroprotection effects even when patients are on dopaminergic treatment. Further, the development of new rating scales, specifically the Movement Disorder Society-initiated revision of the Unified Parkinson's Disease Rating Scale has capitalized on a greater clinical appreciation of non-motor elements of Parkinson's disease. Finally, adaptations of new technologies that are computer-based and enable data transmission from at-home environments allow researchers to capture disease impairment and disability with potentially greater precision and much more frequently than permissible in a hospital clinic or practice setting.

Diagnosis and management of dementia with Lewy bodies: third report of the DLB Consortium

The dementia with Lewy bodies (DLB) Consortium has revised criteria for the clinical and pathologic diagnosis of DLB incorporating new information about the core clinical features and suggesting improved methods to assess them. REM sleep behavior disorder, severe neuroleptic sensitivity, and reduced striatal dopamine transporter activity on functional neuroimaging are given greater diagnostic weighting as features suggestive of a DLB diagnosis. The 1-year rule distinguishing between DLB and Parkinson disease with dementia may be difficult to apply in clinical settings and in such cases the term most appropriate to each individual patient should be used. Generic terms such as Lewy body (LB) disease are often helpful. The authors propose a new scheme for the pathologic assessment of LBs and Lewy neurites (LN) using alpha-synuclein immunohistochemistry and semiquantitative grading of lesion density, with the pattern of regional involvement being more important than total LB count. The new criteria take into account both Lewy-related and Alzheimer disease (AD)-type pathology to allocate a probability that these are associated with the clinical DLB syndrome. Finally, the authors suggest patient management guidelines including the need for accurate diagnosis, a target symptom approach, and use of appropriate outcome measures. There is limited evidence about specific interventions but available data suggest only a partial response of motor symptoms to levodopa: severe sensitivity to typical and atypical antipsychotics in approximately 50%, and improvements in attention, visual hallucinations, and sleep disorders with cholinesterase inhibitors.

Altered cortical visual processing in PD with hallucinations: an fMRI study

OBJECTIVE

To compare fMRI activation during two visual stimulation paradigms in Parkinson disease (PD) subjects with chronic visual hallucinations vs PD patients who had never hallucinated.

METHODS

Twelve pairs of PD subjects, matched for age, PD duration, and dopaminergic drug exposure duration, participated in this study. The authors examined group differences in activation during stroboscopic (flashing) vs no visual stimulation and kinematic (apparent motion) vs stationary visual stimulation.

RESULTS

During stroboscopic stimulation, non-hallucinating PD subjects showed significantly greater activation in the parietal lobe and cingulate gyrus compared to hallucinating PD subjects. In contrast, the hallucinating subjects showed significantly greater activation in the inferior frontal gyrus and the caudate nucleus. During kinematic stimulation, non-hallucinating PD subjects showed significantly greater activation in area V5/MT, parietal lobe, and cingulate gyrus compared to hallucinating PD subjects. Hallucinating PD subjects showed significantly greater activation in the superior frontal gyrus.

CONCLUSIONS

PD patients with chronic visual hallucinations respond to visual stimuli with greater frontal and subcortical activation and less visual cortical activation than non-hallucinating PD subjects. Shifting visual circuitry from posterior to anterior regions associated primarily with attention processes suggests altered network organization may play a role in the pathophysiology of visual hallucinations in PD.

Apolipoprotein E controls the risk and age at onset of Parkinson disease

BACKGROUND

Similarities between Alzheimer disease (AD) and Parkinson disease (PD) suggest a possible role for apolipoprotein E (APOE) in PD. Most previous studies seeking to establish such a link used case-control datasets and results have been inconsistent.

OBJECTIVE

To investigate APOE's role in PD using family-based association analyses.

METHODS

APOE functional polymorphisms were genotyped for 658 PD affected families, including 282 multiplex and 376 singleton families. The pedigree disequilibrium test (PDT) and the genotype-PDT were used to test the risk effect of APOE. The Monks-Kaplan test was used to evaluate the effect of APOE on age at onset of PD.

RESULTS

APOE was significantly associated with risk of developing PD. Stratified analysis revealed that APOE was most strongly associated with families with a positive PD family history (global p = 0.003). Like AD, the APOE-4 allele increases disease risk while the APOE-3 allele decreases risk. We detected a positive association of APOE-3 (p = 0.019) and a negative association of APOE-4 (p = 0.015) with age at onset in PD.

CONCLUSIONS

The APOE-4 allele increases risk and decreases age at onset of PD, an association that may not be dependent upon cognitive impairment.

Objective assessments of longitudinal outcome in Gilles de la Tourette's syndrome

OBJECTIVE

To define the long-term outcome in Gilles de la Tourette syndrome (GTS) using objective rating measures.

BACKGROUND

Previous historical studies suggest spontaneous improvement of tic symptoms after adolescence, but objective longitudinal data are limited.

METHODS

The authors reviewed all videotapes in their database (1978 through 1991) of children with GTS (ages 8 to 14) who were seen in their tertiary care movement disorder center and underwent a standardized 5-minute filming protocol (n = 56). Through multiple contact methods, they successfully located 36 of these patients, who are now adults (age >20 years), and recruited 31 (28 men and 3 women) to volunteer for a second videotape and in-person assessment. A blinded rater evaluated the 62 tapes and rated five tic domains: body areas involved, motor and phonic tic frequency, and motor and phonic tic severity. Using standardized GTS videotape rating scale and Wilcoxon signed-rank tests with Bonferroni correction for multiple comparisons, the authors compared the two videotapes for each tic domain as well as the composite tic disability score.

RESULTS

Ninety percent of adult patients still had tics. Adult patients who considered themselves tic-free were often inaccurate in their self-assessment: 50% had objective evidence of tics. Mean objective tic disability diminished in comparison to childhood (mean composite tic disability score childhood 9.58 vs adulthood 7.52, p = 0.014). All domains improved by adulthood, and significant improvements occurred in motor tic severity (p = 0.008). The improvements in tic disability did not relate to medication use, as only 13% of adults received medications for tics, compared with 81% of children.

CONCLUSIONS

In GTS syndrome, tics objectively improve over time but most adults have persistent tics.

Longitudinal outcome of Parkinson's disease patients with psychosis

OBJECTIVES

To examine the long-term outcome of PD patients with psychosis requiring antipsychotic therapy; to explore predictors of mortality, nursing home placement, dementia, and persistent psychosis; and to compare outcomes of those with persistent psychosis vs those whose psychosis resolved.

METHODS

Baseline data available from 59 patients enrolled in the PSYCLOPS (PSychosis and CLOzapine in PD Study) trial included age, age at onset of PD, duration of PD and psychosis, character of psychosis, medications, living setting, and scores for Mini-Mental State Examination (MMSE), Unified Parkinson's Disease Rating Scale, Hoehn and Yahr Scale, and Clinical Global Impression Scale. Longitudinal data were collected 26 months later regarding four outcomes: death, nursing home placement, diagnosis of dementia, and persistence of psychosis. Logistic regression was used to explore whether any baseline characteristics were associated with an increased likelihood of one of these outcomes.

RESULTS

At baseline, 56% of patients had an MMSE score of <25, 12% were in a nursing home, 95% had hallucinations, and 60% had paranoia. On follow-up, 25% were dead, nursing home placement occurred in 42%, psychosis was persistent in 69%, and dementia was diagnosed in 68%. Select baseline characteristics predicted individual outcomes: Nursing home placement was associated with the presence of paranoia and older age; persistent psychosis was associated with younger age at onset of PD and longer disease duration; dementia was associated with older age at PD onset and lower initial MMSE score; no characteristics predicted death. Whether psychosis persisted or not had no significant effect on the development of the other three outcomes. The prevalence of hallucinations at follow-up was not different between groups currently receiving antipsychotics vs those on no treatment.

CONCLUSIONS

Psychosis in PD requiring antipsychotic therapy is frequently associated with death, nursing home placement, development and progression of dementia, and persistence of psychosis. Still, it appears the prognosis has improved with atypical antipsychotic therapy based on the finding that 28% of NH patients died within 2 years compared with 100% in a previous study done prior to availability of this treatment.

[Progressive supranuclear palsy]

Progressive supranuclear palsy (PSP) is a parkinsonian syndrome 20 to 30 times less common than Parkinson's disease. PSP and Parkinson's disease share certain symptoms, but also present distinctive features. The histopathological features of PSP are highly specific and enable certain diagnosis. Since no biological marker has been identified, clinical signs must be recognized to establish the probability of the histopathological diagnosis. The NINDS program distinguishes two categories: probable PSP and possible PSP with distinctive characteristics. The sensitivity of probable PSP is only 50 p. 100, but the specificity and positive predictive value are 100 p. cent. For possible PSP, specificity is 83 p. cent (93 p. cent if diagnostic errors are included) and the positive predictive value is lower (83 p. cent). Although there number is smaller, patients with probable PSP are retained for research on new treatments. There have been few, non-controlled therapeutic trials in PSP. No drug and no surgical procedure has been demonstrated to be highly effective. Neuroprotection is a new avenue of research which requires knowledge of the natural course of clinical incapacity. A longitudinal study of 50 patients with probable PSP has provided mid-term results on symptom onset and on the development of three key signs, detected with the standard Unified Parkinson's Disease Rating Scale: incapacity to stand alone without help, incapacity to speak intelligently, incapacity to eat (tube feeding). The Kaplan-Meier curves show that the mean duration of the disease before development of one of these signs is 50 months. Research on protocols designed to stop disease progression should be centered on this period.

Genetic polymorphisms of the N-acetyltransferase genes and risk of Parkinson's disease

Recently, the authors demonstrated linkage in idiopathic PD to a region on chromosome 8p that contains the N-acetyltransferase genes, NAT1 and NAT2. The authors examined NAT1 and NAT2 for association with PD using family-based association methods and single nucleotide polymorphisms (SNPs). The authors did not find evidence for association with increased risk for PD between any individual NAT1 or NAT2 SNP or acetylation haplotype (N = 397 families, 1,580 individuals).

Gender and pramipexole effects on levodopa pharmacokinetics and pharmacodynamics

The authors studied the pharmacokinetics of levodopa (LD) with and without pramipexole (PPX) in men and postmenopausal women with PD. Patients on stable dose of carbidopa/LD were randomized to receive escalating doses of placebo or PPX over 7 weeks. LD and PPX pharmacokinetics were performed after a single test dose 25/100 of carbidopa/LD, before initiation of PPX or placebo, at 1.5 mg/d and 4.5 mg/d of PPX or placebo. Compared to men, women had greater LD bioavailability. PPX did not alter LD bioavailability, and PPX pharmacokinetics were equivalent in men and women.

Parkin mutations in a patient with hemiparkinsonism-hemiatrophy: a clinical-genetic and PET study

The authors describe a 37-year-old woman with early-onset hemiparkinsonism (HP) and ipsilateral body hemiatrophy (HA). Genetic analysis revealed a missense mutation (Arg275Trp) and a duplication of exon 7 of parkin. The complementary metabolic and receptor pattern of PET ligands corresponded to that typically found in idiopathic PD, although tracer binding asymmetry was lacking. Parkin mutations should be considered in HPHA, particularly when there is a younger age at onset and dystonia is an early sign.

Prospective longitudinal assessment of hallucinations in Parkinson's disease

OBJECTIVE

To monitor the evolution of hallucinations over 4 years in a stratified sample of patients with PD.

METHODS

Using a modified version of the Unified PD Rating Scale (UPDRS) Thought Disorder question, the authors stratified patients into five baseline behavioral groups. They recruited up to 20 patients for each group to participate in sequential interviews (Rush Hallucination Inventory) at baseline and 6, 18, and 48 months. UPDRS motor examinations and Mini Mental State Examinations (MMSE) were obtained at baseline and 48 months. Data were analyzed with Wilcoxon rank sum tests, Mantel-Haenszel tests, and Spearman correlations. To determine features that influenced the new development of hallucinations, a cumulative logit regression model of hallucination severity over time was fit using generalized estimating equations.

RESULTS

Based on the design stratification, 60 patients had no hallucinations at baseline (20 with no behavioral problems, 20 with sleep fragmentation, 20 with altered dream phenomena). Twenty-nine patients had hallucinations (20 with retained insight and 9 with loss of insight). At 48 months, the authors could account for all but two subjects (98% retrieval). In 4 years, the presence of hallucinations increased (33% at baseline, 44% at 18 months, and 63% at 48 months, p < 0.0001). The presence of frequent hallucinations (at least three times weekly) also increased (p = 0.0002). Having hallucinations at baseline or at any given assessment was a strong predictor at all follow-up evaluations of continued hallucinations (p < 0.0001). Hallucinations were not associated with increased mortality (chi(2) = 0.59, df (1), p = 0.47). Among the 60 subjects without hallucinations at baseline, time was the only significant factor influencing the development of hallucination over 48 months. Baseline age, PD duration, sex, medications, and UPDRS or MMSE scores did not influence the incidence of hallucinations.

CONCLUSIONS

This prospective, longitudinal study documents the persistent and progressive nature of hallucinations in PD patients on chronic dopaminergic therapy. The consistent association of hallucinations with combined levodopa/agonist therapy suggests that these drugs may play a role in the pathophysiology of hallucinations.

The Brown-Séquard and S. Weir Mitchell letters

The two prominent nineteenth-century neurophysiologists/neurologists C.E. Brown-Séquard and S.W. Mitchell maintained an active correspondence during their careers. These letters, never before studied as a unit, provide insight into the men's close collegial association in several domains. They shared camaraderie as pioneer physiologists who tried to bring experimental discoveries from the laboratory to the clinical setting. They critiqued each other's research and facilitated its publication in journals over which they had influence. Through letters of recommendation, they also helped foster each other's local careers. In a period of transition in neuroscience from a traditional anatomic focus to the emerging predominance of neurophysiology and neuropharmacology, their correspondence documents the views of two late nineteenth-century leaders in science and international academic medicine.

Complete genomic screen in Parkinson disease: evidence for multiple genes

CONTEXT

The relative contribution of genes vs environment in idiopathic Parkinson disease (PD) is controversial. Although genetic studies have identified 2 genes in which mutations cause rare single-gene variants of PD and observational studies have suggested a genetic component, twin studies have suggested that little genetic contribution exists in the common forms of PD.

OBJECTIVE

To identify genetic risk factors for idiopathic PD.

DESIGN, SETTING, AND PARTICIPANTS

Genetic linkage study conducted 1995-2000 in which a complete genomic screen (n = 344 markers) was performed in 174 families with multiple individuals diagnosed as having idiopathic PD, identified through probands in 13 clinic populations in the continental United States and Australia. A total of 870 family members were studied: 378 diagnosed as having PD, 379 unaffected by PD, and 113 with unclear status.

MAIN OUTCOME MEASURES

Logarithm of odds (lod) scores generated from parametric and nonparametric genetic linkage analysis.

RESULTS

Two-point parametric maximum parametric lod score (MLOD) and multipoint nonparametric lod score (LOD) linkage analysis detected significant evidence for linkage to 5 distinct chromosomal regions: chromosome 6 in the parkin gene (MLOD = 5.07; LOD = 5.47) in families with at least 1 individual with PD onset at younger than 40 years, chromosomes 17q (MLOD = 2.28; LOD = 2.62), 8p (MLOD = 2.01; LOD = 2.22), and 5q (MLOD = 2.39; LOD = 1.50) overall and in families with late-onset PD, and chromosome 9q (MLOD = 1.52; LOD = 2.59) in families with both levodopa-responsive and levodopa-nonresponsive patients.

CONCLUSIONS

Our data suggest that the parkin gene is important in early-onset PD and that multiple genetic factors may be important in the development of idiopathic late-onset PD.

Association of single-nucleotide polymorphisms of the tau gene with late-onset Parkinson disease

CONTEXT

The human tau gene, which promotes assembly of neuronal microtubules, has been associated with several rare neurologic diseases that clinically include parkinsonian features. We recently observed linkage in idiopathic Parkinson disease (PD) to a region on chromosome 17q21 that contains the tau gene. These factors make tau a good candidate for investigation as a susceptibility gene for idiopathic PD, the most common form of the disease.

OBJECTIVE

To investigate whether the tau gene is involved in idiopathic PD.

DESIGN, SETTING, AND PARTICIPANTS

Among a sample of 1056 individuals from 235 families selected from 13 clinical centers in the United States and Australia and from a family ascertainment core center, we tested 5 single-nucleotide polymorphisms (SNPs) within the tau gene for association with PD, using family-based tests of association. Both affected (n = 426) and unaffected (n = 579) family members were included; 51 individuals had unclear PD status. Analyses were conducted to test individual SNPs and SNP haplotypes within the tau gene.

MAIN OUTCOME MEASURE

Family-based tests of association, calculated using asymptotic distributions.

RESULTS

Analysis of association between the SNPs and PD yielded significant evidence of association for 3 of the 5 SNPs tested: SNP 3, P =.03; SNP 9i, P =.04; and SNP 11, P =.04. The 2 other SNPs did not show evidence of significant association (SNP 9ii, P =.11, and SNP 9iii, P =.87). Strong evidence of association was found with haplotype analysis, with a positive association with one haplotype (P =.009) and a negative association with another haplotype (P =.007). Substantial linkage disequilibrium (P<.001) was detected between 4 of the 5 SNPs (SNPs 3, 9i, 9ii, and 11).

CONCLUSIONS

This integrated approach of genetic linkage and positional association analyses implicates tau as a susceptibility gene for idiopathic PD.

Early morning off-medication dyskinesias, dystonia, and choreic subtypes

BACKGROUND

Abnormal involuntary movements (dyskinesias) are common in patients with Parkinson disease (PD) as a consequence of the disease and dopaminergic replacement therapy. Early morning off-medication choreic dyskinesias have been recently reported after fetal dopaminergic cell transplantations in patients with advanced PD.

OBJECTIVE

To determine the frequency and severity of the early morning off-medication dyskinesias in consecutive patients with advanced PD and an insufficient response to medical management before they undergo neurosurgery.

METHODS

Consecutive patients with advanced idiopathic PD were examined and videotaped before undergoing neurosurgery that included pallidotomy, fetal transplantation, or deep brain stimulation. The examination took place in the morning in the practically defined off state, at least 12 hours after the last dose of dopaminergic drugs. Parkinson disease was characterized using the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr stage. Dyskinesias were rated with the Abnormal Involuntary Movements Scale and the Rush Dyskinesia Rating Scale. Patients' characteristics and medications were compared using the Wilcoxon rank sum and the Fisher exact tests.

RESULTS

Of 68 consecutive patients (44 [65%] men and 24 [35%] women), 11 (16%) had early morning off-medication dyskinesia, with a 95% upper confidence limit of 24%. Focal dystonia was the most common off-medication dyskinesia, and occurred in 10 patients (15%), with a 95% upper confidence limit of 22%; and off-choreic dyskinesia occurred in 1 patient (1.5%), with a 95% upper confidence limit of 4%. There was no difference in PD medications between the patients with and those without dyskinesias.

CONCLUSIONS

The most common form of off-medication dyskinesia seen in patients with advanced PD is dystonia. Early morning off-medication choreic dyskinesias are rare but do occur in patients with advanced PD before surgical intervention. The presence and type of off-medication dyskinesias should be monitored in clinical and surgical studies in patients with PD as part of the safety and evaluation of clinical benefits.

Poor Beard!! Charcot's internationalization of neurasthenia, the "American disease"

OBJECTIVE

To analyze the role of the seminal 19th-century neurologist, Jean-Martin Charcot, in the internationalization of neurasthenia, previously known as "the American disease."

BACKGROUND

The New York neurologist, George Beard, first described neurasthenia in 1869 and considered it a disorder related to the particular stress of modern civilization, most typified in the United States.

METHODS

Charcot's personal files on neurasthenia from the Bibliothèque Charcot, Salpêtrière Hospital, Paris, were studied and his teaching lessons and lectures were examined.

RESULTS

Charcot presented numerous cases of neurasthenia, always crediting Beard with the original name and description. Calling Beard's 1880 work a "remarkable monograph," Charcot emphasized that patients with neurasthenia also comprised the bulk of his own private practice. Focusing on the signs of sexual impotency, fatigue, and a tight band of pressure around the head, Charcot categorically distinguished patients with neurasthenica from patients with hysteria. Like Beard, Charcot concluded that the origin of neurasthenia was psychological stress and felt the European society also fostered the environment to precipitate the disease. Charcot adamantly opposed extrapolations that called for early childhood educational reforms to reduce current classroom stress. Charcot sympathized more with the treating physician than the patient, calling neurasthenics insufferable (insupportables). On the front sheet of his neurasthenia file, he wrote in large script, "Poor Beard!!"

CONCLUSION

By emphasizing the prevalence of neurasthenia and extending Beard's observations, Charcot internationally legitimized the new diagnosis. Adding neurasthenia to the other neurologic descriptions from the United States by Hammond, Mitchell, and Dana, Charcot helped to foster the recognition of the American Neurologic School.

Home alone: methods to maximize tic expression for objective videotape assessments in Gilles de la Tourette syndrome

Our objective was to test whether at-home videotapes yield enhanced information on tics compared to office-based videotapes and a patient questionnaire on the current anatomical distribution of tics. Ten subjects with Gilles de la Tourette syndrome (age range 8-49 years) who were seen for initial evaluation completed a check list of anatomical areas currently affected with tics, and underwent a videotape examination according to the Rush Videotape Protocol. Each patient/family conducted the same protocol at home at the same time of day within 48 hours. We rated two tapes in random order using the modified published scoring method for the Rush Video-based Tic Rating Scale. Two environments were compared, the doctor's office and at home, with videotapes taken in three conditions: patient engaged in relaxed conversation, patient quietly seated with filmer in the room, and patient quietly seated alone in the room. Data were analyzed using a 2-factor repeated-measures analysis of variance (ANOVA), followed by Wilcoxon signed rank tests. All patients provided excellent quality videotapes that could be scored without difficulty. Environment (office vs. home) and Condition (conversation, quiet with observer, quiet and alone) were both highly significant (P < .0001) and did not interact (P = .54). The highest tic scores for total tic impairment occurred at home with the patient alone (mean score 14.5), and the lowest yield occurred in the office with an observer present (mean score 5.4), the setting closest to the clinical neurological examination. The Home/Alone video segments revealed tics not otherwise seen. Patient questionnaires on body regions recorded more areas than observed in the office videotape, but patients were unaware of several tics captured on the Home/Alone segment. Patients can produce videotapes for objective tic assessments. Because at-home videotapes consistently yield higher tic expressions than in-office films and capture tics that are not appreciated by patients, this methodology is well-suited for enhanced retrieval of objective data on tic expression.

Ballistic-choreic movements as the presenting feature of renal cancer

BACKGROUND

The paraneoplastic syndromes can involve multiple areas of the central nervous system and result in a variety of neurological symptoms. To our knowledge, severe, rapidly progressive, and drug-resistant ballistic-choreic movements have not been previously described as the presenting feature of renal cell carcinoma.

PATIENT AND METHODS

A previously healthy 55-year-old man developed limb ballismus and involuntary choreic movements of his face over several weeks. Extensive laboratory, diagnostic, and radiographic studies failed to reveal a cause, until an abnormality on a chest x-ray film prompted a search for a primary neoplasm and a final diagnosis of renal cell carcinoma. High doses of medications traditionally used to treat choreic disorders had no effect on the abnormal movements. A biopsy specimen of the basal ganglia showed focal encephalitic changes but no malignant neoplasm.

CONCLUSIONS

Whereas prior cases of paraneoplastic syndromes with chorea have been reported in other forms of cancer, our case was significant because, to our knowledge, renal cell carcinoma has not been previously reported in association with this syndrome. Furthermore, the chorea was categorically resistant to pharmacological treatment, and the movement disorder was the initial and only focal neurological feature of the primary illness.

Genetic variation analysis in parkinson disease patients with and without hallucinations: case-control study

BACKGROUND

Visual hallucinations in Parkinson disease (PD) occur in approximately one third of patients treated long-term with dopaminergic medications. In Alzheimer disease, hallucinations and psychosis have been linked to increased representations of B2/B2 homozyogotes for the dopamine receptor gene DRD1 and 1/1 or 2/2 homozygotes for DRD3. In addition, a previous study of PD patients with and without hallucinations did not show differences in D2 and D3 polymorphisms, although careful case-control matching was not performed. Another study linked the apolipoprotein E4 (APOE4) allele to hallucinations in PD.

OBJECTIVE

To determine whether the frequency of dopamine receptor genetic variants and APOE alleles in patients with PD with and without chronic visual hallucinations resembles the pattern previously documented in patients with Alzheimer disease.

METHODS

We conducted a case-control study of 44 patients with PD and chronic hallucinations and 44 patients with PD who had never hallucinated. Cases and controls were matched for current age and medications. DNA was isolated from blood samples and assayed for DRD1, DRD2, DRD3, DRD4, and APOE polymorphisms. Receptor polymorphisms were genotyped by polymerase chain reaction. Genotypes in hallucinators and nonhallucinators were compared using Mantel-Haenszel tests stratified by pair, and allele frequencies were compared using Wilcoxon signed rank tests within pairs.

RESULTS

Neither D1 receptor genotypes (P =.37) nor allele frequencies (P =.38) differed, and there was no predominance of B2/B2 homozygotes in the hallucinators. For D3, there was a higher frequency of allele 2 (P =.047), but there was no significant difference between frequencies of homozygotes vs heterozygotes (P =.39) as reported in Alzheimer disease. D4 receptor distribution of long and short alleles did not differ between the 2 patient groups, and there were too few C alleles (3 of 86) to compare D2 allele genotypes or frequencies. For APOE, 12 cases and 12 controls carried E4 alleles (P>.99).

CONCLUSIONS

With careful case-control matching, visual hallucinations in PD are not associated with the pattern seen for patients with Alzheimer disease and visual hallucinations. Furthermore, there was no association between hallucinations and APOE. Similar methods using larger sample sizes might be adapted to test whether specific dopaminergic receptor genetic variants are associated with visual hallucinations in PD. Based on our data, the DRD3 allele 2 may merit further study.

Treatment of tremor and dystonia

Treatment of movement disorders has expanded beyond traditional therapies with oral medications to include injection of drugs like botulinum toxin and the use of surgical interventions in cases that do not respond to medical therapy. This article provides an overview to the diagnosis and treatment of tremor and dystonia. The distinguishing features of rest, postural, and kinectic tremor are detailed with medical and surgical modalities for treatment. A discussion of idiopathic and secondary dystonia with focus on diagnosis and medical and surgical treatments encompasses the second part of the article.

Induction by dopamine D1 receptor agonist ABT-431 of dyskinesia similar to levodopa in patients with Parkinson disease

BACKGROUND

Dyskinesias are a frequent adverse effect of long-term levodopa therapy. The relative contribution of dopamine D(1) and D(2) receptor function to the pathophysiology of levodopa-induced dyskinesias remains a matter of controversy.

OBJECTIVE

To establish whether a selective D(1) dopamine agonist induces more or less dyskinesia than levodopa in primed dyskinetic patients with Parkinson disease.

METHODS

We studied ABT-431, the prodrug of a fully selective D(1) agonist, in 20 subjects with advanced Parkinson disease and a fluctuating response to levodopa complicated by dyskinesias. Eight patients were studied in a double-blind, randomized design (French centers); 12, in an open, randomized design (US centers). We assessed and compared the antiparkinsonian (Unified Parkinson's Disease Rating Scale) and dyskinetic (response induced by an acute challenge of a suprathreshold dose of levodopa and by 4 different ascending doses (5, 10, 20, and 40 mg) of ABT-431 during the 6 hours after the challenge.

RESULTS

The separate analysis of the double-blind and open data led to the same findings, ie, the antiparkinsonian and dyskinetic responses induced by ABT-431 were dose related. At the most effective doses (20 and 40 mg), ABT-431 exhibited similar antiparkinsonian benefit and produced similar dyskinesias as levodopa.

CONCLUSION

Dopamine D(1) agonists can induce a full antiparkinsonian response but do not support previous hypotheses suggesting that D(1) agonists are more or less likely to produce dyskinesias than levodopa.

Estrogen supplementation in the posthypoxic myoclonus rat model

The objective of the study was to investigate the effects of estrogen on severity and duration of myoclonus in the rat cardiac arrest model of posthypoxic myoclonus. Female sex hormones affect a variety of movement disorders and alter dopaminergic and serotonergic pharmacology. Although women represented three-fourths of patients from the original report of Lance and Adams and 80% of the largest published series, the impact of estrogens on myoclonus has never been studied. Twelve previously ovariectomized female rats underwent 8 minutes of mechanically induced cardiac arrest and were resuscitated according to a standardized protocol. On the same day, they were randomly assigned to subcutaneous treatment with a 21-day, 0.5-mg, 17 beta-estradiol or matching placebo pellet. Animals were tested daily with 7 sets of 45 auditory stimuli for 10 days, and myoclonus scores were obtained using a 5-point interval scale. Comparisons were based on two-sample Wilcoxon rank-sum tests. Estrogen treatment significantly enhanced myoclonus intensity and duration: mean peak myoclonus score, 210.2 +/- 18.0 versus 180 +/- 28.5 (p = 0.031); mean number of days above baseline, 9.2 +/- 0.4 versus 5.7 +/- 2.3 (p = 0.004); mean score on day 10, 90.7 +/- 38.7 versus 27.0 +/- 20.6 (p = 0.016). All estrogen-treated animals were above baseline on day 10 compared with none in the placebo group. Estrogen enhances and prolongs posthypoxic myoclonus, suggesting that female gender and estrogen status may play a pivotal role as a risk factor for human posthypoxic myoclonus.