A controlled trial of antidepressants in patients with Parkinson disease and depression

BACKGROUND

Parkinson disease (PD) is a common neurodegenerative disease affecting up to 1 million individuals in the United States. Depression affects up to 50% of these patients and is associated with a variety of poor outcomes for patients and their families. Despite this, there are few evidence-based data to guide clinical care.

METHODS

An NIH-funded, randomized, controlled trial of paroxetine CR, nortriptyline, and placebo in 52 patients with PD and depression. The primary outcomes were the change in the Hamilton Depression Rating Scale (HAM-D) and the percentage of depression responders at 8 weeks.

RESULTS

Nortriptyline was superior to placebo for the change in HAM-D (p < 0.002); paroxetine CR was not. There was a trend for superiority of nortriptyline over paroxetine CR at 8 weeks (p < 0.079). Response rates favored nortriptyline (p = 0.024): nortriptyline 53%, paroxetine CR 11%, placebo 24%. In planned contrasts of response rates, nortriptyline was superior to paroxetine CR (p = 0.034). Nortriptyline was also superior to placebo in many of the secondary outcomes, including sleep, anxiety, and social functioning, while paroxetine CR was not. Both active drug treatments were well tolerated.

CONCLUSIONS

Though relatively modest in size, this is the largest placebo-controlled trial done to date in patients with Parkinson disease (PD) and depression. Nortriptyline was efficacious in the treatment of depression and paroxetine CR was not. When compared directly, nortriptyline produced significantly more responders than did paroxetine CR. The trial suggests that depression in patients with PD is responsive to treatment and raises questions about the relative efficacy of dual reuptake inhibitors and selective serotonin reuptake inhibitors.

Haplotypes and gene expression implicate the MAPT region for Parkinson disease: the GenePD Study

BACKGROUND

Microtubule-associated protein tau (MAPT) has been associated with several neurodegenerative disorders including forms of parkinsonism and Parkinson disease (PD). We evaluated the association of the MAPT region with PD in a large cohort of familial PD cases recruited by the GenePD Study. In addition, postmortem brain samples from patients with PD and neurologically normal controls were used to evaluate whether the expression of the 3-repeat and 4-repeat isoforms of MAPT, and neighboring genes Saitohin (STH) and KIAA1267, are altered in PD cerebellum.

METHODS

Twenty-one single-nucleotide polymorphisms (SNPs) in the region of MAPT on chromosome 17q21 were genotyped in the GenePD Study. Single SNPs and haplotypes, including the H1 haplotype, were evaluated for association to PD. Relative quantification of gene expression was performed using real-time RT-PCR.

RESULTS

After adjusting for multiple comparisons, SNP rs1800547 was significantly associated with PD affection. While the H1 haplotype was associated with a significantly increased risk for PD, a novel H1 subhaplotype was identified that predicted a greater increased risk for PD. The expression of 4-repeat MAPT, STH, and KIAA1267 was significantly increased in PD brains relative to controls. No difference in expression was observed for 3-repeat MAPT.

CONCLUSIONS

This study supports a role for MAPT in the pathogenesis of familial and idiopathic Parkinson disease (PD). Interestingly, the results of the gene expression studies suggest that other genes in the vicinity of MAPT, specifically STH and KIAA1267, may also have a role in PD and suggest complex effects for the genes in this region on PD risk.

Herbicide exposure modifies GSTP1 haplotype association to Parkinson onset age: the GenePD Study

BACKGROUND

Polymorphisms in the glutathione S-transferase pi gene (GSTP1), encoding GSTP1-1, a detoxification enzyme, may increase the risk of Parkinson disease (PD) with exposure to pesticides. Using the GenePD Study sample of familial PD cases, we explored whether GSTP1 polymorphisms were associated with the age at onset of PD symptoms and whether that relation was modified by exposure to herbicides.

METHODS

Seven single-nucleotide polymorphisms (SNPs) were genotyped and tested for association with PD onset age in men in three strata: no exposure to herbicides, residential exposure to herbicides, and occupational exposure to herbicides. Haplotypes were similarly evaluated in stratified analyses.

RESULTS

Three SNPs were associated with PD onset age in the group of men occupationally exposed to herbicides. Three additional SNPs had significant trends for the association of PD onset age across the herbicide exposure groups. Haplotype results also provided evidence that the relation between GSTP1 and onset age is modified by herbicide exposure. One haplotype was associated with an approximately 8-years-earlier onset in the occupationally exposed group and a 2.8-years-later onset in the nonexposed group.

CONCLUSIONS

Herbicide exposure may be an effect modifier of the relation between glutathione S-transferase pi gene polymorphisms and onset age in familial PD.

BDNF genetic variants are associated with onset age of familial Parkinson disease: GenePD Study

Brain-derived neurotrophic factor (BDNF) stimulates neuronal growth and protects nigral dopamine neurons in animal models of Parkinson disease (PD). Therefore, BDNF is a candidate gene for PD. The authors investigated five single-nucleotide polymorphisms in 597 cases of familial PD. Homozygosity for the rare allele of the functional BDNF G196A (Val66Met) variant was associated with a 5.3-year older onset age (p = 0.0001). These findings suggest that BDNF may influence PD onset age.

Absence of previously reported variants in the SCNA (G88C and G209A), NR4A2 (T291D and T245G) and the DJ-1 (T497C) genes in familial Parkinson's disease from the GenePD study

Parkinson's disease (PD) is a neurodegenerative disorder in which relatives of the probands are affected approximately 4 times as frequently as relatives of control subjects. Several genes have been implicated as genetic risk factors for PD. We investigated the presence of six reported genetic variations in the SCNA, NR4A2, and DJ-1 genes in 292 cases of familial Parkinson's disease from the GenePD study. None of the variants were found in the GenePD families. Our results suggest that other variants or genes account for the familial risk of PD within the GenePD study.

A haplotype at the PARK3 locus influences onset age for Parkinson's disease: the GenePD study

OBJECTIVE

To identify a haplotype influencing onset age for Parkinson's disease (PD) in the PARK3 region on chromosome 2p13.

METHODS

Single nucleotide polymorphisms (SNP) spanning 2.2 Mb and located in or near potential candidate genes were used to fine map the PARK3 region in 527 patients with familial PD, from 264 families.

RESULTS

TT homozygotes for rs1876487 (G/T) had a 7.4-year younger mean age at onset (p = 0.005) compared to patients with GT and GG genotypes. Furthermore, SNP flanking the sepiapterin reductase (7,8-dihydrobiopterin: NADP+ oxidoreductase) (SPR) gene, rs1876487 (p = 0.02) and rs1150500 (p = 0.04), were associated with younger onset age among persons who did not carry the 174 allele of D2S1394. The SPR gene is implicated in dopamine synthesis. Haplotype analysis of three SNP-rs2421095, rs1876487, rs1561244-revealed an association with onset age (p = 0.023) and a haplotype of A-T-G alleles was associated with younger onset for PD (p = 0.005).

CONCLUSIONS

A haplotype at the PARK3 locus, harboring the SPR gene, is associated with onset age of PD. This may suggest a role for the SPR gene in modifying the age at onset of PD.

Epidemiologic study of 203 sibling pairs with Parkinson's disease: the GenePD study

OBJECTIVE

To examine patterns of familial aggregation and factors influencing onset age in a sample of siblings with PD.

METHODS

Sibling pairs (n = 203) with PD were collected as part of the GenePD study. Standardized family history, medical history, and risk factor data were collected and analyzed.

RESULTS

The mean age at onset was 61.4 years and did not differ according to sex, exposure to coffee, alcohol, or pesticides. Head trauma was associated with younger onset (p = 0.03) and multivitamin use with later onset (p = 0.007). Age at onset correlation between sibling pairs was significant (r = 0.56, p = 0.001) and was larger than the correlation in year of onset (r = 0.29). The mean difference in onset age between siblings was 8.7 years (range, 0 to 30 years). Female sex was associated with increased frequency of relatives with PD. The frequency of affected parents (7.0%) and siblings (5.1%) was increased when compared with frequency in spouses (2.0%).

CONCLUSIONS

The greater similarity for age at onset than for year of onset in sibling pairs with PD, together with increased risk for biological relatives over spouses of cases, supports a genetic component for PD. Risk to siblings in this series is increased over that seen in random series of PD cases; however, patients in this sample have similar ages at onset and sex distribution as seen for PD generally. These analyses suggest that factors influencing penetrance are critical to the understanding of this disease.

Genome-wide scan for Parkinson's disease: the GenePD Study

A genome-wide scan for idiopathic PD in a sample of 113 PD-affected sibling pairs is reported. Suggestive evidence for linkage was found for chromosomes 1 (214 cM, lod = 1.20), 9 (136 cM, lod = 1.30), 10 (88 cM, lod = 1.07), and 16 (114 cM, lod = 0.93). The chromosome 9 region overlaps the genes for dopamine beta-hydroxylase and torsion dystonia. Although no strong evidence for linkage was found for any locus, these results may be of value in comparison with similar studies by others.

Lumping and splitting the Parkinson Plus syndromes: dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy, and cortical-basal ganglionic degeneration

The atypical parkinsonian or Parkinson Plus syndromes are often difficult to differentiate from Parkinson's disease and each other. In this article, the clinicopathological characteristics of dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy, and cortical-basal ganglionic degeneration are discussed. These disorders, although clinically distinct, may have more similarities than previously thought, based on modern immunocytochemical techniques and new genetic findings. These intriguing interconnections at a basic molecular level have provided the scientific rationale for lumping these diseases into two groups, the synucleinopathies and the tauopathies.

The tau A0 allele in Parkinson's disease

Parkinson's disease (PD) is primarily an alpha-synucleinopathy, rather than a tauopathy, but there is evidence for an indirect association of tau with the pathogenetic process in PD. We therefore assessed the frequency in PD of the tau A0 allele, a dinucleotide repeat marker that has been associated with a sporadic tauopathy, progressive supranuclear palsy (PSP). We found the A0 allele to comprise 79.2% of 758 alleles from PD patients and 71.2% of 264 control alleles (P = 0.008). We also performed a meta-analysis of three previous reports, two of which failed to produce statistically significant results. Taken together, they also support a PD/A0 allelic association, even after correction for misdiagnosis of PSP as PD (P< 0.001). The A0/A0 genotype frequency in our patients (62.3%) did not differ significantly from that in controls (53.0%, P = 0.062), but the meta-analysis, even after correction for misdiagnosis, showed a significant result, with P = 0.002. The frequency of A0 allele and the A0/A0 genotype were compatible with Hardy-Weinberg equilibrium. The frequency of the A0 allele and the A0/A0 genotype in our patients with familial PD was not significantly greater than in those with sporadic PD. We conclude that the tau protein may play a small role in the pathogenesis of PD and that biochemical characterization of this role may suggest opportunities for PD prophylaxis.

Ten years' experience with enteral levodopa infusions for motor fluctuations in Parkinson's disease

We report our long-term experience using enteral levodopa infusions in 22 patients with Parkinson's disease and severe motor fluctuations. Amelioration of intractable dyskinesias was the most important factor that determined whether patients chose to continue using the infusion pump system. Mechanical and physical problems associated with enteral access were the most common reasons for which patients discontinued pump use. Nearly all patients continued to have dramatically increased on time for the duration of follow up, suggesting that technically less-cumbersome systems that provide continuous dopaminergic stimulation are worthwhile and should be developed.

Pharmacokinetics of continuous-release carbidopa/levodopa

This article reviews the pharmacokinetics of Sinemet CR, a controlled-release (CR) levodopa preparation. The main influences on the kinetic profile are as follows: absorption, which depends on the dissolution characteristics of the tablet, the pattern of gastric emptying, and the rate of uptake in the small intestine; distribution, which is determined by rates of levodopa transport from gut to blood and from blood to brain; and biotransformation, which is affected peripherally by L-aromatic amino acid decarboxylase (LAAAD) and catechol-O-methyl transferase (COMT), and centrally by LAAAD, COMT, and monoamine oxidase. The kinetics of Sinemet CR are limited by rates of absorption (which depend on the dose administered), the conformation of the tablet, and daily variations in the patterns of gastric emptying (influenced by the presence or absence of food). Levodopa must also compete with food-derived amino acids for transport across the gut-blood and blood-brain barriers; this competition effectively limits the drug's rate of distribution. Finally, biotransformation is limited by the activity of LAAAD and COMT in the periphery. Plasma profiles of levodopa after administration of Sinemet CR can vary, depending on the age of the patient and the time of day when the drug is administered. Nevertheless, the pharmacokinetic profile of the preparation has a number of advantages over that of Sinemet, in that it offers a steadier climb to peak plasma concentrations that are less extreme and of greater duration.

Dopaminergic function in familial Parkinson's disease: a clinical and 18F-dopa positron emission tomography study

There is increasing evidence for familial aggregation in Parkinson's disease (PD). It is possible that some asymptomatic relatives of PD patients have subclinical nigral Lewy body pathology and their identification could help determine the true prevalence of the disease. We used 18F-dopa positron emission tomography to investigate nigrostriatal dopaminergic terminal function in asymptomatic members of 7 unrelated kindreds in which at least 2 members had parkinsonism. Eight (25%) of the 32 asymptomatic relatives showed abnormal putamen 18F-dopa uptake (2.5 standard deviations below the normal mean). When discriminant function analysis was applied, all of these 8 subjects plus another 3 were classified with high probability as having PD. On neurological examination, 5 of the 32 relatives scanned had an isolated mild postural tremor and 2 of these 5 had reduced putamen uptake. Our findings provide further support for a role of inheritance in the etiology of PD and suggest that the penetrance for nigrostriatal dopaminergic dysfunction in familial clusters of PD is higher than the prevalence of clinical parkinsonism reported in epidemiological surveys.

Complications of disease and therapy: a comparison of younger and older patients with Parkinson's disease

The incidence of complications associated with disease and treatment was compared in younger versus elderly patients with Parkinson's disease (PD). One hundred sixty-five patient records were divided according to patient age into two groups ("younger," 41 to 64, and "elderly," > or = 65 years) and reviewed for the incidence of dyskinesias, fluctuations, freezing, psychosis, dementia, depression, and insomnia. Younger patients had a greater incidence of chorea (75.8 percent vs 49.5 percent), dystonia (82.3 percent vs 49.0 percent), fluctuations (90.1 percent vs 68.1 percent), depression (73.2 percent vs 36.8 percent), and insomnia (57.9 percent vs 18.1 percent). There were no significant differences in the incidence of freezing, dementia, or psychosis. At the time of the first adverse event, there was no difference in patient characteristics such as gender, lag time from disease diagnosis to levodopa initiation, disease symptoms at the time of diagnosis, levodopa dose, or concomitant drug use despite the fact that the older group had a longer duration of disease, higher Hoehn and Yahr stage, an older age at onset of PD, and longer duration of levodopa use. Younger patients with PD experience a greater incidence of adverse effects than do elderly PD patients. The spectrum of adverse effects is comparable to those of young-onset (< or = 40 years) patients.

Follow-up study of risk factors in progressive supranuclear palsy

The cause of progressive supranuclear palsy (PSP) is not known and has been little studied. The one previous controlled epidemiologic survey, performed at our center in 1986, found small-town experience and greater educational attainment as PSP risks, but, in retrospect, these results may have been produced by ascertainment bias. Since that time, several anecdotal reports have implicated heredity and various environmental exposures in the cause of some cases of PSP. To clarify the results of the previous study and to evaluate the more recently implicated candidate factors in a controlled fashion, we mailed a validated 69-item questionnaire to 91 personally examined patients with PSP and 104 unmatched controls with other neurologic conditions for which they had been referred to our tertiary neurologic center. We were able to match 75 subjects from each group by year of birth, sex, and race and subjected them to a separate matched-pair analysis. We allowed surrogates to supply any or all of the responses. Questions concerned hydrocarbon, pesticide, and herbicide exposure; urban/rural living; auto repair and other occupations; head trauma; educational attainment; maternal age; and family history of PSP, parkinsonism, dementia, and other neurologic conditions. A statistically significant finding was that patients with PSP were less likely to have completed at least 12 years of school (matched odds ratio = 0.35, 95% CI = 0.12-0.95, p = 0.022; unmatched odds ratio = 0.44, 95% CI = 0.21-0.89, p = 0.020). We hypothesize that this result may be a proxy for poor early-life nutrition or for occupational or residential exposure to an as-yet unsuspected toxin. Future studies should examine these potential risk factors in PSP.

Binswanger's disease presenting as levodopa-responsive parkinsonism: clinicopathologic study of three cases

We report three cases of autopsy-proven Binswanger's disease (subcortical arteriosclerotic encephalopathy) with unusual clinical features. Two patients had supranuclear gaze disturbances, early gait dysfunction, and speech disorders suggestive of progressive supranuclear palsy. One of these patients was not demented at the time of death. The third patient had features typical of Parkinson's disease. All three patients were responsive to treatment with levodopa. The clinical spectrum of Binswanger's disease should be expanded to include levodopa-responsive parkinsonism.

Drenching sweats as an off phenomenon in Parkinson's disease: treatment and relation to plasma levodopa profile

We followed 4 patients with Parkinson's disease and severe, intermittent, drenching sweats. One patient was studied with serial plasma levodopa levels and simultaneous clinical examinations. She was observed during a severe sweating episode; this was associated with subtherapeutic plasma levodopa levels (low dopa state). All 4 patients' sweats responded favorably to the institution of agonist therapy. Drenching sweats should be considered part of the spectrum of off-period levodopa-related fluctuations in Parkinson's disease.

Personality correlates of [18F]dopa striatal uptake: results of positron-emission tomography in Parkinson's disease

Clinicians have long associated Parkinson's disease (PD) with personality traits such as seriousness and industriousness. In previous studies, patients with PD scored lower than matched orthopedic control subjects on novelty seeking, which is thought to be dopamine dependent. In this pilot study, 6-[18F]fluorodopa ([18F]dopa) uptake in the caudate and putamen was measured by PET in 9 patients with PD. Patients were also rated on three personality traits thought to be related to central monoamine function. Uptake of [18F]dopa in the left caudate, but not in other areas measured, was significantly correlated with novelty seeking. Results suggest that the personality traits long observed in PD patients may be partially mediated by striatal deficits in dopamine.

Meige syndrome in the spectrum of Lewy body disease

We report a patient with Meige syndrome (segmental cranial dystonia) who had neuropathologic changes of Parkinson's disease on postmortem examination. Neuropathologic examination showed typical and atypical Lewy bodies in the pigmented nuclei of the brainstem (substantia nigra, locus ceruleus), the nucleus basalis of Meynert, and the nucleus ambiguus. Neurochemical analysis of postmortem brain tissue showed evidence for decreased dopamine turnover in the substantia nigra, striatum, and nucleus accumbens. We propose that some cases of Meige syndrome may be included in the spectrum of Lewy body disease.

Basic mechanisms of motor fluctuations

Patients with Parkinson's disease generally have a smooth clinical response from levodopa therapy for the first 3 to 5 years. Motor fluctuations later become noticeable and may ultimately give way to unpredictable responses to treatment. Mechanisms responsible for motor fluctuations are not fully understood, but can be separated into three groups: (1) central pharmacokinetics, or delivery of dopamine from the presynaptic to the postsynaptic receptor; (2) peripheral pharmacokinetics, or delivery of levodopa from an exogenous source to the brain; and (3) pharmacodynamics, or alterations in the interactions between dopamine and the striatal receptor. Changes in central pharmacokinetics caused by diminished presynaptic dopamine storage capacity probably account for early end-of-dose "wearing-off." As patients lose further storage capacity, peripheral levodopa pharmacokinetics may play an important role in the fluctuation response from erratic gastric emptying or variables that change gut-to-blood and blood-brain barrier transport. Finally, erratic motor responses (eg, the "on-off" phenomenon) in advanced Parkinson's disease may be caused in part by alterations at the striatal dopamine receptor.

A clinical genetic study of Parkinson's disease: evidence for dominant transmission

We used a family history questionnaire, semi-structured interview, and personal examination of secondary cases to collect data on the prevalence of Parkinson's disease (PD) in relatives of patients seen consecutively for 1 year and assessed the proportion of secondary cases of PD as a function of pedigree completeness. Survival analysis methods were applied to estimate the lifetime risk and age-at-onset distribution of PD among first-degree relatives of probands. When we considered siblings of probands with affected parents, the cumulative risk increased significantly over siblings of probands without affected parents, suggesting significant familial aggregation in a subset of randomly ascertained families. We further analyzed 80 multicase families with two or more affected individuals. Age-adjusted segregation ratios approaching 0.5 and similar proportions of affected parents and siblings, as well as the distribution of ancestral secondary cases, were compatible with an autosomal dominant mode of inheritance with reduced penetrance in a subset of PD.

Severe evening dyskinesias in advanced Parkinson's disease: clinical description, relation to plasma levodopa, and treatment

We report four patients with Parkinson's disease who had an unusual pattern of severe chorea and dystonia in the evenings only. The temporal pattern of abnormal movements and simultaneous monitoring of plasma levodopa and clinical state were consistent with dyskinesias associated with subtherapeutic (low dopa dyskinesias) rather than peak concentrations of levodopa (high dopa dyskinesias). In two patients, addition of a direct-acting dopamine receptor agonist was helpful in ameliorating this complication of antiparkinson therapy.

An analysis of treatment options and outcome in patients with Parkinson's disease and severe dyskinesias

Forty-one patients with Parkinson's disease and severe dyskinesias were analyzed retrospectively to determine if some general principles would emerge to aid physicians handling this complication of treatment. Dyskinesia type (high dopa chorea [HDC], low dopa chorea [LDC], high dopa dystonia [HDD], and low dopa dystonia [LDD]) predicted response to treatment and whether or not levodopa dose reduction would benefit dyskinesias without producing unacceptable "offs." High dopa chorea improved best but at the expense of increased "off" time, followed by LDD, HDD, and LDC. Levodopa reduction was an acceptable strategy in ameliorating HDC and LDD only. Adjunctive therapy benefited all dyskinesia types, although the majority of patients (12/17) helped by selegiline had LDD or LDC. Generally, low doses of dopamine agonists were helpful (bromocriptine < 20 mg/day; pergolide < 2 mg/day). When adding adjunctive therapy (except for selegiline or controlled-release carbidopa/levodopa), concomitant reduction in daily dose of levodopa was not an effective strategy to decrease dyskinesias. Serial trials of multiple drug regimens are useful in these patients.

Parkinson's disease and depression: the relationship to disability and personality

In a study of 104 patients with Parkinson's disease (PD) and 61 control subjects with equal disability scores, PD patients had higher depression scores (P < 0.001) than control subjects. Functional disability was correlated with depression in PD and, in a regression analysis, explained 9% of the variance in depression (P < 0.001). Depression was not correlated with novelty seeking, a personality trait related to dopaminergic pleasure and reward systems. Harm avoidance, a trait related to central serotonergic systems, was, however, correlated with depression (P < 0.001) and explained 31% of the variance in depression scores. Results support the hypotheses that both physiologic and psychologic factors contribute to depression seen in these patients and that serotonergic function plays a more critical role than dopaminergic function.

Autosomal dominant parkinsonism with benign course and typical Lewy-body pathology

The few previously reported patients with familial parkinsonism and Lewy-body pathology in the substantia nigra displayed a variety of clinical and pathologic syndromes. We now describe a family with very slowly progressive Parkinson's disease (PD) that has, in most cases, responded poorly to levodopa and includes subjective visual difficult. Four personally confirmed cases--with onset at ages 35, 25, 16, and 16-have occurred in three generations, and four suspicious cases have occurred in three other generations. There has been a trend toward progressively younger age of onset. One autopsied case showed a distribution of cell loss and Lewy bodies typical of PD. The hereditary pattern is most compatible with autosomal dominance. This kindred's illness shows that a presumably single Mendelian dominant gene can cause the clinical and pathologic features of PD, and further extends the clinical spectrum of pathologically typical Lewy-body PD.

Parkinson's disease in twins studied with 18F-dopa and positron emission tomography

We used 18F-dopa PET to examine concordance for dysfunction of the nigrostriatal dopaminergic system in 18 co-twins of patients with Parkinson's disease (PD) and scanned one clinically concordant monozygotic (MZ) twin pair, 17 asymptomatic co-twins (10 MZ, 7 dizygotic [DZ]), and 13 twins with PD (8 MZ, 5 DZ). Mean 18F-dopa uptake of the twins with PD was significantly reduced in putamen to 38% and in caudate to 66% of normal. Mean putamen 18F-dopa uptake for the 17 asymptomatic co-twins was also significantly reduced (86% of normal), as was putamen tracer uptake for the 10 MZ (87% of normal) and seven DZ (83% of normal) asymptomatic co-twin subgroups. Four of 10 MZ and two of seven DZ asymptomatic co-twins had putamen 18F-dopa uptake reduced more than 2 SDs below the normal mean. Three of these four asymptomatic MZ co-twins had tremor on examination at the time of PET and one has now developed PD 2 years later. Our PET findings give concordances for nigral dysfunction of 45% in the MZ pairs and 29% in the DZ pairs at a 2-SD threshold, and 18% in MZ and 0% in DZ pairs at a 3-SD threshold of significance. These data suggest that the concordance for nigral pathology in PD twins may be higher than previously realized and that the presence of an isolated postural or rest tremor may be a phenotypic expression of PD.

Levodopa-nonresponsive Lewy body parkinsonism: clinicopathologic study of two cases

We report two patients with a primarily akinetic form of parkinsonism who were nonresponsive to treatment with levodopa. At autopsy, both patients had many Lewy bodies in brainstem and diencephalic nuclei, with sparse Lewy bodies in association cortices and more numerous Lewy bodies in the limbic cortices, consistent with the transitional form of Lewy body disease. These cases emphasize that (1) Lewy body Parkinson's disease cannot be excluded on the basis of atypical presentation or levodopa nonresponsiveness, and (2) the clinicopathologic spectrum of Lewy body disease is varied.

The rationale for continuous dopaminergic stimulation in patients with Parkinson's disease

Continuous dopaminergic stimulation has been shown to stabilize motor fluctuations in patients with advanced Parkinson's disease (PD) who do not respond to more conventional forms of therapy. Levodopa infusions confer immediate benefit as a direct result of maintaining steady plasma levodopa concentrations. Fluctuations of synaptic dopamine inherent in the usual oral treatment of PD might result in deleterious postsynaptic changes. Some of these presumed receptor alterations might revert as a consequence of continuous levodopa infusion.

Nighttime levodopa infusions to treat motor fluctuations in advanced Parkinson's disease: preliminary observations

We report the clinical response of a parkinsonian patient with severe motor fluctuations who was begun on continuous, nighttime-only levodopa infusions accompanied by oral carbidopa/levodopa use during the day. Sleep disturbances improved immediately. There was a gradual reduction in "off" time and severity of dyskinesias during the waking day. Nighttime-only levodopa infusions have a carryover benefit to the waking hours and may be suitable for long-term therapy to reduce daily motor fluctuations in some patients with Parkinson's disease.

Hippocampal degeneration differentiates diffuse Lewy body disease (DLBD) from Alzheimer's disease: light and electron microscopic immunocytochemistry of CA2-3 neurites specific to DLBD

Immunocytochemistry with antibodies to ubiquitin is currently the most sensitive method for detecting cortical Lewy bodies, which are a sine qua non for the diagnosis of diffuse Lewy body disease (DLBD), an increasingly recognized form of primary degenerative dementia. In the systematic application of ubiquitin immunocytochemistry to sections of hippocampus from control subjects and patients with a wide spectrum of neurodegenerative diseases, we noted the frequent occurrence of ubiquitin-immunoreactive neurites in the CA2-3 region in DLBD. The nature of these neurites was investigated with immunocytochemistry in DLBD, Alzheimer's disease (AD), normal elderly subjects, and Parkinson's disease (PD). Although the number of neurites varied from case to case, they were virtually always detected in DLBD but not in normal, AD, or PD brains. Double immunolabeling studies with anti-ubiquitin demonstrated a small fraction of double-stained neurites with antibodies to neurofilament or Alz-50, but no double staining with an antibody to Alzheimer neurofibrillary tangles. These results are different from those for neurites in AD, which are rarely seen in CA2-3 and which are immunoreactive with all these antibodies. Neuritic degeneration in the CA2-3 region of the hippocampus appears to be a specific histopathologic feature of DLBD.

Benefits of monitoring plasma levodopa in Parkinson's disease patients with drug-induced chorea

We studied the temporal patterns of chorea and plasma levodopa profiles in 30 patients with Parkinson's disease whose motor fluctuations were difficult to characterize and treat on the basis of observation alone. We were able to determine whether chorea was associated with high levodopa concentrations or low levodopa concentrations or both. We found the following patterns of levodopa-associated chorea: chorea due to inadequate levodopa levels, chorea due to biphasic levodopa absorption, chorea associated with either rapid or slow levodopa absorption, and chorea due to long-duration levodopa absorption mimicking a sustained-release preparation. Seven patients benefited after their dosing schedules were rearranged as a result of information gained from monitoring. We conclude that any patient with levodopa-associated chorea who cannot be regulated on the basis of observation alone should be studied with simultaneous plasma levodopa measurements and clinical monitoring to detect an unusual plasma levodopa pattern that may be improved by adjustment of dosing schedule.

Isolated lingual/palatal dystonia

We report a 45-year-old woman with a 3-year history of continuous dystonic movements of tongue and palate with intermittent episodes of noticeable worsening lasting 6 to 8 h. The movements began immediately after a viral illness. The only contributory history is that the patient received high doses of prochlorperazine 22 years earlier for hyperemesis gravidarum. The patient appears to have an unusual focal lower cranial dystonia. Proposed etiologies may be idiopathic or related to prior use of a phenothiazine with a viral trigger.

Long-term efficacy of controlled-release carbidopa/levodopa in patients with advanced Parkinson's disease

Twenty-one patients with Parkinson's disease and motor fluctuations who completed a double-blind study comparing controlled-release carbidopa/levodopa (Sinemet CR4) with standard Sinemet (SS) were evaluated one year following completion of the study. Five patients remained on CR4 alone; 16 continued on CR4 plus SS, and one also required addition of bromocriptine. Patients were significantly worse (p less than 0.05) at one year compared with double-blind CR4 phase (DBCR) for nine parameters of the motor exam, six activities of daily living (ADL), Hoehn & Yahr staging, and physician's global assessment. Compared with baseline SS, patients were worse at one year for four points of the motor exam, two of mentation, behavior, and mood, and 11 parameters of ADL. Improvement at one year was noted for less action and postural tremor and decreased duration of dyskinesias for both comparison periods. There was elimination of early morning dystonia at one year over the DBCR period and more hours "on" without dyskinesias and fewer hours "on" with dyskinesias compared with baseline SS. Total levodopa dosage was not significantly changed over the year. These data suggest that, in long-term use, CR4 remains more efficacious than SS alone for Parkinson's patients experiencing motor fluctuations, although disease progression continues despite optimal medication.

Controlled-release carbidopa-levodopa (Sinemet) in combination with standard Sinemet in advanced Parkinson's disease

Twelve of 23 patients with Parkinson's disease and motor fluctuations who entered a double-blind study comparing controlled-release carbidopa/levodopa (Sinemet CR-4) with standard Sinemet (SS) continued into open label follow-up on a combination of CR-4 and SS (C/S); the rest continued on CR-4 alone. Significant improvement on C/S compared with CR-4 was noted for shorter duration and reduced disability of dyskinesias, and more hours "on" without dyskinesias (all p less than 0.05). Total number of hours "off" was improved on C/S over SS (p less than 0.01). Sinemet CR-4 proved to be better than C/S for sleep disturbance (p less than 0.05). Although the total number of tablets and doses per day of CR-4 was reduced during the C/S period, total levodopa dosage per day was not significantly changed from either of the previous periods. The C/S therapy for advanced parkinsonism can be more efficacious for fluctuators than either CR-4 or SS alone.

Median nerve neuralgia caused by a fibrovascular band in the distal forearm

A 67-year-old woman had experienced exquisite focal pain and tenderness for more than 1 year in the distal forearm 4.5 cm proximal to the distal wrist crease. Surgical exploration showed a venous fibrovascular band adherent to and transversing the epineurium of the median nerve precisely at the point of maximal tenderness. Resection of the fibrovascular band completely relieved the symptoms of focal pain and tenderness.

The human subfornical organ: an anatomic and ultrastructural study

The subfornical organ (SFO), one of the circumventricular organs (CVO) and a thirst-regulating structure, was examined in humans. In 21 autopsy specimens, the SFO was identified as one mm grey nodule on the ventral surface of the fornix at the foramina of Monro. The SFO is a neuronal-vascular organ on a loose glial background, lined by ependyma. Ultrastructural examination reveals deep, narrow invaginations in most neuronal nuclei, characteristically seen in the SFO of other species, but unlike neuronal nuclei in the rest of the human brain. Ovoid, clear vesicles in synaptic complexes and dense-core granules in non-synaptic neuronal process are seen. Ependymal channels are observed. Capillaries have luminal tongue-like projections and pinocytotic vesicles in the endothelial wall, as well as both tight and non-tight junctions between endothelial cells; endothelial fenestrations are not found. These specializations may permit access of macromolecules to receptor sites in the SFO, facilitating its functions as a chemoreceptor organ in drinking behavior. The anatomy of the human SFO is consistent with that of other CVO's and with that of the SFO in other species.

Ulnar nerve entrapment neuropathy in the forearm

A 74-year-old male attorney developed rapidly progressive weakness of the fourth and fifth digits of the right hand with impairment of his grip and ability to perform cursive writing. Lancinating pain occurred spontaneously and was triggered by pressure along the ulnar border of the forearm about 5 cm proximal to the wrist crease. Nerve conduction studies revealed a complete electrical block to stimulation at a point 5 cm proximal to the wrist crease when recording from the abductor digiti minimi. Distal to this point, responses of normal amplitude and latency were recorded. Surgical exploration disclosed two fibrovascular bands coursing from the ulnar artery to the distal belly of the flexor carpi ulnaris, entrapping and grooving the ulnar nerve. Release of these bands resulted in reversal of the electrical block, complete relief of pain, and a full neurologic recovery during the ensuing six months.

Lingual epilepsy: a case report of an unusual expression of focal cerebral discharge

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