Early-onset vs. Late-onset Parkinson's disease: A Clinical-pathological Study.

BACKGROUND: Several studies have compared early-onset Parkinson disease (EOPD) and late-onset Parkinson disease (LOPD) but most are not based on autopsy confirmed cases. METHODS: We compared clinical and pharmacological profiles, time to reach irreversible Hoehn and Yahr (H&Y) Stage 3 and levodopa motor complications in autopsy confirmed EOPD and LOPD cases. RESULTS: At first clinic visit EOPD cases were younger but had longer disease duration and they died at a younger age (all p<0.0001). Anti-Parkinsonian drug use, including levodopa, was significantly delayed in EOPD. Lifetime use of amantadine (p<0.05) and dopamine agonists (p<0.01) were higher in EOPD. While lifetime use of levodopa was similar in the two groups, levodopa was used for a significantly longer period by EOPD (p< 0.0001). EOPD had a higher cumulative incidence of dyskinesias (p<0.01), wearing-off (p<0.01), and on-off (p<0.01). However, the time to dyskinesia onset was similar in the two groups. The threshold to wearing-off was much longer in EOPD (p<0.01). H&Y stage profile at first visit was similar in the two groups. The duration from disease onset to reach irreversible H&Y stage 3 was significantly longer in EOPD. CONCLUSIONS: Our observations indicate that progression of PD is slower in EOPD and suggest that the pre-clinical interval in this group is longer. These findings can be used for case selection for drug trials and studies of the pathogenesis of PD.

The phenotypic spectrum of progressive supranuclear palsy: a retrospective multicenter study of 100 definite cases.

The phenotypic variability of progressive supranuclear palsy (PSP) may account for its frequent misdiagnosis, in particular in early stages of the disease. However, large multicenter studies to define the frequency and natural history of PSP phenotypes are missing. In a cohort of 100 autopsy-confirmed patients we studied the phenotypic spectrum of PSP by retrospective chart review. Patients were derived from five brain banks with expertise in neurodegenerative disorders with referrals from multiple academic hospitals. The clinical characteristics of the 100 cases showed remarkable heterogeneity. Most strikingly, only 24% of cases presented as Richardson's Syndrome (RS), and more than half of the cases either showed overlapping features of several predescribed phenotypes, or features not fitting proposed classification criteria for PSP phenotypes. Classification of patients according to predominant clinical features in the first 2 years of the disease course allowed a more comprehensive description of the phenotypic spectrum. These predominance types differed significantly with regard to survival time and frequency of cognitive deficits. In summary, the phenotypic spectrum of PSP may be broader and more variable than previously described in single-center studies. Thus, too strict clinical criteria defining distinct phenotypes may not reflect this variability. A more pragmatic clinical approach using predominance types could potentially be more helpful in the early recognition of and for making prognostic predictions for these patients. Given the limitations arising from the retrospective nature of this analysis, a systematic validation in a prospective cohort study is imperative.

Clinical features at first visit and rapid disease progression in Parkinson's disease.

We report a retrospective multivariable analysis of the association between patient characteristics at first clinic visit and rapid disease progression in 1411 Parkinson's disease patients treated between 1985 and 2006. At first visit rapid progression was positively associated with age at onset > or = 70 years (OR=5.77), rigidity (OR=1.94), bradykinesia (OR=1.73), dementia (OR=2.61), and levodopa use (OR=1.74). Rapid progression was negatively associated with disease duration (OR=0.52), male sex (OR=0.49), and resting tremor at first visit (OR=0.44). Family history of movement disorders, while significant for univariable analysis, did not retain significance in multivariable analysis. This initial clinical profile may aid physicians in adjusting treatment and follow-up plans. Further prospective studies are needed to evaluate this relationship.

Alpha-synuclein and tyrosine hydroxylase expression in acute rotenone toxicity.

Chronic low-dose (2-3 mg/kg/day) rotenone infusion produces clinical features and biological markers of Parkinson's disease (PD) in some rats. A significant proportion of rats, however, die of acute rotenone toxicity. Most studies have focused on chronic rotenone-infused rats. It has not been established if the animals that die of acute low-dose rotenone toxicity manifest clinical or pathological evidence of PD. In the present study, six rats that received continuous 3 mg/kg/day subcutaneous rotenone infusion, became moribund and were euthanized after five days were compared with ten vehicle infused animals sacrificed 14, 28 or 56 days after placebo infusion. All rotenone-infused rats had significant motor function decline beginning one day after the infusion and progressive worsening in the physical condition until they became severely akinetic, at which point they were euthanized. In the substantia nigra of rotenone-treated rats, four of six had reduced numbers of tyrosine hydroxylase-positive neurons and all six had increased nigral alpha-synuclein expression. Our observations show that even a short duration of low-dose subcutaneous rotenone infusion can induce clinical and pathological markers of PD in some rats. The pathophysiology of the enhanced susceptibility to PD in some animals remains to be established.

Increased tremor severity in bilineal essential tremor: a report of two families.

Up to 6% of the general population have essential tremor (ET). In a number of couples both partners may have ET. The clinical profile of ET in children and the parents where both parents and the child have ET remains to be established. We report on two families where both parents and one child have ET. The severity of ET was greater in the children than in either parent. Such families could provide special opportunity to determine relation between genotype and phenotypic expression of ET.

Conjugal parkinsonism - Clinical, pathology and genetic study. No evidence of person-to-person transmission.

INTRODUCTION: Neurodegeneration is known basis of several different Parkinson syndromes. The most common Parkinson syndrome is the Parkinson's disease. Distinction between different Parkinson syndromes is based on pathology or genetic findings. Recent studies indicate that several major variants of PS have some characteristics of a prion disease and may therefore be transmissible. Married couples offer a unique opportunity to study person-to-person transmission and the role of shared environments as the cause of parkinsonism. METHODS: Autopsy is offered to patients seen at the Movement Disorders Clinic Saskatchewan at no cost. Five couples seen in our clinic, where each spouse had a clinical diagnosis of parkinsonism, came to autopsy. RESULTS: Median duration of marriage was 42 years before the Parkinson syndrome first manifested in a spouse. Three couples were pathologically or genetically discordant for Parkinson variant. Each spouse in the other two couples had Parkinson's disease. One couple had onset separated by 20 years and one partner had a strong family history of Parkinson's disease. CONCLUSION: Our data indicate that neither of the Parkinson's disease, Progressive Supranuclear Palsy and Multiple System Atrophy are transmitted by sexual or other intimate contact. The data also indicate against shared environments as the cause of these disorders.

Increased myocardial N-myristoyltransferase activity in rotenone model of Parkinsonism.

There is widespread brain pathology in Parkinson's disease (PD), with the primary pathology in the substantia nigra. Oxidative stress is believed to play a role in cell death in PD. Rotenone is a mitochondrial toxin which can produce Parkinson syndrome (PS) in rats. Myristoyl-CoA:protein N-myristoyltransferase (NMT), which catalyzes the co-translational transfer of myristate from myristoyl-CoA to the amino-terminal glycine residue of selected polypeptides, is increased in the myocardium of ischemia-reperfusion rat model myocardium. Animals received rotoneone (n=10) or placebo vehicle (n=6) via Alzet osmotic pumps. Mean cardiac muscle NMT activity of placebo treated (control) rats was 0.608+/-0.366 units/mg protein. Rats with mild or no detectable PS features on rotenone showed slight (mean 0.853+/-0.192) but insignificantly increased activity. Rats that had moderately severe PS features had higher level of NMT activity (mean 1.223+/-0.057), which was borderline significant compared to controls (P=0.066). Rats with severe PS features had the highest NMT activity (1.353+/-0.128) which was significantly greater compared to controls (P=0.003) and to the rats that had equivocal or no motor slowing (P=0.005). Our data show cardiac metabolic dysfunction in a rotenone rat model of PS. The severity of this change correlates with the severity of motor manifestations. Further studies of NMT activity in human PD cases and patients with cardiomyopathy of unknown cause may provide valuable information in these disorders.

Essential tremor course and disability: A clinicopathologic study of 20 cases.

OBJECTIVE: To correlate autopsy findings with the clinical course and disability profile in clinically diagnosed longitudinally followed autopsied essential tremor (ET) patients. METHODS: All ET patients followed by one neurologist between 1970 and 2001 who came to autopsy were included. Clinical features and disability were recorded prospectively. Autopsy studies were performed by a qualified neuropathologist. RESULTS: Twenty cases (10 men and 10 women) had ET onset between childhood and age 68 (median 46.5 years). Six cases had additional features of Parkinson syndrome (PS), with presence of bradykinesia, rigidity, and rest tremor (RT). These included progressive supranuclear palsy (PSP; n = 2), drug-induced parkinsonism (n = 2), idiopathic Parkinson disease (PD; n = 1), and basal ganglia status cribrosus (n = 1). Of the remaining 14 ET cases, 6 had additional RT but no bradykinesia or rigidity. Ten of these 14 (71%) reported physical disability. Eleven of the 14 (79%) had only upper limb (UL) tremor at onset, and 8 of these 11 (73%) had subsequent cranial extension of tremor. Two patients clinically had mild cerebellar ataxia but no cerebellar histologic abnormality. There was no consistent brain pathology in the ET or ET + RT cases. CONCLUSIONS: UL tremor was the most common onset, which often progressed to the cranial musculature. Functional disability and psychological distress were common in these patients. Functional disability was related to the UL tremor. Six of 20 (30%) had additional features of PS. Six of the remaining 14 (43%) had ET and RT; there was no identifiable pathology in these cases. The risk of PD in ET cases was comparable with that in the general population. PSP in two cases was incidental comorbidity.