Biomedical subjects
Publications and source records attributed to J Eric Ahlskog.
A 59-year-old man presented with orthostatic headaches, memory complaints, pronounced choreiform movements, and related hyperkinetic dysarthria and titubations. Head MRI findings were suggestive of CSF leak. CSF pressure was low. CT myelography documented CSF leak at the cervicothoracic junction. Targeted epidural blood patch led to resolution of symptoms, including complete disappearance of choreiform movements.
We established a historical cohort of 7,216 subjects who completed the Minnesota Multiphasic Personality Inventory (MMPI) at the Mayo Clinic from 1962 through 1965 for research (not clinical indication), and who resided within a 120-mile radius centered in Rochester, Minnesota. We describe here the overall cohort design and sampling, we report results concerning reliability and validity, and we describe age and sex patterns at baseline for four MMPI scores of primary interest (depression, anxiety, social introversion, and negativity). Subjects excluded from the cohort because of missing data had MMPI scores similar to subjects included (after appropriate rescaling). A cut-off specific for age and sex at the 75th percentile of the distribution of raw scores was valid compared with the traditional clinical cut-off (T scores plus one standard deviation). Baseline scores for all four scales were higher in women than in men at all ages (all p < 0.0001). Depression and social introversion scores showed an increasing trend with age in both sexes (Spearman rank correlation, rho = 0.05 and 0.08, respectively, p < 0.0001 for both). Baseline scores on the anxiety scale showed a decreasing trend with age in both sexes (rho = -0.06, p < 0.0001). Negativity scores remained relatively stable with age in both sexes (rho = 0.03, p = 0.01). We found a high correlation between the anxiety score and the negativity score (rho = 0.90, p < 0.0001) even after the exclusion of overlapping items (rho = 0.68, p < 0.0001). This newly established historical cohort study provides opportunities to test hypotheses regarding the link between personality and aging, aging-related diseases, and overall mortality.
BACKGROUND: The threat of levodopa-induced dyskinesias often influences early treatment decisions in those with Parkinson disease. OBJECTIVE: To determine the long-term risks of levodopa-associated dyskinesias of any severity, dyskinesias sufficient to require medication adjustment, and dyskinesias failing medication adjustments. DESIGN: The medical records linkage system of the Rochester Epidemiology Project was used to identify all incident Parkinson disease patients treated with levodopa (1976-1990). All records were independently reviewed by 2 neurologists who recorded demographic and drug data, dates when dyskinesias were initially identified, and dates when dyskinesias were sufficient to require medication changes; dyskinesias not controlled by drug adjustments were also tabulated. RESULTS: We identified 126 incident Parkinson disease patients treated with levodopa for at least 2 months. By Kaplan-Meier analysis, the estimated rate of dyskinesias was 30% by 5 treatment years and 59% by 10 years. However, the rate of dyskinesias requiring medication adjustment was estimated to be only 17% by 5 years and 43% by 10 years. At 10 treatment years, the rate of dyskinesias that could not be controlled with medication adjustments was estimated at only 12%. An increased risk was associated with younger age and higher initial levodopa dose, but not with sex. CONCLUSIONS: Levodopa-associated dyskinesias can be expected to develop in nearly 60% of patients in our community after 10 years, but these will be severe enough to require medication adjustments in only 43% of patients. At 10 treatment years, nearly 90% of these patients can expect to be spared dyskinesias that could not be controlled by drug adjustments. This population-based study suggests dyskinesia risk may not be a major concern for most Parkinson disease patients.
BACKGROUND: Benign tremulous parkinsonism has never been precisely defined nor has the long-term course been studied. OBJECTIVE: To report the clinical features and longitudinal course of patients with benign tremulous parkinsonism encountered in our movement disorders practice. DESIGN: Computer search of medical records database. SETTING: Mayo Clinic, Rochester, Minn. PATIENTS: Of 116 patients identified, 16 (10 male and 6 female) had at least an 8-year history of this disease, had been examined by a senior movement disorders specialist, and had ultimately been diagnosed as having benign tremulous parkinsonism after an initial diagnosis of Parkinson disease (PD). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Age at onset of disease, response to levodopa therapy, tremor characteristics, and family history. RESULTS: Mean disease duration was 11 years (range, 8-25 years) at last follow-up. Mean age at onset, 58.5 years, was younger than in most PD series, and most patients had a poor levodopa response (although levodopa trials were inadequate in some). A moderate to marked postural tremor was noted in 13 of the 16 patients, including 6 with a kinetic tremor. A family history of PD and/or tremor was reported in 10 (63%) of our patients. Three patients required thalamic deep brain surgery to treat their tremor. CONCLUSIONS: Benign tremulous parkinsonism may be a distinct clinical entity characterized by tremor predominance plus minimal progression of other aspects of parkinsonism. The tremor is often not very responsive to levodopa therapy. In this series, most patients had immediate family members with a diagnosis of tremor or PD.
BACKGROUND: Respiratory stridor, sleep-disordered breathing, and respiratory insufficiency are part of the clinical spectrum of multiple-system atrophy (MSA). We have encountered cases where these were presenting symptoms, with the diagnosis of MSA being initially unrecognized. OBJECTIVE: To describe cases in which breathing difficulties were the initial and primary manifestation of MSA. DESIGN: Database review from January 1, 1996, through October 31, 2005. SETTING: Mayo Clinic, Rochester, Minn. PATIENTS: All patients diagnosed as having MSA, cross-referenced for apnea, hypopnea, or hypoventilation. On review, we included only cases in which respiratory dysfunction was the primary initial clinical event in MSA, excluding equivocal cases. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Characteristics and clinical course of patients. RESULTS: Six cases were identified in which substantial respiratory insufficiency occurred as an early, presenting symptom of MSA. Three patients had been examined emergently for acute respiratory distress before the ultimate diagnosis of MSA; the other 3 patients were diagnosed as having obstructive sleep apnea unresponsive to therapy, with bilateral vocal cord paralysis found on ear, nose, and throat examination. Stridor was noted early in the course in all. All patients required tracheostomy, and all eventually developed features consistent with probable MSA. CONCLUSIONS: Multiple-system atrophy may occasionally present as primary respiratory failure or dysfunction, with initially mild motor and autonomic symptoms. Otherwise unexplained central respiratory failure, bilateral vocal cord paralysis, stridor, or refractory central sleep apnea should prompt consideration of MSA.
OBJECTIVE: To define the molecular etiology of early-onset parkinsonism and peripheral neuropathy. METHODS: Two sisters had early-onset parkinsonism (dystonic toe curling, action tremor, masked face, bradykinesia, stooped posture, and rigidity), together with clinical and electrophysiological signs of sensorimotor axonal peripheral neuropathy. RESULTS: No mutations were found in the genes for parkin or PINK1. Muscle biopsies showed ragged-red and cytochrome c oxidase-negative fibers, and biochemistry showed decreased activities of respiratory chain complexes containing mitochondrial DNA-encoded subunits. Multiple mitochondrial DNA deletions were seen by long polymerase chain reaction, and sequencing of the POLG gene showed that the patients were compound heterozygous for two patogenic mutations. INTERPRETATION: POLG mutations can cause early-onset parkinsonism in the absence of progressive external ophthalmoplegia.
OBJECTIVE: To conduct complex segregation analyses of Parkinson's disease (PD). METHODS: Data on the familial aggregation of PD remain conflicting. We conducted a historical cohort study of 1,234 relatives of 162 patients with PD representative of people of Olmsted County, MN, and of 3,009 relatives of 411 patients with PD referred to the Mayo Clinic. Relatives were interviewed and screened for parkinsonism either directly or through a proxy, those who screened positive were examined, or a copy of their medical record was obtained to confirm the diagnosis. For subjects who resided in Olmsted County, additional information was obtained from the archives of the Olmsted County Historical Society and from a records-linkage system. RESULTS: Thirty-two relatives of population-based probands and 69 relatives of referral patients developed PD (101 in total). Combining population-based and referral samples, the model that best explained the familial clustering of PD overall was a major gene with additive effect on the penetrance. This model predicted an average decrease in age at onset of PD of approximately 18 years for each copy of the putative high-risk allele. The best fitting model for younger onset PD (age 59 years) were a recessive or an additive model. INTERPRETATION: The familial aggregation of PD may be explained in part by a major gene with additive effect on the penetrance.
The putative association between pesticide exposures and Parkinson's disease (PD) remains controversial. We identified all subjects who developed PD in Olmsted County, Minnesota, from 1976 through 1995, and matched them by age (+/- 1 year) and sex to general population controls. We assessed exposures to chemical products by means of telephone interview with cases, controls, or their proxies (149 cases; 129 controls). Exposure to pesticides related or unrelated to farming was associated with PD in men (odds ratio, 2.4; 95% confidence interval, 1.1-5.4; P = 0.04). The association remained significant after adjustment for education or smoking. Analyses for the other six categories of industrial and household chemicals were all nonsignificant. This population-based study suggests a link between pesticides use and PD that is restricted to men. Pesticides may interact with other genetic or nongenetic factors that are different in men and women.
OBJECTIVE: To describe novel neurological manifestations associated with glutamic acid decarboxylase (GAD65) autoimmunity. PATIENTS AND METHODS: This retrospective study (1987-2003) describes 62 patients Incidentally found to have a serum autoantibody that bound selectively to synapse-rich central nervous system tissues. The immunostaining pattern was determined to be GAD65-specific by radiolmmunoprecipitation assay. These cases were identified among samples submitted for paraneoplastic autoantibody evaluation using indirect immunofluorescence. In no case had GAD65 or any other islet cell antibody testing been requested. RESULTS: In most cases, the patients' presentations were initially considered neurodegenerative or inflammatory (multiple sclerosis or paraneoplastic). Median age at onset was 50 years, and 77% were women. Of the 44 patients seen at the Mayo Clinic, 23% were African American; in contrast, less than 10% of Mayo Clinic's neurology patients are African American. Median follow-up was 24 months. The radioimmunoprecipitation assay values for GAD65 antibody were extremely high (median, 1429 nmol/L; Interquartile range, 643-3078 nmol/L) and correlated significantly with immunofluorescence titers (median, 3840; interquartile range, 1920-15,360; r = 0.81; P < .001). Neurological manifestations were multifocal in 41 patients and included cerebellar ataxia (63%), brainstem involvement (29%), seizures (27%), stiff-man phenomena (26%), extrapyramidal signs (16%), and myelopathy (8%). One third of the patients had type 1 diabetes mellitus, 53% had thyroid autoantibodies, and 16% had vitiligo. Eleven of 20 patients identified as African American had brainstem involvement. Some patients appeared to benefit from short-term immunosuppression (none received long-term therapy). CONCLUSIONS: The neurological spectrum of GAD65 autoimmunity includes brainstem, extrapyramidal, and spinal cord syndromes. In our experience, African American patients were disproportionately affected. A patient with a presumed neurodegenerative disorder of new onset, with high levels of GAD65 antibody (>20 nmol/L), merits consideration of immunotherapy.
Acquired copper deficiency presents with a spastic gait and sensory ataxia. Spinal cord magnetic resonance imaging (MRI) in patients with copper deficiency myelopathy may show increased T2 signal, most commonly in the dorsal midline cervical and thoracic cord. These imaging findings may be reversible with normalization of serum copper. The clinical and imaging picture is very similar to the subacute combined degeneration seen in patients with vitamin B12 deficiency. Neuroradiologists should consider this possibility when a long segment of symmetric dorsal spinal cord T2-hyperintensity is identified.
BACKGROUND: Pathological gambling is a rare potential complication related to treatment of Parkinson disease (PD). However, the etiology of this behavior is poorly understood. OBJECTIVE: To examine the relationship between medical therapy for PD and pathological gambling. METHODS: In our routine movement disorders practice (2002-2004), we encountered 11 patients with idiopathic PD who had recently developed pathological gambling. We assessed the relationship to their medical therapy and compared them with cases identified by systematic review of the existing literature on pathological gambling and PD. RESULTS: All 11 patients with PD and pathological gambling were taking therapeutic doses of a dopamine agonist; 3 of these patients were not treated with levodopa. In 7 patients, pathological gambling developed within 3 months of starting to take or escalating the dose of the agonist; in the other 4 with a longer latency, gambling resolved after the agonist use was discontinued. Pramipexole dihydrochloride was the agonist in 9 of 11 cases in our series and 10 of 17 in the literature (68% in total). CONCLUSIONS: Dopamine agonist therapy was associated with potentially reversible pathological gambling, and pramipexole was the medication predominantly implicated. This may relate to disproportionate stimulation of dopamine D(3) receptors, which are primarily localized to the limbic system.
To avoid the possible confounding effect of population stratification, we employed a discordant sibling study design and a liberalization of the sibling transmission disequilibrium test to confirm the association of the S18Y variant of the ubiquitin carboxi-terminal hydrolase L1 (UCHL1) gene with Parkinson's disease (PD). The study included 497 case-control pairs (427 case-unaffected sibling pairs and 70 case-unrelated control pairs). Analyses confirmed a significant inverse association of the UCHL1 S18Y polymorphism with PD overall (OR=0.18, 95% CI=0.05-0.64, p=0.002, recessive model) and in several strata.
We describe here the Mayo Clinic Family Study of Parkinson's disease (PD), including the overall study design (historical cohort study of relatives from birth to onset of PD or censoring), the data collection instruments, the strategies implemented to prevent or measure biases, and the sample obtained. These methodological details may provide assistance to other investigators designing studies of the familial aggregation of PD or other aging-related chronic diseases. We investigated the incidence of PD and other neurodegenerative diseases among 1,001 first-degree relatives of 162 patients with PD and 851 relatives of 147 controls representative of the population of Olmsted County, Minn., USA. In addition, we studied 2,713 first-degree relatives of 411 patients with PD referred to the Mayo Clinic. Finally, we studied a group of 625 spouses of either cases or controls. Relatives with PD or other neurodegenerative diseases were ascertained using the family study method.
BACKGROUND: An atypical form of parkinsonism has been described in patients with chronic liver disease, associated with increased T1 signal in the basal ganglia on magnetic resonance imaging. The magnetic resonance imaging signal changes are characteristic of manganese accumulation, which has been neuropathologically confirmed. Manganese neurotoxicity may result in additional neurologic findings besides parkinsonism. OBJECTIVE: To fully characterize patients with chronic central nervous system symptoms and chronic liver failure associated with basal ganglia T1 hyperintensity. DESIGN: Prospective and retrospective case study. SETTING: Mayo Clinic, Rochester, Minn. PARTICIPANTS: Eight patients referred for neurologic evaluation and studied prospectively, and 7 additional retrospectively identified patients who had been examined by Mayo Clinic neurologists. MAIN OUTCOME MEASURES: Neurologic syndromes identified. RESULTS: Three syndromes were recognized in these 15 patients with liver failure and basal ganglia T1 hyperintensity on magnetic resonance imaging: (1) isolated parkinsonism, (2) gait ataxia plus other neurologic findings (ataxia-plus), and (3) cognitive impairment with psychiatric features. All but 1 patient had elevated blood manganese levels. Ammonia levels were normal in most, and the neurologic syndromes did not appear to reflect the well-known toxic-metabolic encephalopathy of liver disease. CONCLUSIONS: Chronic liver failure may result in heterogeneous neurologic syndromes that cut across a variety of liver diseases. We selected cases on the basis of evidence of brain manganese accumulation, and this may be a crucial component of these syndromes. Further studies are necessary to explore this issue.
To determine whether the microtubule-associated protein tau (MAPT) and alpha-synuclein (SNCA) genes interact to confer Parkinson's disease (PD) susceptibility, we conducted a study of 557 case-control pairs. There was an increased risk of PD for persons with either SNCA 261/261 or MAPT H1/H1 genotypes as compared with persons with neither (odds ratio, 1.96; 95% confidence interval, 1.34-2.86; p = 0.0003). However, the combined effect of the two genotypes was the same as for either of the genotypes alone (separate and equal). These findings are consistent with in vitro experiments that revealed tau-mediated fibrillization of alpha-synuclein protein at low concentrations (dose threshold effect).
We assessed the 5-year risk of levodopa-induced dyskinesias by age of Parkinson's disease (PD) onset in a population-based cohort. The medical records linkage system of the Rochester Epidemiology project was used to identify residents of Olmsted County, Minnesota, with incident PD for the period 1976 through 1990. In this population-based study, the 5-year dyskinesia incidence declined with age. With PD onset after 70 years of age, the incidence was 16%. With onset from 40 to 59 years of age, the incidence was higher at 50%. These incidence data may overestimate the functional importance, because patients with minimal or reversible dyskinesias were counted.
Oxidative stress is well documented in Parkinson's disease (PD) and has been attributed to dopamine oxidative metabolism. However, evidence of oxidative stress is found in a variety of neurodegenerative disorders, suggesting that more general factors are responsible or that cytodestructive processes secondarily generate oxyradical products. Increasing evidence points away from dopamine metabolism as an important contributor to PD neurodegeneration. Predictions from the dopamine oxidative stress hypothesis of PD reveal multiple inconsistencies. Although the clinical and therapeutic importance of the nigrostriatal dopaminergic system is undeniable, PD neuropathology is much more widespread.
We investigated the risk of cancer after the diagnosis of Parkinson's disease (PD) through a historical cohort study. We used the medical records-linkage system of the Rochester Epidemiology Project to identify all incident cases of PD in Olmsted County, Minnesota from 1976 through 1995. Patients with PD were matched by age (+/- 1 year) and gender to referent subjects from the same population. For 196 patients and 185 referent subjects, we ascertained the incidence of cancer through medical records abstraction between the date of diagnosis (or index date) and death, loss to follow-up, or end of study. The risk of cancer was higher among patients than in referent subjects (relative risk [RR] = 1.64; 95% confidence interval [CI] = 1.15-2.35; P = 0.007). The RR did not change noticeably after adjustment for smoking. The increased risk was significant for nonmelanoma skin cancer (RR = 1.76; 95% CI = 1.07-2.89; P = 0.03), but not for other more severe types of cancer; therefore, we cannot exclude the occurrence of a surveillance bias. Among PD patients, there was no relation between the risk of cancer and the cumulative dose of levodopa received or the use of other PD medications.