Prevalence and incidence of Parkinson's disease in The Faroe Islands

Objective –  A study in The Faroe Islands in 1995 suggested a high prevalence of idiopathic Parkinson's disease (IPD) and total parkinsonism of 187.6 and 233.4 per 100,000 inhabitants respectively.
Methods –  Detailed case-finding methods 10 years later were used and a neurologist has verified the diagnosis.
Results –  The crude prevalence of IPD and total parkinsonism was 206.7 per 100,000 and 227.4 per 100,000 respectively. The age-adjusted prevalence is twice as high as data from Norway and Denmark. Age at initiation of treatment and the fatality rate did not explain the increased prevalence. During 1995–2005, the average annual incidence was 21.1 per 100,000 persons for Parkinson's disease, and 22.9 per 100,000 persons, if including atypical parkinsonism.
Conclusion –  The high prevalence was verified and linked to a high incidence. The cause of the high prevalence is unknown, but neurotoxic contaminants in traditional food may play a role in the pathogenesis in this population, perhaps jointly with genetic predisposition.     

Clinical characteristics of Parkinson's disease among Inuit in Greenland and inhabitants of the Faroe Islands and Als (Denmark).

In earlier studies, we found high age-adjusted prevalences of Parkinson's disease (PD) in the Faroe Islands (209 per 100,000 inhabitants) and in Greenland (187.5 per 100,000 inhabitants) compared to the age-adjusted prevalence on the island of Als in the southern part of Denmark (98.3 per 100,000 inhabitants). We thoroughly examined patients with suspected parkinsonism using internationally accepted diagnostic criteria. In the present study, we found no significant clinical differences between patients with PD in the three areas, despite this high difference in prevalence. However, comparing the age at examination and age at treatment, the patients were younger in Greenland, a higher proportion of patients had cognitive decline, and they had a higher mean Hoehn and Yahr rating score, although they received a lower levodopa dose. A higher proportion of the patients in Greenland were newly diagnosed than in the other two areas.     

Multiple sclerosis in the Faroe Islands

Detailed questionnaires were completed in 1978–79 by 23 of the 28 then known resident Faroese multiple sclerosis (MS) patients and 127 controls. These controls were divided into 69 Group A (patient sibs and other relatives), 37 Group B (matched neighbor controls, their spouses and sibs, plus patient's spouse), and 21 Group C (distant matched controls, spouses, relatives living where MS patients never resided and British troops were not encamped during the war). No differences between cases and controls were found for education, occupation, types of residence, bathing, sanitary or drinking facilities, and nature of house construction or heating. Detailed dietary histories, available for half the subjects, revealed no difference, cases versus controls, for four age periods between age 0 and 30 years, and for 16 specified foodstuffs. Animal exposures showed overall no consistent differences by location or type of animal. There was a tendency to greater exposure to British troops during the war for cases versus Groups A and B, but this did not attain statistical significance. Vaccinations for smallpox, tetanus and diphtheria were less common in the MS; no difference was found for other vaccinations. Except for a relative deficit in the cases for rubella and (insignificantly) for measles, mumps and chicken pox, reported illnesses were equally common among all groups. Operations, hospitalizations and injuries did not differentiate the groups, nor did age at menarche for women. Neurologic symptoms were significantly more common in the cases than in the controls.     

Increased risk of essential tremor in first-degree relatives of patients with Parkinson's disease.

We conducted a historical cohort study of 981 first-degree relatives of 162 patients with Parkinson's disease (PD) and of 838 first-degree relatives of 147 controls representative of the population of Olmsted County, Minnesota. In addition, we studied 2,684 first-degree relatives of 411 patients with PD referred to the Mayo Clinic. Relatives were interviewed and screened for tremor either directly or through a proxy, and those who screened positive were examined or copies of their medical records were obtained to confirm the diagnosis of essential tremor (ET). We also obtained ET information from a medical records-linkage system (family study method). In the population-based sample, the risk of ET was significantly increased for relatives of patients with onset of PD相似文献   

Incidence of amyotrophic lateral sclerosis in the Faroe Islands

Joensen P. Incidence of amyotrophic lateral sclerosis in the Faroe Islands.
Acta Neurol Scand: 2012: 126: 62–66.
© 2011 John Wiley & Sons A/S. Objectives – The establishment of variations in the incidence of amyotrophic lateral sclerosis (ALS) in the Faroese population from that found in other general populations may point to risk factors for the development of this disease among the Faroese. The aim of this study was to estimate the annual incidence of ALS during the period 1987–2009 and to compare the occurrence of ALS in the Faroe Islands with data from three European countries. Method – All Faroese patients diagnosed with ALS in this period are documented in the current longitudinal prospective study. Results – The incidence of ALS in the Faroe Islands during the period 1987–2009 is 2.6 (1.7–3.7) per 100,000 annually. The results yielded no strong evidence of a difference (P = 0.09) in the incidence of ALS between Faroe Islands and Europe. The sample population is small, and this, of course, impacts the statistical precision of the findings. Conclusion – The data clearly suggest, however, that the Faroese population is probably not subject to an increased risk of ALS, even though certain risk factors are present in the general population: (i) a fish‐based diet contaminated with mercury and polychlorinated biphenyl; (ii) the high occurrence of the recessive carnitine transporter genetic defect; and (iii) the anticipated high degree of inbreeding at the fifth generation.     

Autism in the Faroe Islands. An Epidemiological Study

The Faroe Islands are considered to be a genetic isolate. This population study of the prevalence of autism sought to identify a representative cohort for future genetic studies. In 2002 all schools were screened for autism spectrum disorders. The target population were all children born in 1985 through 1994 and living in the Faroe Islands on December 31, 2002. Children who screened positive for autism characteristics were examined using the Diagnostic Interview for Social and Communication Disorders (DISCO). Of the children aged 8 through 17 years, 0.56% had childhood autism, Asperger syndrome or atypical autism. The male:female ratio was just under 6:1. The prevalence of autism in the Faroe Islands was very similar to that reported from many western countries.     

Applause sign in advanced Parkinson's disease

BackgroundThe ‘applause sign’ a tendency to continue applauding in response to instructions to clap three times was described in 1995 and was considered specific to degenerative disease, especially to atypical parkinsonian disorders. In early phase Parkinson's disease (PD) the sign has been reported positive as well. In late stage PD it is unknown whether and to what extent the sign may be elicited and it remains unknown if and to what degree the sign correlates to cognitive impairment and PD related dementia.MethodsNursing home residents with PD (MMSE >17) were included. All patients underwent the clapping test and were tested for cognitive disturbance by making use of accepted clinimetrics (MMSE and Scopa-cog). T-testing was performed with the hypothesis that patients expressing the applause sign would score lower on the MMSE or Scopa-cog.ResultsSeventy three nursing home residents (mainly Hoehn and Yahr 4/5) with a mean disease duration of 10 years and a mean age of 78.7 years were included. The applause sign was found positive in 15 of 73 residents (20.5%). Residents expressing the applause sign had significantly lower mean scores on the MMSE (25.1 vs 22.9 points, p < 0.006) and Scopa-cog (14.8 vs 12.0 points, p < 0.039).ConclusionsThe applause sign is present in late stage PD and correlates with a higher degree of cognitive impairment as established with accepted clinimetric tests. A higher degree of frontal lobe involvement explains the presence of the applause sign.     

Familial aggregation of Parkinson's disease in a multiethnic community‐based case‐control study

To assess the familial aggregation of Parkinson's disease (PD), we compared the cumulative incidence of PD among first‐degree relatives of PD cases and controls. We identified newly diagnosed patients with PD (n = 573) during 1994 to 1995 within Kaiser Permanente Medical Care Program of Northern California and recruited 496 cases (87%) for the case‐control study. Of 720 eligible controls matched by birth year and sex to cases, 541 (75%) agreed to participate. Information on family history of PD and other neurodegenerative diseases was obtained by in‐person structured interview. We used the reconstructed cohort approach that provides a better estimate of the risk. The cumulative incidence of PD was significantly higher among relatives of PD patients compared with relatives of controls (2.0 vs. 0.7%; relative risk (RR) = 3.4, 95% confidence interval (CI) 1.9–5.9; P = 0.0001). The degree of familial aggregation was higher among first‐degree relatives of Hispanic PD cases compared with Hispanic controls (3.7% vs. 0.4%; RR = 8.5, 95% CI 1.0–68.9) than it was among non‐Hispanic Caucasian cases and controls (2.0% vs. 0.8%; RR = 2.7, 95% CI 1.5–5.1; P = 0.02). The familial aggregation of PD was stronger among the siblings of PD cases (RR = 5.4, 95% CI 1.8–16.0) than among parents (RR = 2.7, 95% CI 1.3–5.2). The incidence and familial aggregation of PD is highest among Hispanics, warranting further studies of genetic and environmental risk factors in the Hispanic population. © 2010 Movement Disorder Society     

Comprehensive sequencing of the LRRK2 gene in patients with familial Parkinson's disease from North Africa

The LRRK2 gene is a key player in Parkinson's disease (PD), however prevalence and pathogenicity of LRRK2 variants remain to be investigated in ethnically diverse populations. Herein, we performed comprehensive sequencing of the LRRK2 gene in 92 Tunisian probands with familial PD. We then performed an association study using all identified variants in a series of 167 Lrrk2 p.G2019S‐negative patients with sporadic PD and 365 Lrrk2 p.G2019S‐negative healthy control subjects, all from the same Arab‐Berber ethnicity. We identified one novel coding substitution (p.M2408I) and 24 known coding changes. Only the Lrrk2 p.G2019S mutation segregated with disease within families and was found in 39% of familial probands. None of the variants displayed significant association with risk for sporadic PD, however a trend was observed for Lrrk2 p.Y2189C. The present study underscores the importance of the LRRK2 gene in the Tunisian PD population. © 2010 Movement Disorder Society     

MS in the Faroe Islands and the possible protective effect of early childhood exposure to the "MS agent"

Epidemiologic data on multiple sclerosis (MS) in the Faroe Islands have been interpreted by the original investigators as supporting a particular infectious disease model. They suggest that MS occurs as a late consequence of extended exposure to an infectious agent which cannot be transmitted to subjects younger than 11 years of age. However, the Faroes data may better fit an alternate model, in which MS results from delayed primary exposure to an infectious agent which more commonly produces benign illness and protection against MS in subjects who are exposed in infancy or early childhood.     

Visual symptoms in Parkinson's disease and Parkinson's disease dementia

Visual symptoms are common in PD and PD dementia and include difficulty reading, double vision, illusions, feelings of presence and passage, and complex visual hallucinations. Despite the established prognostic implications of complex visual hallucinations, the interaction between cognitive decline, visual impairment, and other visual symptoms remains poorly understood. Our aim was to characterize the spectrum of visual symptomatology in PD and examine clinical predictors for their occurrence. Sixty-four subjects with PD, 26 with PD dementia, and 32 age-matched controls were assessed for visual symptoms, cognitive impairment, and ocular pathology. Complex visual hallucinations were common in PD (17%) and PD dementia (89%). Dementia subjects reported illusions (65%) and presence (62%) more frequently than PD or control subjects, but the frequency of passage hallucinations in PD and PD dementia groups was equivalent (48% versus 69%, respectively; P = 0.102). Visual acuity and contrast sensitivity was impaired in parkinsonian subjects, with disease severity and age emerging as the key predictors. Regression analysis identified a variety of factors independently predictive of complex visual hallucinations (e.g., dementia, visual acuity, and depression), illusions (e.g., excessive daytime somnolence and disease severity), and presence (e.g., rapid eye movement sleep behavior disorder and excessive daytime somnolence). Our results demonstrate that different "hallucinatory" experiences in PD do not necessarily share common disease predictors and may, therefore, be driven by different pathophysiological mechanisms. If confirmed, such a finding will have important implications for future studies of visual symptoms and cognitive decline in PD and PD dementia.     

Multiple sclerosis incidence in the Faroe Islands 1986–2007

Joensen P. Multiple sclerosis incidence in the Faroe Islands 1986–2007. Acta Neurol Scand: 2010: 121: 348–353.
© 2009 The Author Journal compilation © 2009 Blackwell Munksgaard. Objective – Epidemiological studies of the isolated Faroese population in 1945 identified a high annual incidence of multiple sclerosis (MS) of 10/100,000. At the time, there was speculation that the disease was brought to the country by British occupation forces resident in the islands from 1940 to 1945. The objective of the current study is to determine the incidence of diagnosis of MS in the Faroe Islands during the period 1986–2007. Methods – All patients in the Faroe Islands diagnosed with MS from July 1, 1986 to July 1, 2007 are documented in the current longitudinal, prospective study. The diagnosis is based on clinical observation, magnetic resonance imaging scanning, cerebrospinal fluid tests, and visual evoked potential response testing. Results – The incidence of MS during the period 1986–2007 is 4.5/100,000 annually. This is generally of the same order of magnitude as other research findings in Scandinavia and Iceland. The incidence of MS from 1986 to 2007 is about double the incidence in the Faroe Islands for the period from 1940 to 1986, calculated to be 2.7/100,000 annually. Conclusion – The observed incidence of MS in the Faroe Islands, where the population is genetically homogeneous and where the diet exposes the population to neuro‐toxic contamination, is at the same level as found in other high‐risk regions. The former detected epidemics of MS in Faroe Islands seems apparently to have leveled out and could not be recognized in the recent period covered by the present survey.     

Involuntary commitment in Greenland, the Faroe Islands and Denmark.

Greenland, the Faroe Islands and Denmark have common legislation and registration for involuntary commitment. Commitment rates were calculated based on information from the Danish psychiatric register for 1984-1988. Direct standardization with the Danish male and female population as a standard population (1984-1988) was carried out to evaluate differences in rates. An increased risk of commitment was found in Greenland, where the crude commitment rate was 43.5 commitments per 100,000 inhabitants. The commitment rate on the Faroe Islands was 19.2 per 100,000 and 24.2 per 100,000 in Denmark. The relative risk of commitment in Greenland vs Denmark was 2.0 (1.6-2.4) and increased to the same extent for both sexes. Young men constituted a high-risk group for commitment in Greenland. Males between 15 and 34 years accounted for 55% of the total number of commitments in Greenland. The high relative commitment risk in Greenland is related to higher homicide rates, lower psychiatric bed availability, reduced access to psychiatric treatment, small settlements and increased alcohol consumption and violence than in Denmark.     

Diagnostic problems in Parkinson's disease

The diagnosis of Parkinson's disease is not as easy as previously claimed, and presents a number of pitfalls. We present three rules, or aphorisms, to help the general practitioner in overcoming these diagnostic difficulties: Know well the basic disease and its symptoms. Use tricks to elicit apparently absent 'primary' symptoms. Beware of unusual symptoms or case histories. Examples of difficulties encountered at each level are given. Such analysis should permit the physician to classify his extrapyramidal patient within one of the many types of 'parkinsonism' as shown in Table 1.     

SPECT findings in Alzheimer's disease and Parkinson's disease with dementia

We examined, with single photon emission tomography (SPECT) and (^99mTc)-HMPAO, 18 patients with idiopathic Parkinson's disease and no dementia (PD), 12 patients with PD and dementia, 24 patients with probable Alzheimer's disease (AD) and 14 controls. While the three patient groups showed significantly lower perfusion in frontal inferior and temporal inferior areas as compared to controls, both demented groups showed significantly more severe bilateral hypoperfusion in superior frontal, superior temporal and parietal areas as compared to non-demented PD patients and controls. On the other hand, no significant differences in cerebral perfusion were found between patients with AD and patients with PD and dementia. In conclusion, our findings demonstrated specific but similar cerebral perfusion deficits in demented patients with either AD or PD.     

Different iron deposition patterns in early- and middle-late-onset Parkinson's disease

BackgroundIron deposition may contribute to the clinical symptoms in Parkinson's disease (PD). With partial different clinical manifestations, the iron deposition patterns between patients with early-onset Parkinson's disease (EOPD) and middle-late-onset Parkinson's disease (M-LOPD) are still unclear. This study was designed to investigate the patterns of iron deposition and their clinical relevance in EOPD and M-LOPD patients, using quantitative susceptibility mapping technique.Materials and methodsThirty-five EOPD patients and 24 matched young controls, 33 M-LOPD patients and 22 matched older controls were recruited in the study. The iron content in the deep grey matter nuclei in the basal ganglia and midbrain were measured, and compared between patients and their corresponding controls. The correlations of regional iron content and clinical features were explored in patient groups.ResultsBoth M-LOPD and EOPD patients showed increased iron content in the substantia nigra (SN) pars compacta and SN pars reticulata. Increased iron content in the putamen was only observed in M-LOPD patients. The relationship between the increased iron content and disease severity (H&Y stages, UPDRS II scores and UPDRS III scores) was observed in M-LOPD patients, but not in EOPD patients.ConclusionOur study suggested that the iron deposition pattern was greatly influenced by the age of PD onset, which increases our understanding of the different pathological underpinnings of EOPD and M-LOPD patients.