Incidence of infantile spinal muscular atrophy on Shikoku Island of Japan

Background

Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by homozygous mutations in the SMN1 gene. SMA has long been known to be the most common genetic cause of infant mortality. However, there have been no reports on the epidemiology of infantile SMA (types 1 and 2) based on genetic testing in Japan. In this study, we estimated the incidence of infantile SMA on Shikoku Island, which is a main island of Japan and consists of four prefectures: Ehime, Kagawa, Tokushima and Kochi.

Trends in head injury incidence in New Zealand: a hospital-based study from 1997/1998 to 2003/2004

Traumatic brain injury (TBI) is a leading cause of disability and death in young adults. Globally, the incidence of TBI hospitalizations is estimated at 200-300 people per 100,000 annually. Using a national health database, we examined the incidence of TBI-related hospital discharges (including 1-day stays) to New Zealand Hospitals from 1997/1998 to 2003/2004. Crude annual hospital-based incidence rates for the total population ranged from 226.9 per 100,000 in 1998/1999 to a high rate of 349.2 in 2002/2003. There was a noticeable increase in rates with the change from ICD-9 to ICD-10 diagnostic codes and there was also disparity in incidence rates according to ethnicity, age and gender. Crude annual hospital-based incidence rates for males and females in Maori (689/100,000 and 302.8/100,000 person-years) and Pacific Island populations (582.6/100,000 and 217.6/100,000 person-years) were much higher than those for the remaining population (435.4/100,000 and 200.9/100,000 person-years), particularly for males. The overall age-standardized hospital- based incidence rate for 2003/2004 was 342 per 100,000 per year (95% CI = 337-349/100,000), and 458 per 100,000 per year for Maori (95% CI = 438-479/100,000) with Maori males experiencing a peak in incidence between 30 and 34 years of age that was not evidenced for the wider population. Standardized hospital-based incidence rates for the total population and for Maori by age, gender and ICD-10 diagnostic codes are also examined.     

Epidemiological investigation of spinal muscular atrophy in Japan

BackgroundInternational reporting of epidemiological surveys of spinal muscular atrophy (SMA) in Japan has been limited to Shikoku, despite the epidemiology of the disease in countries worldwide becoming clearer. Treatments of 5q-SMA have been developed, and epidemiological studies are needed.PurposeThis study aimed to conduct a nationwide epidemiological survey of SMA in Japan to clarify the actual situation of SMA in Japan.MethodPatients with all clinical types of SMA, including neonates and adults, were selected from 1,005 medical facilities in Japan.ResultsAs of December 2017, the actual number of reported patients with SMA was 658 and the genetic testing rate was 79.5%. The estimated number of patients was 1,478 (95% confidence interval (CI), 1,122–1,834), with a prevalence of 1.17 (95%CI, 0.89–1.45) per 100,000 people and an incidence of 0.51 (95%CI, 0.32–0.71) per 10,000 live births. Incidence rates of 5q-SMA by clinical type were 0.27 (95%CI, 0.17–0.38) and 0.08 (95%CI, 0.04–0.11) per 10,000 live births for type 1 and 2, respectively, in cases with a definitive diagnosis by genetic testing. We found that 363 cases (82.7%) occurred less than 2 years and 88 (20.0%) occurred age of 2 months old or under.ConclusionThis study clarifies the prevalence and incidence of SMA in Japan. As infantile onset accounts for most cases of SMA, newborn screening and subsequent treatment are important to save lives.     

Epidemiology of spinal muscular atrophies in a sample of the Italian population.

In the course of an epidemiological survey in four provinces of Veneto (northeastern Italy) 67 spinal muscular atrophy (SMA) cases (types I, II and III) were recorded. The survey spanned the period 1960-1983 and involved 859,891 consecutive live-born infants in a population of 2,635,800 inhabitants. The overall prevalence at birth for SMA types I, II and III was 7.8/100,000 live births. Type I alone accounted for 4.1/100,000 live births. If the hypothesis that SMA types I, II and III are clinical manifestations of allelic mutations is assumed, the mutation rate would be about 70 x 10(-6) and the frequency of the heterozygotes 1 in 57.     

Spinal muscular atrophy. Incidence in Iceland.

Spinal muscular atrophy (SMA) is among the commonest degenerative disorders of the nervous system in childhood. This is an inherited autosomal recessive disease which results in premature death of anterior horn cells of the spinal cord and is manifested by progressive weakness and atrophy of skeletal muscles. Few studies have looked at the frequency of the disease in a defined population. We identified all patients diagnosed with SMA in Iceland during a 15-year period. The diagnosis is based on typical symptoms and supported by results of electromyography/nerve conduction studies and muscle biopsy. The average annual incidence was 13.7 per 100,000 live births for all types of SMA, which is similar to that reported in other population-based studies.     

The epidemiology of patients undergoing meningioma resection in Auckland,New Zealand, 2002 to 2011

The incidence of meningioma is known to vary by gender and ethnicity. This study aimed to describe the epidemiological characteristics of a 10-year cohort of patients undergoing meningioma resection at Auckland City Hospital, Auckland, New Zealand. Of particular interest was whether there was any difference in meningioma incidence and recurrence rates between New Zealand Maori and Pacific Island patients compared with other ethnic groups. The study was a retrospective analysis of 493 patients with pathologically confirmed meningioma over the period 1 January 2002 to 31 December 2011. Based on this neurosurgical cohort, the minimum incidence of meningioma in the Auckland region was 3.39 per 100,000 population per year (95% C.I. 3.02–3.80) for the study period. Meningioma was significantly more common in women than men by a ratio of 4.2:1. New Zealand Maori and Pacific Island patients had a significantly higher incidence of meningioma than other ethnic groups. New Zealand Maori had a meningioma incidence 2.74 times that of Europeans (95% C.I. 2.01–3.73, p < 0.001). Pacific Island patients had 2.03 times higher incidence of meningioma than Europeans (95% C.I. 1.42 – 2.89, p < 0.001). The overall meningioma recurrence rate was 21.6% with a mean follow-up of 77 months. Recurrence rates for meningioma among Pacific Island patients were significantly higher than for other ethnic groups (hazard ratio 1.73, p = 0.008). Multivariate analysis of clinical variables confirmed the significance of traditional prognostic factors such as WHO tumour grade and Simpson grade of surgical excision in predicting meningioma recurrence.     

Racial differences in the diagnosis of Parkinson's disease

The objective of this cohort study was to determine the incidence of Parkinson's disease (PD) and the effects of race/ethnicity, other demographic characteristics, geography, and healthcare utilization on probability of diagnosis. The authors used the Pennsylvania state Medicaid claims dataset from 1999 to 2003 to identify newly diagnosed cases of PD among the 182,271 Medicaid enrolled adults age 40–65; 319 incident cases of PD were identified. The 4‐year cumulative incidence of PD was 45 per 100,000; 54 per 100,000 among whites, 23 per 100,000 among African‐Americans and 40 per 100,000 among Latinos (P < 0.0001), corresponding to a relative risk (RR) of PD of 0.43 for African‐Americans (P < 0.0001) compared with whites. After adjusting for age, sex, geography, reason for Medicaid eligibility, and average number of visits, African‐Americans were still half as likely to be diagnosed with PD as whites (RR 0.45, P < 0.0001). Older age, more healthcare visits and Medicaid eligibility because of income alone also were significantly associated with PD diagnosis, while male sex was not. Observed racial differences in incidence of PD are not explained by differences in age, sex, income, insurance or healthcare utilization but still may be explained by biological differences or other factors such as education or aging beliefs. Better understanding of the complex biological and social determinants of these disparities is critical to improve PD care. © 2009 Movement Disorder Society     

Epidemiology of primary tumours of the brain and spinal cord: a regional survey in southern England.

This survey is based upon 894 patients presenting with primary tumours of the brain, spinal cord, and meninges, over a nine year period in the Wessex population of about 1 1/2 million. All patients were 15 years of age or over. Each tumour type is characterized by age, sex, district, social class, and by rural or urban distribution. Standardized morbidity ratios for each tumour type are calculated for each health district. Gliomas are the commonest tumour with an average annual incidence of 3.94 per 100,000; they occur with a lower frequency in large urban areas. Grade 3-4 astrocytomas (glioblastoma multiforme) have a peak annual incidence of 7.53 per 100,000 in the 50-59 years age group and are more common in males. The peak incidence for oligodendrogliomas is also 50-59 years but for grade 1-2 astrocytomas it is 30-39 years. Meningiomas have an average annual incidence of 1.23 per 100,000 with a peak incidence of 2.48 per 100,000 at 60-69 years; they have a female predominance (female 1.76 per 100,000; male of 0.64 per 100,000). Rural districts have a lower incidence of meningiomas than urban areas. There is some variation in the distribution of gliomas, meningiomas, and Schwannomas throughout the Wessex region and there is a suggestion of geographical clustering of ependymomas, acoustic neuromas, and meningiomas. An excess of patients with grade 1-2 astrocytomas and oligodendrogliomas is seen in social classes 1 and 2 and a deficit in classes 4-5; a similar, but less marked, preponderance is seen with meningiomas.     

Incidence of unprovoked seizures and epilepsy in Iceland and assessment of the epilepsy syndrome classification: a prospective study

BACKGROUND: No population-based incidence studies of epilepsy have studied syndrome classification from the outset. We prospectively studied the incidence of a single unprovoked seizure and epilepsy in the population of Iceland, and applied the syndrome classification endorsed by the International League Against Epilepsy to this population. METHODS: We used a nationwide surveillance system to prospectively identify all residents of Iceland who presented with a first diagnosis of a single unprovoked seizure or epilepsy between December 1995 and February 1999. All cases were classified by seizure type, cause or risk factors, and epilepsy syndrome. RESULTS: The mean annual incidence of first unprovoked seizures was 56.8 per 100,000 person-years, 23.5 per 100,000 person-years for single unprovoked seizures, and 33.3 per 100,000 person-years for epilepsy (recurrent unprovoked seizures). Incidence was similar in males and females. Partial seizures occurred in 40% and a putative cause was identified in 33%. Age-specific incidence was highest in the first year of life (130 per 100,000 person-years) and in those 65 years and older (110.5 per 100,000 person-years). Using strict diagnostic criteria for epilepsy syndromes, 58% of cases fell into non-informative categories. Idiopathic epilepsy syndromes were identified in 14% of all cases. INTERPRETATION: Findings are consistent with incidence studies from developed countries. Although the epilepsy syndrome classification might be useful in tertiary epilepsy centers, it has limited practicality in population studies and for use by general neurologists.     

Epidemiology of cerebrovascular disease in Tartu, Estonia, USSR, 1970 through 1973.

This study was undertaken to establish the incidence and mortality for various types of cerebrovascular disease in the population of Tartu. All medical records for this population were reviewed for the period 1970 through 1973, and those with a diagnosis of brain infarction, transient ischemic attacks, cerebral hemorrhage or subarachnoid hemorrhage were identified. Only the first stroke was considered when determining incidence. A total of 786 cases were included in the study. Without cases of transient ischemic attacks, the number was 667 (e.g., cases of stroke). Cerebral infarction accounted for 80% of all strokes, cerebral hemorrhage for 13.5% and subarachnoid hemorrhage for 6.5%. The incidence rate for stroke was higher for men than for women and significantly increased in each older age group. The rate for all persons was 184 per 100,000 population per year. The incidence of transient ischemic attacks was 33 per 100,000 population per year. The mortality rate for stroke for this population was 98/100,000 per year. The data on incidence of stroke and its type, its dependence on age and sex, and mortality rate are close to the corresponding data reported from other countries.     

Survey of patients with spinal muscular atrophy on the island of Shikoku,Japan

BackgroundSpinal muscular atrophy (SMA) is an inherited neuromuscular disorder associated with spinal motor neuron loss and characterized by generalized muscle weakness. Only a few reports exist on SMA epidemiology in Japan. Additionally, nusinersen recently became available as a treatment for this condition. We estimated the prevalence of each type of SMA on Shikoku, Japan’s fourth-largest major island.MethodsWe sent a questionnaire to all 131 hospitals in Shikoku that have pediatrics or neurology departments from March to September 2019, asking whether each hospital had SMA patients at that time. If so, we sent a second questionnaire to obtain more detailed information on the clinical data and treatment of each patient.ResultsA total of 117 hospitals (89.3%) responded to our first questionnaire, and 21 SMA patients were reported, 16 of whom had homozygous deletion of SMN1. Of the 21, nine had SMA type 1, five were type 2, five were type 3, one was type 4, and one was unidentified. The estimated prevalence for all instances of SMA and 5q-SMA was 0.56 and 0.43 per 100,000 people, respectively. Thirteen patients had received nusinersen therapy. Its outcomes varied from no obvious effects and being unable to sit to being able to sit independently.ConclusionOur data showed the prevalence of SMA types 2 and 3 was relatively low on Shikoku compared with previous reports from other countries, suggesting delayed diagnosis may affect the results. Remaining motor function may be one predicting factor. Greater awareness of SMA among clinicians and patients seems necessary for more accurate epidemiological studies.     

Incidence and pattern of cerebrovascular diseases in Benghazi, Libya.

During a 12 month study period, a total of 329 incident cases of stroke occurred in Benghazi, Libya. This provided an unadjusted annual incidence rate for stroke of 63 per 100,000 population; the corresponding rates for the male and female were 69 and 58 per 100,000 respectively. The sex dependent difference in the incidence was not statistically significant. Cerebral infarction was the commonest type of stroke accounting for 80.9%. The incidence rates increased with age in all categories of stroke. Hypertension and ischaemic heart disease were common risk factors among the male patients, while diabetes and hypercholesterolaemia were more frequent in the female patients.     

High incidence of SMN1 gene deletion in Moroccan adult-onset spinal muscular atrophy patients

Abstract. Spinal muscular atrophy (SMA) is an autosomal recessive motor neuropathy characterized by selective degeneration of anterior horn cells of the spinal cord. Childhood SMA is divided into three types (I–III) on the basis of age of onset and severity. These disorders have been linked to the 5q13 region, where mutations in the Survival Motor Neuron 1 (SMN1) gene have been found in affected individuals. In the case of adult-onset SMA (type IV), on the other hand, reports of homozygous absence of SMN1 gene have been rare. We conducted deletion analysis of SMN and a neighboring gene, NAIP (neuronal apoptosis inhibiting protein). Among 54SMA patients (types I–IV), all of Moroccan origin, Exon 7 of the SMN1 gene was homozygously absent in 100% of type I, 90% of type II, 74% of type III and 80% of type IV SMA patients. Deletion of SMN1 exon 8 was detected in 100% of type I, 53% of type II, 53% of type III and 80% of type IV patients. NAIP exon 5 was homozygously deleted in 67% of type I, 32% of type II, 5% of type III and 20% of type IV SMA patients. Thirty control individuals who were studied had normal SMN1 and NAIP genes. Our results show a high incidence of SMN1 gene deletion in adult-onset SMA patients indicating that SMN1 is the autosomal recessive adult SMA-causing gene. While NAIP is commonly deleted in SMA, this is unlikely to affect disease severity; it was deleted in two adult SMA patients with mild phenotypes.     

Descriptive epidemiology of spinal muscular atrophy type I in Estonia

Spinal muscular atrophy is the second most frequent autosomal-recessive disorder in Europeans. There are no published epidemiological data on SMA in Estonia and other Baltic countries. The aim of this study was to estimate the incidence of SMA I in Estonia. All patients with SMA I diagnosed between January 1994 and December 2003 were included in the study. The diagnosis was established on the basis of neurological evaluation, ENMG findings, molecular studies and muscle biopsy. PCR and restriction enzyme analysis was used to detect the homozygous deletion of the SMN1 gene. A total of 9 cases of SMA I were identified during this 10-year period. The incidence of SMA I in Estonia is 1 in 14,400 live births, which is similar to the result from Hungary but lower than average incidence in the world. Only one of the patients was female. Typical SMN1 gene deletion was found in all cases.     

The epidemiology of motor neurone disease in two counties in the southwest of England

The epidemiology of motor neurone disease (MND) in the counties of Devon and Cornwall in the southwest of England has not previously been studied. A previous study of England and Wales has, however, reported a very high death certification rate of MND in Devon. This study was carried out to establish the prevalence and incidence of MND in Devon and Cornwall and make comparisons with published rates in other populations. We attempted to identify all cases of MND diagnosed in Devon and Cornwall between 2002 and 2007. Case identification was centred on the major hospitals in the two counties and multiple sources of ascertainment were used. All identified cases had their case notes reviewed to establish the diagnosis and classify by type of MND. Point prevalence of MND was established for September 1st, 2007. The overall incidence rate standardised to the 2001 United Kingdom population was 2.52 per 100,000 (95% confidence interval 2.20–2.84). The incidence rate was significantly higher in males (P < 0.001). The estimated male to female incidence ratio was 2.10 (95% CI 1.61–2.73). The crude incidence rate in Cornwall was 3.78 per 100,000 (95% CI 3.03–4.53) and this was significantly higher (P = 0.011) than the rate in Devon, which was 2.61 per 100,000 (95% CI 2.19–3.04). The standardised incidence rate for the study period in Devon was 2.26 per 100,000 (95% CI 1.91–2.60) and in Cornwall it was 3.06 per 100,000 (95% CI 2.44–3.68). The overall standardised point prevalence rate was 5.66 per 100,000 (95% CI 4.49–6.83). The incidence rate of MND in our study is similar to reported findings in large prospective studies of the disease. There is a significant difference between the incidence rates in Devon and Cornwall. There is a need to establish a prospective MND Register to accurately document the epidemiological characteristics of the disease in the two counties.     

Regional and temporal variation in the incidence of multiple sclerosis in Finland 1979-1993

Previous surveys in Finland from the 1960s have documented an uneven geographic distribution of multiple sclerosis (MS). In the present study, the incidence of MS was studied during 1979-1993 in the western Vaasa and Sein?joki regions and in southern Uusimaa. The overall difference between the western and southern regions persisted; 8.7 per 100,000 in the western, and 5.1 per 100,000 in the southern region. The incidence of 11.6 per 100,000 in Sein?joki was more than twofold greater than the 5.2 per 100,000 incidence found in neighboring Vaasa. An increasing incidence trend was observed for men in Sein?joki, and a decrease for both sexes in Vaasa, while in Uusimaa the incidence remained stable for both sexes. The different incidence trends could not be readily explained by differences in case ascertainment but suggest the effect of environmental factors that have modulated the incidence of MS during the 15-year study period.     

Incidence of central nervous system tumors in Gironde, France

The incidence of CNS tumors is subject to geographical and temporal variations which are poorly understood. The incidence of these tumors was studied in Gironde, a department of southwestern France with 1,058,911 inhabitants older than 16 years. We recorded any malignant or benign central nervous system (CNS) tumor diagnosed between May 1999 and April 2001 in adults living in Gironde. Three hundred and twenty-nine CNS tumors were diagnosed during the study period. The incidence of CNS tumors in adults was therefore 15.5 per 100,000. Overall, the incidence according to sex was 14.7 for males and 16.2 per 100,000 for females. The incidence rate increased according to age up to 80 years (3.7 per 100,000 for 20-29 years of age to 33.4 per 100,000 for 70-79 years of age) and reduced thereafter for gliomas. Our estimation of the incidence of CNS tumors ranks high among the earlier reports. Further analytic studies are ongoing.     

Prevalence and incidence of multiple sclerosis in Catania, Sicily

OBJECTIVE: An epidemiologic survey was conducted to determine the prevalence and incidence of MS in the city of Catania, Sicily, Italy. Prevalence rate was calculated as point prevalence at January 1,1995, and incidence during 1974 to 1995. METHODS: The authors studied the frequency of MS in the community of Catania in a population of 333,075 inhabitants according to the 1991 census. The primary sources for the case ascertainment were the neurologic and motor rehabilitation departments, the MS Center, the Italian MS Association, private neurologists, and family doctors. All patients who satisfied the Poser criteria for clinically definite MS, laboratory-supported definite MS, clinically probable MS, and laboratory-supported probable MS were considered prevalent and incident cases. RESULTS: One hundred ninety-five patients with MS who had had the onset of disease on prevalence day in a population of 333,075 inhabitants were detected. The prevalence rate was 58.5 per 100,000 (95% CI 50.7 to 67.5). Prevalence was higher in women (62.0/100,000) than in men (54.8/100,000). The age-specific prevalence showed a peak in the group aged 35 to 44 (145.1/100,000). From 1975 to 1994, 170 subjects with MS had the clinical onset of the disease. The mean annual incidence was 2.3 per 100,000 (95% CI 2.0 to 2.6). Age-specific incidence showed a peak in the group aged 25 to 34 (6.32/100,000). Incidence for 5-year intervals increased from 1.3 during 1975 to 1979 to 3.9 during 1990 to 1994. CONCLUSIONS: These prevalence and incidence rates are close to those reported in other similar surveys carried out in Italy and southern Europe.     

Hemifacial spasm in Rochester and Olmsted County, Minnesota, 1960 to 1984

The incidence of hemifacial spasm in residents of Olmsted County, Minnesota, was studied by reviewing the medical records of patients residing in the community between 1960 and 1984. The average annual incidence rate was 0.74 per 100,000 in men and 0.81 per 100,000 in women, age-adjusted to the 1970 US white population. The average prevalence rate was 7.4 per 100,000 population in men and 14.5 per 100,000 in women. The incidence and prevalence rates were highest in those from 40 to 79 years of age.     

Population-based estimates of neuroendovascular procedures: results of a state-wide study

Background: The Brain Attack Coalition identified the availability of neuroendovascular procedures as an essential component of a comprehensive stroke center. Objective: To provide population-based estimates of neuroendovascular procedures. Methods: State-wide estimates of cervicocerebral angiograms, endovascular ischemic stroke treatments, carotid angioplasty and stent placements, intracranial angioplasty and stent placements, endovascular treatment of intracranial aneurysms, and endovascular treatment of intracranial arteriovenous malformations (AVMs) were obtained. We calculated the annual incidence rates of various neuroendovascular and neurosurgical procedures (per 100,000 persons). For the denominator, total persons in each year were categorized in 10-year age intervals. Results: The incidence of carotid endarterectomy (387.6 per 100,000 persons) and carotid stent placement (34.7 per 100,000 persons) peaked at 75-84 years. The incidence of aneurysm embolization also peaked in that population bracket (67.9 per 100,000 persons), yet there was a dramatic reduction in the incidence of surgical aneurysm treatment (3.6 per 100,000 persons) in those aged 75-84 years. There was a prominent reduction in the incidence of all procedures in the population aged ≥85 years, except for intravenous/intra-arterial thrombolytic use in ischemic stroke. The incidence of ischemic stroke increased almost by 50% in the population aged ≥85 years compared to those aged 75-84 years. However, the incidence of endovascular procedures for acute ischemic stroke decreased from 22.8 per 100,000 persons in the population aged 75-84 years to 13.2 per 100,000 persons in the population aged ≥85 years. Conclusions: A marked disproportion of neuroendovascular procedures performed and disease prevalence was noted in persons aged ≥85 years, an increasing segment of the population according to recent Census.