Epidemiology and clinical features of amyotrophic lateral sclerosis in Ireland between 1995 and 2004.

BACKGROUND: We conducted a prospective, population based study to examine trends in incidence and prevalence of amyotrophic lateral sclerosis (ALS) in Ireland from 1995 to 2004. METHODS: The Irish ALS Register was used to identify Irish residents diagnosed with ALS between the 3 year period from 1 January 1995 to 31 December 1997 and the 3 year period from 1 January 2002 to 31 December 2004. RESULTS: 465 Irish residents were diagnosed with ALS during the study periods. The annual incidence rate of ALS in Ireland remained stable over this time (2.0 cases per 100,000 person-years; 95% CI 1.9, 2.2). Median survival of Irish ALS patients was 16.4 months and did not change during the study period. Demographics and clinical features of the incident and prevalent Irish ALS cohorts were markedly different.

A novel candidate region for ALS on chromosome 14q11.2.

Sequence variations with biologic effect in ALS have been identified in the gene for vascular endothelial growth factor (VEGF). The gene for a related protein, angiogenin, lies on chromosome 14q11.2. Analysis of the angiogenin (ANG) gene in the authors' population has demonstrated a significant allelic association with the rs11701 single nucleotide polymorphism (SNP) and identified a novel mutation in two individuals with sporadic ALS that potentially inhibits angiogenin function. These observations propose a candidate region for ALS on chromosome 14q11.2 and suggest that other genes with similar function to VEGF may be important in the pathogenesis of ALS.

Access to health services in Ireland for people with Multiple Sclerosis and Motor Neurone Disease.

We conducted a telephone questionnaire to determine the utilisation of hospital and community based services by patients with Motor Neurone Disease and Multiple Sclerosis in Ireland. 94 MND and 188 MS patients participated in the study. MND patients were more likely to have free medical care than MS patients, despite legislation favouring the converse. Severely disabled MND patients were more successful at accessing free community-based services than were severely disabled MS patients. Private medical insurance conferred no advantage when obtaining services or purchasing equipment. Many patients were unaware of the specific roles of the various clinical professionals. There are significant deficiencies in patients' ability to access multidisciplinary services. Voluntary organisations often bridge the gap in service provision. An investment in services for people with chronic neurological disability is urgently required.

Effect of a multidisciplinary amyotrophic lateral sclerosis (ALS) clinic on ALS survival: a population based study, 1996-2000.

BACKGROUND: In recent years, there has been a paradigm shift in the method of healthcare delivery to amyotrophic lateral sclerosis (ALS) patients with the emergence of multidisciplinary ALS clinics that cater exclusively for patients with this condition. The impact of multidisciplinary management has not been previously evaluated. METHODS: Using data from the Irish ALS Register, we conducted a prospective, population based study of all ALS cases diagnosed in Ireland over a five year period to evaluate the effectiveness of a multidisciplinary clinic on ALS survival. RESULTS: Eighty two (24%) patients attended the multidisciplinary ALS clinic, with the remaining 262 (76%) cases followed in a general neurology clinic. The ALS clinic cohort was an average of five years younger (60.1 v 65.6 years) and were more likely to receive riluzole than the general neurology cohort (99% v 61%). The median survival of the ALS clinic cohort was 7.5 months longer than for patients in the general neurology cohort (logrank = 15.4, p < 0.0001). Overall, one year mortality was decreased by 29.7%. Prognosis of bulbar onset patients was extended by 9.6 months if they attended the ALS clinic. Using multivariate analysis, attendance at the ALS clinic was an independent covariate of survival (HR = 1.47, p = 0.02). CONCLUSIONS: ALS patients who received their care at a multidisciplinary clinic had a better prognosis than patients attending a general neurology clinic. The data suggest that active and aggressive management enhances survival, particularly among ALS patients with bulbar dysfunction. The effect of clinic type must be considered in future clinical trials design.

Clinical features of amyotrophic lateral sclerosis according to the El Escorial and Airlie House diagnostic criteria: A population-based study.

BACKGROUND: The El Escorial and the revised Airlie House diagnostic criteria for amyotrophic lateral sclerosis (ALS) classify patients into categories reflecting different levels of diagnostic certainty. We conducted a prospective, population-based study of the natural course of ALS in the Republic of Ireland during a 6-year period to examine the utility of these ALS diagnostic criteria. METHODS: Using data from the Irish ALS Register, we studied the clinical features of all patients diagnosed as having ALS in Ireland throughout their illness. RESULTS: Between 1993 and 1998, 388 patients were diagnosed as having ALS. Forty percent of patients reported bulbar-onset symptoms. Disease progression occurred over time: at last follow-up, 75% of all patients had bulbar signs, compared with 59% at diagnosis. When the El Escorial criteria were applied, more than half of patients (218 [56%]) had definite or probable ALS at diagnosis. Of the 165 possible and suspected ALS cases at diagnosis (trial ineligible), 110 (67%) were trial eligible at last follow-up. Of the 254 patients who had died, 229 (90%) had definite or probable ALS, whereas 25 patients (10%) remained trial ineligible at death. El Escorial category at diagnosis was not a significant prognostic indicator. Use of the Airlie House criteria had no effect on the median time from symptom onset to trial eligibility (12.9 vs 12.8 months). CONCLUSIONS: The El Escorial and Airlie House diagnostic criteria are excessively restrictive. Furthermore, levels of diagnostic certainty cannot be used as prognostic indicators. Arch Neurol. 2000;57:1171-1176

Amyotrophic lateral sclerosis mimic syndromes: a population-based study.

BACKGROUND: The Irish ALS Register is a population-based register of the epidemiological characteristics of amyotrophic lateral sclerosis (ALS) in the republic of Ireland. OBJECTIVE: To describe the clinical and demographic details of those patients included in the Irish ALS Register who were incorrectly diagnosed as having ALS (patients who were ultimately rediagnosed as having an "ALS mimic syndrome"). METHODS: The medical records of each patient referred to the register are routinely reviewed and, where possible, patients are examined by our group during their illness. RESULTS: Between January 1, 1993, and December 31, 1997, 32 patients (representing 7.3% of 437 referrals) were rediagnosed as having a condition other than ALS. The median age at onset for these 32 patients was 56.0 years (range, 19.5-85.8 years) for men and 53.5 years (range, 39.5-70.4 years) for women. Twenty-nine patients (91%) presented with symptoms referable to the limbs, and the remainder presented with symptoms involving the bulbar musculature. Multifocal motor neuropathy was the most common condition mistaken for ALS, accounting for 7 cases (22%), followed closely by Kennedy disease (4 cases [13%]). Factors leading to diagnostic revision included evolution of atypical symptoms, results of specific investigations, and failure of symptoms to progress. Twenty-seven (84%) of the patients with an ALS mimic syndrome fulfilled the El Escorial criteria for either "suspected" or "possible" ALS, 4 (13%) met the criteria for probable ALS, and 1 (3%) had definite ALS. CONCLUSIONS: The application of the El Escorial diagnostic criteria may facilitate early recognition of non-ALS cases. Misdiagnosis of ALS remains a common clinical problem despite the increased availability of investigations and a greater awareness among neurologists of potential diagnostic pitfalls.

Incidence and prevalence of ALS in Ireland, 1995-1997: a population-based study.

BACKGROUND: We conducted a prospective, population-based study of ALS in the Republic of Ireland for the 3-year period 1995 to 1997. METHODS: To ensure complete case ascertainment, multiple sources of information were used, including consultant neurologists, neurophysiologists, primary care physicians, and the Irish Motor Neuron Disease Association. The El Escorial diagnostic criteria for ALS were applied to all cases enrolled on the register and each patient was regularly followed up during his or her illness. RESULTS: Between January 1, 1995, and December 31, 1997, 231 patients were diagnosed with possible, probable, or definite ALS, including 133 men (57.6%) and 98 women (42.4%). The average annual incidence rate was 2.1 per 100,000 person-years (95% CI, 1.8 to 2.4), and 2.8 per 100,000 person-years for the population older than 15 years (95% CI, 2.4 to 3.1). The incidence rate was higher for men, being 2.5 per 100,000 person-years (95% CI, 2.0 to 2.9), than for women, at 1.8 per 100,000 person-years (95% CI, 1.5 to 2.2), and increased with age for both sexes. The median age at onset was 64.2 years for men and 67.8 years for women. On December 31, 1996, the crude prevalence was 4.7 per 100,000 of the total population (95% CI, 4.0 to 5.5), and 6.2 per 100,000 for the population older than 15 years (95% CI, 5.3 to 7.1). Adjusting to the 1996 Irish population as standard, the incidence of ALS in Ireland during the 3-year study period is the third highest reported to date. CONCLUSIONS: There was a trend toward a higher incidence of ALS in the northwestern region of Ireland, although the numbers of cases involved were small and further study is required.

Service provision for patients with ALS/MND: a cost-effective multidisciplinary approach.

Optimal management of patients with ALS/MND requires a team approach, with early referral to paramedical services for clinical assessment and prompt intervention. As the condition progresses, a flexible approach to management must be adopted by the medical team, with an ability to intervene at very short notice. We have developed an efficient multi-disciplinary clinic that services the ALS/MND population of Ireland by combining the existing infrastructure of community services with a hospital-based specialist clinic. The clinic operates on a weekly basis, and is staffed by a core team including a neurologist, a liaison nurse, and the director of the ALS/MND Association. On-site and same-day physiotherapy, occupational therapy and speech therapy is available, as is pulmonary evaluation. All patients utilising the clinical services are automatically included on the Irish Register of Motor Neurone Disease, and are tracked by the liaison nurse. The core members of the clinic interact regularly with paramedical staff within the community, ensuring that necessary community services are made available within 1-2 weeks of the clinic visit. Equipment necessary for the patient's well being is made available free of charge by the Irish Motor Neurone Disease Association, following an appropriate request from the regional para-medical staff. We have thus demonstrated that an effective multi- disciplinary care service for ALS/MND can be developed at modest cost by close personal liaison between the existing health care structures and core members of a multidisciplinary team.

Familiality of monocyte esterase deficiency in patients on continuous ambulatory peritoneal dialysis.

The purpose of this study was to determine whether or not peripheral blood monocyte esterase deficiency occurring in patients on CAPD was a familial characteristic. The peripheral blood monocyte esterase status of 74 patients on CAPD was determined by a naphthyl acetate esterase staining of cytospin preparations of their mononuclear cells following separation over ficoll. The peripheral blood of first degree relatives and spouses of monocyte esterase deficiency patients was similarly investigated for the deficiency. Three patients bad monocyte esterase deficiency and familiality of the defect was demonstrated in two of their families. The third family was incompletely investigated because of lack of consent. The monocyte esterase deficiency demonstrated in this cohort of patients did not result from their renal failure but was a familial characteristic.

The contribution of nonreentrant mechanisms to malignant ventricular arrhythmias.

Evidence obtained from experimental animals and man indicates that reentry is a major mechanism underlying arrhythmogenesis. However, focal or nonreentrant mechanisms also appear to be operative under a wide variety of pathophysiologic conditions. For example, results obtained using three-dimensional (3D) mapping from 232 simultaneous sites in the feline heart in vivo revealed that nonreentrant or focal mechanisms were prominent during both ischemia and reperfusion. During early ischemia, nonreentrant mechanisms were responsible for initiation of ventricular tachycardia (VT) in 25% of cases and, in cases where VT was initiated by reentry, it often could be maintained by a nonreentrant mechanism. During reperfusion of ischemic myocardium, nonreentrant mechanisms were responsible for initiation of VT in 75% of cases. Most importantly, the transition from VT to ventricular fibrillation in response to reperfusion was secondary to acceleration of a nonreentrant mechanism in either the subendocardium or subepicardium. Potential cellular mechanisms include: 1) sarcolemmal accumulation of amphiphiles such as long-chain acylcarnitines and lysophosphatidylcholine; 2) alpha- and beta-adrenergic mediated effects of catecholamines on the transient inward current (ITI) secondary to an increase in intracellular Ca2+; and 3) alpha-adrenergic receptor-induced decrease in IK mediated by activation of protein kinase C. Recent findings obtained using 3D intraoperative mapping in patients with refractory VT and a previous myocardial infarction also indicate that both reentrant and nonreentrant or focal mechanisms contribute. For example, in 13 selected patients, mapping was of a sufficient resolution to define the mechanisms of 10 runs of VT. Intraoperative mapping indicated that five runs of VT were initiated by intramural reentry, whereas five runs of VT were initiated by a focal or nonreentrant mechanism. The mechanisms underlying ventricular arrhythmias associated with ischemic cardiomyopathy have recently been delineated in dogs after multiple sequential intracoronary embolizations with microspheres (with a decrease in mean ejection fraction from 64% to 25%). Spontaneous VT initiated by focal mechanisms from the subendocardium in 82% and epicardium in 18%, with no evidence of macroreentry. Thus, in divergent pathophysiologic settings, nonreentrant mechanisms appear to contribute importantly to the genesis of lethal ventricular arrhythmias, suggesting that development of novel therapeutic approaches should be directed at inhibition of not only reentrant circuits, but also nonreentrant mechanisms, including triggered activity.