ALS 2000: the past points to the future

Mutant SOD1 mediated pathogenesis of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neural disorder that causes death of the motor neurons in the brain and spinal cord; this affects the voluntary muscles and gradually leads to paralysis of the whole body. Most ALS cases are sporadic, though about 5-10% are familial. ALS is caused by multiple factors including mutation in any one of a number of specific genes, one of the most frequently affected is superoxide dismutase (SOD) 1. Alterations in SOD 1 have been linked with several variants of familial ALS. SOD 1 is a powerful antioxidant enzyme that protects cells from the damaging effects of superoxide radicals. The enzyme binds both copper and zinc ions that are directly involved in the deactivation of toxic superoxide radicals. Mutated SOD1 gene can acquire both gain and loss of function mutations. The most commonly identified mutations in SOD1 that affect protein activity are D90A, A4V and G93A. Deleterious mutations have been shown to modify SOD1 activity, which leads to the accumulation of highly toxic hydroxyl radicals. Accumulation of these free radicals causes degradation of both nuclear and mitochondrial DNA and protein misfolding, features which can be used as pathological indicators associated with ALS. Numerous clinical trials have been carried out over last few years with limited success. In some patients advanced techniques like gene and stem cell therapy have been trialed. However no definitive treatment option can provide a cure and currently ALS is managed by drugs and other supportive therapies. Consequently there is a need to identify new approaches for treatment of this ultimately fatal disease.

Incidence, prevalence, and medical expenditures of classical amyotrophic lateral sclerosis in Taiwan, 1999-2008

BACKGROUND/PURPOSE

Amyotrophic lateral sclerosis (ALS) is a rare disease, which makes the estimation of incidence and prevalence difficult in Taiwan. This study was conducted to investigate the incidence, prevalence, and medical expenditure of ALS in Taiwan.

METHODS

Patients who had at least one service claim either as an outpatient or inpatient between the years 2004 and 2007 and were over 15 years of age with a primary diagnosis of ALS were identified from the National Health Insurance Research Database. Additionally, ALS patients with serious disability database certificates over 15 years of age were included for the calculation of incidence and prevalence between the years 1999 and 2008. Lastly, the total medical expenditure, including ventilator use and riluzole, were reported.

RESULTS

In 2006 and 2008, the average annual incidence and prevalence of ALS was 0.51 and 1.97 (per 10(5)), respectively, in Taiwan. The male-to-female ratio of incidence for ALS was 1.67. The average medical expenditure for ALS patients stayed steady at 16-fold greater than the general population of Taiwan in 2008. The percentage of ventilator and riluzole expenditure as a proportion of total medical expense decreased from 55% in 2000 to 33% in 2008.

CONCLUSION

The incidence and average medical expenditure of ALS patients remained stable over the years in Taiwan, however, as a proportion of total medical expenses, expenditure on ventilator and riluzole decreased over the study period.

Amyotrophic lateral sclerosis: enteral nutrition provision--endoscopic or radiologic gastrostomy?

PURPOSE

To retrospectively evaluate gastrostomy placement in patients with amyotrophic lateral sclerosis (ALS) to determine the insertion method of choice.

MATERIALS AND METHODS

During 3(1/2) years, 36 patients with ALS (19 men, 17 women; mean age, 54 years; age range, 37-69 years) underwent gastrostomy. Twenty patients were primarily referred for percutaneous endoscopic gastrostomy (PEG) and 16 for percutaneous radiologic gastrostomy (PRG). Gastrostomy method, success rate of each technique, and reason for procedure failure were reviewed in each patient. Forced vital capacity (FVC) prior to gastrostomy was recorded. PEG was performed with a pull-through technique after transillumination of the abdominal wall. PRG was performed with fluoroscopic guidance and T-fastener gastropexy. A log-rank test was used to compare survival rates after PRG and PEG, and a Wilcoxon rank sum test was used to evaluate the influence of declining FVC on PEG success. The Kaplan-Meier product limit method was used to estimate survival probabilities.

RESULTS

Of the 20 patients referred for PEG, 11 had successful results. The nine failures (45%) resulted from failure to transilluminate the abdominal wall. All 16 patients primarily referred for PRG underwent successful gastrostomy. The nine patients in whom PEG failed underwent subsequent successful PRG. In patients with diaphragmatic palsy and a high subcostal stomach, an angled subcostal approach (n = 6) or intercostal approach (n = 2) was required at PRG. One death occurred in the PEG group (9%) because of procedure-related aspiration, and a second patient from the PEG group required laparotomy for postprocedural peritonitis. One death occurred in the PRG group (4%) because of inadvertent placement of the feeding tube in the peritoneal cavity. There was no significant difference between PEG and PRG in patient survival. FVC did not have a statistically significant influence on PEG failure.

CONCLUSION

Results show PRG to be the method of choice.