Abstracts

Copper / Zinc SOD

Copper/Zinc SOD

Shown to be uncommon in sporadic amyotrophic lateral sclerosis patients, copper/zinc superoxide dismutase-1 mutations occurred in only 2.6 percent of the 155 cases evaluated. The authors identified three patients with no family history of the disease with SOD-1 mutations identical to those identified in the familial form of ALS. This suggests that these SOD-1 mutations underlie the disease phenotype in these sporadic cases. The study identified a novel insertion mutation in exon 4 in a single SALS patient, suggesting a truncated protein may be the cause for pathogenesis.

Jackson, Mandy, B.Sc., et al: Copper/Zinc Superoxide Dismutase 1 and Sporadic Amyotrophic Lateral Sclerosis: Analysis of 155 Cases and Identification of a Novel Insertion Mutation, Annals of Neurology, November, 1997;42(5):803-807.

Dysphagia

Dysphagia

Oral and pharyngeal dysphagia is a common symptom in patients with amyotrophic lateral sclerosis (ALS) and is the result of a progressive loss of function in bulbar and respiratory muscles.

Clinicians involved in the management of ALS patients should be familiar with the common clinical findings and the usual patterns of temporal progression. The prevention of secondary complications, such as nutritional deficiency and dehydration that compound the deteriorating effects of the disease, requires careful monitoring of each patient's functional status and timely intervention with appropriate management techniques.

Strand EA et al., Management of oral-pharyngeal dysphagia symptoms in amyotrophic lateral sclerosis. Dysphagia, 1996 Spring, 11:2, 129-39.

Enteral Nutrition (ALS)

Enteral Nutrition

Bulbar involvement in amyotrophic lateral sclerosis (ALS) is often related to a worse prognosis on account of the higher risk of pulmonary aspiration and undernutrition due to "dysphagia".

Percutaneous endoscopic gastrostomy (PEG) should be included symptomatic treatment of all ALS patients with bulbar involvement from the onset of symptoms.

Mazzini-L et al: Percutaneous endoscopic gastrostomy and enteral "nutrition" in amyotrophic lateral sclerosis. J-Neurol. 1995 Oct; 242(10): 695-8.

Free Radicals (ALS)

Free Radicals

Recent studies have implicated free radicals in the pathogenesis of amyotrophic lateral sclerosis (ALS), a fatal, paralytic disorder of motor neurons.

Report measurements of erythrocyte activity of the 3 main free radical scavenging enzymes: copper/zinc superoxide dismutase (Cu/Zn-SOD), catalase, and glutathione peroxidase.

Mean Cu/Zn-SOD activity was reduced in eight familial ALS patients with mutations of Cu/Zn-SOD but was normal in patients with both familial ALS without identified Cu/Zn-SOD mutations and sporadic ALS. Glutathione peroxidase activity was significantly reduced only in sporadic ALS patients treated with insulin-like growth factor I (100 micrograms/kg). Catalase activity was normal in sporadic and familial ALS.

Neither glutathione peroxidase nor catalase activities correlated significantly with duration of symptoms or age at onset. Vitamin E, vitamin C, and beta-carotene did not affect any of the three enzyme activities. These observations indicate that disturbances of catalase and glutathione peroxidase function are not likely to be central factors in the pathogenesis of ALS.

Przedborski S et al., Blood superoxide dismutase, catalase and glutathione peroxidase activities in familial and sporadic amyotrophic lateral sclerosis. Neurodegeneration, 1996 Mar, 5:1, 57-64.

Outcomes

Outcomes

The Amyotrophic Lateral Sclerosis Clinical Assessment, Research, and Education Project (ALS CARE) will conduct outcomes research and develop educational programs that benefit ALS patients and neurologists.

A data coordinating center has been established in the Center for Outcomes Research at the University of Massachusetts Medical Center, which will manage a North American Database of ALS Outcomes.

This voluntary database is designed to:
(1) guide the development of educational programs to improve the care of ALS patients and
(2) provide a mechanism for neurologists to evaluate the impact of their diagnostic and therapeutic decisions in a manner that is timely, confidential, and objective.

Anderson FA Jr & Miller RG: ALS care: a resource for measuring and improving ALS outcomes. Neurology, 1996 Oct, 47:4 Suppl 2, S113-5; discussion S115-6.

Tyrosine

Tyrosine

Mutations in superoxide dismutase 1 (SOD1; EC 1.15.1.1) are responsible for a proportion of familial amyotrophic lateral sclerosis (ALS) through acquisition of an as-yet-unidentified toxic property or properties.

Two proposed possibilities are that toxicity may arise from imperfectly folded mutant SOD1 catalyzing the nitration of tyrosines [Beckman] through use of peroxynitrite or from peroxidation arising from elevated production of hydroxyl radicals through use of hydrogen peroxide as a substrate [Wiedau-Pazos].

The presence of elevated nitrotyrosine levels beginning at the earliest stages of cellular pathology and continuing throughout progression of disease demonstrates that tyrosine nitration is one in vivo aberrant property of this ALS-linked SOD1 mutant.

Bruijn LI et al., Elevated free nitrotyrosine levels, but not protein-bound nitrotyrosine or hydroxyl radicals, throughout amyotrophic lateral sclerosis (ALS)-like disease implicate tyrosine nitration as an aberrant in vivo property of one familial ALS-linked superoxide dismutase 1 mutant. Proc Natl Acad Sci U S A, 1997 Jul 8, 94:14, 7606-11.