At the dose studied, topiramate did not have a beneficial effect for patients with ALS. High-dose topiramate treatment was associated with a faster rate of decline in muscle strength as measured by MVIC and with an increased risk for several adverse events in patients with ALS. Given the lack of efficacy and large number of adverse effects, further studies of topiramate at a dose of 800 mg or maximum tolerated dose up to 800 mg/day are not warranted.

Any beneficial effect of creatine at 5 g per day in ALS must be small. Other agents should be considered in future studies of therapeutic agents to address mitochondrial dysfunction in ALS. In addition, motor unit number estimation may be a useful outcome measure for future clinical trials in ALS.

Metal toxicity has been identified as a possible risk factor for amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. We conducted a retrospective chart review of urinary, hair and blood metal levels and serum ferritin in 321 people with ALS seen over a ten-year period at the Massachusetts General Hospital (MGH). We found that hair lead levels and serum ferritin levels were elevated in ALS patients compared to published normal values. Metal levels of arsenic, lead, mercury, cadmium, thallium, cobalt and aluminum in 24-hour urine specimens and lead, mercury and arsenic in serum were within the normal range. We conclude that twenty-four hour urine or blood testing for metals is not warranted as part of the evaluation of ALS. Elevated levels of serum ferritin in ALS population could reflect an underlying perturbation in iron metabolism.

We conducted case-control and prospective longitudinal studies to examine risk factors and predictors of disease progression for ALS. Ninety-five subjects with ALS and 106 healthy control subjects were enrolled. All subjects completed a risk factor questionnaire at enrollment. The ALS subjects were prospectively followed for one year to define factors that influence the rate of disease progression, measured by rate of change in percent predicted forced vital capacity (%FVC) and the ALS functional rating scale (ALSFRS) score. The association of each potential risk factor with ALS was determined using univariate logistic regression. A random slope model was used to determine the association of each risk factor with disease progression. The demographic characteristics of ALS subjects and controls at enrollment did not differ. Significant risk factors for ALS included reported exposure to lead (p = 0.02) and pesticides (p = 0.03). Disease progression was faster in the ALS subjects having bulbar onset and a shorter time period between onset of symptoms and diagnosis. Pertinent variables not associated with either causation or progression of ALS included physical activity, cigarette smoking and a history of physical trauma or other clinical disorders.

In the past two decades new practice parameters for clinical care in ALS were developed and several clinical trials were performed. We sought to review information in these prospective datasets and assess whether natural history of ALS has changed over time. Survival and the rate of functional decline were compared across the placebo arms of efficacy trials conducted from 1999 to 2005 by the Northeast ALS Consortium (NEALS). Similar data from the placebo arms of 12 other published efficacy ALS trials conducted between 1990 and 2008 were compared descriptively. In the three NEALS clinical trials, survival improved over time in the placebo cohort (p=0.05) while the rate of change in maximum voluntary isometric contraction (MVIC) (p=0.15), ALS Functional Rating Scale (ALSFRS) (p=0.6) and vital capacity (%VC) (p=0.5) was unchanged. No differences were observed in the mean rates of decline of these outcome measures in the published clinical trials. However, survival improved in the more recently conducted trials. Survival improved over time in placebo controlled participants enrolled in clinical trials in ALS since 1990. However, the decline in measures of function appears unchanged since then. These changes in natural history reflect improvements in symptomatic care of ALS.