Antecedent Disease is Less Prevalent in Amyotrophic Lateral Sclerosis.

BACKGROUND/AIMS: Recent studies suggest that antecedent disease could impact the pathophysiology of the motoneuron disease Amyotrophic Lateral Sclerosis (ALS). We performed a case-control study to examine the prevalence of 11 antecedent diseases in ALS. METHODS: Prevalence of antecedent disease in a 1,288 patient ALS population (Emory University ALS Clinic, Atlanta, Ga., USA) is compared to an age, gender, and geography-matched 7,561 subject control population using a statistical odds ratio (OR) with 95% confidence interval. RESULTS: Association of ALS with odds of arthritis (OR = 0.14); non-ALS neurological disease (OR = 0.14); liver disease (OR = 0.19); chronic obstructive pulmonary disorder or COPD (OR = 0.23); kidney disease (OR = 0.32); adult asthma (OR = 0.39); diabetes (OR = 0.47); hypertension (OR = 0.56); obesity (OR = 0.6); hyperlipidemia or hypercholesterolemia (OR = 0.62); and thyroid disease (OR = 0.78). CONCLUSIONS: The prevalence of antecedent disease was overall less in the ALS population. We present two potential lines of inquiry to explain these results: (1) 'Other disease as ALS protection'--antecedent diseases infer biochemical neuroprotection to ALS; (2) 'ALS as other disease protection'--the underpinnings of ALS could infer protection to other diseases, possibly via the mechanism hypervigilant regulation or 'too-high' regulatory feedback gains.

Amyotrophic lateral sclerosis is a distal axonopathy: evidence in mice and man.

The SOD1 mutant mouse is the most widely used model of human amyotrophic lateral sclerosis (ALS). To determine where and when the pathological changes of motor neuron disease begins, we performed a comprehensive spatiotemporal analysis of disease progression in SOD1(G93A) mice. Quantitative pathological analysis was performed in the same mice at multiple ages at neuromuscular junctions (NMJ), ventral roots, and spinal cord. In addition, a patient with sporadic ALS who died unexpectedly was examined at autopsy. Mice became clinically weak at 80 days and died at 131 +/- 5 days. At 47 days, 40% of end-plates were denervated whereas there was no evidence of ventral root or cell body loss. At 80 days, 60% of ventral root axons were lost but there was no loss of motor neurons. Motor neuron loss was well underway by 100 days. Microglial and astrocytic activation around motor neurons was not identified until after the onset of distal axon degeneration. Autopsy of the ALS patient demonstrated denervation and reinnervation changes in muscle but normal appearing motor neurons. We conclude that in this widely studied animal model of human ALS, and in this single human case, motor neuron pathology begins at the distal axon and proceeds in a "dying back" pattern.