As in idiopathic Parkinson's disease, there is no definitive rise in age-specific sALS incidence after that age. Paraneoplastic variants of particularly lower MND have been frequently associated with lymphoma. For example, an arbitrary observation period of 3 years does not help to identify different disease entities in the temporo-spatial continuum of central motor neuron death. Further complicating the process of better defining the different disease entities and prognoses is the fact that interindividual variability is great. A reliable measure of disease state is also problematic, and therefore comparisons in clinical trials remain difficult.
All available parameters are dependent on many variables difficult to control simultaneously.
Both the nucleus of Onufrowicz and the external ocular motor nuclei are polysynaptically connected to cortical motor tracts. They receive, in contrast to the more susceptible monosynaptic motoneurons, few, if any, direct cortical projections. Frequently an asymmetrical, predominantly distal onset is appreciated. No gender-specific differences have been detected within or outside the central nervous system neither with respect to ALS cerebrospinal fluid, ultrastructural dermal involvement, circulating IgG immune complexes or IgG seroreactivity against diverse human retroviral antigens. Combined motoneuron degeneration on a genetic basis In both familial ALS and sporadic ALS, survival is inversely correlated with age at diagnosis or clinical onset of the disease.