Epidemiological studies for rare diseases are difficult to have exact and known values that are still difficult to find. However, most studies show the mean age of onset was 43 years old (range 18–78 years old), with a mean death at 53 years (range 23–84 years) and the mean disease duration was found to be 6.8 years (range 1–29 years). History LENAS was first reported in multiple members of a large Swedish pedigree in 1984. In this family, 17 out of 71 subjects from 4 generations were affected with this disease. It was found that the age onset of this family varied from 8 to 60 years of age. The age of death in this family was 39 to 89 years with a time between onset and death varied from 3 months to over 30 years. Some patients in this family rapidly developed severe dementia and died a few months after this onset whereas others had a more prolonged progression of the disease. This family was also to have reported sporadic patients as well. Prevalence To date, the prevalence of this disease is unclear. Literature has few publications to date of this due to the rarity of the disease. However, a study done in 2011 found information dating back to 1970 that identified 51 individual cases fulfilling criteria to be identified. Today, there could be more confirmed cases but these data have not increased significantly.
Leukoencephalopathy with neuroaxonal spheroids
Leukoencephalopathy with vanishing white matter
Megalencephalic leukoencephalopathy with subcortical cysts
Neurodegeneration with brain iron accumulation
Camel spongiform encephalopathy
Neurofibrillary tangle
Limbic-predominant age-related TDP-43 encephalopathy
Variably protease-sensitive prionopathy