{'fraction_non_alphanumeric': 0.015909090909090907, 'fraction_numerical': 0.0022727272727272726, 'mean_word_length': 5.292857142857143, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A catastrophe theory approach to cognitive decline

The prevalence of dementia in old age, primarily resulting from Alzheimer's disease, doubles every five years after the age of 65. The natural history of dementia in the elderly usually begins during the phase of age associated memory impairment, proceeding to a phase where individuals complain of memory loss (but without objective evidence), then to the prodromal stage of mild cognitive impairment (MCI) prior to the onset of clinical dementia. We propose that the deterioration of cognitive and neural functions follow an orderly pattern that can be modeled with a simple mathematical expression. We describe here such a model of cognitive decline based on catastrophe theory that not only accounts for the worsening of the clinical manifestations of the brain dysfunction, but how such dysfunction may become irreversible.