The aim of the present study was to estimate free radicals cascade i.e. damage caused in terms of malondialdehyde (MDA) and defense system Superoxide dismutase (SOD) and catalase in blood and cerebro-spinal fluid (CSF) of neurodegenerative diseases (MND, CA and PD), to analyze correlation with level of free radical and the clinical variables like age, severity of diseases and duration of illness and any possibility from this clinical parameters to identify a biomarker for diagnosis of neurodegenerative diseases.