Table 1. International Classification of Diseases, Ninth Revision (ICD-9) and ICD-10 Codes Used to Ascertain Neurodegenerative Disease.

Disease	ICD-9	ICD-10
All neurodegenerative disease	290.0-290.4; 294.1; 294.2; 331.0-331.2; 331.6-331.9; 332; 335.2	F01-F03; G12.2; G20; G21; G23.1-G23.3; G23.8; G23.9; G30; G31
Dementia not otherwise specified	290.0-290.4; 294.1, 294.2; 331.0; 331.1, 331.2; 331.6-331.9	F01-F03; G23.1-G23.3; G30; G31
Alzheimer disease	331.0	G30
Non-Alzheimer dementia	290.0-290.4; 294.1 294.2; 331.1, 331.2; 331.6-331.9	F01-F03; G23.1- G23.3; G31
Motor neuron disease (amyotrophic lateral sclerosis)	335.2	G12.2
Parkinson disease	332	G20; G21; G23.8; G23.9