Degenerative
Alzheimer's disease
Huntington's disease<unk> 
Vascular
Multiple infarcts
Hypoperfusion (MI, profound hypotension)
Subdural hematoma
SAH
Infectious
Meningitis (sequelae of bacterial, fungal, or tubercular)
Neurosyphilis
Viral encephalitis (HSV, HIV), Creutzfeldt-Jakob disease
Inflammatory
SLE
Demyelinating disease (e.g. multiple sclerosis)
Neoplastic
Primary brain tumor / metastatic disease
Carcinomatous meningitis
Paraneoplastic syndromes
Traumatic
Traumatic brain injury
Subdural hematoma
Toxic
ETOH 
Meds (anticholinergics, polypharmacy)
Metabolic
B12 deficiency or folate deficiency
Thyroid Disease
Uremia
Psychiatric
Depression (pseudodementia)
Hydrocephalic
Normal pressure hydrocephalus (communicating hydrocephalus)
Noncommunicating hydrocephalus
Alzheimer's disease
Huntington's disease<unk> 
Multiple infarcts
Hypoperfusion (MI, profound hypotension)
Subdural hematoma
SAH
Meningitis (sequelae of bacterial, fungal, or tubercular)
Neurosyphilis
Viral encephalitis (HSV, HIV), Creutzfeldt-Jakob disease
SLE
Demyelinating disease (e.g. multiple sclerosis)
Primary brain tumor / metastatic disease
Carcinomatous meningitis
Paraneoplastic syndromes
Traumatic brain injury
Subdural hematoma
ETOH 
Meds (anticholinergics, polypharmacy)
B12 deficiency or folate deficiency
Thyroid Disease
Uremia
Depression (pseudodementia)
Normal pressure hydrocephalus (communicating hydrocephalus)
Noncommunicating hydrocephalus
Chorea
Sydenham's chorea
Neuroleptic malignant syndrome
Serotonin syndrome
Hypocalcemia
Strychnine toxicity
Acute tetanus<unk> 
Mono amine oxidase inhibitor toxicity
Phencyclidine toxicity
Anti-NMDA receptor encephalitis
Huntington disease
Wilson's disease 
CVA
Schizophrenia
Psychotic agitation
Dementia
Lewy body dementia
Vascular dementia
Frontotemporal dementia
Dystonic reaction
Extrapyramidal reaction
Torticollis
Idiopathic movement disorder
Sydenham's chorea
Lewy body dementia
Vascular dementia
Frontotemporal dementia
Parkinson's disease
Degenerative
Dementia with Lewy bodies
Alzheimer's disease
Sydenham's chorea
Huntington's disease
Prion disease
Dementia