Auxiliary examination methods: biochemical and toxicological tests, imaging methods, electroencephalography, and phalopletysmography

Biochemical and toxicological tests

• urinary tox screen for drugs (psychosis can be caused by drugs, think LSD), metabolites of neurotransmitters
• CBC: Anemia (DDx depression), for individual drugs (drug levels: e.g. lithium -> therapeutic vs toxic effects), indirectly alcohol consumption (MCV, vitamins)
• LFTs: GGT, ALT, AST (e.g. hepatic encephalopathy)
• Thyroid function tests: DDx Dementia, depression, sexual dysfunction

Imaging methods

• CT, MRI, PET, SPECT → very important to identify and differentiate from neurologic/somatic etiology (think of stroke, tumor...)
• Example: Everyone with the first diagnosis of Alzheimer disease should get at least one imaging of the brain to rule out secondary causes...
• Functional imaging such as fMRI are still things reserved mainly for research purposes and don´t have a place (yet) in routine medicine

Electroencephalography

• e.g. encephalitis, schizophrenia, ECT, delirium, CJD, absence seizures, sleep disorder, narcolepsy

Phalopletysmography

• controversial instrument → since 2010 CR only state in the EU that does it
• Freund in 1950 Czechoslovakia
• auxillary method for diagnosis of paraphilia (?)