Table 4.

Different approaches to AD diagnosis used in clinical practice

	Target	Advantages	Disadvantages
Cognitive and neuropsychological assessment	Provides a detailed picture of cognitive status. Thinking skills that are explored include memory, language, visual-spatial perception, attention, motor function, and executive function (e. g. MMSE, NPI, ADL, IADL)	Identifies very early subtle cognitive changes and which areas of mental functioning are affected. It can help distinguish AD from other forms of dementia. The cost is low and the tests are not invasive.	An abnormal result can have many explanations other than AD. It can miss cognitive impairment in those who are highly educated. It can be tiring and stressful for patients being tested.
Brain imaging	CT scans and MRI examine structural changes of the brain. PET scans can show metabolic changes and amyloid deposition.	Allows finding possible other causes of dementia symptoms (brain trauma, tumor, or stroke). PET scans can help distinguish AD from frontotemporal dementia.	Brain imaging may require the use of intravenous "tracing" agents, that can cause side effects. MRI scanners can induce claustrophobia and may not be compatible with pacemakers or other devices. The cost is notably high.
Spinal tests	The amounts of three AD biomarkers, amyloid-β 42, total tau, phosphorylated tau, are determined in CSF through a lumbar spine puncture.	CSF biomarkers can identify patients without clinical or preclinical signs of AD. A low level of amyloid-β 42 in patients with mild cognitive impairment seems to predict with 80-90 % accuracy who will not develop AD.	It is an invasive test to be performed by an expert high qualified specialist. Risk exists for infection, ble eding, and pain .

MMSE: Mini-Mental State Examination; NPI: Neuropsychiatric Inventory; ADL: Activities Daily Living; IADL: Instrumental Activities of Daily Living; AD: Alzheimer Disease; CT: Computed Tomography; MRI: Magnetic Resonance Imaging; PET: Positron Emission Tomography; CSF: Cerebrospinal Fluid