Table 1.
Preclinical markers of neurodegenerative diseases
| Disease | Major symptoms | Preclinical biomarkers | Ref. |
| Alzheimer’s disease | Cognitive impairment | PET (Aβ, tau) | 8–11 |
| CSF (Aβ, tau) | |||
| Cognitive composite | |||
| Parkinson’s disease | Parkinsonism | DaT SPECT | 24–26 |
| Cognitive impairment | Transcranial sonography | ||
| Polysomnography (detection of RBD) | |||
| Polyglutamine diseases | |||
| Huntington’s disease | Chorea | Symbol Digital Modality Test | 30, 31 |
| Cognitive impairment | MRI (striatal volume) | ||
| Spinocerebellar ataxias | Ataxia | Scale for the assessment and rating of ataxia | 35–37 |
| MRI (brainstem volume) | |||
| Spinal and bulbar muscular atrophy | Muscle weakness | Serum creatinine | 41, 42 |
| Amyotrophic lateral sclerosis | Muscle weakness | CSF (dipeptide repeat proteins)* | 52, 56, 57 |
| Electrophysiology (cortical hyperexcitability and motor unit number estimate) |
PET, positron emission computer tomography; CSF, cerebrospinal fluid; DaT SPECT, Dopamine transporter single photon emission computed tomography (DaT SPECT; RBD, rapid eye movement sleep behavior disorder. *This marker is applicable for C9orf72-linked familial ALS.