Diagnostic investigations in adults
| Primary care | Serum urea and electrolytes, serum creatinine, full blood count ESR/C-reactive protein | Liver enzymes, serum γ-GT, thyroid function tests Vitamin B12 | Serum folate, plasma glucose, chest X-ray |
| Secondary care (first line) | αFP Blood film Caeruloplasmin/copper Coeliac disease screen, serum creatine kinase Genetic tests for Friedreich’s ataxia, SCA 1, 2, 3, 6, 7 (12, 17) and fragile X tremor-ataxia syndrome | Lactate Lipid-adjusted vitamin E and lipoproteins Lumbar puncture (cells, protein, glucose, cytology, oligoclonal bands, lactate, ferritin) MR scan of brain and cervical spine | Anti-Hu/Yo and other paraneoplastic antibodies Anti-GAD antibody Anti-voltage-gated calcium channel antibody CT scan of chest, abdomen, pelvis 14-3-3 and other proteins in CSF (prion diseases) |
| Secondary care (second line) | Cholestanol Plasma oxysterols Bile acids Coenzyme Q10 (ubiquinone) Electroencephalography Very-long-chain fatty acids | Muscle biopsy Ophthalmology/optical coherence tomography Peripheral nerve conduction studies Phytanic acid | Remaining genetic tests (next-generation sequencing) Total body PET scan White cell enzymes |
CSF, cerebrospinal fluid; ESR, erythrocyte sedimentation rate; αFP, alpha-fetoprotein; GAD, glutamic acid decarboxylase; γ-GT, gamma-glutamyltransferase; PET, positron emission tomography; SCA, spinocerebellar ataxia.