• Glucose, FBC, U+Es, LFTs, calcium, magnesium, ESR/CRP, clotting, TFTs, ABGs, cultures, ECG, CXR

If acute stroke possible

• Urgent CT head +/– CT-A, lipids, carotid Dopplers (if anterior circulation)

Spinal cord/cauda equina syndromes

• MRI spine +/– LP, B₁₂/folate, copper, syphilis, HIV, CMV and VZV serology

Polyradiculopathy/acute neuropathy

• NCS, LP, blood film, B₁₂/folate/thiamine, Borrelia/C;jejuni/CMV/EBV/HIV/Mycoplasma serology, anti-ganglioside and anti-paraneoplastic antibodies, serum and urine protein electrophoresis with immunofixation, urinary porphyrins

Multiple mononeuropathies/mononeuritis multiplex

• ANA/ENA, ANCA, Cryoglobulins, ACE, HIV serology, paraneoplastic antibodies, blood film, NCS/EMG, Schirmer's test, LP, nerve biopsy, PMP22 genetics (of multiple pressure palsies), anti-GM1 antibodies (if pure motor)

Mononeuropathy

• No tests may be required, NCS (rarely helpful acutely)

Myasthenic syndromes

• NCS/EMG (with repetitive stimulation/single fibre EMG), anti-acetylcholine receptor and anti-MUSK antibodies (myasthenia gravis), anti-voltage gated calcium channel antibodies (LEMS), CT thorax (both)