Table 3.

Diagnostic approach in NPSLE

All patients	Measure disease activity
	Therapy history	SLE-specific therapy/psychoactive drugs
	Laboratory tests	aCL and LAC/complement/urine sediment/exclude metabolic abnormalities/autoantibody profiling
Aseptic meningitis	LP	Exclude infection
	MRI	Exclude infection/exclude subarachnoid hemorrhage
	Additional laboratory tests	Serology testing for infectious diseases/cultures
Cerebrovascular disease (TIA/stroke)	MRI	Evaluation infarcts
	Echocardiogram
	Doppler ultrasonography of the carotid arteries
	MRA and LP	If suspicion of cerebral vasculitis
Demyelinating syndrome	MRI	Exclude infection/exclude malignancy/signs of MS
	LP	Exclude infection/oligoclonal bands
	Additional laboratory tests	Vitamin B12/serology testing for infectious diseases
Headache (if chronic and recalcitrant)	MRI	Exclude infection/exclude infarction/exclude malignancy/exclude PRES
	LP	Exclude infection and cranial hypertension
Movement disorder	MRI	Exclude stroke/exclude infection/exclude malignancy
	Additional laboratory tests	Copper (Wilson disease)
Myelopathy	MRI	Exclude infection/exclude malignancy/signs of MS/signs of optic neuritis
	MRI–spine	Exclude infection/exclude malignancy/exclude AVM/confirm LETM
	LP	Exclude infection/oligoclonal bands
	Additional laboratory tests	Serology testing for infectious diseases/anti-NMO antibodies
Seizure	MRI	Exclude infection/exclude malignancy
	EEG	Confirm seizure
	LP	Exclude infection
	Additional laboratory tests	Serology testing for infectious diseases
Acute confusional state	MRI	Exclude infection/exclude malignancy/exclude other neurological diseases
	LP	Exclude infection
	Additional laboratory tests	Serology testing for infectious diseases/cultures
Anxiety disorder	Additional laboratory tests	Exclude thyroid disease and pheochromocytoma
Cognitive dysfunction	MRI	Exclude infection/exclude infarction/exclude malignancy/exclude other neurological diseases
	Additional laboratory tests	Vitamin B12, exclude DM, thyroid disease/serology testing for infectious diseases
Mood disorder, psychosis	No specific laboratory tests are required
	Neuroimaging only required if additional neurological symptoms or signs are present
Guillain Barré	MRI spine	Exclude myelopathies
	Additional laboratory tests	Serology testing for infectious diseases
Autonomic disorder	Autonomic testing	Assessment of severity and parts of autonomic nervous system involved
	EMG and NCS	Characterization of neuropathy
	Additional laboratory tests	Exclude DM, uremic neuropathy and vitamin deficiencies/plasma norepinephrine levels/serology testing for infectious diseases/exclude celiac disease/AChR
Mononeuropathy	Additional laboratory tests	Exclude DM/ANCA/serology testing for infectious diseases
Myasthenia gravis	MRI	Exclude compression cranial nerves/signs of MS
	CT scan	Exclude thyroid disease
	Additional laboratory tests	Specific antibodies (AChR, MuSK, LRP4)/exclude thyroid disease
Cranial neuropathy	MRI	Exclude infection/exclude malignancy
	Evoked potentials	Characterization of neuropathy
Plexopathy	MRI spine	Exclude compression due to malignancy
	Electrodiagnosis	Characterization of plexopathy
	Additional laboratory tests	Vitamin B12, exclude DM, thyroid disease/serology testing for infectious diseases
Polyneuropathy	EMG	Characterization neuropathy
	Punch skin biopsy	Exclude small-fiber neuropathy if EMG normal
	Laboratory tests	Vitamin B12 and exclude DM

AChR ganglionic acetylcholine receptor autoantibody, aCL anticardiolipin antibodies, ANCA antineutrophil cytoplasmatic antibodies, AVM arteriovenous malformation, CT computed tomography, DM diabetes mellitus, EEG electroencephalogram, EMG electromyogram, LAC lupus anticoagulant, LP lumbar puncture, LETM longitudinally extensive transverse myelitis, LRP4 low-density lipoprotein receptor-related protein 4, MRA magnetic resonance angiography, MRI magnetic resonance imaging, MS multiple sclerosis, MuSK muscle-specific tyrosine kinase, NCS nerve conduction studies, NMO neuromyelitis optica, NPSLE neuropsychiatric systemic lupus erythematosus, PRES posterior reversible encephalopathy syndrome, SLE systemic lupus erythematosus, TIA transient ischemic attack