Table 1.

Clinical presentations and their characteristics as reported in NS

Clinical presentation	Characteristics in NS
Aseptic meningitis [2, 6, 9, 18–22, 24]	Mostly this is asymptomatic and inferred from CSF abnormalities. Where patients are symptomatic, the presentation is usually subacute or chronic
	Typical CSF finds are: pleocytosis (<220 cells/mm3) with a lymphocytic predominance and/or raised protein (<4.3 g/l). Reduced CSF glucose is also reported
Conus or cauda equina syndrome [9, 19, 43]	This may be of acute or subacute onset. CSF and imaging abnormalities usually confirm a neuro-inflammatory basis
Cranial neuropathy [2, 6, 8, 18–22, 24]	This is the most frequently reported manifestation of NS. Any cranial nerve can be involved but facial and optic nerves are most frequently affected
	Facial nerve palsies often spontaneously remit and carry a good prognosis
	Cranial oligoneuropathy or polyneuropathy (e.g. bilateral facial nerve palsy) is suggestive of NS
	Optic nerve involvement may have a more difficult disease course with refractory disease and relapse on corticosteroid dose reduction
	A pharynx, soft palate and vocal cord syndrome from glossopharyngeal and vagus nerve involvement is recognised
	Basal meningitis may be the pathophysiological substrate of cranial neuropathies
Focal neurology, multifocal neurology or diffuse encephalopathy due to parenchymal lesions of the brain or brainstem [2, 8, 9, 18–22, 44]	Lesions may be multiple and often enhance. Biopsy of mass lesions is recommended for a definitive diagnosis
	Behaviour change, confusional states and psychosis are reported
Hypothamic and pituitary dysfunction [2, 6, 8, 9, 20, 22, 28, 29, 44–46]	Usually of insidious onset, due to suprasellar inflammatory lesions. The most eminent symptoms are bitemporal visual failure, polydipsia and polyuria (diabetes insipidus), and galactorrhoea
	Symptoms may arise from hypothalamic dysfunction, hypopituitarism or compression of the optic chiasm by mass effect
	An aseptic meningitis is often seen
Myopathy [6, 19, 20, 22, 38]	Usually asymptomatic. Where symptomatic, this presents as proximal weakness. Biopsy is reported to have a high diagnostic yield
Peripheral polyneuropathy [6, 8, 19, 20, 22, 24]	Pure sensory and mixed neuropathies are reported. Mononeuritis multiplex is also described
Raised intracranial pressure [2, 6, 9, 19–22]	Patients usually present non-specifically with a headache and visual disturbance. Clinical signs may include papilloedema
	CSF and imaging show evidence of active inflammation, including meningeal enhancement and ventriculitis
	Hydrocephalus may develop and may require surgical management
Seizures [8, 9, 18, 21, 22, 38]	Can be a feature of cortical or subcortical disease
Spinal cord syndromes and radiculitis [2, 6, 9, 20, 22–24]	Mass lesions and inflammatory lesions are reported. A Guillain–Barré-like syndrome is occasionally described
	In longitudinally extensive myelitis where aquaporin antibodies are negative, NS should be considered
Uveoparotid fever [13]	Uveitis, parotid gland swelling, fever and facial nerve palsy constitute this syndrome which is pathognomonic of sarcoidosis
	CSF often shows evidence of an aseptic meningitis
Vascular syndromes [8, 20, 47–49]	Ischaemic stroke, haemorrhagic stroke and dural venous sinus thrombosis are infrequently reported
	Perivascular inflammation has been demonstrated in biopsy and post-mortem specimen