Table 2 Potential diagnostic features of NS

Serum testing

Hypervitaminosis D and hypercalcemia/hypercalciuria occasionally present

Serum angiotensin converting enzyme (ACE) levels are elevated in up to 60% of cases

Both these findings showed low sensitivity and specificity

Cerebrospinal fluid (CSF) analysis

Mild/moderate pleocytosis with lymphocyte predominance and elevated protein is typical; particularly in the acute phase, neutrophiles may be present

CSF protein elevation is a nonspecific marker of neuroinflammation; oligoclonal bands and elevated immunoglobulin G (IgG) index are found in 20–40% of cases

In one study, CD4/CD8 ratio and IL-6 concentration were elevated in NS compared with multiple sclerosis patients

None of the above-mentioned findings are specific for NS

MRI

MRI with and without gadolinium is the most appropriate imaging modality. Gadolinium enhancement is a marker of active disease. The findings differ accordingly to clinical presentation, as described in Table 1