Background
Spontaneous intracranial hypotension (SIH) is caused by cerebrospinal fluid (CSF) leakage. Definitive diagnosis can be difficult by clinical examinations and imaging studies.
Conclusion
L-PGDS and brain-type Tf can be biomarkers for diagnosing SIH. General significance: L-PGDS and brain-type Tf biosynthesized in the brain appears to be markers for abnormal metabolism of CSF.
Methods
SIH was diagnosed with the following criteria: (i) evidence of CSF leakage by cranial magnetic resonance imaging (MRI) findings of intracranial hypotension and/or low CSF opening pressure; (ii) no recent history of dural puncture. We quantified CSF proteins by ELISA or Western blotting.
Results
Comparing with non-SIH patients, SIH patients showed significant increase of brain-derived CSF glycoproteins such as lipocalin-type prostaglandin D synthase (L-PGDS), soluble protein fragments generated from amyloid precursor protein (sAPP) and "brain-type" transferrin (Tf). Serum-derived proteins such as albumin, immunoglobulin G, and serum Tf were also increased. A combination of L-PGDS and brain-type Tf differentiated SIH from non-SIH with sensitivity 94.7% and specificity 72.6%.
Significance
L-PGDS and brain-type Tf biosynthesized in the brain appears to be markers for abnormal metabolism of CSF.