Elevated nerve growth factor levels in cerebrospinal fluid associated with progressive cortical atrophy

Using a two-site enzyme-linked immunosorbent assay, we measured nerve growth factor (NGF) levels in cerebrospinal fluid (CSF) from 40 patients with or without brain atrophy due to various neurologic disorders. White matter and cortical atrophies were assessed by frontal horn index (FHI) and subarachnoid space area/inner skull space area (SSA/ISSA) ratio, respectively. CT findings of 40 patients were classified into 4 grades: normal (< mean + 2SD), grade I (mean + 2SD < or = or < mean + 4SD), grade II (mean + 4SD < or = < mean + 8SD), and grade III (mean + 8SD < or =). NGF levels in CSF were significantly elevated in 3 of 6 patients with grade III cortical atrophy and normal in 2 with grade II atrophy, 4 with grade I atrophy and 28 without atrophy. Cortical atrophy was progressive in the 3 with NGF elevation in CSF. With respect to white matter atrophy, NGF elevation was observed in none of 3 with grade III white matter atrophy, two of 4 with grade II atrophy, none of 3 with grade I atrophy and one of 30 without atrophy. The symptoms of the two of three with NGF elevation were progressive at the time of obtaining the CSF samples, while those of other patients without NGF elevation were non-progressive. The present study suggests that NGF elevation in CSF may reflect extensive cortical degenerative change.