Lumbar Cerebrospinal Fluid Biomarkers of Posthemorrhagic Hydrocephalus of Prematurity: Amyloid Precursor Protein, Soluble Amyloid Precursor Protein α, and L1 Cell Adhesion Molecule.

BACKGROUND: Intraventricular hemorrhage (IVH) is the most frequent, severe neurological complication of prematurity and is associated with posthemorrhagic hydrocephalus (PHH) in up to half of cases. PHH requires lifelong neurosurgical care and is associated with significant cognitive and psychomotor disability. Cerebrospinal fluid (CSF) biomarkers may provide both diagnostic information for PHH and novel insights into its pathophysiology. OBJECTIVE: To explore the diagnostic ability of candidate CSF biomarkers for PHH. METHODS: Concentrations of amyloid precursor protein (APP), soluble APPα (sAPPα), soluble APPß, neural cell adhesion molecule-1 (NCAM-1), L1 cell adhesion molecule (L1CAM), tau, phosphorylated tau, and total protein (TP) were measured in lumbar CSF from neonates in 6 groups: (1) no known neurological disease (n = 33); (2) IVH grades I to II (n = 13); (3) IVH grades III to IV (n = 12); (4) PHH (n = 12); (5) ventricular enlargement without hydrocephalus (n = 10); and (6) hypoxic ischemic encephalopathy (n = 13). CSF protein levels were compared using analysis of variance, and logistic regression was performed to examine the predictive ability of each marker for PHH. RESULTS: Lumbar CSF levels of APP, sAPPα, L1CAM, and TP were selectively increased in PHH compared with all other conditions (all P < .001). The sensitivity, specificity, and odds ratios of candidate CSF biomarkers for PHH were determined for APP, sAPPα, and L1CAM; cut points of 699, 514, and 113 ng/mL yielded odds ratios for PHH of 80.0, 200.0, and 68.75, respectively. CONCLUSION: Lumbar CSF APP, sAPPα, L1CAM, and TP were selectively increased in PHH. These proteins, and sAPPα, in particular, hold promise as biomarkers of PHH and provide novel insight into PHH-associated neural injury and repair.

Impact of time of day on outcomes after stereotactic radiosurgery for non-small cell lung cancer brain metastases.

BACKGROUND: This study tested the hypothesis that time of day of treatment with stereotactic radiosurgery (SRS) has an effect on local control (LC) and overall survival (OS) in a large cohort of patients with non-small cell lung cancer (NSCLC) brain metastases. METHODS: At Washington University in St. Louis, 437 patients with NSCLC were treated with SRS for NSCLC brain metastases. Receiver operating characteristics analysis was used to identify an optimal cut-point for OS relative to time of day. Kaplan-Meier log-rank statistics, and Cox regression univariate and multivariate analysis were employed to isolate any independent effect of treatment time on OS and LC. Matched-pair analysis was performed to isolate any independent effect of time on OS and LC of day while controlling for confounding variables. RESULTS: Receiver operating characteristics analysis identified a cut-point of 11:41 AM as providing the highest predictive value for OS. On univariate analysis, late SRS was associated with decreased OS, as was age, Karnofsky performance status, risk-stratification schemes, extracranial disease status, and overall burden of brain metastases. On univariate analysis for LC, late SRS was associated with decreased LC, as was burden of brain metastases. On multivariate analysis, only Graded Prognostic Assessment remained predictive of OS, and total number of targets and total tumor volume remained predictive of LC. Matched-pair analysis demonstrated no significant effect of time of day on LC or OS. CONCLUSIONS: Although earlier treatment appears to be associated with improved LC and OS, treatment time fails to remain significant when accounting for confounding variables.