Children with macrocrania: clinical and imaging predictors of disorders requiring surgery.

BACKGROUND AND PURPOSE: Macrocrania is a common pediatric clinical condition affecting up to 5% of the population. The purpose of this study was to determine clinical and imaging predictors that are useful in the differentiation of disorders requiring surgical treatment from those that can be treated medically in children with macrocrania. METHODS: In a 3-year 7-month retrospective study, 88 patients (median age, 8 months; interquartile range, 5--13 months) with macrocrania and no known underlying neurologic disorder underwent imaging of the brain (sonography, n = 36; CT, n = 31; MR imaging = 21). The study was conducted in a pediatric tertiary care referral center. Clinical and imaging data were correlated to final diagnosis by means of logistic regression and receiver operating characteristic curves. RESULTS: Sixteen (18%) of the patients had disorders requiring surgery: communicating hydrocephalus, n = 7; noncommunicating hydrocephalus, n = 3; hemorrhagic subdural collections, n = 3; neoplasm, n = 1; encysted cavum septi pellucidi, n = 1; and vein of Galen malformation, n = 1. Clinical predictors of disorders requiring surgery included vomiting (P =.007), labor instrumentation (P =.026), developmental delay (P =.008), and abnormal neurologic findings (P =.028). Imaging predictors of disorders requiring surgery included a focal space-occupying lesion (P <.0001) and moderate-to-severe ventriculomegaly (P <.0001). The diagnostic sensitivity of the combination of independent clinical and imaging predictors was higher than that of independent clinical predictors alone, being 100% (95% confidence interval = 96.9%, 100%) and 93.8% (95% confidence interval = 88.7%, 98.8%), respectively. A trend indicated that the area under the receiver operating characteristic curve for clinical plus imaging findings (0.95) was greater than that for clinical findings alone (0.85) (P =.09). An increase in the number of clinical and imaging predictors was highly correlated with an increased risk of a disorder requiring surgery (P <.0001). CONCLUSION: Baseline neuroimaging is indicated for children with macrocrania because the combination of clinical and imaging predictors has the best diagnostic performance in determining the need for surgical versus nonsurgical management.

HPLC analysis of reduced and oxidized coenzyme Q(10) in human plasma.

BACKGROUND: The percentage of reduced coenzyme Q(10) (CoQ(10)H(2)) in total coenzyme Q(10) (TQ(10)) is decreased in plasma of patients with prematurity, hyperlipidemia, and liver disease. CoQ(10)H(2) is, however, easily oxidized and difficult to measure, and therefore reliable quantification of plasma CoQ(10)H(2) is of clinical importance. METHODS: Venous blood was collected into evacuated tubes containing heparin, which were immediately placed on ice and promptly centrifuged at 4 degrees C. The plasma was harvested and stored in screw-top polypropylene tubes at -80 degrees C until analysis. After extraction with 1-propanol and centrifugation, the supernatant was injected directly into an HPLC system with coulometric detection. RESULTS: The in-line reduction procedure permitted transformation of CoQ(10) into CoQ(10)H(2) and avoided artifactual oxidation of CoQ(10)H(2). The electrochemical reduction yielded 99% CoQ(10)H(2). Only 100 microL of plasma was required to simultaneously measure CoQ(10)H(2) and CoQ(10) over an analytical range of 10 microg/L to 4 mg/L. Intra- and interassay CVs for CoQ(10) in human plasma were 1.2-4.9% across this range. Analytical recoveries were 95.8-101.0%. The percentage of CoQ(10)H(2) in TQ(10) was approximately 96% in apparently healthy individuals. The method allowed analysis of up to 40 samples within an 8-h period. CONCLUSIONS: This optimized method for CoQ(10)H(2) analysis provides rapid and precise results with the potential for high throughput. This method is specific and sufficiently sensitive for use in both clinical and research laboratories.

Protein C deficiency related to valproic acid therapy: a possible association with childhood stroke.

We report a case of stroke in a child with acquired protein C deficiency receiving valproic acid (VPA). To investigate the possible association of VPA with protein C deficiency, protein C levels were measured in 20 children receiving VPA monotherapy and 20 children receiving other anticonvulsants. Protein C levels were reduced in up to 45% of the VPA-treated subjects.

An improved gas chromatography assay for topiramate monitoring in pediatric patients.

An improved micromethod involving capillary gas chromatographic assay with liquid-liquid extraction and nitrogen phosphorus detection (GC/NPD) was developed and validated for the determination of topiramate (TPM) in human body fluids. The galactopyranose analog of TPM was used as the internal standard. Capillary gas chromatographic conditions yielded typical retention times of 6.8 min for TPM and 7.2 min for the internal standard. Calibrations were linear between 1.0 and 32 microg/mL. Between-day precision (n = 17) for three serum controls (3.0, 10, and 24.5 microg/mL) resulted in coefficients of variation of 6.9%, 7.3%, and 4.9%, respectively. The limit of detection was 0.42 microg/mL. There was an excellent linear correlation between the fluorescence-polarization immunoassay (FPIA) and GC/NPD determinations of 56 patient specimens (r2 = 0.981). Chromatograms showed no interfering peaks with the respective blank human samples or from many commonly prescribed drugs. Because of improved specificity and decreased sample volume requirements, this micromethod should be particularly useful for monitoring TPM therapy in pediatric patients, for patients with impaired renal function, and for research studies.