Renal tubular dysfunction in epileptic children on valproic acid therapy

To investigate the effects of valproic acid (VPA) on renal tubular function, we examined 15 ambulatory children with epilepsy who received VPA for at least 6 months. None of the patients had mental retardation. Fourteen age- and sex-matched children were used as a control group. No statistically significant differences were found between patients and control subjects with respect to blood urea nitrogen (BUN), creatinine (Cr), uric acid, creatinine clearance (Ccr), tubular reabsorption of phosphorus (TRP), urinary Ca:creatinine ratio, urinary pH and mean urinary beta2-microglobulin concentrations (P>0.05). Protein and glucose in patient urine samples were negative. Urine microscopic examinations and amino acid chromatographies of patients were also normal. However, significant differences were found between patient and control groups with respect to mean urinary N-acetyl-beta-D-glucosamine:creatinine ratio (NAG:Cr) and mean urinary malondialdehyde:creatinine (MDA:Cr) ratio (P<0.05). In conclusion, ambulatory children with epilepsy taking VPA therapy may develop proximal renal tubular dysfunction. Although this finding is clini-cally insignificant, it should be kept in mind during VPA therapy.

Correlation of the relationships of brain-tumor interfaces, magnetic resonance imaging, and angiographic findings to predict cleavage of meningiomas

OBJECT

The authors examined the relationships of brain-tumor interfaces, specific magnetic resonance (MR) imaging features, and angiographic findings in meningiomas to predict tumor cleavage and difficulty of resection.

METHODS

Magnetic resonance imaging studies, angiographic data, operative reports, clinical data, and histopathological findings were examined retrospectively in this series, which included 126 patients with intracranial meningiomas who underwent operations in which microsurgical techniques were used. The authors have identified three kinds of brain-tumor interfaces characterized by various difficulties in microsurgical dissection: smooth type, intermediate type, and invasive type. The signal intensity on T1-weighted MR images was very similar regardless of the type of brain-tumor interface (p > 0.1). However, on T2-weighted images the different interfaces seemed to correlate very precisely with the signal intensity and the amount of peritumoral edema (p < 0.01), allowing the prediction of microsurgical effort required during surgery. On angiographic studies, the pial-cortical arterial supply was seen to participate almost equally with the meningeal-dural arterial supply in vascularizing the tumor in 57.9% of patients. Meningiomas demonstrating hypervascularization on angiography, particularly those fed by the pial-cortical arteries, exhibited significantly more severe edema compared with those supplied only from meningeal arteries (p < 0.01). Indeed, a positive correlation was found between the vascular supply from pial-cortical arteries and the type of cleavage (p < 0.05).

CONCLUSIONS

In this analysis the authors proved that there is a strong correlation between the amount of peritumoral edema, hyperintensity of the tumor on T2-weighted images, cortical penetration, vascular supply from pial-cortical arteries, and cleavage of the meningioma. Therefore, the consequent difficulty of microsurgical dissection can be predicted preoperatively by analyzing MR imaging and angiographic studies.

Serum and hair zinc levels in epileptic children taking valproic acid

This study was performed to investigate the serum and hair zinc levels in patients epilepsy diagnoses who were intended to be put on valproic acid (VA) monotherapy and had never ingested antiepileptics before. A total of 16 patients having normal growth, development and nutrition was selected as Group 1, and Group 2 was made up of 10 patients who had received VA monotherapy for 2 yrs or more and had normal growth, development, and nutrition characteristics. A control group (Group 3) was formed of 15 subjects who applied to the hospital for upper respiratory tract disorders. Serum and hair samples were taken for zinc assays from the Group 1 patients on the d 0, 15, 30, 45, 60, 75, and 180. Groups 2 and 3 were sampled only once, and zinc levels were determined. We found that both serum and hair zinc levels in Group 1 were higher than those of Group 2 and control group before the beginning of VA therapy, but they returned to normal during VA treatment. There was no zinc deficiency, and zinc replacement treatment may therefore be considered as unnecessary.