Acetazolamide-Induced Nephrolithiasis in Idiopathic Intracranial Hypertension Patients.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a neurological disorder characterized by elevated intracranial pressure of unknown cause. Acetazolamide is widely used as the initial treatment option; however, previously published evidence suggests that this drug may also increase the risk of nephrolithiasis. The purpose of this study was to examine daily acetazolamide use and its relationship to nephrolithiasis and compare clinical presentation of IIH between those with and without nephrolithiasis. METHODS: We conducted a case-control study using patient data collected by the Intracranial Hypertension Registry. A total of 670 patients were identified as potential study participants, 19 meeting the case definition of developing a stone during acetazolamide treatment for IIH. From the remaining pool of eligible participants, 40 controls were randomly selected. Two-sampled t tests, Fisher exact testing, and exact logistic regression were used to examine differences between cases and controls and to ascertain associations with IIH clinical features and mean daily acetazolamide dosage. RESULTS: Among all eligible patients, 19 (2.8%) developed a stone during acetazolamide treatment for IIH. Among these patients, 17 (89.5%) developed a stone within 1.5 years of initial acetazolamide treatment. Daily acetazolamide use was not significantly related to stone development (odds ratio = 0.95; 95% confidence intervals: 0.86-1.05). Additionally, the relationship between the clinical presentation of IIH at the time of diagnosis (signs and symptoms) and stone development did not reach statistical significance (P > 0.05). CONCLUSIONS: Our results demonstrate that: 1) stone formation during acetazolamide treatment is a relatively infrequent occurrence within the IIH population; 2) among patients who develop a stone, formation is likely to occur within the first year and half; 3) there is no evidence to support the association between acetazolamide daily dosage and stone development; and 4) no unique IIH disease features at the time of diagnosis are associated with stone development. Treatment with acetazolamide should be administered to IIH patients with caution and closely monitored for stone development especially within the first year and a half of treatment.

Manifestations of Pediatric Intracranial Hypertension From the Intracranial Hypertension Registry.

OBJECTIVE: The purpose of this study was to examine the presenting symptoms, demographics, and interventions in pediatric patients enrolled in the Intracranial Hypertension Registry. METHODS: We analyzed confirmed intracranial hypertension patients ≤18 years at the time of initial diagnosis who were enrolled in the registry. RESULTS: A total of 203 patients met the criteria for inclusion; 142 (70%) were considered primary intracranial hypertension. Females made up 72.5% (103 of 142) and 75.8% (47 of 61) in the primary intracranial hypertension and secondary intracranial hypertension groups, respectively. There were no clinically significant differences in age, body mass index, or opening pressure between the primary intracranial hypertension and secondary intracranial hypertension groups. Symptoms most often reported were headache and blurred vision. Bilateral optic disc edema occurred in 89.3% of primary intracranial hypertension and 78.7% of secondary intracranial hypertension patients. When divided into pre- and postpubertal status, 32.5% of patients were classified prepubertal; 77.3% of these had primary intracranial hypertension. This resulted in a female to male ratio of 1:1.04 for prepubertal and 6:1 for postpubertal primary intracranial hypertension patients. The body mass index was significantly higher in the postpubertal primary intracranial hypertension group (P = 0.0014). There was no significant difference in opening pressure. CONCLUSIONS: The common symptoms of intracranial hypertension, including headache, optic disc edema, and vision changes, occurred with similar frequencies in our cohort to those reported in the literature. In separate subanalyses, we found significantly higher rates of obesity in postpubertal females with primary intracranial hypertension. The female-to-male ratios in the postpubertal primary intracranial hypertension and secondary intracranial hypertension groups were higher than reported in the literature.