A Comparison Between the Clinical Features of Pseudotumor Cerebri Secondary to Tetracyclines and Idiopathic Intracranial Hypertension

Abstract

Comparisons between clinical features of tetracycline-induced pseudotumor cerebri (PTC-T) and those of idiopathic intracranial hypertension (IIH) are absent in the literature. We hypothesized that significant clinical differences between these etiologies exist and could be better understood by retrospective analysis. Retrospective cohort study. We reviewed patients diagnosed with pseudotumor cerebri syndrome (PTCS) at our center and identified those who developed PTC-T after treatment with a tetracycline-class antibiotic and those with IIH. Groups were compared by demographics, body mass index, ophthalmic examination, treatment, clinical course, and visual outcomes. We identified 52 cases of PTC-T and 302 cases of IIH. Obesity rates were significantly different (43.8% for PTC-T vs 79.2% for IIH, P < .001). The mean age at diagnosis was younger for PTC-T (19.8 years vs 28.1 years for IIH, P < .001). Diplopia was more common with PTC-T (40.4% vs 20.1% for IIH, P= .001). The mean illness duration was shorter for PTC-T (18.3weeks vs 62.9weeks for IIH, P <.0001). Recurrence rates were significantly different (4.0% for PTC-T vs 16.5% for IIH, P <.001). The frequency of surgical intervention was similar. Vision loss was uncommon but occurred with similar frequency. We identified significant clinical differences but also identified important similarities between the 2 groups. There appear to be nonobese patients who develop PTC-T, discontinue the antibiotic, and never develop PTCS again. There are other patients who develop PTC-T, discontinue the antibiotic, and later develop IIH. We conclude that PTC-T represents a spectrum of disease in susceptible individuals.