IDIOPATHIC HYPERTROPHIC PACHYMENINGEAL LESIONS - CORRELATION BETWEEN CLINICAL-PATTERNS AND NEUROIMAGING CHARACTERISTICS

Nine patients with intracranial pachymeningeal thickening and enhancem ent on magnetic resonance imaging (MRI) completed a short-term clinica l and MRI follow-up study. Based on clinical pictures, 4 of them were found to have spontaneous intracranial hypotension (SIH) and the remai ning 5 had idiopathic intracranial pachymeningitis (IIP). Both groups were compared regarding their clinical and MRI characteristics. In 4 p atients with SIH, gadolinium-enhanced T-1-weighted images (WI) showed a diffuse and even enhancement of the entire intracranial and spinal d ura mater. These thickened dura was slightly hyperintense on T-2-WI. T hey had a favorable prognosis. In 2 patients with IIP, MRI demonstrate d a relatively focal and even thickening and enhancement of the intrac ranial dura which was slightly hyperintense with a central hypointense area on T-2-WI. These patients showed a very favorable course with or without steroid pulse therapy. In the remaining 3 patients with IIP, MRI depicted a focal, uneven enhancement of the intracranial dura whic h was relatively hypointense on T-2-WI. Two of them with prolonged sym ptoms had a remitting and relapsing course, and 1 had a favorable outc ome. In spite of current limitations in identifying the underlying cau ses of idiopathic pachymeningeal abnormalities, MRI can characterize t he different patterns of pachymeningeal thickening. These findings may also correlate with the clinical picture and may be useful in predict ing the response to treatment and prognosis.