Özlem Terzi, Esra Meltem KAYAHAN ULU, Hülya İNCE

Diffusion-weighted imaging findings of brain parenchyma in pediatric pseudotumor cerebri

Pseudotumor cerebri (PTC) or idiopathic intracranial hypertension (IIH) is a confounding clinical entity encompassing a variety of assumed mechanisms. The chief aim of the study was to determine brain edema by documenting the findings of diffusion magnetic resonance imaging (MRI) conducted to evaluate the brain parenchyma in patients with pediatric PTC. In this study, 19 patients participated, which were categorized into 2 groups as per Friedman’s criteria. First group comprised of 11 patients diagnosed with PTC while the second group comprised of remaining 8 patients diagnosed with ‘probable PTC’. Conventional MRI findings and magnetic resonance venography (MRV) findings were noted. Transverse sinus variations were grouped according to the modified Fofi criteria. The apparent diffusion coefficient (ADC) values (ADC mean, ADC min, and ADC max) of the splenium and genu of the corpus callosum, bilateral occipital, parietal, temporal, and frontal cortex and white matter along with the bilateral head of caudate nucleus, putamen and thalamus were evaluated. The control group was formed with corresponding ages and gender of the patients and the ADC values (ADC mean, ADC min, and ADC max) for brain parenchyma in same localisations of the brain were also evaluated in controls. The findings showed that there is no statistically significant difference between two groups of patients regarding their ages (p: 0.06). The mean cerebrospinal fluid (CSF) opening pressure was found to be 35.5 ± 9.0 cmH2O and 25.5 ± 2.8 cmH2O for first and second group respectively with significant difference (p < 0.001). Headache was found to be the most common symptom (50%) followed by double vision (30%). The most common conventional MRI finding was perioptic nerve sheath distension (37%). 52% children had transverse sinus hypoplasia demonstrated by MRV. The ADC values (ADC mean, ADC min, and ADC max) for brain parenchyma evaluated in various regions for the groups and controls did not show any significant difference. The detection of a high percentage of the transverse sinus variations in patients with PTC supports the finding that PTC is accompanied by secondary obstruction of the transverse sinuses. The cerebral ADC values did not differ between age and gender matched control groups, showing there is no detectable cerebral edema in PTC with diffusion MRI.

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