Intravoxel incoherent motion magnetic resonance imaging in the assessment of brain microstructure and perfusion in idiopathic normal-pressure hydrocephalus.

PURPOSE: To determine the relationship between intravoxel incoherent motion (IVIM) MRI parameters and clinical changes post-tap test (TT) in idiopathic normal-pressure hydrocephalus (iNPH) patients. METHODS: Forty-four probable iNPH patients underwent 3 T MRI before and after TT. IVIM parameters were calculated from eight different bilateral regions of interest in basal ganglia, centrum semiovale, and corona radiata. Patients were categorized based on TT response into positive (group 1) and negative (group 2) groups. A Welch two-sample t-test was used to compare differences in D, D*, f, and ADC between the two groups, while a paired t-test was employed to assess the changes within each group before and after TT. These parameters were then correlated with clinical results. RESULTS: In the lenticular and thalamic nuclei, D value was significantly lower in the group 1 compared to group 2 both pre- and post-TT (p = 0.002 and p = 0.007 respectively). Post-TT, the positive response group exhibited a notably reduced D* value (p = 0.012) and significantly higher f values (p = 0.028). In the corona radiata and centrum semiovale, a significant post-TT reduction in D* was observed in the positive response group (p = 0.017). Within groups, the positive response cohort showed a significant post-TT increase in ADC (p < 0.001) and a decrease in D* (p = 0.007). CONCLUSION: IVIM permits the acquisition of important non-invasive information about tissue and vascularization in iNPH patients. Enhanced perfusion in the lenticular and thalamic nuclei may suggest the role of re-established microvascular and glymphatic pathways, potentially elucidating the functional improvement in motor function after TT in iNPH patients.

Intracranial Meningiomas in the Elderly: Clinical, Surgical and Economic Evaluation. A Multicentric Experience.

Meningioma is one of the most common intracranial tumors. It is benign and slow growing in the majority of cases. Given the increase in life expectancy and the number of radiological tests performed, the incidence in the elderly population (≥65 years) is continuously increasing. The surgical outcomes and prognostic factors in this age group are unclear. A retrospective analysis of all the patients treated for intracranial meningiomas in two different Italian institutions was performed. The clinical, radiological, surgical and follow-up data were retrospectively reviewed. Statistical analyses were performed to identify relationships between factors and outcomes. We also carried out an economic analysis. We analyzed 321 patients with intracranial meningioma. The mean age was 72.6 years (range, 65-90), with a female predominance (F/M, 1.41). Pre-operative deficits, cognitive impairment and seizures (p < 0.001) were associated with a worse post-operative Karnofsky performance scale (KPS) score (<80). A high pre-operative KPS score was associated with a good clinical and neurological outcome (p < 0.001). Being aged between 65 and 74 years, low surgical timing and Simpson removal grades of I and II were associated with a good outcome (p < 0.001). The length of hospitalization was significantly related to the outcome (p < 0.001). The complication rate was 14.3%. At 6-month follow-up, the mortality rate was 2.5%. The average cost was higher in patients with a pre-operative KPS score lower than 80. The outcome of intracranial-meningioma resection in elderly individuals is favorable when the pre-operative KPS score is >80. Treatment should be patient-specific, and additional factors should be considered. Patients with poor pre-operative clinical conditions might benefit from a combined strategy with partial resection and radiosurgery in order to reduce surgical timing and the complication rate.