Evaluation of normal pressure hydrocephalus with brain MRG findings

The aim of this study is to reveal the profile of imaging findings in patients with idiopathic Normal Pressure Hydrocephalus (iNBH), to determine the correlation between these imaging findings and clinical findings, and to investigate the possibility of predicting the response to surgery based on imaging findings before ventriculo-peritoneal shunt surgery. Between December 2020 and December 2022, patients who presented with one or more of the following complaints: gait disturbance, cognitive impairment, or urinary incontinence and had ventriculomegaly on cranial Magnetic Resonance Imaging (MRI) and met the 2021 iNBH diagnostic criteria were included in the study. Neuroimaging findings were analyzed both qualitatively and quantitatively with volumetric calculations using volBrain software. The clinical course of the patients after VP shunt surgery was followed prospectively. The study included 75 patients (44% female, 56% male; mean age 71.23 years). Pre-treatment qualitative and quantitative MRI findings were correlated with the classic clinical triad of dementia, gait disturbance and urinary incontinence. Disproportionate widening of the sylvian sulcus or other sulci (DESH) was found in 73 patients (98%) and narrowing of the callosal angle in 71 patients (95%). Widening of the calcarine sulcus was found in 20% of patients and parietooccipital sulcus in 32%. Compressed mesencephalon was observed in 26 patients (35%). The incidence of dementia was significantly higher in patients with normal CSF flow rate (p=0.033). No significant correlation was found between pre-treatment gait disturbance and urinary incontinence and any imaging findings (p>0.05). In our study, we also used the 'Decision Tree' method to determine how the variables affect the clinical findings together. Separate models were created for each complaint. According to the decision tree evaluating the effect of variables on gait disturbance: Gait-balance impairment was seen in patients with DESH findings. Gait impairment was seen in patients without DESH but with sulcal narrowing from the level of the vertex and compressed mesencephalon. Diagnostic draining lumbar puncture (LP) was performed in 64 and external lumbar drainage (ELD) in 9 of the 75 patients included in the study. Patients without periventricular T2 hyperintensities had a significantly higher positive response to LP. A total of 42 patients underwent VP shunt surgery. When the change in dementia after treatment was analyzed in relation to MRI findings, it was found that improvement in dementia was significantly lower only in the presence of interhemispheric DESH (p=0.011). When the relationship between the change in gait disturbance and MRI findings after treatment was analyzed, improvement in gait disturbance was found in all patients with sulcal narrowing at the level of the vertex (p=0.004). In addition, the mean volume of the fourth ventricle was 1.55 cm3 in patients who did not respond to surgical intervention and 3.28 cm3 in patients who responded (p=0.024). There was no significant correlation between improvement in urinary incontinence after treatment and any MRI findings (p>0.05). The findings showed that enlargement of the parietooccipital and calcarine sulci and compressed mesencephalon findings are not uncommon in patients with iNBH, response to LP was increased in patients without periventricular white matter lesions, and response to VP shunt was increased in patients with mesial sulcal narrowing.