Postsurgical Cerebral Perfusion Changes in Idiopathic Normal Pressure Hydrocephalus: A Statistical Parametric Mapping Study of SPECT Images

Abstract

Our goal was to study cerebral blood flow (CBF) changes after surgery in a group of 15 patients with idiopathic normal pressure hydrocephalus (NPH). Methods: We used hexamethylpropyleneamine oxime SPECT and statistical parametric mapping (SPM), an image analysis method that does not require prior selection of regions of interest. Results: Our study showed areas of significant increase in perfusion in specific regions of both frontal lobes and the right parietal lobe. Regions of increased perfusion were found in the left prefrontal dorsolateral areas (Brodmann’s areas 9 and 45 or 47), right frontal premotor area (Brodmann’s area 44), right medial prefrontal region (Brodmann’s area 10 or 32), right frontal white matter area (superior longitudinalis fasciculus), and right basal ganglia (lenticular nucleus, putamen, and globus pallidus). In the right hemisphere, another region of increased perfusion was found in the inferior parietal lobule (Brodmann’s area 40). The 2 areas most related to clinical improvement were Brodmann’s area 32 and the frontal part of the left lobule of Reil insula. Conclusion: The results obtained with the SPM method of image analysis confirm and expand on previous CBF literature in NPH, with specific CBF regions located in frontal and parietal areas that improve after surgery in idiopathic NPH.