Arterial spin labelled imaging for idiopathic normal pressure hydrocephalus

• Comment on clinical applicability of arterial spin labeling magnetic resonance imaging in patients with possible idiopathic normal pressure hydrocephalus: A prospective preliminary study''
• Clinical applicability of arterial spin labeling magnetic resonance imaging in patients with possible idiopathic normal pressure hydrocephalus: A prospective preliminary study
• Shunt Surgery Efficacy Is Correlated With Baseline Cerebrum Perfusion in Idiopathic Normal Pressure Hydrocephalus: A 3D Pulsed Arterial-Spin Labeling Study
• Cerebral Perfusion Does Not Increase after Shunt Surgery for Normal Pressure Hydrocephalus
• Normal-pressure hydrocephalus: A critical review
• Arterial Spin-Labeling Perfusion MR Imaging Demonstrates Regional CBF Decrease in Idiopathic Normal Pressure Hydrocephalus
• MRI assessment of the effects of acetazolamide and external lumbar drainage in idiopathic normal pressure hydrocephalus
• Idiopathic normal pressure hydrocephalus: cerebral perfusion measured with pCASL before and repeatedly after CSF removal

Arterial spin labeling magnetic resonance imaging seems to be a promising non-invasive technique in the preoperative selection of patients affected by possible iNPH ¹⁾.

A total of 32 patients with diagnosed Idiopathic normal pressure hydrocephalus and 18 age-matched healthy controls (HCs) were involved in a study. All subjects underwent magnetic resonance imaging (MRI), including 3D pulsed arterial spin labeling (PASL) for non-invasive perfusion imaging, and clinical symptom evaluation at baseline, and all patients with INPH were reexamined with clinical tests 1 month postoperatively. Patients with INPH had significantly lower whole-brain CBF than HCs, with the most significant differences in the high convexity, temporal lobe, precuneus, and thalamus. At baseline, there was a significant correlation between the CBF in the middle frontal gyrus, calcarine, inferior and middle temporal gyrus, thalamus, and posterior cingulate gyrus and poor gait manifestation. After shunting, improvements were negatively correlated with preoperative perfusion in the inferior parietal gyrus, inferior occipital gyrus, and middle temporal gyrus. Preoperative CBF in the middle frontal gyrus was positively correlated with the severity of preoperative cognitive impairment and negatively correlated with the change of postoperative MMSE score. There was a moderate positive correlation between anterior cingulate hypoperfusion and improved postoperative urination. The study revealed that widely distributed and intercorrelated cortical and subcortical pathways are involved in the development of INPH symptoms, and preoperative CBF may be correlative to short-term shunt outcomes ²⁾

Results indicate that CBF in white matter close to the lateral ventricles plays a role in the reversibility of symptoms after CSF removal in patients with iNPH ³⁾.

Using pseudocontinuous arterial spin labelled imaging, Virhammar et al. could confirm findings of a reduced perfusion in the periventricular white matter, basal ganglia, and thalamus in patients with idiopathic normal pressure hydrocephalus previously observed with other imaging techniques ⁴⁾

The clinical value of ASL in the work-up of patients with iNPH is uncertain. In a study, ASL could not predict outcome after shunt surgery and there were no correlations between change in CBF and change in clinical symptoms after shunt surgery ⁵⁾