Cerebral hemodynamics in normal-pressure hydrocephalus. Evaluation by 133Xe inhalation method and dynamic CT study

Area of Science:

• Neurology
• Neurosurgery
• Radiology

Background:

• Normal-pressure hydrocephalus (NPH) is a condition characterized by impaired cerebrospinal fluid (CSF) circulation.
• Reduced cerebral blood flow (CBF) is often observed in patients with dementia, including those with suspected NPH.

Purpose of the Study:

• To investigate cerebral hemodynamics in patients with suspected NPH using xenon-133 (133Xe) inhalation and dynamic CT scanning.
• To correlate CBF patterns and changes with clinical outcomes after CSF shunting.

Main Methods:

• Utilized the xenon-133 (133Xe) inhalation method to measure CBF in 31 patients with suspected NPH.
• Employed dynamic computerized tomography (CT) scanning to assess contrast material transit times.
• Compared hemodynamic data between patients with good and poor outcomes post-shunting.

Main Results:

• Hypoperfusion was observed in the frontal lobes of NPH patients compared to controls.
• CSF shunting increased CBF in patients who responded clinically, with normalization of flow patterns.
• Patients with degenerative dementia showed decreased CBF after shunting, and dynamic CT revealed increased transit times.

Conclusions:

• CBF changes following CSF shunting can differentiate NPH responders from non-responders.
• Improved CBF, particularly in frontal and temporal regions, is associated with positive clinical outcomes in NPH.
• Dynamic CT findings of reduced transit times correlate with successful shunting in NPH patients.