Are gait changes linked to CSF flow changes in the sagittal sinus?

Area of Science:

• Neurology
• Neurosurgery
• Radiology

Background:

• Idiopathic normal pressure hydrocephalus (iNPH) is a neurological condition characterized by gait disturbance, urinary incontinence, and cognitive impairment.
• The cerebrospinal fluid (CSF) tap test (TT) is used to predict response to shunting surgery, but identifying responders remains challenging.

Purpose of the Study:

• To determine if specific magnetic resonance imaging (MRI) cerebrospinal fluid (CSF) flow study findings can predict gait improvement in patients with idiopathic normal pressure hydrocephalus (iNPH) following a CSF tap test (TT).

Main Methods:

• A prospective study involving 53 patients with iNPH undergoing a CSF TT.
• Gait was assessed using the Timed Up and Go (TUG) test before and after the CSF TT.
• MRI CSF flow studies were performed concurrently with the CSF TT, with responders defined by a clinically important difference in TUG scores.

Main Results:

• Significant differences were observed in superior sagittal sinus flow, stroke volume, stroke volume ratio, area, and circumference between responders and non-responders to the CSF TT.
• No significant differences were found in aqueduct stroke volume, arterial stroke volume, or aqueduct net flow between the groups.

Conclusions:

• Sagittal sinus measurements correlate with gait improvement after CSF drainage in iNPH patients.
• These findings suggest the sagittal sinus plays a role in iNPH symptom manifestation and may aid in diagnosis and surgical decision-making.