A Randomized Trial of Shunting for Idiopathic Normal-Pressure Hydrocephalus

Area of Science:

• Neurology
• Neurosurgery

Background:

• Idiopathic normal-pressure hydrocephalus (iNPH) is a neurologic disorder affecting gait, balance, cognition, and bladder control in older adults.
• Shunt surgery is a common treatment for iNPH, but its effectiveness remains uncertain.

Purpose of the Study:

• To evaluate the effectiveness of shunt surgery in improving gait, balance, cognition, and bladder control in patients with iNPH.

Main Methods:

• A double-blind, randomized, placebo-controlled trial was conducted with 99 participants selected for shunt surgery based on gait-velocity improvement after CSF drainage.
• Participants received either an open-shunt valve or a placebo valve.
• Primary outcome was change in gait velocity at 3 months; secondary outcomes included changes in the Tinetti scale, MoCA, and Overactive Bladder Questionnaire scores.

Main Results:

• Shunt surgery significantly increased gait velocity (0.21 m/s difference; P<0.001) and improved Tinetti scale scores (P=0.003) at 3 months compared to placebo.
• No significant improvements were observed in MoCA or Overactive Bladder Questionnaire scores.
• Adverse events varied, with more falls in the placebo group and more subdural bleeding and positional headaches in the open-shunt group.

Conclusions:

• Shunting in iNPH patients who respond to CSF drainage leads to significant improvements in gait velocity and balance at 3 months.
• Shunt surgery did not demonstrate significant benefits for cognitive function or urinary incontinence in this study.
• Further research may be needed to clarify the long-term effects and optimal patient selection for iNPH shunting.