A simplified pressure adjustment clinical pathway for programmable valves in NPH patients

The goal of this study is to provide a clinical pathway for shunt valve adjustment in the treatment of normal pressure hydrocephalus (NPH) patients.

The authors conducted a single-center retrospective study of 102 patients (mean age 74 years, 66 men, 36 women) diagnosed with NPH. In all cases, a Medtronic Strata Adjustable Pressure valve set initially at 1.5 was implanted. Outcome was based on the clinical status of the patient at the last contact point with the senior author. Patients were adjusted with reductions or increases of 0.5 per follow-up visit to achieve the best clinical outcome and avoid complications. Complications were categorized as infection, shunt malfunction, subdural hygroma/hematoma, or any adverse event able to be attributed to a change in shunt setting or surgical procedure.

Of the 102 patients, 60% had the triad of clinical symptoms, 5% had gait dysfunction only, 2% had dementia only, 4% had urine incontinence and gait dysfunction, 1% had urine incontinence and dementia, and 28% had gait dysfunction and dementia. Over a mean clinical follow-up of 19 months, 71 patients had improvement or resolution of NPH symptoms at the last point of contact with the senior author. Of the 71 patients, 24% improved in all 3 symptoms, 8% improved in urine incontinence only, 17% improved in gait dysfunction only, 15% improved in dementia only, 15% improved in urine incontinence and gait dysfunction only, 4% improved in urine incontinence and dementia only, and 15% improved in gait dysfunction and dementia only. Valve pressure adjustment was required at least once in 85 patients (mean number of 1.68 adjustments, 7 maximum); 10% had 0.5 as the final setting, 47% had 1.0 as the final setting, 36% had 1.5 as the final setting, 7% had 2.0 as the final setting, and 0% had 2.5 as the final setting. There were 41 (40%) complications overall: 28 subdural hygromas/hematomas, of which 5 required surgical evacuation; 9 distal obstructions requiring surgical revision; 4 seizures; 2 infections; 1 exposed shunt tubing; 1 intraparenchymal hematoma of unknown etiology.

Standardization of post-operative care for patients with NPH is possible. The present manuscript offers a safe and effective pathway for treatment of NPH patients with the Strata Adjustable Pressure Valve.