Inclusion Criteria:

1. Age ≥ 60 years; and

2. Diagnosis of iNPH and recommendation for shunt surgery based on the Investigator's
clinical judgement based on criteria and testing as described in the iNPH Guidelines;

3. Evans Ratio ≥ 0.30; and

4. One positive supplementary test to include either large volume Lumbar Puncture or
extended CSF drainage per institutional standards; and

5. History or evidence of gait impairment (such as decreased step height or length,
decreased speed, retropulsion as described in the iNPH Guidelines) duration ≥ 6
months; and

6. Participant has the sensory motor skills, communication skills and understanding to
comply with the testing and reporting required in the PENS trial; and

7. Participant is able to give written informed consent.

Exclusion Criteria:

1. Unable to walk 10 meters with or without an assistive device; or

2. Baseline fastest gait velocity (out of three gait trials) >1 m/sec prior to drainage
trial and fastest gait velocity improvement is < 30% with or without an assistive
device; or

3. Unable to return to the study center for follow up evaluation and shunt programming;
or

4. Participant is not medically cleared for shunt surgery per local standards; or

5. Secondary NPH. (Prior encephalitis, meningitis, subarachnoid hemorrhage, traumatic
brain injury (including concussion) within two years or with brain injury or skull
fracture on baseline imaging, brain abscess, brain tumor, obstructive hydrocephalus
(including acquired aqueductal stenosis and carcinomatous meningitis); or

6. Prior or existing shunts, endoscopic third ventriculostomy, or any previous surgical
intervention for hydrocephalus; or

7. Previous intracranial neurosurgical procedure; or

8. Symptomatic cerebral or cerebellar infarction occurring within 6 months from screening
(asymptomatic lacunar infarctions are permitted); or

9. Diagnosis of Parkinsonian syndrome that, in the investigator's judgment, will
complicate the outcome evaluation; or

10. Diagnosis of schizophrenia or any psychiatric diagnosis (including depression) that,
in the investigator's judgment, will complicate the outcome evaluation (such as
neuroleptic treatment for schizophrenia); or

11. Diagnosis of dementia disorder where the investigator considers cognition deficit
limits participation in the study; or

12. Conditions impairing gait that are considered to be unrelated to hydrocephalus, such
as hemiparesis, spasticity, cerebellar ataxia or musculoskeletal and joint disease,
which will interfere with gait assessment or the potential for gait improvement.

13. Individuals with contraindication to MRI (e.g., implanted electric and electronic
devices, aneurysm clip(s), any metallic fragment or foreign body, coronary and
peripheral artery stents, cardiac pacemaker, known claustrophobia, or known/possible
pregnancy or breast-feeding) will be excluded according to institutional guidelines.