Normal Pressure Hydrocephalus in Kathmandu — Reversible Cause of Dementia and Gait Disorder

Normal pressure hydrocephalus (NPH) is a condition characterized by the triad of gait disturbance, cognitive impairment, and urinary incontinence, occurring in the setting of ventricular enlargement without significantly elevated cerebrospinal fluid pressure. What makes NPH particularly important is that it is one of the potentially reversible causes of dementia and gait disorders when identified and treated appropriately.

The classic triad of symptoms has a characteristic pattern. Gait disturbance is typically the earliest and most prominent symptom. Patients describe difficulty walking, feeling unsteady, or having "magnetic gait" — feet feeling stuck to the floor. Steps become short and shuffling, and turning requires multiple small steps. Cognitive impairment involves slowing of thinking, reduced attention, and apathy rather than the profound memory loss typical of Alzheimer's disease. Urinary incontinence develops later, initially as urgency and frequency before progressing to incontinence.

Dr. Jitendra Prasad Yadav — consultant neurologist & headache specialist at Kathmandu Neurology Clinic & Cognitive Center provides evidence-based evaluation for dementia.

NPH is most common in older adults, typically affecting people over age 60. The exact cause is often unknown (idiopathic NPH), but it can also develop after subarachnoid hemorrhage, meningitis, head injury, or brain tumors (secondary NPH). The condition results from impaired cerebrospinal fluid absorption, leading to gradual ventricular enlargement.

Diagnosis requires distinguishing NPH from other causes of gait disorder and cognitive decline, particularly vascular dementia, Alzheimer's disease, and Parkinson's disease. Brain MRI shows ventricular enlargement out of proportion to cortical atrophy. CSF flow studies may be used to assess CSF dynamics. A diagnostic lumbar puncture with removal of 30-50 mL of CSF, followed by assessment of gait improvement, helps predict shunt responsiveness.

Treatment involves surgical placement of a ventriculoperitoneal shunt to divert excess CSF from the ventricles to the abdominal cavity, where it is absorbed. When carefully selected patients undergo shunting, significant improvement in gait occurs in 60-80% of cases, and cognitive and bladder function may also improve. The greatest improvement is typically seen in gait, while cognitive recovery is more variable.

Not all patients with the clinical triad have shunt-responsive NPH. Careful patient selection is crucial to avoid unnecessary surgery in patients whose symptoms are due to other, irreversible conditions. Factors predicting better shunt response include shorter symptom duration, more prominent gait disturbance relative to cognitive impairment, and marked gait improvement after diagnostic CSF removal.

At Kathmandu Neurology Clinic & Cognitive Center, Dr. Jitendra Prasad Yadav (NMC 8029) evaluates suspected NPH with detailed gait assessment, cognitive screening, MRI review, and diagnostic CSF testing when appropriate. Patients who are good shunt candidates are referred for neurosurgical evaluation.

This article is educational and does not replace individual medical advice.

**Frequently Asked Questions**

Q: Is normal pressure hydrocephalus curable? A: NPH is not curable in the sense that the underlying condition is not eliminated, but shunt surgery can significantly improve symptoms, particularly gait disturbance. Many patients experience meaningful improvement in walking and daily function after shunting.

Q: What are the first symptoms of normal pressure hydrocephalus? A: Gait disturbance is typically the first and most prominent symptom. Patients notice difficulty walking, unsteadiness, short shuffling steps, and trouble turning. Cognitive slowing and urinary urgency usually develop later.

Q: How is normal pressure hydrocephalus diagnosed? A: Diagnosis involves brain MRI showing ventricular enlargement, clinical assessment of the characteristic symptom triad, and often a diagnostic lumbar puncture to assess whether CSF removal improves gait. CSF flow studies may also be used.

Q: Who is a good candidate for shunt surgery? A: Good candidates have the classic symptom triad with gait as the most prominent feature, MRI findings consistent with NPH, and demonstrated gait improvement after diagnostic CSF removal. Shorter symptom duration and absence of severe cognitive impairment also predict better outcomes.

Q: What are the risks of shunt surgery? A: Shunt surgery carries risks including infection, over-drainage (causing headaches or subdural hematoma), under-drainage (persistent symptoms), and mechanical shunt malfunction requiring revision. The decision to proceed with surgery balances these risks against potential symptom improvement.

Q: Can NPH be mistaken for other conditions? A: Yes, NPH is frequently mistaken for Alzheimer's disease, vascular dementia, Parkinson's disease, or normal aging. The key distinguishing feature is that NPH is potentially treatable with shunt surgery, making accurate diagnosis important.