<br />Introduction<br />Normal Pressure Hydrocephalus (NPH) is a neurological disorder that primarily affects older adults and is characterized by the triad of gait disturbance, urinary incontinence, and cognitive impairment. Despite being a potentially reversible cause of dementia, NPH is often underdiagnosed or mistaken for conditions like Alzheimer’s disease or Parkinson’s disease. Early identification and appropriate intervention can significantly improve quality of life in affected individuals.<br />________________________________________<br />Pathophysiology<br />NPH is a form of communicating hydrocephalus, where cerebrospinal fluid (CSF) flows freely between the ventricles and the subarachnoid space but is not properly reabsorbed. This leads to gradual accumulation of CSF in the lateral ventricles, causing ventricular enlargement without a significant increase in intracranial pressure—hence the term "normal pressure."<br />The exact mechanism is not fully understood, but it is believed that impaired CSF absorption by the arachnoid granulations results in ventricular dilation, which in turn compresses adjacent brain structures, especially the periventricular white matter. This pressure affects pathways responsible for motor control, cognition, and bladder function.<br />________________________________________<br /><br /><br />Clinical Features<br />NPH typically presents with the classic triad:<br />1. Gait Disturbance – Often the earliest and most prominent symptom. Patients may have a broad-based, shuffling walk described as “magnetic gait,” where the feet seem stuck to the floor.<br />2. Cognitive Decline – Resembles subcortical dementia with symptoms such as slowed thinking, reduced attention, and impaired executive function. Memory loss is usually less prominent than in Alzheimer’s disease.<br />3. Urinary Incontinence – May begin as increased urgency or frequency and progress to loss of bladder control.<br />Not all patients will exhibit all three symptoms, and the severity can vary. Gait disturbance is considered the most responsive to treatment.<br />________________________________________<br /><br />Diagnosis<br />Diagnosing NPH involves a combination of clinical evaluation and neuroimaging:<br />• Neuroimaging:<br />o MRI or CT scan reveals ventriculomegaly (enlarged ventricles) out of proportion to cortical atrophy.<br />o Evans index > 0.3 (ratio of the frontal horn width to the width of the inner skull at the same level) is suggestive of NPH.<br />• CSF Tap Test:<br />o Removal of 30–50 mL of CSF via lumbar puncture may lead to temporary improvement in gait or cognition, supporting the diagnosis.<br />• Lumbar Drain Trial:<br />o Continuous CSF drainage over 2–3 days to assess symptom improvement.<br />Differential diagnoses include Alzheimer’s disease, Parkinson’s disease, vascular dementia, and cerebellar ataxia.<br />________________________________________<br />Treatment<br />The primary treatment for NPH is surgical intervention via ventriculoperitoneal (VP) shunt placement. This involves inserting a catheter into the ventricles to divert excess CSF to the peritoneal cavity, where it can be absorbed.<br />• Shunt response is variable but can lead to dramatic improvement, particularly in gait.<br />• Complications include shunt malfunction, infection, subdural hematoma, and overdrainage.<br />• Patient selection is critical—those with good response to the CSF tap test are more likely to benefit.<br />________________________________________<br />Prognosis<br />When diagnosed and treated early, NPH offers a good prognosis with significant symptom relief. Gait improvement is often the most pronounced, while cognitive and urinary symptoms may respond more slowly or incompletely. Delay in diagnosis can result in irreversible damage, reducing the chances of recovery.<br />________________________________________<br /><br /><br />Conclusion<br />Normal Pressure Hydrocephalus is a potentially reversible condition that mimics more common neurodegenerative disorders in the elderly. Recognizing the clinical triad and conducting appropriate diagnostic tests, especially imaging and CSF removal, are essential for early diagnosis. With timely shunt surgery, many patients can regain mobility, independence, and cognitive function, making NPH one of the few treatable causes of dementia in older adults<br />Dr.Zahraa Tariq Hasson<br />Al-Mustaqbal University is the number one university in Iraq.<br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br />