Triad of normal pressure hydrocephalus does not include:
**Core Concept**
Normal pressure hydrocephalus (NPH) is a clinical condition characterized by an accumulation of cerebrospinal fluid (CSF) in the brain, leading to ventricular enlargement and increased intracranial pressure. The classic triad of symptoms associated with NPH includes gait disturbance, dementia, and urinary incontinence.
**Why the Correct Answer is Right**
The mechanism underlying NPH involves impaired CSF reabsorption, leading to a buildup of fluid in the ventricles. This increased fluid pressure causes damage to surrounding brain tissue, resulting in the characteristic symptoms. The gait disturbance is thought to be due to the compression of the frontal lobe, while dementia is attributed to the involvement of the hippocampus and surrounding structures. Urinary incontinence is believed to result from the disruption of the normal micturition reflex.
**Why Each Wrong Option is Incorrect**
**Option A:** This option might be tempting, but it is not a component of the classic NPH triad.
**Option B:** This option is incorrect because it is actually a symptom of normal pressure hydrocephalus.
**Option C:** This option is also incorrect because it is a symptom of normal pressure hydrocephalus.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the diagnosis of NPH relies heavily on clinical presentation and imaging findings. The classic triad is often used as a screening tool, but a definitive diagnosis requires a lumbar puncture to assess CSF dynamics.
**Correct Answer:**
C.