A 65-year-old man complains of difficulty in walking. He has a history of chronic subdural hematomas. Neurologic examination reveals psychomotor slowing, sphincter incontinence, and enlarged ventricles without convolutional atrophy. The most likely diagnosis is:
## **Core Concept**
The question tests knowledge of neurological conditions associated with gait disturbances, cognitive decline, and specific radiological findings. The key concepts here involve understanding the clinical presentation and imaging characteristics of conditions affecting the brain, particularly those that could lead to enlarged ventricles and symptoms like psychomotor slowing and sphincter incontinence.
## **Why the Correct Answer is Right**
The clinical presentation of difficulty walking, psychomotor slowing, sphincter incontinence, and enlarged ventricles without convolutional atrophy in a patient with a history of chronic subdural hematomas strongly suggests **Normal Pressure Hydrocephalus (NPH)**. NPH is characterized by the triad of gait disturbance, dementia (or psychomotor slowing), and urinary incontinence. The condition is associated with enlarged ventricles on imaging without significant cortical atrophy, and it can be secondary to various causes, including chronic subdural hematomas which can obstruct cerebrospinal fluid (CSF) pathways.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but typically, other diagnoses such as Alzheimer's disease, vascular dementia, or other forms of hydrocephalus might be considered. However, these conditions do not typically present with the specific combination of symptoms and imaging findings seen in NPH.
- **Option B:** Similarly, without the specific text, we can infer that any condition not matching the NPH profile (e.g., cerebral atrophy, different types of dementia) would be incorrect.
- **Option C:** Again, without specifics, any alternative diagnosis not aligning with NPH's clinical and radiological features would not be correct.
## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that Normal Pressure Hydrocephalus (NPH) is a reversible cause of dementia. The condition is often tested with a **lumbar puncture** to assess for improvement in symptoms (especially gait) after removal of CSF, and a **shunt surgery** is often the definitive treatment. The association of NPH with reversible dementia makes it a critical diagnosis to consider in patients with gait disturbances and cognitive decline.
## **Correct Answer:** D. Normal Pressure Hydrocephalus.