neurologic disorders
Normal–Pressure Hydrocephalus
Diagnosis of Normal–Pressure Hydrocephalus
Clinical evaluation Neuroimaging Sometimes removal of CSF The classic symptoms (gait disturbance, urinary incontinence, and dementia), even combined, are nonspecific for normal-pressure hydrocephalus, particularly in older people. For example, some forms of Vascular Cognitive Impairment and Dementia can cause dementia, gait disturbance, and, less commonly, urinary incontinence. A general Clinical criteria requires all of the following: Cognitive or behavioral (neuropsychiatric) symptoms interfere with the ability to function at work or do usual daily activities. These symptoms represent a decline from previous levels of functioning. These symptoms are not explained by delirium or a major psychiatric disorder. Evaluation of cognitive function involves taking a history from the patient and from someone who knows the patient plus doing a bedside How to Assess Mental Status or, if bedside testing is inconclusive, Brain imaging may show ventricular enlargement disproportionate to cortical atrophy; this finding is nonspecific but may support the diagnosis of normal-pressure hydrocephalus. Sulci high on the cortical convexity are often compressed, and the Sylvian fissures are disproportionately atrophic. Lumbar Puncture (Spinal Tap) is done. CSF opening pressure should be normal in patients with normal-pressure hydrocephalus. Removal of 30 to 50 mL of CSF can be done as a diagnostic trial. Improvement in gait, continence, and cognition after removal suggests that the patient can be a good candidate for ventriculoperitoneal shunting surgery, but improvement may not be evident until several hours after removal. Additional CSF may leak out after lumbar puncture, sometimes contributing to neurologic improvement. 