Normal pressure hydrocephalus
Background
- Possible reversible cause of dementia
- CSF buildup in the ventricles leading to increased intracranial pressure with edema of the periventricular white matter and corona radiata
- Sacral motor nerve fibers that produce gait instability; incontinence ensues when compressed
Clinical Features
- Gait disturbance is most common and earliest finding
- "Glue-footed" gait: move slowly, take small steps, often wide base, with difficulty turning
- Memory loss and dementia symptoms may be mild, subtle
- Incontinence is usually later stage, though sensation of urinary urgency is usually present before incontinence
- Usually do not have symptoms of increased intracranial pressure, such as headache, nausea, vomiting, visual loss
Differential Diagnosis
- Alzheimer's
- Stroke
- Parkinson's disease
- Electrolyte abnormality
- Malignancy
- Uremic encephalopathy
- Hydrocephalus ex vacuo (diffuse cerebral atrophy on CT)
Evaluation
- Initial ED workup
- CBC
- Chem 7
- CT brain non-con: Ventriculomegaly without signs of obstruction at the level of the third or fourth ventricles
- Additional workup (in coordination with neurology/neurosurgery), consider:
Normal pressure hydrocephalus vs brain atrophy[2]
| Normal pressure hydrocephalus | Brain atrophy | |
|---|---|---|
|
| |
| Preferable projection | Coronal plane at the level of the posterior commissure of the brain. | |
| Modality in this example | CT | MRI |
| CSF spaces over the convexity near the vertex (red ellipse) | Narrowed convexity ("tight convexity") as well as medial cisterns | Widened vertex (red arrow) and medial cisterns (green arrow) |
| Callosal angle (blue V) | Acute angle | Obtuse angle |
| Most likely cause of leucoaraiosis (periventricular signal alterations, blue arrows) | Transependymal cerebrospinal fluid diapedesis | Vascular encephalopathy, in this case suggested by unilateral occurrence |
Evan's index is the ratio of maximum width of the frontal horns to the maximum width of the inner table of the cranium. An Evan's index more than 0.31 indicates hydrocephalus.[3]
Management
- Fall precautions
- Consult neurology and/or neurosurgery to decide if patient is candidate for inpatient vs outpatient MRI and LP.
- LP is rarely done in the ED as it requires MRI before LP, and workup is typically non-emergent and can often be done as outpatient.
Disposition
- Workup typically is extensive, but can often be done as outpatient, depending on your institution.
- Decide plan for workup with neurology and/or neurosurgery
- Consider admission if patient lives alone (fall risk), has no follow-up, or is significantly altered.
Also See
References
- ↑ Schneck MJ. Normal pressure hydrocephalus. Medscape. Retrieved 8/4/2016
- ↑ Ishii M, Kawamata T, Akiguchi I, Yagi H, Watanabe Y, Watanabe T, Mashimo H (March 2010). "Parkinsonian Symptomatology May Correlate with CT Findings before and after Shunting in Idiopathic Normal Pressure Hydrocephalus". Parkinson's Disease. 2010: 1–7. doi:10.4061/2010/201089. PMC 2951141. PMID 20948890.
- ↑ hii M, Kawamata T, Akiguchi I, Yagi H, Watanabe Y, Watanabe T, Mashimo H (March 2010). "Parkinsonian Symptomatology May Correlate with CT Findings before and after Shunting in Idiopathic Normal Pressure Hydrocephalus". Parkinson's Disease. 2010: 1–7. doi:10.4061/2010/201089. PMC 2951141. PMID 20948890.