Small Ventricles

Bronwyn E. Hamilton, MD

DIFFERENTIAL DIAGNOSIS

Common

Less Common

Rare but Important

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Clinical presenting features usually help define the category of disease in question

Helpful Clues for Common Diagnoses

Normal Variant (Young Brain)
- Ventricles in children, young adults can normally appear quite small
CSF Shunts and Complications
- CSF diversion
  - ± Reduced ventricular compliance
- Compliance changes caused by
  - Ependymal scar/adhesions
- Cause shunted ventricle to collapse
Cerebral Edema, Traumatic
- Low density parenchyma with sulcal & ventricular effacement
- Hyperdense cerebellum, “reversal sign”
Herniation Syndromes, Intracranial
- Ventricular effacement common

Helpful Clues for Less Common Diagnoses

Encephalitis (Miscellaneous)
- White matter T2 hyperintensity & edema
- Mild restriction on DWI common
Intracranial Hypotension
- “Slumping” midbrain, acquired tonsillar herniation/ectopia, enhancing dura
Intracranial Hypertension, Idiopathic
- “Pseudotumor cerebri”
- Dilated optic nerve sheaths, basal cisterns effaced, small ventricles
Intracranial Hypertension, Secondary
- Etiology: Any causes of high intracranial pressure or diffuse edema: Trauma, venous outflow obstruction, anoxic or metabolic encephalopathy, mass, brain death
HIE, NOS
- Global anoxic/ischemic event results in DWI changes
  - Basal ganglia > diffuse cortex bright
  - Diffuse white matter restriction (may be subacute manifestation)
- DWI abnormalities evolve slower than thromboembolic infarction
Meningitis
- Mild hydrocephalus > > > small ventricles