Subdural hygroma

Subdural hygromas refer to a cerebrospinal fluid (CSF) accumulation in the subdural space. In many cases it is considered an epiphenomenon of head injury when it is called a traumatic subdural hygroma

The vast majority of patients are asymptomatic, however some symptoms uncommonly reported include 5:

  • headaches
  • changes in mental status
  • nausea and vomiting
  • focal neurological deficits
  • seizures

They generally occur along the supratentorial cerebral convexities; occurrence in the posterior fossa is generally rare 4.

A subdural hygroma radiographically appears as a crescentic CSF density/signal accumulation in the subdural space that does not extend into the sulci and rarely exerts mass-effect 5. Vessels rarely cross through the lesion in contrast enhanced studies (see cortical vein sign) 1.

The vast majority of patients with subdural hygroma are asymptomatic without radiographic evidence of mass-effect, and thus neurosurgical intervention is rarely required 5. In cases where mass-effect is radiographically demonstrated, then neurosurgically evacuated 5

Imaging differential considerations include:

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Article information

rID: 18609
Section: Pathology
Synonyms or Alternate Spellings:
  • Subdural hygromas
  • Subdural hygromata
  • Traumatic subdural hygroma
  • CSF hygromas
  • CSF hygroma

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Cases and figures

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    Figure 1: subdural hygroma
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    Case 1
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    Case 2: left frontal convexity
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    Case 3
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    Case 4
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