Synonyms:
- Extradural hematoma
Diagnosis:
CT or MRI:
- Biconvex shape a.k.a. ‘lentiform’, usually over the temporal lobe
- Can cross the falx, tentorium, can cross the midline, but doesn’t cross the suture lines
- Associated with skull fracture
Clinical features:
- Usually there is a history of trauma
- Often the patient is knocked unconscious with the initial trauma. They may regain consciousness (lucid period) and then become unconscious again
- Neurological examination may reveal features suggesting a structural cause of coma: asymmetric weakness or posturing response, disconjugate gaze or dilate pupil ipsilateral to the hematoma
Pathology:
- Acute: gelatinous clotted blood. Microscopically, red blood cells +/-macrophages +/-hemosiderin
- Chronic: Dark brown clot adherent to the skull or dura. Or replaced by fibrous tissue. Microscopically: Fibrous tissue, venules & membrane.
Treatment:
- Surgical: craniotomy & evacuation under direct vision