Images in Clinical Radiology

Global Ischemia of The Cerebellum: The Dark Cerebellar Sign

Authors: {'first_name': 'Cengiz', 'last_name': 'Y\xc4\xb1lmaz'},{'first_name': 'Ender', 'last_name': 'Alkan'},{'first_name': 'Hasan', 'last_name': 'Erdo\xc4\x9fan'}
Keywords: Dark cerebellumWhite cerebellumCTTrauma 
 Accepted on 17 Dec 2018            Submitted on 04 Dec 2018

Case History

A three-year-old boy with a history of motor vehicle accident presented with loss of consciousness. Non-enhanced cranial computed tomography (CT) (Figure 1) showed diffuse cerebellar hypodensity (open arrows) compared to supratentorial brain parenchyma (arrows). There was also a fracture dislocation of C1-C2 (Figure 2, arrow).

Figure 1 
Figure 2 


We want to present the dark cerebellar sign, which is not known as well as the white cerebellar sign. White cerebellar sign refers to a normal cerebellum and brainstem that appear hyperdense in comparison to the supratentorial brain on non-enhanced CT. The cerebellum and brainstem are believed to be more resistant to hypoxia-ischemia than the supratentorial brain [1]. A diffuse hypodensity of the cerebrum is seen in cases of profound and sustained hypoxia. This may occur in prolonged cardiac arrest, poisoning (carbon monoxide, cyanide, hydrogen sulfide, barbiturate), or as a complication of a severe meningo-encephalitis. On the other hand, the dark cerebellar sign is a much rarer finding and is characterized by a diffuse hypodense cerebellum compared to the normal density of the supratentorial brain parenchyma. The hypodensity of the cerebellum is caused by diffuse parenchymal cerebellar edema and/or infarction [2]. The prognosis is usually very poor. Acute cerebellitis should be in the differential diagnosis of a hypodense, edematous cerebellum [3]. At this situation clinical information may aid differential diagnosis.

In conclusion, dark cerebellar sign refers to diffuse hypodensity of the cerebellum at non-enhanced CT, and develops secondary to diffuse cerebellar ischemia/infarction. In our case diffuse cerebellar infarction probably developed secondary to transection of the vertebral artery.

Competing Interests

The authors have no competing interests to declare.


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  2. Huisman, TAGM, Kubat, SH and Eckhardt, BP. The dark cerebellar sign. Neuropediatrics. 2007; 38: 160–3. DOI: 

  3. Sawaishi, Y and Takada, G. Acute cerebellitis. Cerebellum. 2002; 1: 223–8. DOI: