Hummingbird sign

The hummingbird sign, also known as the penguin sign, refers to the appearance of the brainstem in patients with progressive supranuclear palsy (PSP)

The atrophy of the midbrain results in a profile of the brainstem (in the sagittal plane) in which the preserved pons forms the body of the bird, and the atrophic midbrain the head, with beak extending anteriorly towards the optic chiasm. Midbrain atrophy is best confirmed with reduction in the midbrain to pons ratio.


Neurodegenerative diseases

Neurodegenerative diseases are legion and their classification just as protean. A useful approach is to divide them according to underlying pathological process, although even using this schema, there is much overlap and thus resulting confusion.

Inspired signs
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Article Information

rID: 14393
Section: Signs
Tags: stub, refs
Synonyms or Alternate Spellings:
  • Penguin sign

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