Topics

Topic

design image
Uvula of vermis (IX)

The uvula of the vermis is lobule IX of the inferior cerebellar vermis, situated posteriorly between the tonsils of the cerebellum. It is a small midline structure forming part of the paleocerebellum (spinocerebellum), connected anteriorly with the pyramid of the vermis and posteriorly to the nodulus via the inferior vermis. The uvula plays an important role in posture control, axial coordination, and vestibular function, integrating sensory input from the spinal cord and vestibular nuclei to maintain balance. It is also implicated in the coordination of oculomotor and truncal movements.

Function

  • Coordinates axial musculature and trunk stability

  • Contributes to balance and posture control via vestibulospinal pathways

  • Integrates vestibular and spinal sensory input with cerebellar processing

  • Participates in eye–head coordination and gait regulation

Synonyms

  • Uvula of the vermis

  • Vermis lobule IX

  • Cerebellar uvula

  • Vermian uvula

MRI Appearance

T1-weighted images:

  • The uvula of the vermis appears as isointense to gray matter, located midline between the cerebellar tonsils

  • Surrounded by hypointense CSF within the fourth ventricle and cisterna magna, creating contrast

  • Pathological changes such as atrophy, ischemia, or tumor infiltration appear as volume loss or altered signal

T2-weighted images:

  • Iso- to slightly hyperintense relative to cerebellar gray matter

  • Surrounded by hyperintense CSF, sharply outlining the uvula

  • Sensitive for detecting edema, demyelination, or ischemic lesions

STIR (Short Tau Inversion Recovery):

  • Normal uvula remains isointense to cerebellar gray matter

  • Edema, inflammation, or infiltrative lesions appear hyperintense against suppressed fat and bright CSF

T1 Post-Contrast (Gadolinium-enhanced):

  • Normal uvula shows no enhancement

  • Pathological lesions (e.g., medulloblastoma, ependymoma, metastasis) show variable enhancement depending on tumor vascularity

  • Contrast helps distinguish neoplastic from non-neoplastic lesions in the posterior fossa

CT Appearance:

  • The uvula of the vermis appears as a soft tissue density midline cerebellar structure, not individually distinguishable without contrast in normal conditions

  • Surrounded by hypodense CSF in the fourth ventricle and cisterna magna

  • CT is useful for detecting posterior fossa hemorrhage, calcification, mass lesions, or midline shift affecting the uvula

  • Bone window reconstructions delineate the surrounding posterior fossa and foramen magnum region

MRI images

Uvula of vermis (IX) of Cerebellum mri sag image -img-00000-00000