Topics

Topic

design image
Parabrachial recess

The parabrachial recess is a distinct anatomical groove or depression on the lateral surface of the brainstem, most clearly identified at the level of the pons. It is defined by its position between the superior cerebellar peduncle medially and the middle cerebellar peduncle laterally. Rather than being a cavity or CSF-filled space, it represents a surface landmark used for anatomical orientation.

The parabrachial recess is important in gross neuroanatomy and cross-sectional imaging as a reliable reference point for identifying cerebellar peduncles and the dorsolateral pontine surface.

Synonyms

  • Parabrachial groove

  • Parabrachial depression

Location

  • Located on the lateral surface of the pons

  • Situated between two major cerebellar connections

  • Medial boundary: Superior cerebellar peduncle (brachium conjunctivum)

  • Lateral boundary: Middle cerebellar peduncle (brachium pontis)

  • Appears as a shallow surface indentation rather than an internal space

  • Best appreciated on axial and oblique axial brainstem sections

Anatomical characteristics

  • Surface feature: Represents a contour change on the brainstem, not a ventricle or cistern

  • Peduncular relationship:

    • Separates ascending fibers of the superior cerebellar peduncle

    • From transverse pontocerebellar fibers of the middle cerebellar peduncle

  • Depth association: Overlies dorsolateral pontine parenchyma

Relations

Medially:

  • Superior cerebellar peduncle

Laterally:

  • Middle cerebellar peduncle

Anteriorly:

  • Lateral pontine surface

Posteriorly:

  • Cerebellar hemisphere adjacent to peduncular attachments

Function

  • Anatomical landmark: Used to identify the interface between the superior and middle cerebellar peduncles

  • Orientation aid: Helps localize dorsolateral pontine anatomy during dissection and imaging review

  • Descriptive reference: Assists in precise communication of brainstem surface anatomy

MRI appearance (normal)

T1-weighted images:

  • Recess: Identified by a subtle surface indentation; no intrinsic signal

  • Peduncles: Low-to-intermediate signal typical of compact white matter

T2-weighted images:

  • Recess: Appreciated as a contour change along the lateral pons

  • Peduncles: Low-to-intermediate signal intensity

FLAIR:

  • Recess: No intrinsic signal; recognition relies on surrounding anatomy

Diffusion-weighted imaging (DWI):

  • Normal: No diffusion restriction; not used to define the recess itself

Post-contrast T1-weighted images:

  • Normal: No enhancement related to the recess

CT appearance 

Non-contrast CT:

  • Recess: Typically not directly visualized

MRI image

MRI Parabrachial recess axial anatomy image -img-00000-00000