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Topic

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Caudatolenticular gray bridges

The caudatolenticular gray bridges are thin bands of gray matter that connect the head of the caudate nucleus with the lentiform nucleus across the anterior limb of the internal capsule. They represent remnants of the embryologic continuity of the striatum and give rise to the characteristic striated appearance of the internal capsule on imaging.

These bridges are normal anatomical structures and are important landmarks in basal ganglia anatomy and neuroimaging interpretation.

Synonyms

  • Striatal gray bridges

  • Caudatolenticular connections

  • Gray matter bridges of the internal capsule

Location

  • Situated within the anterior limb of the internal capsule

  • Extend between the head of the caudate nucleus medially and the lentiform nucleus laterally

  • Located superior to the anterior commissure

  • Part of the basal ganglia region in the supratentorial brain

  • Best appreciated on axial sections through the frontal horns of the lateral ventricles

Anatomical components

  • Gray matter strands:

    • Composed of neuronal cell bodies and neuropil

    • Continuous with striatal gray matter

  • Interposed white matter:

    • Internal capsule fibers pass between gray bridges

    • Creates alternating gray–white appearance

Relations

Medially:

  • Head of the caudate nucleus

  • Lateral ventricle (frontal horn)

Laterally:

  • Lentiform nucleus (putamen and globus pallidus)

Anteriorly:

  • Frontal lobe white matter

Posteriorly:

  • Anterior commissure region

Inferiorly:

  • Basal forebrain structures

Structures connected

  • Caudate nucleus (striatal component)

  • Putamen (striatal component of lentiform nucleus)

  • Functional continuity of the striatum across the internal capsule

Function

  • Structural continuity: Reflects the embryologic unity of the striatum

  • Neuronal integration: Allows interconnections between caudate and putamen

  • Basal ganglia organization: Contributes to coordination of motor and associative circuits

  • Anatomical landmark: Helps identify internal capsule subdivisions on imaging

MRI appearance

T1-weighted images:

  • Gray bridges: Intermediate signal intensity similar to other gray matter

  • Internal capsule fibers: Lower signal intensity than gray bridges

  • Overall pattern: Alternating gray and white bands

T2-weighted images:

  • Gray bridges: Intermediate-to-slightly higher signal than surrounding white matter

  • Symmetry: Bilateral and symmetric appearance

  • Characteristic striated pattern within the anterior limb of the internal capsule

FLAIR:

  • Gray bridges: Intermediate signal similar to basal ganglia gray matter

  • White matter: Relatively suppressed compared with gray matter

Diffusion-weighted imaging (DWI):

  • Normal: No diffusion restriction

Post-contrast T1-weighted images:

  • Normal: No enhancement

CT appearance 

Non-contrast CT:

  • Gray bridges: Not individually conspicuous but identifiable by location

Post-contrast CT:

  • Normal: No enhancement

MRI images

MRI Caudatolenticular gray bridges anatomy image -img-00000-00000

MRI images

MRI Caudatolenticular gray bridges coronal anatomy image -img-00000-00000