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Marginal branch of cingulate sulcus

The marginal branch of the cingulate sulcus (also called the marginal ramus) is a prominent vertical sulcus on the medial surface of the cerebral hemisphere. It represents the posterior ascending continuation of the cingulate sulcus and serves as a key landmark separating motor and sensory cortical regions related to the lower limb.

It is of major importance in neuroanatomy, neuroimaging, functional localization, and neurosurgical planning, particularly for lesions involving the medial frontal and parietal lobes.

Synonyms

  • Marginal ramus of the cingulate sulcus

  • Marginal sulcus

Location

  • Located on the medial surface of the cerebral hemisphere

  • Arises as the posterior upward continuation of the cingulate sulcus

  • Extends superiorly toward the superomedial border of the hemisphere

  • Often reaches or nearly reaches the superior margin

  • Forms the posterior boundary of the paracentral lobule

  • Marks the transition between medial frontal and medial parietal lobes

Anatomical characteristics

  • Orientation:

    • Predominantly vertical or obliquely vertical

  • Cortical boundaries:

    • Anterior to it lies the medial frontal cortex

    • Posterior to it lies the medial parietal cortex

  • Continuity:

    • Continuous inferiorly with the cingulate sulcus

  • Variability:

    • Length and exact termination at the superior margin vary between individuals

Relations

Anteriorly:

  • Paracentral lobule (motor component)

  • Medial frontal gyrus

Posteriorly:

  • Paracentral lobule (sensory component)

  • Precuneus

Inferiorly:

  • Cingulate gyrus

  • Cingulate sulcus

Superiorly:

  • Superomedial border of the cerebral hemisphere

  • May join or approach the superior frontal sulcus

Functional relevance

  • Motor localization:

    • Anterior to the marginal branch lies the medial primary motor cortex (lower limb)

  • Sensory localization:

    • Posterior to the sulcus lies the medial primary somatosensory cortex (lower limb)

  • Paracentral lobule landmark:

    • Essential for identifying bladder, bowel, and lower extremity cortical representation

MRI appearance

T1-weighted images:

  • Normal: Clearly defined CSF-filled sulcus with low signal intensity

  • Adjacent cortex: Intermediate signal gray matter bordering the sulcus

T2-weighted images:

  • Normal: Hyperintense CSF within the sulcus

  • Cortex: Intermediate-to-slightly hyperintense gray matter

FLAIR:

  • Normal: CSF signal suppressed within the sulcus

  • Cortical pathology: Hyperintense signal in adjacent cortex in infarction, inflammation, or demyelination

Diffusion-weighted imaging (DWI):

  • Normal: No diffusion restriction

Post-contrast T1-weighted images:

  • Normal: No enhancement of the sulcus

CT appearance

Non-contrast CT:

  • Normal: Seen as a CSF-density sulcus on the medial hemisphere

Post-contrast CT:

  • Normal: No enhancement of the sulcus

MRI image

MRIMarginal branch of cingulate sulcus sagittal anatomy image -img-00000-00000