Middle cerebral artery variations: duplicated and accessory arteries

Area of Science:

• Neuroanatomy
• Vascular Neurology
• Developmental Neuroscience

Background:

• The middle cerebral artery (MCA) is a major cerebral artery supplying blood to large areas of the brain.
• Variations in MCA anatomy, such as duplicated or accessory MCAs, can occur but their developmental origins and precise vascular territories are not fully understood.
• Understanding these variations is crucial for interpreting neuroimaging and surgical planning.

Purpose of the Study:

• To analyze the anatomical similarities between duplicated middle cerebral artery (MCA) and accessory MCA.
• To investigate the relationship of these anomalous MCAs to the early branching patterns of the typical MCA.
• To determine the cortical territories supplied by duplicated and accessory MCAs.

Main Methods:

• Review of stereoscopic angiograms from four patients with duplicated MCAs and four patients with accessory MCAs.
• Analysis focused on the origin, size, and cortical supply of anomalous vessels.
• Assessment included the presence of perforating arteries and the recurrent artery of Heubner (RAH).

Main Results:

• Duplicated MCAs supplied temporopolar and anterior/middle temporal arteries; accessory MCAs supplied orbitofrontal/prefrontal arteries.
• Duplicated MCAs frequently had perforating arteries and coexisted with the RAH.
• Accessory MCAs consistently had perforating arteries and often coexisted with the RAH, unlike the main MCA.

Conclusions:

• Consistent cortical supply patterns suggest duplicated and accessory MCAs represent early, anomalous branching of typical MCA branches.
• Duplicated MCAs supply the anterior temporal lobe, while accessory MCAs supply the anterior frontal lobe.
• The findings support a developmental hypothesis of anomalously early ramification leading to these MCA variations.