The similarities and differences among the cerebral perforating arteries, and their clinical implications.

purposeOur hypothesis was that some differences exist among the corresponding groups of the perforating arteries (PAs), which could have important implications in radiology, neurology, and neurosurgery. To test the hypothesis, we performed a detailed study of these vessels.

methodsThe vasculature of 22 cerebral hemispheres was injected with a 10% India ink and gelatin. After fixation, all the perforators were microdissected under the stereoscopic microscope. The PAs territories were examined as much as possible. The remaining 4 hemispheres were injected with methylmethacrylate to obtain the vascular casts. KEY

findingsThe PAs are very rarely absent on one side (7.8%, and 11.6%; p < 0.01). They range from 0 to 12 in number (mean, 3.22), and between 0.06 and 1.32 mm in diameter (mean, 0.31 mm) (p = 0.022 each). They originate from the parent arteries (46.2-100.0%), either solely or by common stems (0.0-65.4%), or along with certain pial vessels (0.0-69.3%), with significant correlation among them (p < 0.029, p = 0.001, p = 0.038). Larger and smaller PAs are distinguished. An occlusion of the larger common stems could cause a massive central hemispheric, or a larger thalamic or paramedian brain stem infarction, associated with certain symptoms and neurologic signs. An obturation of both PAs and pial arteries could result in a combined deep and peripheral ischemia. The smaller PAs mostly nourish the hypothalamus and optic structures. Close proximity of the PAs and aneurysms or arteriovenous malformations could complicate surgical or endovascular interventions.

conclusionKnowledge of the PAs microanatomic similarity and differences, including their supplying regions, can help in understanding neurologic signs following their occlusion. This is also important in neuroradiologic diagnostics, and for safe neurosurgical and endovascular interventions.