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

Purpose There is not a single article dealing with such characteristics of the perforating arteries (PAs), which could have important clinical implications. Methods The 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. Results The PAs are very rarely absent on one side (7.8%, and 11.6%; p <0.01). They range from 1 to 12 in number (mean, 3.24), and between 0.06 and 1.32 mm in diameter (mean, 0.32 mm) ( p =0.20 each). They originate from the parent arteries (46.2-100.0%; p <0.01), either solely or by common stems (0.0-65.4%; p =0.002), or along with certain pial vessels (0.0-69.3%; p =0.01). Typical and atypical PAs are distinguished. The former are larger in size and rarely tortuous. An occlusion of their own 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 atypical PAs mostly nourish the hypothalamus and optic structures. Close proximity of the PAs and aneurysms or arteriovenous malformations could complicate surgical interventions. Conclusion Knowledge 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.