Innervation pattern of malformative cortical vessels in Sturge-Weber disease: an histochemical, immunohistochemical, and ultrastructural study

This study was undertaken to elucidate the pattern of vascular innervation in areas of pial angiomatosis in Sturge-Weber disease (SWD) and eventually correlating it with the pathophysiology of the disease, namely its chronic ischemic changes. We processed part of a surgical specimen resected from a 3-year-old female patient who underwent functional hemispherectomy for SWD and characterized the pattern of innervation of the malformative cortical vessels using histochemical, immunohistochemical, and ultrastructural techniques. Cortical vessels were observed to be supplied with numerous varicose nerve fibers containing immunoreactivity for neuropeptide tyrosine and the catecholamine-synthesizing enzyme, tyrosine, tyrosine hydroxylase. In contrast, no nerve fibers containing acetylcholinesterase activity and immunoreactivity for Substance P, a calcitonin gene-related peptide and vasoactive intestinal peptide, were detected. Ultrastructural studies revealed the presence of numerous axon varicosities at the adventitial-medial border. Neuropeptide tyrosine immunoreactivity was localized in large granular vesicles in nerve varicosities that also contained numerous small granular vesicles. These results demonstrate that nerve supplying cortical vessels in SWD are arranged in a distribution pattern similar to the one observed in human normal cortical veins and suggest that these abnormal vessels are innervated only with noradrenergic sympathetic nerve fibers. This represents a clear difference from the pattern of innervation observed in both normal cortical arteries and veins, and is the consequence of the anatomic and functional dysangiogenic process characteristic of the affected cortical areas in SWD.