1. This space is continuous with the peribronchial and pulmonary perivascular sheaths. 2. Dilated perivascular spaces are common among the elderly and uncommon in children. 3. The clusters of perivascular plasma cells still appears from the established lesion. 4. The clinical significance of perivascular spaces comes primarily from their tendency to dilate. 5. The subclavian perivascular block was first described by Winnie and Collins in 1964. 6. In the brain, mild to severe encephalitis occurs, with lymphocytic perivascular cuffing. 7. Other findings include myositis, myonecrosis, perivascular and interstitial inflammation, vasculitis and eosinophilic myositis. 8. Perivascular spaces may be enlarged to a diameter of five millimeters in healthy humans and are usually harmless.9. The histologic features are capillary proliferation and perivascular inflammation involving eosinophils in the dermis with minimal epidermal changes. 10. From there on, umbellulone is able to reach the perivascular sensory nerve endings of the meningeal vessels.
