THE DRAINAGE OF CEREBROSPINAL-FLUID INTO THE LYMPHATIC-SYSTEM OF THE NECK IN HUMANS

A histo- and immunohistochemical examination of the superior deep cerv ical lymph nodes was performed in a group of 19 patients who died from intracerebral haemorrhage. For comparison two control groups without cerebral lesions were studied (n = 17, n = 13). Free iron deposits as shown within the lymph nodes by Prussian blue reaction were seen signi ficantly more often following intracerebral haemorrhage than without b leeding. The expression of CD 68 (a marker for macrophages) or CR 3/43 (microglia) gave a strong reaction, but there are no significant diff erences between the three groups. Glial fibrillary acidic protein was rarely seen in the three groups. Raising the CSF pressure results in i ncreased CSF drainage into the cervical lymph nodes. The clinical impo rtance of this lymphatic drainage suggests a communication between the brain and the immune system of the head and neck, with a possible sel ective up- and down-regulation.