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.