Surgeons routinely remove neck lymph nodes to stop head and neck cancers from spreading, a procedure known to cause swelling from disrupted lymphatic drainage. A Weill Cornell Medicine-led study published in Neuron now suggests the operation may also impair the brain's own waste clearance, with consequences for cognition. The work combined patient records, brain imaging and animal experiments across Weill Cornell, Montefiore Einstein and the Technical University of Munich.
A retrospective review of 1,035 patients who had neck lymphadenectomy without chemotherapy or radiation found that about 18 per cent of those under 65 showed cognitive impairment within two years, against an estimated 4 to 6 per cent of the general population in that age group. Among over-65s the figure was 25 per cent. MRI scans of 59 patients imaged before and after surgery showed accelerated enlargement of the ventricular temporal horns, a signature of brain atrophy, strongest when nodes were removed from both sides of the neck.
Animal models offered a mechanism: abruptly disrupting fluid drainage from the brain raised oxidative stress and inflammation-related proteins, and damaged synapsin, a protein central to neuronal signalling, which formed clumps distinct from the amyloid plaques and tau tangles of Alzheimer's disease. The human findings remain an association rather than proof of cause, and the team, led by Laura Santambrogio, plans a prospective study following patients through surgery.