Summary:
Surgical removal of cervical lymph nodes during treatment for head and neck cancer can block normal cerebrospinal fluid (CSF) outflow from the skull, which may accelerate brain tissue loss and increase the risk of cognitive decline. A multicenter study published in Neuron reports that interrupting cervical lymphatic drainage produces CSF stasis, neuroinflammation, oxidative stress, and abnormal aggregation of synaptic proteins, linking neck lymphadenectomy to structural and functional brain changes.
Key Facts:
- Elevated cognitive risk: In patients younger than 65 who underwent neck lymphadenectomy without radiation or chemotherapy, 18% developed clinically recognized cognitive impairment within two years—substantially higher than the 4–6% baseline expected for this age group. In patients aged 65 and older, the rate was 25%.
- Accelerated ventricular enlargement: Longitudinal MRI scans showed widening of the temporal horns of the lateral ventricles after surgery, a radiologic sign of regional brain atrophy that was most pronounced after bilateral lymph node resection.
- Mechanism of acute obstruction: Animal models indicate that sudden interruption of cervical lymphatic outflow provokes oxidative stress, inflammatory signaling, and unusual clumping of synapsin proteins—distinct from classical amyloid-beta or tau pathologies associated with Alzheimer’s disease.
Source: Weill Cornell Medicine
Cervical lymphadenectomy—the surgical removal of lymph nodes in the neck—remains a standard, often life-saving intervention to control regional spread of head and neck cancers. While surgeons and patients are accustomed to peripheral complications such as neck lymphedema, the potential intracranial consequences of eliminating these lymphatic drainage sites have been less examined.
Recent advances in neuroscience have outlined the brain’s glymphatic and meningeal lymphatic pathways, showing that cerebrospinal fluid and metabolic waste normally drain from the cranial cavity toward deep cervical lymph nodes. Disrupting those drainage routes may therefore alter brain fluid homeostasis.
A multicenter team led by researchers at Weill Cornell Medicine analyzed clinical records, neuroimaging, and preclinical experiments to establish a clinical-mechanistic link between neck lymph node resection, impaired brain clearance, and subsequent cognitive decline. Their results, published September 29 in Neuron, show that surgically severing these anatomical outlets can produce CSF stagnation, inflammation inside the brain, and measurable structural change.
“The lymphatic system helps clear waste from every organ, including the brain,” said senior author Dr. Laura Santambrogio, professor and associate director of precision immunology at Weill Cornell. “When that drainage is disrupted, harmful processes can accumulate over time.”
Disproportionate Rates of Postoperative Cognitive Impairment
To isolate the effect of lymphadenectomy from neurotoxic cancer treatments, investigators reviewed records for 1,035 patients treated at Montefiore Einstein who had neck lymph node removal without adjuvant radiotherapy or chemotherapy. The retrospective analysis revealed an unexpected excess of cognitive problems within two years after surgery:
- Patients under 65: About 18% developed clinically documented cognitive impairment, compared with an expected 4–6% baseline in the general population for that age range.
- Patients 65 and older: Approximately 25% showed cognitive impairment, exceeding the expected demographic range of 10–22%.
To corroborate structural brain changes, the team examined a separate cohort of 59 patients from the Technical University of Munich who underwent pre- and post-operative MRI. Paired imaging revealed accelerated enlargement of the temporal horns of the lateral ventricles after surgery—an established marker of regional brain tissue loss—especially in patients who had bilateral neck dissection.
Oxidative Stress and Atypical Protein Clumping
Preclinical experiments modeled abrupt disruption of lymphatic drainage to cervical and submandibular nodes in mice and rats. These studies showed that sudden loss of a patent lymphatic outlet leads to CSF accumulation, which raises tissue pressure and triggers oxidative stress and a pro-inflammatory cytokine response within the brain.
In the hippocampus, oxidative post-translational modifications promoted microaggregation of synapsin, a presynaptic phosphoprotein critical for neurotransmitter release. These synapsin aggregates had biochemical and structural features that differed from amyloid-beta plaques and hyperphosphorylated tau tangles seen in Alzheimer’s models, indicating an alternative pathway to synaptic dysfunction. Notably, such changes did not occur when lymphatic drainage declined slowly, emphasizing that sudden surgical interruption has unique biological consequences.
Improving Drainage and Surgical Innovations
Because the principal clinical analyses were retrospective, the authors are initiating prospective longitudinal studies that will track cognitive outcomes and CSF or blood biomarkers in head and neck cancer patients before and after lymphadenectomy. These studies aim to clarify timing, risk factors, and potential windows for intervention.
Concurrently, surgical teams are investigating reconstructive options designed to preserve or restore fluid egress, including autologous lymph node transplantation and microvascular lymphaticovenous anastomosis. Such procedures seek to reroute lymph flow into the venous circulation, potentially reducing peripheral lymphedema while protecting cranial fluid clearance and long-term brain health.
“Transplanting a lymph node from elsewhere in the body or creating a lymphatic-to-venous connection may allow trapped lymph to drain and could help prevent downstream complications,” Dr. Santambrogio said.
Funding: This work was supported by the National Center for Complementary and Integrative Health (grant 1R01AT011419-01) and The Cure Alzheimer grant CAF222829-01.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by staff.
About this genetics and neurodevelopment Research:
- Media Contact: Corinne Esposito
- Source: Weill Cornell Medicine
- Image Credit: Image credited to Neuroscience News
- Original Research is Open Access: Neuron (Sept 29, 2026). “Cervical lymphadenectomy impairs brain lymphatic clearance and synaptic proteostasis.” Authors: Zohaib N. Khan, Cristina C. Clement, Paula Roßmüller, Salli Antila, Lincoln Sutherland, Rafi Kabarriti, Justina Shafik, Igor Smirnov, Angelo D’Alessandro, Monika Dzieciatkowska, Barbara Roda, Valentina Marassi, Wanxia Li Tsai, Massimo Gadina, Allen Tannenbaum, Markku Varjosalo, Salla Keskitalo, András Piffkó, Sunil Koundal, Zachary Gursky, Ralph R. Weichselbaum, Michael B. Prystowsky, Thomas J. Ow, Silvia Formenti, Christian Sorg, Benedikt Zott, Kari Alitalo, Helene Benveniste, Jonathan Kipnis, and Laura Santambrogio.
- DOI: 10.1016/j.neuron.2026.09.005
Abstract
Cervical lymphadenectomy impairs brain lymphatic clearance and synaptic proteostasis
Meningeal lymphatic vessels normally drain cerebrospinal fluid and metabolic waste into cervical lymph nodes, but the consequences of removing those nodes during surgery have been unclear. Retrospective analysis of cancer patients who had neck lymphadenectomy without chemo- or radiotherapy identified up to 25% incidence of mild-to-severe cognitive impairment and showed accelerated enlargement of the temporal horns on MRI following bilateral surgery.
Mechanistic studies in mouse and rat models that reproduced abrupt disruption of lymphatic outflow demonstrated a CSF signature of metabolic stress and inflammation. In the hippocampus, oxidative stress induced atypical post-translational protein modifications and synapsin microaggregation with molecular features distinct from classical amyloid pathology. These alterations were not seen when lymphatic drainage declined gradually, linking acute interruption of cervical lymphatic flow to biochemical events that may underlie postoperative cognitive decline.