Nélaton Syndrome

At a glance

Paraneoplastic Autonomic Neuropathic Syndrome occurring in association with several primary neoplasias, characterized by antibodies directed against a cellular nuclear component expressed in nearly all nervous tissues.

Synonyms

Paraneoplastic Autonomic Neuropathy; Anti-Hu Syndrome; Denny-Brown Neuronopathy; Subacute Paraneoplastic Sensory Neuropathy; Autoimmune Paraneoplastic Neurologic Syndrome; Paraneoplastic Sensory Neuropathy.

Incidence

Clinically a rare disease. Less than 0.01% of patients with small cell lung cancer have a Paraneoplastic Syndrome, but antibodies can be found in up to 20% of pulmonary small cell tumors.

Genetic inheritance

Acquired autoimmune disease. Not linked to a particular genotype.

Pathophysiology

Autoantibodies directed against a nuclear component of nervous system cells (anti-Hu or ANNA-1). This antigen is expressed in the central and peripheral nervous systems, but can also be expressed by neoplastic cells. It may play a role in nervous system development. Loss of ganglion cells in sacral and lumbar dorsal root ganglia. Other antibodies identified are directed against neuronal cytoplasm (anti-CV2) and the anti-ganglionic nicotinic acetylcholine antibody.

Diagnosis

Clinical expression of a subacute mainly sensory neuronopathy, with demonstration of polyclonal anti-Hu or anti-CV2 antibodies in the plasma. Axons and neuromuscular junctions appear normal on electrophysiologic studies.

Clinical aspects

Mainly found in conjunction with pulmonary small cells tumors, but may be encountered with other types of tumors. The sensory neuronopathy can be found up to 1 year before clinical discovery of the tumor. Clinically, there is a subacute neuronopathy, sometimes associated with central limbic symptomatology. It may be misdiagnosed as “herpetic encephalitis.” Immunosuppression and plasmapheresis have not shown any benefit.

Precautions before anesthesia

Usually, patients present for surgical treatment of the underlying tumor. It is judicious to request a complete neurologic evaluation before and after the procedure to confirm maintenance of neurologic status. In this setting, general anesthesia is preferable, and central neuraxial blockade techniques are not recommended. Look for signs of autonomic dysfunction before induction.

Anesthetic considerations

Anesthetic considerations are those associated with the surgical procedure and not the patient’s condition. However, in the presence of neuronopathy, use of anesthetic agent associated with rapid elimination might be appropriate. Usually uneventful recovery.

Pharmacological implications

No specific implications; however, it is believed that the response to local anesthetics is poorly managed.

Other condition to be considered

• Sohar Crisponi Syndrome: Very rare autosomal recessive disorder described in several families originating in Italy, Spain, Turkey, and Saudi Arabia. It is characterized by neonatal paroxysmal trismus, excessive salivation, orofacial weakness with impaired sucking and swallowing resulting in poor feeding. Associated physical ...