[Paraneoplastic neuropathies].

RARE AND INAUGURAL

Paraneoplastic neuropathies (PN) are rare, affecting approximately 4-5% of patients with cancer. Their diagnosis is difficult because the clinical picture is nonspecific and because the neuropathy precedes the discovery of the cancer in a majority of patients. SUBACUTE SENSORY NEUROPATHY (SSN): Initially described by Denny-Brown, subacute sensory neuropathy is characterized by a severe inflammatory loss of the dorsal roots ganglia. The clinical hallmark is a severe, asymmetric sensory neuropathy progressing over a few weeks to months until the patient is bedridden. The underlying cancer is most often a small-cell lung cancer (SCLC) and the presence of anti-Hu antibodies is almost specific of SSN associated with SCLC. MOTOR NEURON DISEASES: Motor neuron diseases are rarely of paraneoplastic origin save for subacute sensory neuropathy associated with Hodgkin's disease. SENSORIMOTOR NEUROPATHIES: Sensorimotor neuropathies are the most frequent PN but constitute a hetereogeneous group. Acute Guillain-Barré syndrome occurs in patients with Hodgkin's syndrome. Paraneoplastic chronic inflammatory demyelinating polyneuropathy probably exists during lymphomas and carcinomas but a fortuitous association has not been formally excluded. Paraneolastic peripheral nerve microvasculitis often presents as mononeuritis multiplex and complicates mainly lymphoma and SCLC. Other PN are generally of the chronic and axonal type. Among them are the so-called "terminal neuropathies" which are linked to weight loss. AUTONOMIC NEUROPATHIES: Autonomic neuropathis occur during SCLC or Hodgkin's disease. Their most frequent clinical presentation is a pseudo-obstruction which is rarely isolated but which generally occurs as part of diffuse encephalomyelitis.