[Sensory neuronopathy. Its recognition and early treatment]

Sensory neuronopathies or ganglionopathies, or dorsal root ganglion disorders, represent a subgroup of peripheral nervous system diseases, frequently associated with dysinmune or neoplastic disorders and with toxic agents. A degeneration of both central and peripheral sensory proyections is present. Patients typically show early ataxia, loss of deep tendon reflexes and positive sensory symptoms present both in proximal and distal sites of the body. We retrospectively studied 10 cases with a final diagnosis of sensory neuronopathy. Sensory neuropathy was the presenting symptom and the course was subacute in all cases. Paresthesias in upper limbs were a predominant manifestation (100%). Other manifestations included: hypoesthesia (10/10), gait ataxia (8/10), autonomic symptoms (3/10) and perioral paresthesias (3/10). Electrophysiology showed sensory axonal neuronal pattern, with normal motor responses. Final diagnosis was acquired sensory neuronopathy in all patients, associated with Sjögren's syndrome in 2, with lupus erythematosus in 1, with rheumatoid arthritis in 1, with a cancer in 2 (paraneoplastic) and idiopathic in 4. In paraneoplastic cases, the tumor was small cell lung cancer in 1 (with positive anti-Hu antibodies), and epidermoid lung cancer in the other. Eight patients were treated with immunotherapy, high dose intravenous methylprednisolone and/or intravenous immunoglobulin; with poor response in 4 cases, neurologic improvement in 5, and without any change in 1 patient. The present work shows the typical clinical and electrophysiological pattern of subacute sensory neuronopathy, and the relevance of early treatment.