Sensory Neuronopathies: Clinical Presentation, Management, and Outcome

Sensory neuronopathies (SNNs) are a rare group of pure sensory disorders causing asymmetrical, multifocal pattern of sensory loss with distinct clinical and electrophysiological features. We aimed to study the clinical features and etiology and share the experience of treating SNN from our center.

A prospective observational study was conducted over 3 years. Patients with predominant sensory complaints and electrophysiological evidence of neuropathy were evaluated. Possible/probable SNN was diagnosed using Camdessanch´e criteria. Detailed workup was done to determine the etiology and treatment given accordingly. Follow-up was done and response to treatment was assessed using modified Rankin Scale grading at 12 months.

Fourteen patients with SNN were studied. Two (14.3%) patients were diagnosed with Sjogren's syndrome (SS-SNN), two (14.3%) with paraneoplastic syndrome, one (7.1%) with leprous ganglionitis, and nine (64.3%) were idiopathic sensory neuronopathy (I-SNN) cases. Improvement occurred in nine (64.3%), stability in three (21.4%), and worsening in two (14.3%) patients. Out of 11 SS-SNN and I-SNN patients, eight showed improvement on follow-up, seven with injection rituximab (RTX) and one with azathioprine. We found positive correlation between RTX treatment and improvement on follow-up ( P = 0.0256). Six (66.66%) out of nine I-SNN patients had early initiation of immunotherapy, of which all improved. There was positive correlation between early treatment initiation time in I-SNN patients and improvement ( P = 0.0119).

Promising results were noted in SS-SNN and I-SNN patients with intensive treatment approach using RTX. Hit hard and early treatment approach is crucial for achieving improvement in sensory neuronopathies.