Thoracic sensory neuropathy as an extraglandular manifestation of Sjögren’s syndrome: a case report

Abstract Background Peripheral neuropathy associated with Sjögren’s syndrome typically presents as a distal symmetric polyneuropathy or a generalized sensory ganglionopathy. Focal thoracic dermatomal sensory involvement is rare and remains under-recognized. Case presentation We report the case of a 29-year-old Hispanic woman diagnosed with primary Sjögren’s syndrome who presented with glandular and extraglandular manifestations, including a localized bilateral sensory axonal neuropathy strictly involving the thoracic T4–T5 dermatomes. Axonal sensory involvement was inferred rather than directly demonstrated. Nerve conduction studies (NCS) and electromyography (EMG) were normal, which is expected in isolated dorsal root ganglion (DRG) pathology. A focal DRG lesion may produce sensory axonal dysfunction without abnormalities on routine electrophysiological studies, as motor conduction parameters and paraspinal muscles are supplied by multiple nerve roots and can remain normal when a single thoracic DRG is affected. This electrophysiological pattern supports a focal sensory neuronopathy localized to the DRG rather than a length-dependent peripheral axonal neuropathy. She developed recurrent neuropathic pain and allodynia with limited response to neuromodulatory therapy. Given the atypical distribution and clinical refractoriness, an immune-mediated etiology was considered, and immunomodulatory treatment was initiated. The patient subsequently experienced marked clinical improvement and sustained remission during follow-up. Conclusions This case highlights an unusual focal thoracic dermatomal sensory neuropathy as an atypical extraglandular manifestation of Sjögren’s syndrome. Recognition of this rare phenotype expands the clinical spectrum of Sjögren’s-associated neuropathy and underscores the importance of considering autoimmune mechanisms in focal thoracic sensory syndromes, which may otherwise be misdiagnosed as radiculopathy or herpes zoster.