Sensory Neuronopathy (SN) represents a distinct peripheral nervous system disorder associated with degeneration of the Dorsal Root Ganglia. We present our retrospective review of 103 patients with an electro-clinical diagnosis of SN.
Average age of onset was 54 yr. Aetiologies included Sjogrens (21%), Probable Inflammatory (16%), Idiopathic (29%), Inherited (20%), Toxic (5%) and paraneoplastic (9%).
Of those with inherited SN (n=21); CANVAS syndrome 2/21, mitochrondrial cytopathy 9/21 with 4 confirmed POLG1 mutations, 3/21 presumed HSANIIb, Frederich's Ataxia 1/21 and 6/21 unidentified phenotypes.
Clinically, acquired causes commonly presented with pain (62%), asymmetrical/non-length dependent sensory disturbance (91%) as compared to the inherited group who are more likely to present with gait disturbance without prominent sensory symptoms (52%).
Of the cohort with presumed inflammatory disease, 29 patients were immunosuppressed with 12 patients responding to a combination of steroids and Mycophenolate. IVIG was not found to be beneficial with no sustained benefit in 7 patients.
Paraneoplastic causes (n=9) included Breast (n=2), Neuroendocrine tumours (n=2), Carcinoid (n=2), Bowel (n=1), SCLC (n=1) and unknown primary (n=1) with only 4 Hu positive
Conclusions Sensory neuronopathy is clinically and aetiologically pleomorphic. In cases with a suspected inflammatory cause it is worthwhile considering a trial of immunomodulatory treatment.