Chronic Inflammatory Demyelinating Polyneuropathy in a Patient With Autoimmune Autonomic Ganglionopathy: A Case Report.

This case describes a 61-year-old woman with autoimmune autonomic ganglionopathy (AAG) on long-term intravenous immunoglobulin (IVIG) who developed progressive weakness and sensory loss, ultimately diagnosed as chronic inflammatory demyelinating polyneuropathy (CIDP). Initially evaluated for Guillain-Barré syndrome, cerebrospinal fluid analysis revealed albuminocytologic dissociation without central lesions on MRI. Despite IVIG therapy, symptoms worsened, and electrodiagnostic testing demonstrated demyelination with conduction block and secondary axonal loss, confirming CIDP. Subsequent plasma exchange therapy led to gradual improvement in strength, reflexes, and ambulation while autonomic function remained stable. The coexistence of CIDP and AAG is exceedingly rare and emphasizes the potential for shared autoimmune mechanisms within the peripheral nervous system. This case highlights the importance of recognizing overlapping autoimmune neuropathies, particularly when new or progressive symptoms arise despite appropriate therapy and adapting immunomodulatory treatment accordingly to optimize long-term outcomes.