n-Hexane-Toxic Neuropathy Presenting with Cauda Equina Inflammation.

BACKGROUND: Habitual exposure to n-hexane can cause polyneuropathy through axonal degeneration and secondary demyelination. To our knowledge, n-hexane-toxic neuropathy presenting with a cauda equina-like syndrome has not previously been reported. CASE PRESENTATION: A 55-year-old man developed sensory and motor polyneuropathy over a 3-month period, with nerve conduction studies indicating demyelination. Initial treatment for suspected chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with steroids and plasma exchange was ineffective, leading to worsening symptoms. The patient and his colleagues were found to have been habitually exposed to n-hexane in their printing work, and a sural nerve biopsy revealed the pathological findings typical of n-hexane-toxic neuropathy. Notably, cauda equina inflammation was observed on MRI and in the cerebrospinal fluid. Following intravenous immunoglobulin therapy, both neurological symptoms and findings from nerve conduction studies, MRI, and cerebrospinal fluid analysis gradually improved, eventually leading the absence of impairment in activities of daily living. CONCLUSION: In cases of polyneuropathy accompanied by inflammation of the cauda equina, and if exposure to n-hexane cannot be ruled out, sural nerve biopsy could be considered to assess for n-hexane-toxic neuropathy.