Clinical analysis on two patients with N-hexane toxic peripheral neuropathy misdiagnosed as chronic inflammatory demyelinating polyradiculoneuropathy

Abstract

Objective To investigate the clinical and neuropathological features of N-hexane toxic peripheral neuropathy which was misdiagnosed as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Methods and Results Two patients presented with subacute or chronic peripheral neuropathies after close exposure of N-hexane for 6 to 8 months, starting from weakness and numbness of bilateral distal lower limbs and gradually progressing to proximal lower limbs and upper limbs. The worsening of clinical symptoms was delayed after keeping out of toxic working environment. Decreased motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV) of all limbs as well as marked decrease of amplitude, with lower extremities predominantly, were detected in both cases. Sural nerve biopsies revealed mild to moderate loss of myelinated fibers, formation of giant axons, Wallerian degeneration and rare regenerating clusters. The giant axons were filled with neurofilaments and granular materials. The patients were required to keep away from toxic working environment and were treated with vitamin B, and the prognosis was good. Conclusions The clinical symptoms and cerebrospinal fluid (CSF) findings of N-hexane toxic peripheral neuropathy are similiar to CIDP. Peripheral nerve biopsy can play a key role in the diagnosis of the disease.

DOI: 10.3969/j.issn.1672-6731.2019.06.006