Axonal common peroneal nerve palsy and delayed proximal motor radial conduction block following infliximab treatment

Foot drop in patients treated with bortezomib - a case series and review of the literature

Bortezomib-induced peripheral neuropathy (BIPN) has a profound impact on quality of life, which is an important issue considering the growing number of survivors of multiple myeloma and amyloidosis. BIPN is typically symmetric, distal, "stocking and glove" distribution and predominantly consists of sensory rather than motor symptoms. In this case series, we report an acute neurotoxicity syndrome induced by bortezomib, which is clinically distinct from BIPN by not being peripheral and distal. We describe six patients that developed unilateral or bilateral foot drop attributed to bortezomib. With bortezomib discontinuation symptoms improved gradually over months to years.

Peripheral neuropathies during biologic therapies

Peripheral neuropathies should be recognized as the adverse effects of biological agents, especially anti-TNF agents. However, no solid clinical databases for biological agent-associated peripheral neuropathies (BAPN) have been established in Japan. Here we report two cases of peripheral neuropathy associated with anti-TNF agents. One was peroneal motor neuropathy. The other case was chronic inflammatory demyelinating polyradiculoneuropathy. In addition, we summarize the previous reports on BAPN and discuss their prevalence rate, pathogenesis and management.

Non-length-dependent and length-dependent small-fiber neuropathies associated with tumor necrosis factor (TNF)-inhibitor therapy in patients with rheumatoid arthritis: expanding the spectrum of neurological disease associated with TNF-inhibitors

OBJECTIVE

Small-fiber neuropathy causes severe burning pain, requires diagnostic approaches such as skin biopsy, and encompasses two subtypes based on distribution of neuropathic pain. Such biopsy-proven subtypes of small-fiber neuropathies have not been previously described as complications of tumor necrosis factor (TNF)-inhibitor therapy.

METHODS

We therefore characterized clinical and skin biopsy findings in three rheumatoid arthritis (RA) patients who developed small-fiber neuropathies associated with TNF-inhibitors. We also conducted a systematic review of the literature to characterize subtypes of neuropathies previously reported in association with TNF-inhibitor therapy.

RESULTS

Two patients presented with a "non-length-dependent" small-fiber neuropathy, experiencing unorthodox patterns of burning pain affecting the face, torso, and proximal extremities. Abnormal skin biopsy findings were limited to the proximal thigh, which is a marker of proximal-most dorsal root ganglia degeneration. In contrast, one patient presented with a "length-dependent" small-fiber neuropathy, experiencing burning pain only in the feet. Abnormal skin biopsy findings were limited to the distal feet, which is a marker of distal-most axonal degeneration. One patient developed a small-fiber neuropathy in the context of TNF-inhibitor-induced lupus. In all patients, neuropathies occurred during TNF-inhibitor-induced remission of RA disease activity and improved on withdrawal of TNF-inhibitors.

CONCLUSIONS

We describe a spectrum of small-fiber neuropathies not previously reported in association with TNF-inhibitor therapy, with clinical and skin biopsy findings suggestive of dorsal root ganglia as well as axonal degeneration. The development of small-fiber neuropathies during inactive joint disease and improvement of neuropathic pain upon withdrawal of TNF-inhibitor suggest a causative role of TNF-inhibitors.

Inflammatory neurological disease in patients treated with tumor necrosis factor alpha inhibitors

Background: TNF alpha inhibitor (TNFAI) therapy has been associated with inflammatory neurological syndromes.

Objectives: To present 10 new cases of TNFAI associated neurological disease and a review of the literature.

Methods: The design and methods were based on case series collected from Oregon Health & Sciences University and the Department of Veterans Affairs Hospital in Portland, Oregon and PubMed review.

Results: We describe eight demyelinating central nervous system syndromes and two peripheral nervous system syndromes associated with TNFAI therapy. Characteristics from these cases are analyzed with data from 141 additional cases from the literature. Onset was between the ages of 36 and 65 years in 84% of CNS cases, distinguishing TNFAI-associated disease from sporadic multiple sclerosis. Symptoms occurred within one year of TNFAI therapy in 71%. Etanercept therapy was reported in the majority of cases of CNS syndromes and infliximab therapy in the majority of neuromuscular syndromes. Significant disability remained in 67% of cases although 82% had been followed for less than one year.

Conclusions: Our case series and literature review demonstrates an association between TNFAI therapy and inflammatory neurological disease. While a causal relationship is suggested, this remains uncertain. TNFAI-associated neurological syndromes are associated with significant disability and longer follow-up is needed to better determine natural history and evaluate appropriate treatment interventions.