Case Presentation

A 64-year-old Iranian man presented to our outpatient neurology clinic with paresthesia of distal lower extremities that had started in the left lower extremity and progressed to the right side. Within one week, he developed asymmetrical weakness in distal lower extremities that sequentially involved both proximal lower extremities over one month.
He also reported a loss of appetite and a 10-kg weight loss within one and a half months.
He did not take any medications, did not smoke or use illicit drugs, and had no history of exposure to chemicals or toxins. He had no history of autoimmune or neoplastic diseases and his family history was unremarkable.
Upon physical examination, he was a middle-aged man with average body habitus. His general physical examination, including examination of the skin and lymph nodes, was unremarkable. The neurologic exam was significant for decreased muscle force in lower extremities that was more severe on the left side and absent deep tendon reflexes in the lower limbs. He had asymmetric distal hypoesthesia in both upper and lower limbs. His first dorsal interosseous muscle was atrophic on both sides.
The patient was admitted to the neurology ward for further workup and emergency treatment with a clinical diagnosis of multiple mononeuropathy. Electrophysiologic studies revealed distal axonal sensory-motor polyneuropathy with ongoing axonal loss and multiple mono-neuropathy. Initial lab tests revealed microcytic anemia. He underwent chest and abdominopelvic CT with contrast and left superficial peroneal nerve biopsy. Moreover, laboratory investigations were done in search of an underlying systemic disease that could cause anemia and multiple mononeuropathy (table 1).
Table 1: Table 1 Para-clinical work-up for our patient who presented with mononeuropathy multiplex. CBC: Complete blood count; ESR: Erythrocyte sedimentation rate; ANA: Anti-nuclear antibody; RF: Rheumatoid factor; p-ANCA: perinuclear anti-neutrophil cytoplasmic antibodies; CEA: Carcinoembryonic antigen; PSA: Prostate-specific antigen; AFP: Alpha-fetoprotein; βHCG: Beta-Human Chorionic Gonadotropin; HCV: Hepatitis C virus; HIV: Human Immunodeficiency virus; VDRL: venereal disease research laboratory (VDRL); Pb: Lead; PPD: Purified protein derivative; HbA1C: glycated hemoglobin; CT: Computed tomography. Cell counts were performed using the automated cell counter Sysmex® KP300, Biochemistry analyses were done using the Roche Hitachi 917 Rack Chemistry Analyzer, Japan; Serologic markers were checked using the ELISA kits from AUTOBIO DIAGNOSTICS CO. and Liason Autobio A 2000 automated ELISA reader.