Pain, Tingling, and Numbness in the Extremities With Foot Drop and Progressive Weakening of the Legs

Sumaira Nabi, MBBS; Rao Suhail, MBBS, FCPS Neurology; Shahzad Ahmed, MBBS


May 19, 2014

Physical Examination and Workup

On physical examination, the patient is found to be alert and oriented to time, place, and person. The patient's oral temperature is 98.6°F. He has a regular pulse of 68 beats/minute. His blood pressure is 130/80 mm Hg, with no postural drop, and his respiratory rate is 14 breaths/minute. His Glasgow Coma Scale score is 15. His cranial nerves are intact and symmetrical. He has a left foot drop and paraparesis with areflexia and bilateral mute plantar response. (Figure 1)

The patient also has a bilateral glove-and-stocking loss of sensations in the upper and lower extremities, with normal perianal sensation, and a high-stepping gait. Signs of meningeal irritation are absent. His abdomen is soft and nontender. There is no clinical evidence of palpable masses, organomegaly, or ascites. His bowel sounds are audible. The patient's precordial examination reveals normal heart sounds. Auscultation of the lung fields reveals normal breath sounds bilaterally.

Laboratory analysis demonstrates a normal complete blood count (CBC) and erythrocyte sedimentation rate. Liver function tests, renal function tests, serum glucose level, muscle enzymes, electrocardiogram, and chest radiograph are unremarkable. His nerve conduction studies and electromyography are consistent with a chronic demyelinating polyneuropathy. (Figure 2)

Lumbar puncture for cerebrospinal fluid (CSF) analysis is performed, revealing a mildly elevated protein level of 0.52 g/L. All other CSF studies are normal. His hemoglobin A1C, thyroid function tests, and serum B-12 levels are normal. Results for antinuclear antibodies, rheumatoid factor, HIV serology, hepatitis B surface antigens, and hepatitis C antibodies are negative. Computed tomography (CT) scan with contrast of the chest, abdomen, and pelvis is unremarkable. His bone marrow biopsy, bone scan, skeletal survey, and urine test for Bence-Jones protein are negative. His serum protein electrophoresis reveals a discrete, narrow spike in the gamma-globulin region of 1.96 g/L, consistent with monoclonal protein (M-protein; also called paraprotein), and serum immunoglobulin-M (IgM) levels are markedly raised at 13.6 g/L (normal range 0.4-2.3 g/L). (Figure 3)