New onset of lower extremity weakness after a viral illness
The patient's leg weakness began after illness kept him in bed for several days.
Mr. A, age 22 years, came to the campus health services with a chief complaint of bilateral lower-extremity weakness that began several days earlier. He explained that he had an upper respiratory infection two weeks prior to the visit. Symptoms included rhinorrhea, sore throat, cough, fever (103˚F) for five days, diffuse muscle pain, headache, weakness, and fatigue. He was confined to his bed for several days. After feeling better, Mr. A continued to have a productive cough. He reported severe lower back pain in the coccyx area that had quickly spread to his bilateral hips, legs, and knees. He complained of bladder urgency and frequency but reported no constipation or leakage. Upon entering the health services, he requested crutches for ambulation.
Mr. A's recent viral illness, progressiveness of the bilateral lower-extremity weakness, and urinary urgency pointed toward a number of conditions to consider. My initial guesses were Guillain-Barrѐ syndrome (GBS) or multiple sclerosis (MS). Since the weakness occurred suddenly, a tumor was the least likely of the differential diagnoses.
1. Physical examination
Mr. A entered the exam room dragging his left lower extremity and using the wall for support. BP was 128/78 mm/Hg, pulse 68 beats per minute, respiratory rate 12 breaths per minute, and temperature 97.8˚F. The patient was unable to curl his toes independently. He reported no numbness but had a pins-and-needles sensation in his bilateral lower extremities (most prevalent in the left leg and pelvic area). Musculature was symmetric in bulk in all limbs. Strength on the right lower extremities measured 4/5, and 2/5 on the left. Mr. A needed assistance with flexion and extension of his bilateral extremities. He had an asymmetrical plantar movement and was unable to dorsiflex his left foot. Deep tendon reflexes to bilateral biceps, triceps, brachioradialis, and patellar were 2+ and symmetrical bilaterally. Achilles reflex was 2+ on the right and zero on the left. Mr. A had a left-foot drag along with a very slow, unsteady gait. Romberg was not performed because of the patient's instability. Rectal sphincter was weak.
Mr. A needed an MRI and a lumbar puncture (LP) as well as further consultation with a neurologist. It was also determined that Mr. A might need treatment with high-dose steroids and antibiotics, so a local emergency department (ED) was notified. After further consultation with the neurologist, Mr. A was transported and admitted to the ED.
2. Tests and scans
Electromyograph indicated diffuse weakness in the left lower extremity. MRI of the thoracic and lumbar spine showed a subtle expansion and intrinsic signal abnormality in the distal thoracic cord at T10-conus area. CT of the head was normal. Complete blood count revealed WBC 12,600/μL, neutrophils 85%, and absolute neutrophils 10.7. Urine was negative. Folate was 20.8 ng/mL and B12 713 pg/mL. Antinuclear antibody was negative. Immunoglobulin A was 245 mg/dL. LP revealed clear and colorless cerebrospinal fluid (CSF) and RBC 1 mm3. CSF nucleated cell count was 21 mm3, lymphocytes 99%, monocytes 1%, CSF glucose 80 mg/dL, and CSF albumin 5,110 mg/dL. CSF culture was negative for aerobic and anaerobic bacterial growth. CSF Lyme and cytomegalovirus titers were negative. CSF was also negative for oligoclonal bands, which are present in 90% of patients with MS. Diagnostic testing for Campylobacter jejuni, Helicobacter pylori, and Borelli burgdorferi was negative.