Back pain in a young adult

A 32 year old man was referred to the emergency department with a one week history of worsening mid-thoracic back pain. The pain radiated bilaterally and he occasionally felt it anteriorly in the chest. It was constant in nature and there were no associated symptoms.

He did not look unkempt and was accompanied by his girlfriend and brother. He had no medical history of note but was a known intravenous drug user. He admitted to injecting drugs through “a vein in his armpit” and claimed that the last time he had heroin it looked “thicker” than usual.

His physical examination was unremarkable and the following blood test results were obtained: white blood cell count 11.0×10⁹/L (reference range 4.3-11.4), haemoglobin (11.9 g/L (14.1-17.2), and troponin <0.01 µg/L (0.006-0.04).

A chest radiograph was normal.

He was sent home with advice about back pain and analgesia.

The pain persisted and he re-presented to the emergency department but was discharged again after a normal physical examination and thoracic spine radiography, which was reported as normal.

Two days later he returned with worsening back pain, which was now waking him up at night. On percussion of the spine he was tender over the mid-thoracic area. At this stage he was febrile and had a wide based gait, with his left lower limb being spastic when compared with the right. Tone was increased on the left, whereas his lower limb power was decreased on the left (4/5) compared with the right. Sensation to light touch and pin prick was decreased (but present) from the nipple downwards on both sides. Joint position sense was present at both ankles and vibratory sensation was decreased but present at both big toes and normal at the ankles. Knee and ankle jerks were increased on the left more than …