A painful right legBMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d1009 (Published 17 March 2011) Cite this as: BMJ 2011;342:d1009
- Laura-Jane E Smith, core medical trainee year 1 1,
- Sinéad M Murphy, senior clinical research fellow2,
- Paul Holmes, consultant neurologist4,
- Mary M Reilly, consultant neurologist2,
- Lilla Reiniger, neuropathology specialty registrar3,
- Maria Thom, consultant neuropathologist3,
- Michael P Lunn, consultant neurologist2
- Correspondence to: M P Lunn
A 68 year old man was referred for assessment of a painful right leg. The symptoms had started three years previously with intermittent pain on the lateral aspect of the right calf. The pain had gradually become more persistent and spread to the sole of the foot, the back of the leg, and the buttock. Within six months the painful area had become numb, and within one year he noticed onset of right leg weakness, which was progressive. The pain was severe, worse when lying down, and he required considerable doses of opiates, which did not fully relieve the pain. He had longstanding constipation, but no recent change in bladder or sexual function.
He had a history of Gleason grade 3+3 prostatic carcinoma, for which he had undergone radical prostatectomy four years earlier. This had been followed by radiotherapy to the prostate bed, and he was being treated with ongoing goserelin injections. His prostate specific antigen level was 8.17 µg/L when first seen; however, when repeated it was 3.14 µg/L. He also had a history of well controlled non-insulin dependent diabetes and hypertension.
On examination the patient was in pain. He had wasting of the right gluteus maximus and hamstrings, without fasciculations. Tone was normal. Hip flexion and knee extension power was Medical Research Council grade 5/5; however, there was weakness of hip extension to 4/5, knee flexion to 3/5, and ankle dorsiflexion and plantarflexion to 0/5. Reflexes were initially absent in the right leg with reinforcement; however, when the patient’s pain was under better control the knee jerk was present but ankle jerk remained absent. He had sensory loss to pinprick in the distribution of L5 to S3 dermatomes on the right, whereas perianal sensation was intact (S4 and S5). There was impaired proprioception and vibration sense to the …