Peroneal neuropathy in giant cell arteritis

Extract

...

Sir, Peripheral nerve involvement is frequent in systemic vasculitis, typically either mononeuritis multiplex or sensorimotor peripheral polyneuropathy. However, these are distinctly uncommon in GCA [1, 2] and should prompt consideration of alternative causes of neuropathy and reconsideration of the underlying diagnosis of GCA. We present three cases of peroneal neuropathy in patients with recently diagnosed GCA presenting to our institution over a 2 month period.

Patient 1 was a 57-year-old male who presented initially with bitemporal headache, recurrent amaurosis fugax, bilateral shoulder girdle pain and weight loss of 12 kg. Both temporal arteries (TAs) were tender. ESR was 26 mm/h and CRP was 16 mg/l. TA US demonstrated a positive halo sign. TA biopsy showed adventitial and intimal inflammatory infiltrates with no giant cells. He was diagnosed with GCA and had a complete response to 60 mg prednisolone. He re-presented 3 months later on a tapering dose of 20 mg prednisolone with acute left foot drop. He reported paraesthesia and a cold sensation on the dorsum of the foot. On examination, ankle dorsiflexion and eversion demonstrated reduced power of Medical Research Council (MRC) grade 3/5. He had no other symptoms and the remainder of the neurologic exam was normal. ESR was 6 mm/h and CRP was 1 mg/l, the remainder of his laboratory workup, including haemoglobin A1c, serum protein electrophoresis, ANCAs, ANA and viral serology, was normal. A nerve conduction study (NCS) confirmed a compressive left common peroneal neuropathy at the knee. He was managed conservatively with improvement in power to MRC grade 4+/5.