case presentation:

A 27-year-old secretary presented to an orthopaedic outpatients department with a 1-month history of left wrist drop following dry needling.

The patient attended physiotherapy occasionally for deep tissue massage and dry needling for shoulder pain. On this particular occasion, as the physiotherapist inserted a needle, she reported that she felt spasms in her left hand followed by a wrist drop. The needle was inserted in the lateral aspect of her arm, approximately at the level of the junction of the middle and distal third of her left humerus. The patient reported that the needle was applied with equal vigour to other needles applied that day. A filiform needle 0.25 mm in diameter and 50 mm in length was used.

The patient attended the emergency department where an MRI scan of her arm showed no evidence of pathology at or around her left humerus.

reference: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5786962/