Article ID: 11256
The patient was a 72-year-old man. He came to our hospital with a complaint of left wrist drop. He was suspected of having radial nerve palsy, but there was preserved synkinetic wrist extension, a phenomenon that clenching the fist leads to slight extension at the wrist. He was hospitalized due to a head MRI showing acute ischemic stroke of the right precentral knob (PK). Since lupus anticoagulant positivity was detected, he was diagnosed with antiphospholipid antibody syndrome (APS) and started on aspirin. His symptoms rapidly improved, and he was discharged on the 9th hospital day. The PK infarction would result in an inability to initiate an extension movement of the contralateral wrist and fingers, which can mimic radial nerve palsy, but the synkinetic contraction of the forearm extensors with the forearm flexors is preserved, and synkinetic wrist extension that may help in the diagnosis of the PK infarction is present. Although PK infarction is generally associated with embolic mechanisms, arterial thrombosis with APS is also a cause and should be given attention.
