One of the uncommon stroke presentations is the isolated wrist drop syndrome, caused by a stroke affecting the hand knob area, with the embolic mechanism being the most commonly identified mechanism. Here, we present the case of a 62-year-old female patient who presented with acute-onset isolated wrist drop secondary to right internal carotid artery fibromuscular dysplasia with a string of beads appearance and coexisting proximal atherosclerotic severe stenosis. The patient underwent successful carotid artery stenting. Patients with hand knob stroke may present a diagnostic dilemma and can be misdiagnosed as having peripheral neuropathy due to the absence of pyramidal signs and other symptoms of cortical involvement, leading to delayed or inappropriate treatment.