If the diagnosis is made preoperatively radiation treatment may be an option. Others propose that higher-order aberrations are present preoperatively. Nonetheless, it is often impossible to distinguish the two preoperatively. It is achieved preoperatively with a local anaesthetic. Measures should be taken to control hypertension preoperatively to reduce the risk of AF. Fine-needle aspiration (FNA) helps distinguish the two entities preoperatively. Patients have to be screened preoperatively with a full neurological examination, and subsequent Botox injection. X-ray may be used in conjunction with MRI or sonogram images to assist preoperatively. Preoperatively, the perforators are located using a hand held doppler.