Magnetic resonance imaging‐guided focused ultrasound thalamotomy for essential tremor patient with a clipped cerebral aneurysm and Alzheimer’s disease: A case report

We report a 78-year-old, right-handed woman with a medication-refractory essential tremor. She underwent clipping of an unruptured cerebral aneurysm 17 years ago. Furthermore, she had suffered from Alzheimer's disease for 3 years; however, she could communicate courteously. We performed MRI-guided focused ultrasound (MRgFUS) left ventral intermediate nucleus thalamotomy, which prevented ultrasound from being delivered to the aneurysm clip. We sedated her in the planning stage and calmed her down with a frequent communication in the sonication stage. She was not delirious and her right-hand tremor improved immediately after the final sonication. Mild dysarthria and hypotonus of the right extremities occurred the next day; however, these symptoms improved with steroids. This case indicates that patients with a clipped cerebral aneurysm or dementia could undergo MRgFUS.