Resolution of Late-Onset Hypomania After Repair of Carotid Artery Stenosis

Abstract

3Further research has described the relationship between right-sided lesions and secondary mania. 4 We describe the resolution of hypomanic symptoms after bilateral carotid endarterectomy in a patient with long-standing unipolar depression who developed late-onset hypomania with MRI white matter hyperintensities. Case report. Mr. A, a 67-year-old left-handed man with long-standing diabetes mellitus and coronary artery disease, was diagnosed with unipolar recurrent depression 40 years ago. Three years ago, he developed decreased sleep, increased energy, racing thoughts, and prominent irritability while taking his long-standing maintenance antidepressant, escitalopram 20 mg q.d. These symptoms responded only partially to the addition of lamotrigine, aripiprazole, and daily clonazepam and the eventual discontinuation of escitalopram. His diagnosis was subsequently changed to DSM-IV bipolar II disorder. Two separate attempts to taper off both the aripiprazole and the clonazepam failed when the patient experienced worsening insomnia and extreme irritability. The patient remained stable, but with subsyndromal symptoms, on this medication regimen for approximately 2 years. He then underwent a right carotid endarterectomy for critical stenosis of the right internal carotid artery followed 3 months later by a left carotid endarterectomy for occlusion of the cervical segment of the internal carotid artery, both discovered when he developed episodic aphasia. Prior to surgery, he had an MRI with contrast that revealed small foci of white matter hyperintensity in the right periventricular subependymal region, in the right superior frontal gyrus, and in the left cingulate gyrus. There were no infarcts observed. Within 3 weeks after his first surgery, he reported a dramatic improvement in his mood, and 1 month after his second surgery, his symptoms completely remitted, and he felt himself again. Aripiprazole and clonazepam were discontinued, and at his 4-month follow-up, he remains well, taking lamotrigine, without any irritability or difficulties sleeping. The temporal relationship between the resolution of this patient’s symptoms and his surgeries suggests that his irritability and insomnia, the cornerstones of his bipolar II diagnosis, were at least in part mediated by decreased cerebral blood flow due to carotid stenosis. When the blood flow was restored, his symptoms abated. The MRI findings are consistent with previous research that demonstrated a relationship between right-sided lesions and secondary mania 4 as well as a correlation between bipolar disorder and hyperintensities in the subependymal region, deep white matter, and subcortical gray