A 48-year-old man came to our attention for some relapsing episodes of right hemiparesis. He had also reported many episodes of involuntary movements in the right arm for about 2 weeks before the hospital admission and other episodes of loss of consciousness, without prodromes and with spontaneous recovery. His medical history was unremarkable; in particular, he had no history of headache, hypertension, dyslipidemia, diabetes mellitus, or stroke. He was a current smoker (30 packages/years) and overweight (BMI 33 kg/m2). He did not take any therapy.
During his first hospital access, the non-contrast brain CT (NCCT) and the electroencephalogram showed no abnormalities and he refused the hospitalization. A few days later, for the persistence of the recurrent symptoms, he returned to the hospital. The neurological evaluation showed very mild right hemiparesis and myoclonic-like episodes in the right limbs (probably limb-shaking TIA). Atrial fibrillation was also detected, and anticoagulant therapy with low-molecular-weight heparin was started, and the patient was admitted to our ward. Neurological examination was completely negative after a few hours.
A transcranial color-coded duplex (TCCD), a CT angiography, and an MR angiography were performed and showed multiple severe intracranial arterial stenosis involving the left carotid terminus, the right carotid terminus, the anterior and the posterior cerebral artery bilaterally, with post-stenotic aneurysmal dilatations (Fig. 1a). Diffusion-weighted images revealed no recent ischemic infarction or signs suggestive of encephalitis. Additional MRI with perfusion sequences showed an area with prolonged mean transit time in the left hemisphere, without evidence of ischemic core. The "black-blood" T1-weighted images showed strong contrast enhancement in the left carotid terminus, particularly in the cavernous and petrous segments.
A brain angiography was subsequently performed, confirming the suspicion of cerebral arteritis, with involvement of the large- and medium-sized cerebral vessels. Further exams were performed, including total-body CT-positron emission tomography scanning, and no findings suggestive for an extracranic vessel inflammatory involvement were detected. Other causes of secondary vasculitis were excluded. The biopsy of the temporal artery was not suggestive for GCA. Blood tests showed no signs of systemic inflammation or coagulopathy; toxicological screening was negative. Transthoracic echocardiography did not reveal any pathological findings, except for a mild left ventricular hypertrophy. Duplex sonography of supra-aortic trunks revealed no significant stenosis in the cervical arteries. Lumbar puncture was performed, analysis of cerebrospinal fluid (CSF) was normal, and isoelectric focusing showed a polyclonal pattern. PCR for HSV 1-2, varicella-zoster virus, Epstein-Barr virus, adenovirus, parvovirus B19, Enterovirus, cytomegalovirus, and Borrelia burgdorferi was negative. Serological screening for vasculitis like rheumatic factors, complement C3/C4, antinuclear antibody, antineutrophil cytoplasmic antibody, angiotensin-converting enzyme, lymphocyte typing was negative. No neoplasm was found during neoplastic screening (colonoscopy, testicular ultrasound, blood neoplastic markers, abdomen tomography, peripheral blood film). Chest tomography showed only mild emphysema findings, and gastroscopy showed an erosive gastritis with duodenal ulcer, with negative Helicobacter pylori research. Biopsy of the lesion was not typical for neoplasm, and PPI therapy was started. The quantiFERON test was positive, but no signs of acute TBC pathology were found. Blood exams revealed mild hyperthyroidism, and a thyrostatic therapy with Tapazole was started.
Neuropsychological tests showed alterations in visual, spatial, and verbal learning skills, with a deficit in language tests, but a limitation related to the significant language barrier was present. The rheumatological evaluation confirmed the suspicion of probable primary angiitis of CNS, and the patient was treated with a high dose of intravenous corticosteroids (with successive prednisone at daily dose 1 mg/kg) and mycophenolate mofetil (2,000 mg/daily). Because of immunosuppressant therapy, for the patient who was positive for the quantiFERON test, a preventive therapy with isoniazid was started.
Despite the immunosuppressant therapy, neurosonological and neuroradiological follow-up exams showed a worsening of the aforementioned stenosis, especially in the left carotid terminus. Brain MRI follow-up showed new small acute ischemic lesions in the left middle cerebral artery (MCA) territory. During the hospitalization, the patient complained of numerous transient episodes of severe weakness in the right limbs and aphasia, many of them evoked by postural changes and arterial hypotension, with spontaneous regression and no paroxysmal activity at the EEGs.
This clinical evolution occurred under combined therapy with a high dose of steroids, immunosuppressant, and antithrombotic therapy, and a new brain CT perfusion exam showed a worsening of the left hemispherical hypoperfusion (Fig. 1b). After a multidisciplinary evaluation with an interventional neuroradiologist, a treatment of intracranial stenting of the left carotid siphon was purposed. Dual antiplatelet therapy with Cardioaspirin and clopidogrel was started, and anticoagulant was stopped.
The endovascular procedure was performed 30 days after the first DSA angiography and after the initiation of immunosuppressive therapy, in general anesthesia. First angiographic sequences confirmed the complete occlusion of the carotid terminus on the left side and a marked slowing of the flow on the sylvian branches of the ipsilateral MCA. An intracranial stent, Solitaire  (Medtronic), was positioned from the distal tract of the carotid siphon to the first tract of the MCA on the left side, without any procedural complication (Fig. 1c).
After the procedure, CT perfusion showed a marked improvement, with no more hypoperfusion areas in the left hemisphere, and no more clinical episodes of hemiparesis or aphasia were reported. Moreover, transcranial color Doppler ultrasound revealed a strong improvement in left MCA blood flow.
At discharge, neurological evaluation was normal. Anticoagulation therapy with apixaban was started in association with dual antiplatelet therapy.