Background. The 40-year-old patient developed headache, dyscoordination, imbalance, memory problems, fever, and somnolence. Two days after manifestation, the patient was hospitalized with an altered mental state (GCS of 12). No previous history of atrial fibrillation, persistent headache, migraine, drug abuse, autoimmune, or systemic inflammatory disorders. Results. CSF analysis revealed 10 WBC/μL with normal glucose and protein levels, no atypical cells or culture growth. No antibodies to TORCH infections or Borrelia were identified. CRP was elevated at 11.5 mg/dL, as well as ESR at 39 mm/hr, IgE at 1120.2 mU/L, and CD16+ NK cells in the blood, indicating inflammation. The rheumatologic workup was negative. Duplex ultrasound revealed bilateral resistive vertebral artery Doppler waveforms with no evident signs of atherosclerosis. Echocardiography was normal without valvular or septal pathology. The combination of multifocal middle-small caliber vessel stenotic changes, inflammatory signs, and no specific autoimmune antibodies is suggestive of primary CNS vasculitis. The patient was initiated with a short-term course of corticosteroids, long-term therapy with immunosuppressive drug, pentoxifylline, and antiplatelet drugs. During the 1-year follow-up, he responded to the therapy with clinical improvement and a radiologically stable state. Conclusions. The uniqueness of this clinical case is the coexistence of two clinically challenging disorders. The occlusion of the artery of Percheron, a rare anatomical variant of posterior cerebral perforator arteries 2, was caused by no less rare inflammatory neurological disease - primary CNS vasculitis.
Keywords. Artery of Percheron, artery of Percheron territory infarct, bithalamic lesions, brainstem stroke syndromes, central nervous system vasculitis, posterior circulation infarction, posterior inferior cerebellar artery (PICA) infarct, superior cerebellar artery