RESUMO
BACKGROUND: In patients with moyamoya disease (MMD) who receive superficial temporal artery (STA) to middle cerebral artery (MCA) bypass, hypoperfusion remote from the anastomosis site rarely occurs. Watershed shift due to direct bypass has been proposed as the mechanism; however, no report has confirmed this phenomenon using angiography. OBSERVATIONS: A 48-year-old man presented with transient weakness in his left arm. Angiography revealed severe bilateral stenosis of the MCAs and moyamoya vessels. The right anterior cerebral artery (ACA) had short stenosis at A2 but ample blood supply to the cortical area of the right ACA and MCA regions. The patient was diagnosed with MMD and received a single STA-MCA bypass. The next day, he had difficulty communicating, and a cerebral infarction away from the anastomosis site was identified. Perfusion examination revealed hyperperfusion around the direct bypass and hypoperfusion away from the anastomosis site. Angiography revealed bypass patency; however, the original anterograde flow of the right ACA decreased significantly at the stenosed point, indicating an improper watershed shift. LESSONS: STA-MCA bypass for patients with MMD can cause an improper watershed shift decreasing cerebral flow. Donor flow should be prepared based on each angiographic characteristic, and the risk of the improper watershed shift should be considered.
RESUMO
Primary leptomeningeal malignant lymphoma (PLML) is a rare variant of primary central nerve system malignant lymphoma (PCNSL) which is restricted to leptomeninges. The lesions of PLML can often be detected as abnormal enhancement on the surface of central nervous system or the ventricular wall on magnetic resonance imaging (MRIs). Cerebrospinal fluid (CSF) evaluation together with such MRI findings provides the definitive diagnosis of PLML. Here, we present a 45-year-old female case of PLML in which hydrocephalus with disproportionately large fourth ventricle was observed at presentation with gait instability. Head MRI revealed no abnormal enhancement and CSF cytology was negative, leaving the cause of hydrocephalus undetermined. Endoscopic third ventriculostomy (ETV) was effectively performed for hydrocephalus and her symptoms disappeared. Nearly 2 years later, she was brought to emergent room due to unconsciousness with the recurrence of hydrocephalus. MRI showed expanded fourth ventricle and abnormal enhancement on the ventricular wall. The endoscopic surgery for improving CSF flow was successful and inflammatory change was endoscopically observed on the ventricular wall involving aqueduct. Pathological diagnosis of the specimen from the ventricular wall proved B-cell lymphoma. Because neither brain parenchymal masses nor systemic tumors were identified, she was diagnosed with PLML and treated by high-dose methotrexate. She was in a stable state 2 years after the diagnosis of PLML. We report and discuss the characteristics of this case.
