Cerebral microvascular abnormalities in patients with idiopathic intracranial hypertension

• Published in: Brain research 2018-05, Vol.1686, p.72-82
• Main Authors: Eidsvaag, Vigdis Andersen, Hansson, Hans-Arne, Heuser, Kjell, Nagelhus, Erlend A., Eide, Per Kristian
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aquaporin 4 - metabolism; Benign intracranial hypertension; Brain capillary basement membrane; Capillaries - physiopathology; Cell and Molecular Biology; Cell- och molekylärbiologi; Cerebral Cortex - blood supply; Cerebral Cortex - pathology; Female; Headache - physiopathology; Humans; Intracranial Hypertension - physiopathology; Intracranial Pressure - physiology; Male; Middle Aged; Pathology; Pericyte coverage; Pseudotumor cerebri; Pseudotumor Cerebri - pathology; Pulsatile intracranial pressure; Young Adult
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2018.02.017

•Ultrastructural changes in cerebral capillaries were examined in idiopathic intracranial hypertension cases and controls.•Electron microscopy revealed abnormal pericyte cell bodies and processes in idiopathic intracranial hypertension.•The basement membrane showed evidence of degeneration in idiopathic intracranial hypertension.•The study disclosed marked changes of the cerebral cortical capillaries in idiopathic intracranial hypertension patients.•Microvascular alterations seem to be involved in the evolvement of idiopathic intracranial hypertension. Idiopathic intracranial hypertension (IIH) is characterized by symptoms indicative of increased intracranial pressure (ICP), such as headache and visual impairment. We have previously reported that brain biopsies from IIH patients show patchy astrogliosis and increased expression of the water channel aquaporin-4 (AQP4) at perivascular astrocytic endfeet. The present study was undertaken to investigate for ultrastructural changes of the cerebral capillaries in individuals with IIH. We examined by electron microscopy (EM) biopsies from the cortical parenchyma of 10 IIH patients and 8 reference subjects (patients, not healthy individuals), in whom tissue was retrieved from other elective and necessary brain surgeries (epilepsy, tumors or vascular diseases). IIH patients were diagnosed on the basis of typical clinical symptoms and abnormal intracranial pressure wave amplitudes during overnight ICP monitoring. All 10 IIH patients underwent shunt surgery followed by favorable clinical outcome. EM revealed abnormal pericyte processes in IIH. The basement membrane (BM) showed more frequently evidence of degeneration in IIH, but neither the BM dimensions nor the pericyte coverage differed between IIH and reference tissue. The BM thickness increased significantly with increasing age. Reference individuals were older than IIH cases; observations may to some extent be age-related. The present study disclosed marked changes of the cerebral cortical capillaries in IIH patients, suggesting that microvascular alterations are involved in the evolvement of IIH.