الفهرس 
Introduction.Only 14 pages are availabe for public view
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Abstract
Neurovascular compression syndrome (NVCS) is a disease caused by presence of contact between a vascular loop in the cerebellopontine angle (CPA) and one of the cranial nerves. Normally, the CPA is characterized by presence of many vascular and neural structures, which are normally in contact with each other without causing a problem; however, sometimes this contact causes a problem to the patient and becomes symptomatic leading to the so-called NVCS, the symptom of which depends on the compressed cranial nerve and the compressing vessel is called an off ending vessel⁽¹⁾. Pathophysiology of the syndrome include two theories; the “ephaptic peripheral” theory refers to the development of a true short-circuit electric activity that may occur by time between fibers constituting the nerve. Similarly, a hyper reactivity at the core of the cranial nerves in the brainstem known as the “central nuclear” theory may cause the sign and symptoms of these disorders⁽⁶⁾. NVCS is diagnosed by exclusion of other pathologies beside clinical and radiological assessment⁽¹⁾. The following are the imaging criteria of a conflicting vessel in neurovascular compression syndrome in CPA: (1) Presence of vascular contact with the cranial nerve, but this criterion alone is not sufficient, (2) Orthogonal (perpendicular) contact of the vessel with the cranial nerve, (3) Distortion of the course of the cranial nerve, (4) Distortion of the adjacent neural structure (brain stem), (5) Reduction of the nerve caliber and (6) Site of contact between the vessel and the cranial nerve; for the facial nerve, the weakest point is the root exit zone (REZ) as it is the transition zone between central and peripheral myelin, and for the trigeminal nerve, usually any site
along its course from the root entry zone (REZ) to the pes caves (Meckel’s cave) ⁽⁵⁾.
NVCS is treated medically and mainly surgically by Micro-Vascular Decompression
(MVD) using Endoscopic Assisted Minimally Invasive Retrosigmoid Approach (EA
MIRA) ⁽¹⁾