(3) Concomitant tinnitus seemed to be affected by the configuration of AICA categorized by Kazawa system, while the Chavda and Gorrie classification of AICA loop was unassociated with tinnitus. (2) There was no significant association between the AICA loop and concomitant vertigo or pre‐treatment audiometric configuration in the affected ear.
(1) No significant interaural difference in the position, configuration and neurovascular contact of AICA was observed. The association between radiological findings and clinical data were analyzed. The MRI findings of both ears were evaluated by the Chavda, Gorrie and Kazawa systems. Pure tone audiometry and magnetic resonance imaging (MRI) of CPA‐IAC were performed. All patients received detailed history inquiry and standard treatments. One hundred and thirty‐six patients with unilateral ISSNHL were enrolled. We aimed to investigate the impact of the position, configuration and neurovascular contact of the anterior inferior cerebellar artery (AICA) in cerebellopontine angle (CPA) and internal auditory canal (IAC) on the clinical features of patients with unilateral idiopathic sudden sensorineural hearing loss (ISSNHL). 7 Using a recently developed grading system, that is, Kazawa system, which describes the loop formation of AICA or posterior inferior cerebellar artery (PICA) branch and its extension in IAC region, 8 In this study, initial pure-tone audiometry curves were categorized into four types: (1) low-frequency hearing loss (the average threshold of 0.25 and 0.5 kHz is 20 dB higher than that of 4 and 8 kHz), (2) highfrequency hearing loss (the average threshold of 4 and 8 kHz is 20 dB higher than that of 0.25 and 0.5 kHz), (3) flat-type hearing loss (similar threshold is observed across the entire frequency range and the average threshold is less than 90 dB HL), and (4) profound hearing loss (the average threshold of 0.5, 1, 2, and 4 kHz exceeds 90 dB HL). found no significant association between AICA loop that made no contact with the vestibulocochlear nerve, ran adjacent to the nerve, or displaced the nerve and hearing loss in unselected patients with asymmetric hearing loss. By means of this classification, Gorrie et al. Moreover, the degrees of the classification were related to the complexity of the anatomical relationships and, therefore, to the difficulty of the maneuvers required to overcome them.Ĭonclusion The proposed AICA-SAA complex classification allowed to distinguish and objectify pre- and intraoperatively the spectrum of variations, to thoroughly plan the required actions and instrumentation. The proportions found in the gradation remained within the range of previous publications (Grade 0: 42.2% Grade 1: 11.2% Grade 2: 35.4% Grade 3: 10.6% and Grade 4: 0.6%). Results Eighty-four patients were evaluated, including 161 CPA.
#PICA SYNDROME RADIOPAEDIA SERIES#
The classification was applied to a series of patients assessed by magnetic resonance constructive interference in steady state sequence. Methods The variations were defined as follow: Grade 0: free, purely cisternal AICA, unidentifiable or absent SAA Grade 1: purely cisternal AICA, loose SL, SAA > 3 mm Grade 2: AICA near the subarcuate fossa, pronounced SL, SAA <3 mm Grade 3: “duralized” AICA, unidentifiable SAA, or included in the petromastoid canal (PMC) and Grade 4: intraosseous AICA, unidentifiable SAA, or included in the PMC. As the spectrum of configurations is originated during the development, a systematized classification was proposed based on the interaction between the petrosal bone and the AICA in the embryonic period. AICA-SAA complex's variations may represent major issues in cerebellopontine angle (CPA) surgery. Objective To hierarchize the anterior inferior cerebellar artery (AICA)–subarcuate artery (SAA) complex's variations in the surgical field.īackground The AICA's “subarcuate loop” (SL) presents multiple variations, closely related to the SAA.
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