Magnetic resonance imaging based classification of anatomic relationship between the cochleovestibular nerve and anterior inferior cerebellar artery in patients with non-specific neuro-otologic symptoms

Abstract

In this study, we aimed to assess anatomical relationship between the anterior inferior cerebellar artery (AICA) and cochleovestibular nerve (CNV) in patients with non-specific cochleovestibular symptoms using magnetic resonance imaging (MRI). One-hundred and forty patients with non-specific neuro-otologic symptoms were assessed using cranial and temporal MRI. Classification was performed according to four different types of anatomical relationship observed between the AICA and CVN. In type 1 (point compression), the AICA compresses only a limited portion of the CVN. In type 2 (longitudinal compression), the AICA approaches the CVN as both traverse parallel to each other. In type 3 (loop compression), the vascular loop of the AICA encircles the CVN. In type 4 (indentation), the AICA compresses the CVN so as to make an indentation in the nerve. The anatomical relationship between the CVN and AICA was encountered in 19 out of 140 (13.6%) patients (20 ears). The VCC was unilateral in 18 patients (94.7%) and bilateral in one patient (5.3%). There was no other vascular structure causing VCC to the CVN except for vertebral artery that was seen in 2 out of 140 patients (1.4%). These were unilateral cases. There were tinnitus, vertigo or dizziness, hearing loss, and both hearing loss and vertigo in 5 (25%), 13 (65%), 1 (5%) and 1 (5%) ears of 20 patients, respectively. There was no relationship between the cochleovestibular symptoms and type of compression (p>0.05). Neurovascular relationship between the CVN and AICA can be imaged properly using MR and MR based classification may help reporting this relationship in a standard way. Although, MR images can show the anatomical relationship accurately, diagnosis of vascular conflict should not be based on imaging findings alone.

Evaluation of the vascular contacts of the facial nerve on three-dimensional fast imaging employing steady-state acquisition MRI in Bell's palsy

“…In the previous studies, direct contact of cranial nerves by blood vessels depicted on MRI has been proposed as a cause of trigeminal neuralgia, hemifacial spasm, vestibulocochlear paroxysmia, and glossopharyngeal neuralgia. [11,[18][19][20] In our study, we found that multiple vascular contacts of the facial nerve were more common in patients with Bell's palsy and the presence of these vascular contacts was associated with poor recovery after standard treatment. While most patients with Bell's palsy show complete recovery within 3 to 4 months, 30% of patients do not recover completely and have poor outcomes.…”

MRI Sequences in Head & Neck Radiology – State of the Art

“…It is based on GE sequences with a short TR using the phenomenon of inflow-related enhancement of spins to obtain a difference between the unsaturated and presaturated spins in order to create a bright vascular image. Vessels in the cerebellopontine angle from the circle of Willis can be clearly detected and in combination with SSFP images, vascular contact syndromes related to point, longitudinal and loop compression as well as indentation of cranial nerves can be reliably diagnosed [26].…”

“…high-resolution dark signal of cranial nerves and very high signal of liquor in SSFP [20] labyrinthitis lower signal intensity than liquor on SSFP [22] menière's disease endolymphatic hydrops as ratio of high post-gadolinium 3D-FLAIR signal intensity in the perilymphatic space and the high signal in MRI cisternographic sequences in both endolymph and perilymph: vestibule (mild: 34 -50 %, significant: > 50) cochlea (mild: extrusion of the scala media, significant: scala media larger than scala vestibuli) [25] 3D-TOF, TWIST/ TRICKS angiography, DCE vascular contact syndromes point, longitudinal and loop compression as well as indentation of cranial nerves on 3D-TOF [26] infantile hemangioma arterial enhancement on TWIST with gadofosveset trisodium [30] venous malformation venous enhancement on TWIST with gadofosveset trisodium [30] lymphatic malformation no enhancement on TWIST with gadofosveset trisodium [30] arteriovenous malformation arterial and venous enhancement on TWIST with gadofosveset trisodium [30] hypoxia low K trans [32] bone do not cause severe artifacts (as typically seen in computed tomography CT), which makes MRI a superior image modality for delineating tumors in the oropharynx and oral cavity [5]. The ability to discriminate fluid and mucus from soft tissue is extremely helpful in the imaging of sinonasal tumors.…”

The neurovascular conflict of the vestibulocochlear nerve. Etiology, diagnostics, the methods for the surgical and conservative treatment

“…Чаще наблюдаются аномалии передненижней мозжечко-вой артерии (ПНМА), проявляющиеся в виде петли, про-висания, долихоэктазии [12]. ПНМА отходит от базиляр-ной артерии и входит в мостомозжечковый угол, где тесно связана с VIII нервом [13,14].…”

“…[14] оценили анато-мические соотношения при помощи МРТ ПУН и ПНМА у 140 пациентов с неспецифическими кохлеовестибуляр-ными симптомами. Были выделены IV типа контакта со-суда с нервом.…”