3D Constructive Interference Research Articles

Measuring the Influence of Magnetic Vestibular Stimulation on Nystagmus, Self-Motion Perception, and Cognitive Performance in a 7T MRT.

Strong magnetic fields induce dizziness, vertigo, and nystagmus due to Lorentz forces acting on the cupula in the semi-circular canals, an effect called magnetic vestibular stimulation (MVS). In this article, we present an experimental setup in a 7T MRT scanner (MRI scanner) that allows the investigation of the influence of strong magnetic fields on nystagmus as well as perceptual and cognitive responses. The strength of MVS is manipulated by altering the head positions of the participants. The orientation of the participants' semicircular canals with respect to the static magnetic field is assessed by combining a 3D magnetometer and 3D constructive interference in steady-state (3D-CISS) images. This approach allows to account for intra- and inter-individual differences in participants' responses to MVS. In the future, MVS can be useful for clinical research, for example, in the investigation of compensatory processes in vestibular disorders. Furthermore, it could foster insights into the interplay between vestibular information and cognitive processes in terms of spatial cognition and the emergence of self-motion percepts under conflicting sensory information. In fMRI studies, MVS can elicit a possible confounding effect, especially in tasks influenced by vestibular information or in studies comparing vestibular patients with healthy controls.

Tortuous is Torturing: An Unusual Case of Basilar Dolichoectasia Causing Trigeminal Neuralgia, as Demonstrated on 3D Constructive Interference in Steady State Images on MRI.

Tortuous is Torturing: An Unusual Case of Basilar Dolichoectasia Causing Trigeminal Neuralgia, as Demonstrated on 3D Constructive Interference in Steady State Images on MRI.

Comparison of 3D constructive interference in steady state (CISS) and T2 sampling perfection with application optimized contrasts using different flip angle evolution MR imaging of the intracranial trigeminal nerve and central skull base neuroforamina.

Due to surgical advancements, the accurate detection of perineural disease spread has become increasingly important in the management and prognostication of head and neck cancers, though MR evaluation has thus far been limited by technical and logistic challenges. The purpose of this study was to specifically evaluate the relative capability of 3D CISS and 3D T2-SPACE imaging to delineate the proximal intracranial divisions of the normal trigeminal nerve, an area important in determining the resectability of intracranial perineural disease. A single center HIPAA-compliant, IRB approved retrospective review of 40 patients with clinical temporal bone/internal auditory canal MR imaging was conducted. 20 patients with 3D CISS images and 20 patients with 3D T2-SPACE images met inclusion criteria. Two radiologists scored the sequences on a 3-point scale based on ability to visualize anatomic structures surrounding the trigeminal nerve in Meckel's cave, intracranial trigeminal divisions, skull base neuroforamina, and proximal extracranial mandibular division. The following anatomic locations scored significantly better in the T2-SPACE sequence compared to the CISS sequence for both raters: intracranial V3 (p < .05), foramen ovale (p < .05), and extracranial V3 (p < .01). The average scores for the anterior Meckel's cave and foramen rotundum were higher for the T2-SPACE sequence, although not significantly. Percent interobserver agreement ranged from 50 to 90% and 65-100% for the different anatomic locations on the CISS and T2-SPACE sequences, respectively. 3D T2-SPACE was found to be superior to 3D CISS in the evaluation of the distal intracranial and extracranial portions of the normal trigeminal nerve.

Presence of vascular loop in patients with audio-vestibular symptoms: is it a significant finding? Evaluation with 3-tesla MRI 3D constructive interference steady state (CISS) sequence

BackgroundTinnitus, sensory neural hearing loss (SNHL), and vertigo are common audio-vestibular symptoms. Many diseases are associated with these symptoms; however, the exact cause is not always identified. Some studies show that the etiology could be related to the presence of a vascular loop in contact with the 8th cranial nerve. Three-dimensional (3D) constructive interference in steady state (CISS) is a fully refocused gradient-echo magnetic resonance imaging (MRI) sequence that has high sensitivity in evaluation of the cranial nerves. This high sensitivity is a result of its inherent ability to accentuate the T2 values between cerebrospinal fluid (CSF) and adjacent anatomical or pathological structures. We aimed to evaluate the association of audio-vestibular symptoms with the presence of vascular loops and vascular contact in cerebellopontine angle (CPA) and the internal auditory canal (IAC) using 3Tesla MRI. The study included 98 patients (196 ears); 51 females and 47 males with audio-vestibular dysfunction symptoms in isolation or combined; 40 patients with tinnitus, 50 with sensory neural hearing loss, and 32 with vertigo. The healthy control group with no symptoms in either ear, n = 60 (120 ears): 32 females and 28 males. The non-symptomatic ears in the patients were added to the healthy control group. All MRI examinations were performed by using a 3 T (Magnetom Verio 3 T; Siemens Medical Solutions, Erlangen, Germany).ResultsNo statistically significant association was detected between the presence of different grades of vascular loop or types of vascular contact and any of the studied audio-vestibular symptoms.ConclusionNo possible role of the presence of vascular loop/contact was identified in causing tinnitus, deafness, or vertigo as evaluated by 3D-CISS sequence. Therefore, presence of vascular loops in contact with the 8th cranial nerve is not certainly considered pathological but possibly to be a normal anatomical coincidental finding.

Bilateral transient olfactory bulb edema during COVID-19–related anosmia

An asymptomatic 27-year-old man was diagnosed with coronavirus disease 2019 (COVID-19) by occupational medicine after contagion (reverse transcription polymerase chain reaction [ RT - PCR ]). Four days after the diagnosis, he experienced complete anosmia and dysgeusia.1 On day 7, 1.5T MRI showed signs of bilateral olfactory bulb edema on 3D constructive interference in steady state T2-weighted imaging, demonstrated by severe enlargement2 (left: 73 mm3, right: 64 mm3) and an abnormally high signal intensity (figure). Olfactory clefts showed mild edema. The olfactory pathways, including the cortical projections (fluid-attenuated inversion recovery and diffusion-weighted imaging not shown), were normal. Sensory recovery and negative RT-PCR (positive on days 1, 2, and 10) appeared on day 14. MRI on day 24 confirmed the normalization of olfactory bulb signal and volumes (left: 22 mm3, right: 17 mm3).

Clinical utility and value contribution of an MRI-positive line marker for image-guided brachytherapy in gynecologic malignancies

PurposeThe purpose of this study was to investigate the utility of a novel MRI-positive line marker, composed of C4:S (cobalt chloride–based contrast agent) encapsulated in high-density polyethylene tubing, in permitting dosimetry and treatment planning directly on MRI. Methods and MaterialsWe evaluated the clinical feasibility of the C4:S line markers in nine sequential brachytherapy procedures for gynecologic malignancies, including six tandem-and-ovoid and three interstitial cases. We then quantified the internal resource utilization of an intraoperative MRI-guided procedural episode via time-driven activity-based costing, identifying opportunities for cost-containment with use of the C4:S line markers. ResultsThe C4:S line markers demonstrated the strongest positive signal visibility on 3D constructive interference in steady state (CISS)/FIESTA-C followed by T1-weighted sequences, permitting accurate delineation of the applicator lumen and thus the source path. These images may be fused along with traditional T2-weighted sequences for optimal tumor and anatomy contouring, followed by treatment planning directly on MRI. By eliminating postoperative CT for fusion and applicator registration from the procedural episode, use of the C4:S line markers could decrease workflow time and lower total delivery costs per procedure. ConclusionsThis analysis supports the clinical utility and value contribution of the C4:S line markers, which permit accurate MRI-based dosimetry and treatment planning, thereby eliminating the need for postoperative CT for fusion and applicator registration.

English

English

Feasibility of three-dimensional constructive interference in steady state sequences for evaluating the anterolateral ligament

The purpose of the study was to determine the feasibility of three-dimensional (3D) constructive interference in steady state (CISS) sequences for evaluating the anterolateral ligament (ALL). Magnetic resonance imaging (MRI) of the right knee joint in 30 healthy volunteers was performed using a 3 T MRI machine. Axial T2-weighted imaging with fat saturation (T2WI-FS), coronal proton-density-weighted imaging with fat saturation (PDWI-FS), and 3D-CISS were included in the protocol. Multiplanar reconstruction (MPR) and rotating stretched curved planar reconstructions (CPRs) of the ALL at 30°, 60°, 90°, 120°, and 150° were generated from the 3D-CISS images. The visibility of the femoral part, meniscal part, tibial part, meniscal insertion, femoral footprint, and tibial footprint of the ALL on the imaging of all sequences was recorded. Based on the CPR of 3D-CISS MRI, the presence of tibial and femoral footprints of the ALL was rated superior to MPR and PDWI-FS (96.67% and 96.67%, respectively; p<0.017). Rotating CPR of 3D-CISS MRI imaging was rated superior to PDWI-FS with respect to the tibial part, meniscal part, and meniscal insertion of the ALL (96.67%, 83.33%, and 83.33%, respectively; p<0.05). Rotating CPR of 3D-CISS MRI was rated superior to PDWI-FS with respect to the femoral part of the ALL, but the difference was not statistically significant (p=0.095). The angle between the ALL and lateral collateral ligament (LCL) on the oblique sagittal image was 18.34±1.88°. The MRI 3D-CISS sequences significantly enhanced the ability to identify the ALL compared to the 2D MRI sequences.

Preoperative MRI Evaluation of Relationship between Trigeminal Nerve and Superior Petrosal Vein: Its Role in Treating Trigeminal Neuralgia.

To assess the value of high-resolution magnetic resonance imaging (MRI) and three-dimensional (3D) reconstruction of the trigeminal nerve and the superior petrosal vein (SPV) in visualizing their anatomical relationship in patients with trigeminal neuralgia (TN). This study included 97 patients with primary TN who underwent preoperative 3D constructive interference in steady state (CISS) MRI. Image analysis was performed by an independent observer blinded to the operative findings and then compared with surgical data. The 3D reconstruction was assessed dynamically using MIMICS software (Materialise Inc., Leuven, Belgium). The 3D relationship between visible structures seen on MRI was consistent with the intraoperative findings in all patients. All cases were divided into three groups by the degree of trigeminal nerve encroachment by SPV. Statistical analysis revealed that the distance from the SPV to the trigeminal nerve was significantly different among the three groups. The diameter of the SPV also differed among the three groups. Preoperative 3D imaging provides reliable and detailed information about the intraoperative anatomical relationship between the trigeminal nerve and the SPV. This evaluation is useful for preoperative planning.

Superficial Siderosis of the Central Nervous System: Neurotological Findings Related to Magnetic Resonance Imaging.

To compare the neurotological results of five patients suffering from progressive hearing loss and ataxia due to superficial siderosis (SS) with the magnetic resonance imaging (MRI) findings. Retrospective case review. Primary and hospital care center. Five adult patients with neurotological symptoms of SS underwent MRI with acquisition of our temporal bone protocol including 3D-constructive interference in steady state (3D-CISS) and susceptibility-weighted imaging (SWI). All patients underwent a complete neurotological examination, the results of which were compared with the imaging findings. Cochleovestibular deficits were present in all five patients as determined by uni- or bilateral bithermal caloric testing and/or video head impulse tests. Sacculocollic reflex was present with increased P1 and N1 latencies on both sides in all patients. MRI revealed an extensive hypointense SWI signal outlining the surface of the brain and the VIIIth cranial nerve in all five patients. Desynchronization of the brainstem auditory evoked potentials (BAEP) and partial or complete absence of the visual suppression of vestibulo-ocular reflex during the pendular rotatory test was particularly consistent with the lesions of the cochleovestibular nerves as well as the cerebellar atrophy seen on MRI. The MRI results with SWI were related to neurotological findings in patients suffering from sensorineural deafness with ataxia due to SS. Our findings support the integration of the SWI and 3D-CISS sequences into the MRI protocol for all patients referred for evaluation of the extent of SS.

Radiosurgery of vestibular schwannoma: prognostic factors for hearing outcome using 3D-constructive interference in steady state (3D-CISS).

Stereotactic radiosurgery (SRS) is an effective treatment for vestibular schwannoma (VS). Three-dimensional (3D) constructive interference in steady state (CISS) is the preferred magnetic resonance imaging (MRI) sequence for evaluating signal changes in the inner ear endolymph. Previous studies demonstrated acorrelation between pretreatment cochlear signal intensity in 3D-CISS and posttherapeutic hearing outcomes. The purpose of our study was to compare 3D-CISS sequences before and after primary SRS of unilateral VSs to evaluate the effect of radiosurgery on the 3D-CISS signal intensities of cochlea and sacculus/utriculus. We retrospectively reviewed 47patients with unilateral VS treated with SRS. The neuroradiological MRI datasets were analysed to evaluate the signal intensity of the inner ear structure, tumour size, Koos grade, tumour volume, and infiltration of the cochlear aperture before therapy and at follow-up. The differences in these signal intensities before SRS and at follow-up were correlated with clinical symptoms, cochlear radiation dose, tumour volume and infiltration of the cochlear aperture. No differences were found between signal intensities in cochlea and utriculus/sacculus before and after SRS and no correlation with clinical symptoms, cochlear radiation dose, tumour volume, Koos grade or infiltration of the cochlear aperture (all p > 0.05). Our study supports the theory of acomplex interaction causing alteration of the endolymph protein concentration and not adirect dependency on the SRS. Use of modern dosing schemes will have apositive impact on clinical outcome with preservation of hearing in patients with VS.

Contrast-Enhanced CISS Imaging for Evaluation of Neurovascular Compression in Trigeminal Neuralgia: Improved Correlation with Symptoms and Prediction of Surgical Outcomes.

Thin-section MR imaging through the posterior fossa is frequently used for trigeminal neuralgia. Typical heavily T2-weighted imaging methods yield high anatomic detail and contrast between CSF and neurovascular structures, but poor contrast between vessels and nerves. We hypothesized that the addition of gadolinium-based contrast material to 3D-constructive interference in steady-state imaging would improve the characterization of trigeminal compression. Retrospective review of high-resolution MRIs was performed in patients without prior microvascular decompression. 3D-CISS imaging without contrast and with contrast for 81 patients with trigeminal neuralgia and 15 controls was intermixed and independently reviewed in a blinded fashion. Cisternal segments of both trigeminal nerves were assessed for the grade of neurovascular conflict, cross-sectional area, and degree of flattening. Data were correlated with symptom side and pain relief after microvascular decompression using the Fisher exact test, receiver operating curve analysis, and a paired t test. Contrast-enhanced CISS more than doubled the prevalence of the highest grade of neurovascular conflict (14.8% versus 33.3%, P = .001) and yielded significantly lower cross-sectional area (P = 8.6 × 10-6) and greater degree of flattening (P = .02) for advanced-grade neurovascular conflict on the symptoms side compared with non-contrast-enhanced CISS. Patients with complete pain relief after microvascular decompression had significantly lower cross-sectional area on contrast-enhanced CISS compared with non-contrast-enhanced CISS on preoperative imaging (P = 2.0 × 10-7). Performance based on receiver operating curve analysis was significantly improved for contrast-enhanced CISS compared with non-contrast-enhanced CISS. The addition of contrast material to 3D-CISS imaging improves the performance of identifying unilateral neurovascular compression for symptomatic trigeminal neuralgia and predicting outcomes after microvascular decompression.

Usefulness of High-Resolution 3D Multi-Sequences for Peripheral Facial Palsy: Differentiation Between Bell's Palsy and Ramsay Hunt Syndrome.

To investigate the usefulness of magnetic resonance imaging (MRI) including three-dimensional (3D) sequences in the differentiation between Bell's palsy (BP) and Ramsay Hunt syndrome (RHS). A prospective study. Tertiary care center. Twenty patients: 15 patients with BP and five patients with RHS. Diagnostic. Clinical diagnosis (BP or RHS). The presence of hyperintensity on 3D-fluid-attenuated inversion recovery sequence (3D-FLAIR) and enhancement on gadolinium-enhanced (CE)-3D-FLAIR and CE-3D-T1-weighted image (3D-T1WI) along the internal auditory canal (IAC) wall were significantly associated with RHS (p < 0.05). Hyperintensity in the inner ear was observed on pre- and postcontrast 3D-FLAIR, and enhancement of the cranial nerve (CN)-VIII was observed only on CE-3D-FLAIR. The presence of these findings also showed significant relationships with RHS (p < 0.05). Moreover, thickening of the CN-VII in the fundus of the IAC in 3D-constructive interference on steady state sequence (3D-CISS) also showed a significant association with RHS (p < 0.05). In contrast, the presence of hyperintensity of the CN-VII in the fundus of the IAC on 3D-FLAIR did not demonstrate a significant relationship (p = 0.95), and enhancement in this region was observed in all cases on CE-3D-FLAIR and gadolinium-enhanced-three-dimensional-T1-weighted gradient echo sequence (CE-3D-T1WI). 3D MRI sequences are useful for differentiating RHS from BP. In particular, the enhancement in the CN-VIII and/or along the IAC wall are valuable findings, and CE-3D-FLAIR is the most useful sequence to evaluate these findings. Thickening of the CN-VII on 3D-CISS is also an important finding.

Additive Value of 3T 3D CISS Imaging to Conventional MRI for Assessing the Abnormal Vessels of Spinal Dural Arteriovenous Fistulae.

Introduction:We investigated the additive value of the 3T 3D constructive interference in steady state (CISS) sequence to conventional MRI for the evaluation of spinal dural arteriovenous fistulae (SDAVF).Materials and Methods:We included 16 consecutive patients (15 men, 1 woman; age range 42–81 years; mean 64 years) with SDAVF who underwent 3T MRI and digital subtraction angiography (DSA) before treatment. Two neuroradiologists independently evaluated the presence of abnormal vessels on 3D CISS-, T2- and T1-weighted images (T1WI, T2WI), and contrast-enhanced T1WI using a 3-point grading system. Interobserver agreement was assessed by calculating the κ coefficient.Results:The SDAVF site was the cervical region in one patient, the thoracic region in 12 patients, the lumbar region in two, and the sacral region in one. For the visualization of abnormal vessels, the mean score was significantly higher for 3D CISS than the other sequences (P < 0.05). In 12 of 16 cases (75%) both readers made definite positive findings on additional 3D-CISS images. Interobserver agreement was excellent for 3D CISS images (κ = 1.0), good for T1WI (κ = 0.78; 95% confidence interval [CI] 0.54–1.00) and T2WI (κ = 0.74; 95% CI 0.48–1.00) and moderate for contrast-enhanced T1WI (CET1WI) (κ = 0.50; 95% CI 0.21–0.80).Conclusion:For the assessment of abnormal vessels of SDAVF, the 3T 3D CISS sequence adds value to conventional MRI.

The value of MRI 3D-CISS sequence in trigeminal neuralgia-related diseases

Objective To explore 3D constructive interference insteady state sequence value of related diseases in trigeminal neuralgia. Methods A retrospective analysis of 62 cases of trigeminal neuralgia as the main symptoms of patients with brain magnetic resonance imaging (MRI) routine scan and 3D constructive interference insteady state (3D-CISS) sequence images, of which 12 cases were enhanced scan, comparative analysis of MRI 3D-CISS sequence and conventional sequence of trigeminal nerve. The lesion showed the condition and was compared with the outcome of the operation. Trigeminal neuralgia-related lesions mainly included the trigeminal nerve brain pool around the vascular compression or transition, solid tumors and tumor-like lesions. Results Preoperative MRI 3D-CISS sequence was used to diagnose the vascular compression or metastasis of the trigeminal nerve pool segment in 46 cases. Forty-five patients were found to be responsible blood vessels. The 3D-CISS sequence showed 95.83% coincidence with surgical exploration. The routine sequence could not show the trigeminal The brain around the brain was forced or pushed. 3D-CISS sequence showed eight cases of solid tumors, routine scan showed six cases of solid tumors. Tumor-like lesions were shown in 6 cases of MRI3D-CISS sequences and routine plain scan sequences. The sensitivity of 3D-CISS sequence to trigeminal neuralgia-related disease was 96.77%, and the sensitivity of MRI routine scan to trigeminal neuralgia was only 19.35%. There was significant difference in the sensitivity of 3D-CISS sequence and conventional plain scan sequence to trigeminal neuralgia-related diseases (P<0.01). Conclusions MRI 3D-CISS sequence has a significant advantage in trigeminal neuralgia-related disease, and patients with trigeminal neuralgia should routinely use 3D-CISS sequences. Key words: Magnetic resonance imaging; Trigeminal neuralgia/CO/DI

Analogous Three-Dimensional Constructive Interference in Steady State Sequences Enhance the Utility of Three-Dimensional Time of Flight Magnetic Resonance Angiography in Delineating Lenticulostriate Arteries in Insular Gliomas: Evidence from a Prospective Clinicoradiologic Analysis of 48 Patients

Three-dimensional (3D) time of flight (TOF) imaging is the current gold standard for noninvasive, preoperative localization of lenticulostriate arteries (LSAs) in insular gliomas; however, the utility of this modality depends on tumor intensity. Over a 3-year period, 48 consecutive patients with insular gliomas were prospectively evaluated. Location of LSAs and their relationship with the tumor were determined using a combination of contrast-enhanced coronal 3D TOF magnetic resonance angiography and coronal 3D constructive interference in steady state (CISS) sequences. These findings were analyzed with respect to extent of tumor resection and early postoperative motor outcome. Tumor was clearly visualized in 29 (60.4%) patients with T1-hypointense tumors using 3D TOF and in all patients using CISS sequences. Using combined 3D TOF and CISS, LSA-tumor interface was well seen in 47 patients, including all patients with T1-heterointense or T1-isointense tumors. Extent of resection was higher in the LSA-pushed group compared with the LSA-encased group. In the LSA-encased group, 6 (12.5%) patients developed postoperative hemiparesis; 2 (4.2%) cases were attributed to LSA injury. Contrast-enhanced 3D TOF can delineate LSAs in almost all insular gliomas but is limited in identifying the LSA-tumor interface. This limitation can be overcome by addition of analogous CISS sequences that delineate the LSA-tumor interface regardless of tumor intensity. Combined 3D TOF and 3D CISS is a useful tool for surgical planning and safer resections of insular tumors and may have added surgical relevance when included as an intraoperative adjunct.

3D-constructive interference into steady state (3D-CISS) labyrinth signal alteration in patients with vestibular schwannoma

ObjectiveTo evaluate signal intensity of the inner ear using 3D-CISS imaging and correlated signal characteristics in patients with vestibular schwannoma to neuro-otological symptoms. MethodsSixty patients with unilateral vestibular schwannoma were retrospectively reviewed. All patients had had initial and follow-up magnetic resonance imaging (MRI). Individual treatment strategies consisted of “wait-and-watch”, surgical tumour resection, stereotactic radiosurgery or both surgery and stereotactic radiosurgery. For all patients a complete baseline and treatment course neuro-otological examination was re-studied. ResultsOn initial MRI, 3D-CISS sequence signal loss of the membranous labyrinth was present in 20 patients (33.3%); signal loss of cochlea in 20 (33.3%) and coincident signal loss of sacculus/utriculus in 17 (85%) of them. Sequential analysis of follow-up MRI series demonstrated slightly increased labyrinthine signal degradation, independently of the chosen therapy. Correlation of initial MRI results with initial neuro-otological symptoms showed significance only for cochlear obstruction versus vertigo (p=0.0397) and sacculus/utriculus obstruction versus vertigo (p=0.0336). No other statistically significant relationships were noted. Conclusion3D-constructive interference into steady state (3D-CISS) is appropriate for observing inner ear signal loss in patients with vestibular schwannoma. However, except for vertigo, no significant correlation was noted between initial neuro-otological symptomatology and signal loss of the inner ear.

Comparison of manual and computer-assisted measurement of cochlear nerve obtained from magnetic resonance imaging

Objectives: Cochlear implantation of sensorineural hearing loss requires accurate measurement of cochlear nerve (CN). The precise measurement of very small structures can be improved by automated segmentation and measurement. The variability and reproducibility of the computer-assisted measurement were compared with manual measurements. Materials and Methods: The 3D-constructive interference in steady state magnetic resonance imaging (MRI) images of twenty patients who were referred for MRI in the assessment of giddiness/vertigo or fitness for cochlear implant during the period from June 2013 to June 2014 were analyzed. The CN sizes were measured manually by two independent radiologists. The automatic measurements were then performed on the same images, and its correlation and agreement were calculated between automated and manual measurements. Results: The intra-observer correlation coefficients were significantly larger for cross-sectional area (CSA) of CN using automated measurements when compared to manual measurement (intra-observer r: 0.94021 vs. 0.91437). Similarly, the inter-observer correlation for CSA of CN is also higher in automated measurements (inter measurement r: 0.94786 vs. 0.92013). Conclusions: Using computer-assisted CN dimension measurement, the intra- and inter-observer correlation can be improved when compared to manual measurements. The automated measurement can assist the radiologist in eliminating the need for tedious manual tracing and thus, the time and effort for manual segmentation are also significantly reduced.

Image-fusion Technique in Microvascular Decompression Surgery with 3D Constructive Interference in Steady-state and Modified 3D Time of Flight MR Images: Superior Detection of Possible Offending Vessels over Conventional Imaging

Image-fusion Technique in Microvascular Decompression Surgery with 3D Constructive Interference in Steady-state and Modified 3D Time of Flight MR Images: Superior Detection of Possible Offending Vessels over Conventional Imaging

Vestibular paroxysmia: a treatable neurovascular cross-compression syndrome.

The leading symptoms of vestibular paroxysmia (VP) are recurrent, spontaneous, short attacks of spinning or non-spinning vertigo that generally last less than one minute and occur in a series of up to 30 or more per day. VP may manifest when arteries in the cerebellar pontine angle cause a segmental, pressure-induced dysfunction of the eighth nerve. The symptoms are usually triggered by direct pulsatile compression with ephaptic discharges, less often by conduction blocks. MR imaging reveals the neurovascular compression of the eighth nerve (3D constructive interference in steady state and 3D time-of-flight sequences) in more than 95 % of cases. A loop of the anterior inferior cerebellar artery seems to be most often involved, less so the posterior inferior cerebellar artery, the vertebral artery, or a vein. The frequent attacks of vertigo respond to carbamazepine or oxcarbazepine, even in low dosages (200–600 mg/d or 300–900 mg/d, respectively), which have been shown to also be effective in children. Alternative drugs to try are lamotrigine, phenytoin, gabapentin, topiramate or baclofen or other non-antiepileptic drugs used in trigeminal neuralgia. The results of ongoing randomized placebo-controlled treatment studies, however, are not yet available. Surgical microvascular decompression of the eighth nerve is the “ultima ratio” for medically intractable cases or in exceptional cases of non-vascular compression of the eighth nerve by a tumor or cyst. The International Barany Society for Neuro-Otology is currently working on a consensus document on the clinical criteria for establishing a diagnosis of VP as a clinical entity.