Microvascular decompression of cochleovestibular nerve

Microvascular decompression for intermediate nerve neuralgia: a case report and literature review

Intermediate nerve neuralgia (INN) is a rare craniofacial pain syndrome. The diagnosis of INN is challenging because of the complex ear sensory innervation that results in a clinical overlap with both trigeminal neuralgia (TN) and glossopharyngeal neuralgia (GPN). A 76-year-old woman with a remarkable medical history presented with right otalgia and mandibular pain for 7 years. Neurological examination revealed a diminished sensation in the distribution of the intermediate nerve (IN). Magnetic resonance imaging demonstrated an impression of the anterior inferior cerebellar artery (AICA) on the facial-vestibulocochlear nerve complex (VII/VIII complex). The patient underwent microvascular decompression (MVD) after long-term oral medication. We confirmed that the responsible vessel was close to the VII/VIII complex and isolated the vessel under the microscope via a right-sided suboccipital retrosigmoid approach. The patient's otalgia and mandibular pain disappeared after the operation. There were no additional neurological deficits. In conclusion, MVD is a safe and feasible option for patients with INN who fail to respond to adequate pharmacotherapy.

Application of ABR in pathogenic neurovascular compression of the 8th cranial nerve in vestibular paroxysmia

PURPOSE

To investigate the clinical value of electrophysiological tests in indicating pathogenic vascular contact of the 8th nerve in definite vestibular paroxysmia (VP) cases to provide a reference for decompression surgery.

METHODS

We retrospectively analyzed patients who had vertigo, unilateral tinnitus, or hearing loss and exhibited vascular contact of the 8th cranial nerve by MRI. Participants were classified into the VP or non-VP group according to the criteria of the Bárány Society in 2016. The demographic characteristics and audiological and electrophysiological test results of the two groups were compared. Receiver operating characteristic (ROC) curves were calculated for ABR to determine the best parameters and cutoff values to predict the existence of pathological neurovascular contact in VP.

RESULTS

Thirteen patients in the VP group and 66 patients in the non-VP group were included. VP patients had longer interpeak latency (IPL) I-III and wave III latency compared to non-VP patients (p < 0.001; p < 0.001). According to the ROC analyses, IPL I-III and wave III latency were the best indicators for the diagnosis of VP. The optimal cutoff for IPL I-III was 2.3 ms (sensitivity 84.6%, specificity 95.5%), and that for wave III latency was 4.0 ms (sensitivity 92.3%, specificity 77.3%). There were no differences in the PTA, caloric test, o-VEMP, or c-VEMP results between the two groups.

CONCLUSION

Prolonged IPL I-III and the wave III latency of ABR strongly suggested that vascular contact of the 8th cranial nerve was pathological, which may provide some references for microvascular decompression surgery of VP.

Microvascular compression of the vestibulocochlear nerve

PURPOSE

Vascular compression of cranial nerves has been widely accepted as a cause for trigeminal neuralgia and hemifacial spasm. In contrast, vascular compression of the vestibulocochlear nerve remains controversial.

METHOD

A comprehensive literature review including 175 articles between 1960 and 2020 was performed in an attempt to summarise the published hypotheses of the pathophysiological mechanisms of vascular compression of the vestibulocochlear nerve and their management strategies.

RESULTS

Vascular loops in the cerebellopontine angle (CPA) and internal auditory meatus (IAM) are very common and should be regarded primarily as a normal variant. Advances in anatomical understanding with the development of models for the tonotopy of the vestibulocochlear nerve help explain the complexity of symptoms created by possible neurovascular interaction.

CONCLUSION

Widely accepted, validated and sensitive diagnostic criteria and outcome measures need to be established in order to evaluate the role of surgery in vestibulocochlear nerve vascular compression.

Geniculate neuralgia in an adolescent treated via sectioning of the nervus intermedius and microvascular decompression

Geniculate neuralgia or nervus intermedius (NI) neuralgia is a rare condition characterized by intermittent, severe, stabbing deep ear pain. The pain can be triggered by stimulation of the external ear and is sometimes accompanied by facial pain. The condition is thought to result, in part, from vascular compression of the NI, although other etiologies exist. To date, fewer than 150 cases have been described in the English-language literature, and only 1 case of surgically treated geniculate neuralgia with microvascular decompression (MVD) of cranial nerves VIII, IX, and X has been described in a pediatric patient. Here, the authors present the case of an adolescent boy with bilateral geniculate neuralgia treated at two different time points with sectioning of the NI and MVD.

Clinical long-term observation of the keyhole microvascular decompression with local anesthesia on diagnosis and treatment of vestibular paroxysmia

Background: The pathophysiology and etiology of vestibular paroxysmia (VP) remains unclear, moreover, due to the lack of reliable diagnostic features for VP, the clinical diagnosis will be made mainly by exclusion.Aims/objectives: To evaluate the diagnostic value and curative effect of keyhole microvascular decompression with local anesthesia for VP.Material and methods: 54 patients with trigeminal neuralgia, hemifacial spasm and glossopharyngeal neuralgia underwent keyhole microvascular decompression with local anesthesia, twelve of whom were coexistent with VP. The evaluation of the vertigo after operation was performed with symptom report card for 12 patients with VP and the mean follow-up period was 116 months (range 114-118 months).Results: The cochleovestibular neurovascular compression at the root zone of vestibular nerve was found in 12 patients with VP, of whom 11 patients had the neurovascular compressive vertigo induced intra-operatively and the vertigo disappeared postoperatively, moreover, one patient had no neurovascular compressive vertigo induced intra-operatively and the vertigo was not improved significantly after operation. Of 12 patients with VP during the mean 116-month follow-up, 11 patients had no recurrence of neurovascular compressive vertigo and the effective control rate of vertigo was 91.7%.Conclusions and significance: Keyhole microvascular decompression with local anesthesia is not only an effective method for treating VP and controlling neurovascular compressive vertigo, but also has definite clinical significance in the diagnosis of VP.

The association between auditory nerve neurovascular conflict and sudden unilateral sensorineural hearing loss

HYPOTHESIS

There may be an association between a neurovascular conflict (NVC) of the auditory nerve and unilateral sudden sensorineural hearing loss (SSNHL).

BACKGROUND

Compression of cranial nerves by vascular structures can lead to significant symptomatology that may require surgical decompression. Notable examples are trigeminal neuralgia and hemifacial spasm. Magnetic resonance imaging (MRI) is part of the workup for SSNHL, and it may depict an NVC of the auditory nerve. Here we look into the association between this NVC and unilateral SSNHL.

METHODS

A retrospective analysis was performed on all consecutive patients with unilateral SSNHL who underwent an MRI scan in our medical center. The data collected included age, gender, side and severity of hearing loss, and accompanying complaints. Each MRI scan was reviewed by a neuroradiologist who was unaware of hearing loss laterality. The presence, side, extent, and location of a potential NVC involving the auditory nerve were determined, and a correlation between radiological findings and auditory parameters was sought.

RESULTS

Fifty-four patients (male-to-female ratio 26:28, age range 25-80 years) were enrolled into the study. Fourteen of them (25.9%) had normal MRI findings. Twenty-six patients had a unilateral NVC, and the pathology was ipsilateral to the side of hearing loss in only 12 of them (46.2%). Fourteen (25.9%) patients had MRI findings of bilateral NVCs. There was no significant correlation between the side of the SSNHL and any radiological findings (P = .314).

CONCLUSION

The data presented herein support the conclusion that there is no association between CN8 NVC and unilateral SSNHL.

LEVEL OF EVIDENCE

2b.

Vestibular paroxysmia: Diagnostic criteria

This paper describes the diagnostic criteria for vestibular paroxysmia (VP) as defined by the Classification Committee of the Bárány Society. The diagnosis of VP is mainly based on the patient history and requires: A) at least ten attacks of spontaneous spinning or non-spinning vertigo; B) duration less than 1 minute; C) stereotyped phenomenology in a particular patient; D) response to a treatment with carbamazepine/oxcarbazepine; and F) not better accounted for by another diagnosis. Probable VP is defined as follows: A) at least five attacks of spinning or non-spinning vertigo; B) duration less than 5 minutes; C) spontaneous occurrence or provoked by certain head-movements; D) stereotyped phenomenology in a particular patient; E) not better accounted for by another diagnosis.

Ephaptic discharges in the proximal part of the 8th cranial nerve, which is covered by oligodendrocytes, are the assumed mechanism. Important differential diagnoses are Menière’s disease, vestibular migraine, benign paroxysmal positional vertigo, epileptic vestibular aura, paroxysmal brainstem attacks (in multiple sclerosis or after brainstem stroke), superior canal dehiscence syndrome, perilymph fistula, transient ischemic attacks and panic attacks. Current areas of uncertainty in the diagnosis of VP are: a) MRI findings of vascular compression which are not diagnostic of the disease or predictive for the affected side because they are also observed in about 30% of healthy asymptomatic subjects; and b) response to treatment with carbamazepine/oxcarbazepine supports the diagnosis but there are so far no randomized controlled trials for treatment of VP.

Is Presence of Vascular Loop in Magnetic Resonance Imaging Always Related to Tinnitus?

INTRODUCTION

One of the most common otological complaints is tinnitus in adults. When there is a complaint of unilateral tinnitus and retrocochlear pathology is suspected, imaging methods are applied. However, the imaging findings obtained may not always be compatible with the severity and localization of the tinnitus.

AIM

The aim of the present study was to determine whether or not there was a significant correlation between the findings on magnetic resonance imaging (MRI) and the presence and severity of tinnitus in patients with the complaint of unilateral tinnitus.

METHOD

The study included 44 patients with no loss of hearing who presented with the complaint of unilateral tinnitus. The relationship between tinnitus severity and vascular loop presence was investigated.

RESULTS

Various types of vascular loop were determined in 14 patients. No statistically significant relationship was determined between the presence of vascular loop and the Tinnitus Handicap Inventory scores.

CONCLUSION

The results of this study showed no significant difference in respect of the presence of vascular loop on the MRI findings of symptomatic and healthy ears. The presence of vascular loop on MRI is not always a pathological event and should be considered only as an examination finding that could be an anatomic variation.

The Role of MRI in Diagnosing Neurovascular Compression of the Cochlear Nerve Resulting in Typewriter Tinnitus

BACKGROUND AND PURPOSE

Typewriter tinnitus, a symptom characterized by paroxysmal attacks of staccato sounds, has been thought to be caused by neurovascular compression of the cochlear nerve, but the correlation between radiologic evidence of neurovascular compression of the cochlear nerve and symptom presentation has not been thoroughly investigated. The purpose of this study was to examine whether radiologic evidence of neurovascular compression of the cochlear nerve is pathognomonic in typewriter tinnitus.

MATERIALS AND METHODS

Fifteen carbamazepine-responding patients with typewriter tinnitus and 8 control subjects were evaluated with a 3D T2-weighted volume isotropic turbo spin-echo acquisition sequence. Groups 1 (16 symptomatic sides), 2 (14 asymptomatic sides), and 3 (16 control sides) were compared with regard to the anatomic relation between the vascular loop and the internal auditory canal and the presence of neurovascular compression of the cochlear nerve with/without angulation/indentation.

RESULTS

The anatomic location of the vascular loop was not significantly different among the 3 groups (all, P > .05). Meanwhile, neurovascular compression of the cochlear nerve on MR imaging was significantly higher in group 1 than in group 3 (P = .032). However, considerable false-positive (no symptoms with neurovascular compression of the cochlear nerve on MR imaging) and false-negative (typewriter tinnitus without demonstrable neurovascular compression of the cochlear nerve) findings were also observed.

CONCLUSIONS

Neurovascular compression of the cochlear nerve was more frequently detected on the symptomatic side of patients with typewriter tinnitus compared with the asymptomatic side of these patients or on both sides of control subjects on MR imaging. However, considering false-positive and false-negative findings, meticulous history-taking and the response to the initial carbamazepine trial should be regarded as more reliable diagnostic clues than radiologic evidence of neurovascular compression of the cochlear nerve.

Microvascular decompression for tinnitus: systematic review

OBJECTIVE

The objective of this study was to examine operative outcomes in cases of microvascular decompression (MVD) of cranial nerve (CN) VIII for tinnitus through a critical review of the literature.

METHODS

Forty-three English-language articles were gathered from PubMed and analyzed. In this review, two different case types were distinguished: 1) tinnitus-only symptomatology, which was defined as a patient with tinnitus with or without sensorineural hearing loss; and 2) mixed symptomatology, which was defined as tinnitus with symptoms of other CN dysfunction. This review reports outcomes of those with tinnitus-only symptoms.

RESULTS

Forty-three tinnitus-only cases were found in the literature with a 60% positive outcome rate following MVD. Analysis revealed a 5-year cutoff of preoperative symptom duration before which a good outcome can be predicted with 78.6% sensitivity, and after which a poor outcome can be predicted with 80% specificity.

CONCLUSIONS

As the 60% success rate is more promising than several other therapeutic options open to the chronic tinnitus sufferer, future research into this field is warranted.

Microvascular decompression of the cochleovestibular nerve for treatment of tinnitus and vertigo: a systematic review and meta-analysis of individual patient data

OBJECTIVE Microvascular decompression (MVD) is regarded as a valid treatment modality in neurovascular conflicts (NVCs) causing, for example, trigeminal neuralgia and hemifacial spasms. An NVC of the cochleovestibular nerve might cause tinnitus and/or vertigo; however, general acceptance of MVD for this indication is lacking. The aim of this study was to investigate the effectiveness, safety, and prognostic factors for success of MVD of the cochleovestibular nerve. METHODS A systematic review and meta-analysis of individual patient data (IPD) were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Individual Patient Data (PRISMA-IPD) guidelines. By a comprehensive search (conducted in January 2016) in MEDLINE, EMBASE, and Google Scholar, eligible studies were identified. The collected outcome was a global measurement of improvement of 1) tinnitus, 2) vertigo, and 3) tinnitus combined with vertigo. For the meta-analysis, IPD were collected from the papers and/or from the authors. IPD were analyzed with logistic regression analysis while accounting for study clustering. RESULTS Thirty-five studies (572 patients) were included. The level of evidence provided by these studies was low. In 28% of patients with tinnitus and 32% of patients with vertigo, complete relief following MVD was reported. Patients with both tinnitus and vertigo had complete relief in 62% of cases. In 11% of patients, ≥ 1 complications were reported. Meta-analysis of IPD (165 patients) demonstrated that patients with both tinnitus and vertigo had a higher chance of success (OR 3.8, 95% CI 1.45-10.10) than patients with tinnitus alone. No other variables were significantly related to success. CONCLUSIONS Due to low success rates, MVD cannot be considered as a standard treatment method for tinnitus or vertigo. Moreover, a substantial complication rate was found. However, patients with combined symptoms had a higher chance of success. When combined symptoms occur, it is more likely that an NVC is the underlying pathology and MVD might be appropriate. Due to the low level of evidence in the included studies, this conclusion must be taken with caution. Further validation is necessary to evaluate whether patients with combined symptoms are indeed better candidates for MVD.

Cochleovestibular Nerve Compression Syndrome Caused by Intrameatal Anterior Inferior Cerebellar Artery Loop: Synthesis of Best Evidence for Clinical Decisions

INTRODUCTION

Intrameatal cochleovestibular neurovascular conflict is a rare condition with specific clinical and therapeutic implications. Although surgery is commonly indicated in other neurovascular conflicts, for this subset of patients there is little evidence to guide treatment decisions. Moving from a case description, we performed a review of the literature on this topic to systematically present the best available evidence to guide clinical decisions.

METHODS

We performed a literature review on reported cases of surgically treated intrameatal anterior inferior cerebellar artery (AICA)-cochleovestibular nerve neurovascular conflict, analyzing preoperative clinical data, surgical techniques, and outcomes. We analyzed the levels of evidence using the King's College guidelines.

DISCUSSION

We found 35 studies of neurovascular compression of the cochleovestibular nerve by AICA for 536 patients operated on to resolve their neurovascular conflict. Only 4 of these studies describe intrameatal AICA neurovascular conflicts, for 9 cases, including our own. Tinnitus was the most frequent symptom (9/9), followed by vertigo (2/9). Our case was the only one showing unilateral hearing loss. Surgery consisted of microsurgical mobilization of the AICA loop performed through a retrosigmoid craniotomy. Tinnitus and vertigo resolved after surgery in all cases, whereas hearing loss did not improve after surgery.

CONCLUSIONS

Surgical treatment offers the best results for tinnitus and vertigo, but it seems to have no effect on hearing loss, not even at long-term follow-up. Microvascular decompression should be proposed to intrameatal symptomatic patients before the onset of hearing loss.

Therapy of Vestibular Paroxysmia, Superior Oblique Myokymia, and Ocular Neuromyotonia

OPINION STATEMENT

Neurovascular compression syndromes are characterized by recurrent attacks of neurological symptoms and clinical signs depending on the cranial nerve affected. It is assumed that pulsatile compression of the nerve is caused mainly by an artery. The result is segmental demyelination of the transition zone or the central part of the cranial nerve, which is covered by oligodendrocytes, and subsequent ephaptic axonal transmission. Compression of the vestibular nerve can cause attacks of spinning or non-spinning vertigo: vestibular paroxysmia. Compression of the trochlear nerve is characterized by attacks of monocular oscillopsia: superior oblique myokymia. Damage to ocular motor nerves due to local radiation or rarely neurovascular compression can also lead to oscillopsia and double vision precipitated by sustained excentric gaze: ocular neuromyotonia. It is important to note that controlled trials have so far not been performed for any of these three syndromes, mainly because of their low prevalence. Therefore, treatment recommendations are based on single cases or small case series and thus have the lowest level of evidence. The sodium channel blockers carbamazepine (50 to 200 mg tid) or oxcarbazepine (100 to 300 mg tid) are evidently effective in most of the patients who have these three syndromes. However, one should always keep in mind the contraindications, side effects, and interactions with other drugs of carbamazepine ( http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682237.html ) All patients require regular laboratory examinations. Alternatives are other sodium channel blockers such as phenytoin (100 to 300 mg tid), gabapentin (100 to 600 mg tid), or valproic acid (100 to 300 mg tid). Furthermore, there are also few reports on the effects of beta blockers, which may be explained by their reduction of the amplitude of blood pressure. Patients who do not respond to pharmacotherapy require further diagnostics to determine the possibility of other etiologies. Some of these patients benefit from surgical decompression of the affected nerve.

Surgery for vertigo: 10-year audit from a contemporary vertigo clinic

OBJECTIVE

To present the profile of patients undergoing surgical treatment for vertigo at a contemporary institutional vertigo clinic.

STUDY DESIGN

A retrospective analysis of clinical charts.

METHODS

The charts of 1060 patients, referred to an institutional vertigo clinic from January 2003 to December 2012, were studied. The clinical profile and long-term outcomes of patients who underwent surgery were analysed.

RESULTS

Of 1060 patients, 12 (1.13 per cent) were managed surgically. Of these, disease-modifying surgical procedures included perilymphatic fistula repair (n = 7) and microvascular decompression of the vestibular nerve (n = 1). Labyrinth destructive procedures included transmastoid labyrinthectomy (n = 2) and labyrinthectomy with vestibular nerve section (n = 1). One patient with vestibular schwannoma underwent both a disease-modifying and destructive procedure (translabyrinthine excision). All patients achieved excellent vertigo control, classified as per the American Academy of Otolaryngology - Head and Neck Surgery 1995 criteria.

CONCLUSION

With the advent of intratympanic treatments, surgical treatments for vertigo have become further limited. However, surgery with directed intent, in select patients, can give excellent results.

Effects of microvascular decompression surgery on posture control: A case report in an elderly patient

AIMS OF THE STUDY

We report the case of an 84-year-old woman with neurovascular conflict of the left cochleovestibular nerve. Prior to surgery, the patient complained of positional vertigo and dizziness for the past two years, and marked instability. Hearing loss and tinnitus were reported on the left side. The aim of this study was to investigate the effects of microvascular decompression of the cochleovestibular nerve on posture control.

MATERIALS AND METHODS

Evaluation of cochleovestibular function and posture control was performed before and after surgery. Postural performance was analyzed in static and dynamic conditions, with and without vision, and with optokinetic stimulation. Perception of the static visual vertical (SVV) was recorded in darkness.

RESULTS

Positional vertigo and tinnitus disappeared immediately after the decompression. The SVV remained unchanged one week after the surgery. Speech intelligibility of the left ear was improved (30 dB), and the vestibular deficit on this side was also significantly reduced (54% versus 18%). However, the more spectacular result was the effect on postural control. This elderly patient improved her postural balance in both static and dynamic conditions, and became able to maintain her equilibrium in the more challenging dynamic conditions, with and without vision, as early as one week after the surgery, a postural performance that she had been unable to do preoperatively.

CONCLUSION

This work is the first to show that the postural deficits resulting from neurovascular conflict of the cochleovestibular nerve are strongly improved after microvascular decompression.

Evaluation of internal auditory canal structures in tinnitus of unknown origin

Objectives

The aim of the present study was to evaluate the internal auditory canal (IAC) and the nerves inside it to define possible structural differences in cases with subjective tinnitus of unknown origin.

Methods

Cases applying to the ear, nose and throat department with the complaint of tinnitus with unknown origin and having normal physical examination and test results were included in the study (n=78). Patients admitted to the radiology clinic for routine cranial magnetic resonance imaging (MRI) and whose MRI findings revealed no pathologies were enrolled as the control group (n=79). Data for the control group were obtained from the radiology department and informed consent was obtained from all the patients. Diameters of the IAC and the nerves inside it were measured through enhanced images obtained by routine temporal bone MRIs in all cases. Statistical evaluations were performed using Student t-test and statistical significance was defined as P<0.05.

Results

Measurements of IAC diameters revealed statistically significant differences between the controls and the tinnitus group (P<0.05). Regarding the diameters of the cochlear nerve, facial nerve, inferior vestibular nerve, superior vestibular nerve, and total vestibular nerve, no statistically significant difference was found between the controls and the tinnitus group.

Conclusion

Narrowed IAC has to be assessed as an etiological factor in cases with subjective tinnitus of unknown origin.

Geniculate neuralgia: a systematic review

OBJECTIVE

To systematically summarise the peer-reviewed literature relating to the aetiology, clinical presentation, investigation and treatment of geniculate neuralgia.

DATA SOURCES

Articles published in English between 1932 and 2012, identified using Medline, Embase and Cochrane databases.

METHODS

The search terms 'geniculate neuralgia', 'nervus intermedius neuralgia', 'facial pain', 'otalgia' and 'neuralgia' were used to identify relevant papers.

RESULTS

Fewer than 150 reported cases were published in English between 1932 and 2012. The aetiology of the condition remains unknown, and clinical presentation varies. Non-neuralgic causes of otalgia should always be excluded by a thorough clinical examination, audiological assessment and radiological investigations before making a diagnosis of geniculate neuralgia. Conservative medical treatment is always the first-line therapy. Surgical treatment should be offered if medical treatment fails. The two commonest surgical options are transection of the nervus intermedius, and microvascular decompression of the nerve at the nerve root entry zone of the brainstem. However, extracranial intratemporal division of the cutaneous branches of the facial nerve may offer a safer and similarly effective treatment.

CONCLUSION

The response to medical treatment for this condition varies between individuals. The long-term outcomes of surgery remain unknown because of limited data.

Assessment of non-motor hearing symptoms in hemifacial spasm using magnetoencephalography

BACKGROUND

Hemifacial spasm patients often suffer from non-motor symptoms such as tinnitus. These non-motor symptoms are known to be associated with changes in cortical activity. Magnetoencephalography (MEG) is a technique that can record brain activity noninvasively. To determine the usefulness of MEG in assessing changes in cortical activity associated with non-motor hearing symptoms in hemifacial spasm patients.

METHODS

We used MEG to evaluate the reactivity of the auditory cortex in 26 hemifacial spasm patients. We divided patients into a subjective tinnitus group (n = 10) and a non-tinnitus group (n = 16). The latency and amplitude of the most prominent deflection, N100m, was compared between the two groups.

RESULTS

There was a significant difference in the pure tone audiogram on the spasm side compared with the non-spasm side. After stimulation on the spasm side, the amplitude of the N100m peak in the contralateral hemisphere was lower in the subjective tinnitus group than in the non-tinnitus group.

CONCLUSIONS

Our results indicate that MEG can detect differences in cortical activity between hemifacial spasm patients with and without tinnitus. This suggests that MEG can identify changes in cortical activity associated with non-motor symptoms.

[Adjunctive use of endoscopy during microvascular decompression in the cerebellopontine angle: 27 case reports]

Microvascular decompression is an important procedure for the management of microvascular compression syndromes in the cerebellopontine angle (CPA) like trigeminal neuralgia or hemifacial spasm. The ability to identify the offending vessel is the key to success. Can the endoscope help surgeons to identify and understand the responsible conflict in order to treat them? Our series concerns 27 consecutive patients who underwent microvascular decompression systematically using an endoscope with an angulation of 30° at the beginning and the end of the intervention. The decompression procedure was done under microscope. Endoscopic exploration was successful for all patients. Endoscopy improved visualization of the cranial nerves and allowed to see and understand the neurovascular conflicts, which were not able to be observed using the microscope alone for two of the 27 patients. The endoscope is a useful adjunct to microscopic exploration of the cranial nerves in the CPA avoiding significant cerebellar or brainstem retraction.

Microvascular decompression may be an effective treatment for nervus intermedius neuralgia

Objective:

To report microvascular decompression as a possible effective treatment for patients with nervus intermedius neuralgia, and to contribute to the literature regarding both this syndrome and this specific form of treatment.

Method:

Case report of a patient with intermedius neuralgia. The main complaint was severe otalgia in the area innervated by the nervus intermedius, possibly caused by neurovascular compression of the nervus intermedius by the anterior inferior cerebellar artery. Microvascular decompression was undertaken, with good results.

Results:

Post-operatively, the patient felt immediate and total relief of her otalgia, with normal facial nerve function and no otological morbidity. One year post-operatively, she was still free from otalgia.

Conclusion:

Patients with nervus intermedius neuralgia who do not respond to medical treatment may benefit from microvascular decompression.

Incidental findings on MRI scans of patients presenting with audiovestibular symptoms

Background

The evaluation of patients presenting with audiovestibular symptoms usually includes MRI of the internal auditory meatus, the cerebellopontine angle and the brain. A significant percentage of these scans will present unexpected, incidental findings, which could have important clinical significance.

Objective

To determine the frequency and clinical significance of incidental findings on MRI scans of patients with audiovestibular symptoms.

Materials and methods

A retrospective analysis of 200 serial MRI scans.

Results

Gender distribution: equal. Age range: 17-82 years. One-hundred and four scans (52%) were normal and 1 scan (0.5%) demonstrated a unilateral vestibular schwannoma. Ninety-five scans (47.5%) demonstrated incidental findings. Sixty-six of these (33%) were considered of ishaemic origin and did not require further action. Five (2.5%) scans demonstrated significant findings which warranted appropriate referral; Two Gliomas (1%), 2 cases of extensive White Matter Lesions (1%), 1 lipoma (0.5%). The remaining scans demonstrated various other findings.

Conclusion

Investigation of patients with audiovestibular symptoms with MRI scans revealed incidental findings in a significant percentage (47.5%). The majority of these findings were benign warranting no further action and only 2.5% required further referral. It is the responsibility of the referring Otolaryngologist to be aware of these findings, to be able to assess their significance, to inform the patient and if needed to refer for further evaluation.