Cerebellopontine Angle Tumors Research Articles

Full Recovery of Hearing After Resection of a Large Epidermoid Tumor at the Cerebellopontine Angle: 2-Dimensional Operative Video.

Epidermoid tumors are benign, slow-growing lesions, originating from misplaced ectodermal cells that become trapped during neural tube closure.1 The cerebellopontine angle (CPA) is the most common intracranial location for epidermoid tumors, accounting for approximately 60% of cases.2 Treatment of epidermoid tumors consists of surgical resection, with the goal of gross total resection.3 Here, we describe the case of a patient with a large epidermoid tumor at the CPA causing near-complete hearing loss, who remarkably experienced full recovery of hearing after resection of the tumor. The patient is a 37-year-old woman who presented to our clinic with a CPA tumor causing severe hearing loss consisting of class D hearing and a word recognition score of 5% on audiological examination. Radiographically, the tumor demonstrated significant mass effect on the right cranial nerves VII and VIII with prominent extension into the internal auditory canal. Given the patient's profound hearing loss, she consented to receive a right retrosigmoid craniotomy for resection of the lesion. Although cranial nerves VII and VIII were heavily invested in the tumor, we were able to systematically resect the lesion from the CPA and internal auditory canal, and achieve a gross total resection. Histological examination confirmed the diagnosis of an epidermoid tumor. Remarkably, the patient's audiogram at 3-month follow-up demonstrated complete recovery of hearing in her right ear with a word recognition score of 100% and normal hearing sensitivity across all tested frequencies.

Utility and Prognostic Value of Intraoperative Blink Reflex in Trigeminal or Facial Nerve Monitoring in Skull Base Surgeries: A Systematic Review

Blink reflex (BR) is an oligosynaptic reflex that involves the ophthalmic branch of the trigeminal nerve (TN), ipsilateral main sensory and trigeminospinal nuclei, bilateral facial nuclei, and the facial nerves (FN). Theoretically, as it tests the function of both TN and FN simultaneously, it is an ideal tool for monitoring the status of TN and FN during skull base surgeries. Nevertheless, it is only recently utilized in surgeries as the use of anesthesia limits its use. Two authors inputted the search terms: [(Blink Reflex) AND (Intraoperative Neuromonitoring OR Neuro Intraoperative Monitoring OR Intraoperative OR NIOM OR IONM) AND (skull base surgery OR Facial Nerve OR Trigeminal Nerve OR Microvascular Decompression OR Hemifacial Spasm)] in Medline through its Pubmed interface and other search engines. Papers that fulfilled the inclusion and exclusion criteria were obtained and scrutinized. Only 7 observational papers with a total of 437 participants were included in the current systematic review. All studies (n=5) involving the use of BR in FN surgery noted that IOBR is beneficial, safe, sensitive, specific, and predictive of outcomes while all 2 papers involving trigeminal neuralgia patients recommended BR's use in microvascular decompression (MVD) of TN. IOBR is a sensitive, specific and safe monitoring technique that has good predictability of facial paresis and paresthesia among patients undergoing MVD for trigeminal neuralgia and primary hemifacial spasm and those who are for cerebellopontine angle tumor resection.

Predictive value of Blink reflex and facial corticobulbar motor evoked potential in cerebellopontine angle tumor surgery

ObjectiveThe current study examined the efficacy of the facial corticobulbar motor evoked potentials (FCoMEPs) and blink reflex (BR) on predicting postoperative facial nerve function during cerebellopontine angle (CPA) tumor surgery. MethodsData from 110 patients who underwent CPA tumor resection with intraoperative FCoMEPs and BR monitoring were retrospectively reviewed. The association between the amplitude reduction ratios of FCoMEPs and BR at the end of surgery and postoperative facial nerve function was determined. Subsequently, the optimal threshold of FCoMEPs and BR for predicting postoperative facial nerve dysfunction were determined by receiver operating characteristic curve analysis. ResultsValid BR was record in 103 of 110 patients, whereas only 43 patients successfully recorded FCoMEP in orbicularis oculi muscle. A reduction over 50.3% in FCoMEP (O. oris) amplitude was identified as a predictor of postoperative facial nerve dysfunction (sensitivity, 77.1%; specificity, 83.6%). BR was another independent predictor of postoperative facial nerve deficit with excellent predictive performance, especially eyelid closure function. Its optimal cut-off value for predicting long-term postoperative eyelid closure dysfunction was was 51.0% (sensitivity, 94.4%; specificity, 94.4%). ConclusionsBR can compensate for the deficiencies of the FCoMEPs. The combination of BR and FCoMEPs can be used in CPA tumor surgery. SignificanceThe study first proposed an optimal cut-off value of BR amplitude deterioration (50.0%) for predicting postoperative eyelid closure deficits in patients undergoing CPA tumor surgery.

Outcomes of Trigeminal Ganglion Sparing Surgical Resection of Nonacoustic Cerebellopontine Angle Tumors Causing Trigeminal Neuralgia

ObjectiveTumors may be responsible for up to 5% of trigeminal neuralgia (TN) cases. Predictors of long-term pain relief after surgical resection of various cerebellopontine angle (CPA) tumor types are not well understood. Previous studies found that size and extent of resection predict long-term pain status, although resection of tumor involving the trigeminal ganglion (TG) may be associated with high morbidity. This study evaluated predictors of TN pain freedom after resection of a non-acoustic CPA tumor, with avoidance of any portion involving the TG. MethodsIn a retrospective cohort study, we evaluated clinical outcomes and complications after surgical resection of non-acoustic CPA tumors with purposeful avoidance of the TG causing trigeminal neuralgia. The primary outcome was pain-freedom. We performed logistic regression analyses to examine the relationship between pain-freedom at last follow-up and age, side of symptoms, pre-operative symptom duration, tumor diameter, tumor type, and concurrent neurovascular compression (NVC). ResultsOf 18 patients with non-acoustic CPA tumors causing TN treated with surgical resection, 83.3% were pain-free at last follow-up (mean 44.6 months). Age(p=0.12), side (p=0.41), pre-operative symptom duration(p=0.85), tumor diameter(p=0.29), tumor type(p=0.37), and NVC presence (p=0.075) were not associated with long-term pain freedom. ConclusionsThis study provides additional evidence that various tumor types causing trigeminal neuralgia may safely undergo surgical resection and decompression of the trigeminal nerve to treat TN. This study presents a cohort of patients that underwent resection of a non-acoustic CPA tumor, with purposeful avoidance of the TG to minimize complications, demonstrating high rates of long-term pain freedom.

Tumor shape as a prognostic factor for the growth of intracanalicular vestibular schwannoma: a long-term observational study.

To evaluate the predictive factors of tumor growth in patients with vestibular schwannoma (VS) managed with the wait-and-scan approach. The data of 31 patients diagnosed with intracanalicular VS and followed for > 5years were retrospectively analyzed. VS was diagnosed according to MRI findings and tumor growth was monitored. Tumor growth was defined as an increase of 2mm or more in the maximal tumor diameter. The association between the initial tumor size and shape and tumor growth was assessed. Tumor growth was observed in 16 of 31 patients (51.6%) over a mean follow-up duration of 7.3years. The initial tumor size was not statistically correlated with tumor growth. However, fusiform or cylindrical tumors exhibited higher growth rates than oval or round tumors. Additionally, a significant correlation was observed between cerebellopontine angle extension and tumor shape. In this study, 51.6% of the patients with intracanalicular VS who were managed with the wait-and-scan strategy over a follow-up period of > 5years showed tumor growth. Tumor shape, especially fusiform or cylindrical shape, was found to be a significant predictor of tumor growth.

Effect of deep learning-based reconstruction on high-resolution three-dimensional T2-weighted fast asymmetric spin-echo imaging in the preoperative evaluation of cerebellopontine angle tumors.

We aimed to evaluate the effect of deep learning-based reconstruction (DLR) on high-spatial-resolution three-dimensional T2-weighted fast asymmetric spin-echo (HR-3D T2-FASE) imaging in the preoperative evaluation of cerebellopontine angle (CPA) tumors. This study included 13 consecutive patients who underwent preoperative HR-3D T2-FASE imaging using a 3T MRI scanner. The reconstruction voxel size of HR-3D T2-FASE imaging was 0.23 × 0.23 × 0.5mm. The contrast-to-noise ratios (CNRs) of the structures were compared between HR-3D T2-FASE images with and without DLR. The observers' preferences based on four categories on the tumor side on HR-3D T2-FASE images were evaluated. The facial nerve in relation to the tumor on HR-3D T2-FASE images was assessed with reference to intraoperative findings. The mean CNR between the tumor and trigeminal nerve and between the cerebrospinal fluid and trigeminal nerve was significantly higher for DLR images than non-DLR-based images (14.3 ± 8.9 vs. 12.0 ± 7.6, and 66.4 ± 12.0 vs. 53.9 ± 8.5, P < 0.001, respectively). The observer's preference for the depiction and delineation of the tumor, cranial nerves, vessels, and location relation on DLR HR-3D T2FASE images was superior to that on non-DLR HR-3D T2FASE images in 7 (54%), 6 (46%), 6 (46%), and 6 (46%) of 13 cases, respectively. The facial nerves around the tumor on HR-3D T2-FASE images were visualized accurately in five (38%) cases with DLR and in four (31%) without DLR. DLR HR-3D T2-FASE imaging is useful for the preoperative assessment of CPA tumors.

Case report: Cystic vestibular schwannoma

Background: Cerebellopontine angle tumors are a severe condition because of their life-threatening and functional loss potential, explained by the narrowness of the posterior fossa. The vestibular schwannoma, or acoustic neuroma, is a benign, well-circumscribed extraaxial tumor that arises from Schwann cells of the vestibulocochlear cranial nerve. The tumor is usually mainly solid, but can sometimes develop small cystic areas, due to degenerative modifications, causing microcyst formation. The coalescent of small cysts leading to forming a larger one, and responsible of a predominant cystic contingent, is rare, which makes interesting the case we are about to present. Case report: We are about to report the case of a 64-year-old male patient, with no particular medical history, which clinical interview has noted only tinnitus as a present symptom. He had experienced one year ago several disequilibrium and dizziness episodes, who have subsequently stopped over time, without any particular treatment. He also felt a little loss of hearing, especially in the left ear, but thought it was probably age related. No clinical abnormality including the facial nerve palsy was found. The MRI showed a stage 4 (Koos classification) left cystic vestibular schwannoma. This lesion was compressing the left vertebral and basilar arteries, the brain stream, the left cerebellar hemisphere, the left middle cerebellar peduncle, and the fourth ventricle, causing a triventricular hydrocephalus. After reviewing all potential therapeutic options, the patient declined surgery and decided to postpone the treatment. Conclusion: MRI is definitely the best way to explore the posterior fossa, especially the cerebellopontine angle, and helps us differentiate between all numerous tumors than can develop in this space.

Salvage Microsurgery Following Failed Primary Radiosurgery in Sporadic Vestibular Schwannoma

Management of sporadic vestibular schwannoma with radiosurgery is becoming increasingly common globally; however, limited data currently characterize patient outcomes in the setting of microsurgical salvage for radiosurgical failure. To describe the clinical outcomes of salvage microsurgery following failed primary stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) among patients with sporadic vestibular schwannoma. This was a cohort study of adults (≥18 years old) with sporadic vestibular schwannoma who underwent salvage microsurgery following failed primary SRS/FSRT in 7 vestibular schwannoma treatment centers across the US and Norway. Data collection was performed between July 2022 and January 2023, with data analysis performed between January and July 2023. Salvage microsurgical tumor resection. Composite outcome of undergoing less than gross total resection (GTR) or experiencing long-term facial paresis. Among 126 patients, the median (IQR) age at time of salvage microsurgery was 62 (53-70) years, 69 (55%) were female, and 113 of 117 (97%) had tumors that extended into the cerebellopontine angle at time of salvage. Of 125 patients, 96 (76%) underwent primary gamma knife SRS, while 24 (19%) underwent linear accelerator-based SRS; the remaining patients underwent FSRT using other modalities. Postoperative cerebrospinal fluid leak was seen in 15 of 126 patients (12%), hydrocephalus in 8 (6%), symptomatic stroke in 7 (6%), and meningitis in 2 (2%). Each 1-mm increase in cerebellopontine angle tumor size was associated with a 13% increased likelihood of foregoing GTR (64 of 102 patients [63%]) or long-term postoperative House-Brackmann grade higher than I (48 of 102 patients [47%]) (odds ratio, 1.13; 95% CI, 1.04-1.23). Following salvage microsurgery, tumor growth-free survival rates at 1, 3, and 5 years were 97% (95% CI, 94%-100%), 93% (95% CI, 87%-99%), and 91% (95% CI, 84%-98%), respectively. In this cohort study, more than half of patients who received salvage microsurgery following primary SRS/FSRT underwent less than GTR or experienced some degree of facial paresis long term. These data suggest that the cumulative risk of developing facial paresis following primary SRS/FSRT by the end of the patient's journey with treatment approximates 2.5% to 7.5% when using published primary SRS/FSRT long-term tumor control rates.

Fully neuroendoscopic resection of cerebellopontine angle tumors through a retrosigmoid approach: a retrospective single-center study

Fully neuroendoscopic resection of cerebellopontine angle tumors through a retrosigmoid approach: a retrospective single-center study

Cerebellopontine angle tumor presenting as acute audiovestibular syndrome

Background Acute audiovestibular deficits may be a harbinger of vestibular schwannoma (VS). Objective To investigate clinical and laboratory features of 25 consecutive patients with VS presenting with acute audiovestibular deficits. Methods A symptomatic combination of acute audiovestibular deficits was investigated. Audiometric and vestibular function tests, and internal auditory canal magnetic resonance imaging (IAC MRI) results were evaluated. Results Varying combinations of symptoms may develop in VS patients with acute audiovestibular deficits, of whom sudden hearing loss (HL) without acute vertigo or acute facial nerve palsy (FNP) was most common. The most common audiometric configuration was high-tone hearing loss, and no patient showed low-tone hearing loss. IAC MRI demonstrated that the tumor had an intracanalicular portion and attachment to the bony IAC wall in all patients and widened the IAC wall in some patients. Conclusion Different symptomatic combinations of acute audiovestibular deficits may develop in patients with VS. Awareness about the possibility of VS as a cause of sudden HL, acute vertigo, and acute FNP, as well as subsequent IAC MRI scanning is vital to earlier diagnosis of VS in these patients.

A Surprise Diagnosis from a Unilateral Hearing Loss and Vertigo Case from Cerebellopontine Angle Tumor

Cerebellar pontine angle meningioma is rare in ophthalmic practices because it has a variety of nonspecific symptoms that can be misleading...

A SURPRISE DIAGNOSIS FROM A UNILATERAL HEARING LOSS AND VERTIGO CASE FROM CEREBELLOPONTINE ANGLE TUMOR

Meningiomas are generally benign intracranial tumors that arise from the dural coverings of the brain. They represent approximately one-third of all primary intracranial tumors and about 10-15% of cerebellopontine angle (CPA) tumors. Meningiomas develop from arachnoid cells and have been previously observed to be slow-growing. Despite their benign classification, these tumors can impact cranial nerves leading to a myriad of symptoms including hearing loss, imbalance or vertigo, tinnitus, and diminished facial sensation. Technology such as computerized tomography (CT) and magnetic resonance imaging (MRI) are vital tools in the definitive diagnosis of CPA meningiomas.

MRI evaluation of trigeminal neuralgia patients in a rural hospital of central India

Background Trigeminal neuralgia is characterized by repetitive paroxysmal electric shock-like pain in the trigeminal nerve distribution. The most common cause implicated in this condition is neurovascular conflict, primarily by the superior cerebellar artery in the prepontine cistern. Other common causes include cerebellopontine angle tumours and aneurysms at the brainstem level. Magnetic resonance imaging (MRI) is the imaging modality of choice in evaluating trigeminal neuralgia, with 3D-FIESTA (Fast Imaging employing steady-state acquisition) being the mainstay for assessing neurovascular conflict. This study’s objective is to assess the role of MRI in evaluating trigeminal neuralgia and to study the spectrum of MRI findings associated with various causes. Methods The study type is a cross-sectional observational prospective study conducted at Acharya Vinoba Bhave Rural Hospital, Sawangi, on 41 patients coming to the Radiology department with clinical suspicion of trigeminal neuralgia. Descriptive statistics will summarize participants’ imaging characteristics. At the same time, comparison tests will be employed to assess the association between imaging features and diagnosis of MRI with the distribution of patient symptoms, laterality, aetiology, artery, and branch of trigeminal nerve involved. Considering ethical concerns, participants’ privacy will be protected, and all data will be handled with the utmost confidentiality.

The role of artificial intelligence in the management of trigeminal neuralgia.

Trigeminal neuralgia (TN) is the most frequent facial pain. It is difficult to treat pharmacologically and a significant amount of patients can become drug-resistant requiring surgical intervention. From an etiologically point of view TN can be distinguished in a classic form, usually due to a neurovascular conflict, a secondary form (for example related to multiple sclerosis or a cerebello-pontine angle tumor) and an idiopathic form in which no anatomical cause is identifiable. Despite numerous efforts to treat TN, many patients experience recurrence after multiple operations. This fact reflects our incomplete understanding of TN pathogenesis. Artificial intelligence (AI) uses computer technology to develop systems for extension of human intelligence. In the last few years, it has been a widespread of AI in different areas of medicine to implement diagnostic accuracy, treatment selection and even drug production. The aim of this mini-review is to provide an up to date of the state-of-art of AI applications in TN diagnosis and management.

70 Visual Attention and Emotion Recognition Deficits in Patients with Cerebellar Tumors

Objective:Social cognition refers to processing, analyzing and understanding information about emotions and social situations. Many studies indicate a frequent deficit of these functions in people with tumors of the cerebellum. Visual search is an important attention process prior to information processing. It also mediates the relationship between cognitive function (attention) and social cognition. There are numerous data showing that disorders of various aspects of attention are fairly common in patients with tumors of the cerebellum. The question arises whether there is any relationship between these functions. The purpose of this study was to find out if there is a relationship between visual search performance and the ability to recognize emotions.Participants and Methods:The study included 19 patients with the cerebello-pontine angle (CPA) tumors (mean age = 38.84, SD = 14.27; 10 women and 9 men) and 19 healthy controls (mean age 38.26, SD = 10.40; 10 women and 9 men). The research group consisted of patients from the Department of Neurosurgery, UCK Medical University of Warsaw, the control group was healthy. The groups did not differ demographically. At the beginning, the respondents completed a questionnaire in which they were asked about demographic data and health status. Then, a series of 40 boards presenting the letters T in two colors, blue and orange, scattered in different planes was presented. The letters were right or upside down. The test person’s task was to find and click the correctly positioned orange T letter as quickly as possible. Then, a series of 56 photos of faces representing seven different emotions was presented (happiness, anger, sadness, surprise, disgust, fear and a neutral face). The test person’s task was to decide which of the emotions mentioned under the photo were presented by the presented face.Results:The results indicated that patients with tumors in the CPA area had a longer mean reaction time and lower accuracy when performing visual searches than subjects from the control group. Likewise, there were longer times and lower accuracy in the emotional recognition task. Moreover, in the group of patients with CPA tumor, the response time during visual search was negatively associated with the correctness of the response in visual search (p = -0.57, p &lt;0.05). There were also negative correlations between the reaction time and the correctness of recognizing particular emotional states: anger (p = -0.48, p &lt;0.05), disgust (p = -0.62, p &lt;0.01) and neutral (p = -0.64, p &lt;0.01). The correctness of answers in visual search correlated positively with the accuracy of emotion recognition (p = 0.72, p &lt;0.01). None of the above-mentioned relationships were found in the control group.Conclusions:The obtained results indicate a relationship between the quality of visual attention and the ability to recognize emotions in people with cerebellar lesions. In order to better understand this phenomenon, it is necessary to continue research in this field.

A retrospective study of cerebellopontine angle tumours: A single instituitional study

: Cerebellopontine angle (CPA) tumors are rare intracranial neoplasms that arise in the region between the cerebellum and the pons. These tumors can be challenging to treat due to their complex anatomy and proximity to critical neurovascular structures. Surgical intervention is often necessary to achieve a favorable outcome. The primary objectives of this retrospective study are to analyze the clinical and radiological characteristics of cerebellopontine angle tumors, identify pathological types, assess surgical resectability, and evaluate postoperative outcomes.: The study enrolled 14 patients who underwent surgical intervention for cerebellopontine angle tumors at Armed forces medical college, Pune. A retrospective analysis was performed, considering demographic data, clinical presentations, imaging characteristics and surgical outcomes.: Vestibular schwannoma was the predominant tumor type with majority of tumors manifesting between third to fifth decades. Clinical manifestation included SNHL, cerebellar dysfunction, headache and sensory trigeminal dysfunction. A substantial proportion (86%) presented with no useful hearing preoperatively. Surgical outcomes indicated varying degrees of success, with total resection achieved in a subset of cases. Notably, anatomical preservation of the facial nerve was accomplished in a significant proportion of patients. Postoperative assessments, using the House Brackmann system, revealed positive facial nerve function outcomes in a substantial percentage. Complications included cerebrospinal fluid leak (14%), meningitis(7%) and lower cranial nerve paresis (7%). : In conclusion, surgical intervention plays a crucial role in the management of cerebellopontine tumors. The choice of surgical approach should be individualized based on tumor characteristics and patient factors, with the goal of achieving maximum tumor resection while minimizing complications. Further research and advancements in surgical techniques are needed to optimize outcomes for patients with cerebellopontine tumors.

Nationwide clinico-epidemiological treatment analysis of adult patients with tumors of cerebellopontine angle and internal acoustic meatus in Poland during 2011–2020

ObjectiveThe aim of this study is to report the epidemiologic characteristics of tumors of the cerebellopontine angle (CPAT) and internal acoustic meatus in adult Polish population throughout the second decade of XXI century and to analyze their treatment.Material and methodsA retrospective analysis of patients with cerebellopontine angle (CPA) and internal acoustic meatus tumors diagnosed in Poland in 2011–2020 was performed. Data recorded in the National Health Fund (NHF) database were analyzed. International Classification of Diseases codes (ICD-9 and ICD-10) were used to identify study group patients and treatment procedures.ResultsFrom 2011 to 2020 6,173 Polish adult patients were diagnosed with cerebellopontine angle and internal acoustic meatus tumors. The average incidence in Poland is 1.99 per 100,000 residents/year. It mostly affects women (61.64%), and the average age of patients is 53.78 years. The incidence has steadily increased over the past decade. Treatment has changed significantly over the years, with a definite increase in the number of patients treated with radiotherapy (from 0.54 to 19.34%), and a decrease in surgical therapies (from 41.67 to 6.8%). The most common symptoms were vertigo and/or dizziness (43.48%) and sensorineural hearing loss (39.58%). 4.65% of patients suffered from sudden deafness, in this group of patients the risk of CPAT detection was the highest (6.25 / 1000 patients).ConclusionsThe total incidence of CPAT and demographic characteristics of patients were comparable to other studies. Our study demonstrated the increased number of patients are being treated with radiotherapy and fewer with microsurgery. Sudden sensorineural hearing loss (SSNHL) is an uncommon manifestation of CPAT but proper diagnosis should be undertaken because the risk of diagnosis such tumors is greater in this group.

Surgical treatment for extremely rare solitary fibrous tumors of the central nervous system originating from cranial nerve VIII: new clinicopathological findings. Illustrative case.

Reports of solitary fibrous tumors (SFTs) of the central nervous system (CNS) originating from cranial nerves are extremely rare. The origins of these neurogenic SFTs of the CNS have been determined only by intraoperative findings, and there is no pathological evidence of whether they really originated from cranial nerves. A 54-year-old female with hearing loss and facial paralysis presented with a giant right cerebellopontine angle tumor. She was diagnosed with a petrous meningioma based on preoperative imaging, and the tumor was removed via the retrosigmoid approach after embolization of the tumor-feeding vessels. Intraoperatively, the tumor was not attached to the dura mater but extended from the internal auditory canal to the cisternal portion. The acoustic nerve was not identified, but it was possible to separate the tumor from the facial nerve. The tumor was removed as an acoustic schwannoma intraoperatively. Postoperative pathological examination revealed an SFT. Immunostaining revealed peripheral nerve bundles entrapped within the tumor tissue. The patient was diagnosed with an SFT of the CNS originating from the acoustic nerve. A neurogenic SFT of the CNS was diagnosed based on both intraoperative and pathological findings.

Trigeminal Neuralgia as An Atypical Manifestation of Intracranial Hypertension. Case Report and Literature Review

Trigeminal neuralgia, a chronic neuropathic pain, is characterized by frequent episodes of stabbing facial pain, in the territory of the trigeminal nerve, which can severely impair patient’s quality of life. It is primarily caused by vascular compression of the trigeminal nerve root, but it is sometimes secondary to other identifiable neurological conditions, such as multiple sclerosis or a cerebellopontine angle tumor. Uncommonly, it may be caused by the presence of idiopathic intracranial hypertension, a condition most likely identified by headache, visual disturbances, and sixth nerve palsy, among other manifestations. Secondary causes of trigeminal neuralgia are usually detected after an atypical clinical manifestation, such as ophthalmic rather than maxillary or mandibular nerve involvement, more than one branch affected, or bilateral symptoms. We present a patient who presented with trigeminal neuralgia as a primary manifestation, and after thorough evaluation she was diagnosed with intracranial hypertension as the underlying mechanism responsible of the trigeminal neuralgia.

Investigation of tissue perfusion of the brain in patients with large and giant tumors of the bridge-cerebellar angle

The article presents the results of the study of pons and cerebellar tissue perfusion in patients with large and giant cerebellopontine angle tumors. Perfusion computed tomography was performed in 10 patients with vestibular schwannomas and 8 patients with temporal bone meningiomas. The parameters of cerebral blood flow were calculated in 6 regions of interest in the area of the pons and the cerebellar hemispheres. There are manifestations of brain tissue hypoperfusion in the pons and hyperemia in the nearby parts of the cerebellar hemisphere. The revealed changes indicate the possibility of disorders of local cerebral blood flow after surgery.