MRI Differentiation Diagnosis of Occupying Lesions in Cerebellopontine Angle Area

Objective： To explore the value of magnetic resonance imaging （MRI） in diagnosis of occupying lesions in cerebellopontine angle area. Methods： MRI records of 78 patients with pathologically confirmed occupied lesions in cerebellopontine angle area were analyzed. Results： Of the 78 cases, 48 （61.5%） were unilateral acoustic neuroma, 5 （6.4%） were bilateral acoustic neuroma, 12 （15.4%） were meningioma, 4 （5.1%） were trigeminal neuroma, 3 （3.8%） were lipoma, 2 （2.6%） were melanoma, and 1 （1.3%） was medulloblastoma. According to the anatomic site, tumor lesion character, and MRI signal, the majority of cerebellopontine angle area tumors were diagnosed accurately. Conclusion： MRI plays an important role in diagnosis of occupying lesions in cerebellopontine angle area.

Clinical Application of Quantitative Nursing for Lower Cranial Nerves Injury after Cerebellopontine Angle Tumors

Objective: To retrospectively analyze the clinical utility of quantitative nursing measures of 10 cases of lower cranial nerves injury after cerebellopontine angle tumors surgery to provide the experience for improving the recovery rate and living quality of these patients. Methods: The clinical data of 10 cases of lower cranial nerves injury after cerebellopontine angle tumors surgery was analyzed. For problems such as dysphagia and dyspnea of these patients, the nursing care focused on strict monitoring, timely oxygen inhalation nursing, posture nursing, ventilator nursing, swallowing function training, etc. Results: After received quantitative care, 10 patients with lower cranial nerves injury after cerebellopontine angle tumors surgery were recovered well, and their symptoms such as dysphagia and dyspnea were gradually improved and safely discharged. Conclusion: Lower cranial nerves injury is one of the serious complications after removal of cerebellopontine angle tumors, which impacts the life and health of patients. Caregivers should accurately understand and analyze the symptoms, and quantitative and targeted nursing measures for posterior cranial nerves injury are helpful in the postoperative rehabilitation of patients and improve their living quality.

An adult case of medulloblastoma in the cerebellopontine angle extending to the supratentorial area

Medulloblastoma is an undifferentiated embryonic neuroepithelial tumor. It is a rare tumor in the central nervous system, with an even rarer occurrence during adulthood. It may develop at an atypical and uncommon site, such as the cerebellopontine angle （CPA）, and such tumors rarely present with supratentorial extension. The present study reports an adult case of medulloblastoma in the CPA extending to the supratentorial area. The patient presented with complaints of headache, vertigo, hearing difficulty in the left ear, nausea/vomiting, and unsteady gait. Disequilibrium began 4 weeks earlier. Examination revealed normal cranial nerves, and computed tomography showed a hyperdense lesion, with a heterogeneously enhancing mass, in the left CPA region. The patient underwent a nearly total excision of the lesion in the CPA region. Histopathological examination confirmed medulloblastoma, WHO grade IV. Postoperatively, the patient received radiotherapy and remained asymptomatic for 30 months. However, he received two more surgeries for relapse and progression of medulloblastoma and eventually died. A CPA medulloblastoma with supratentorial extension is relatively rare in the clinic.

Meningeal melanocytoma in the cerebellopontine angle:A rare case report and review of the literature

Primary meningeal melanocytoma(MM)in the cerebellopontine angle(CPA)region is an extremely rare neoplasm that originates from the melanocytes in the leptomeninges.These lesions are usually misdiagnosed as they mimic other common CPA lesions through their nonspecific presenting symptoms,signs,and radiological characteristics.Here,we report a 47-year-old Chinese female patient who presented with a 1-month history of the right-sided tongue numbness and 1-week history of the right-sided face numbness that had been worsening for 2 days.The tumor,in the right CPA region,showed a slight isointensity on T1-weighted image and mixed signal intensity on T2-weighted image.The clinical presentation,surgical treatment,and pathologic characteristics were determined.The tumor was microsurgically resected and gross-total resection was achieved.The tumor revealed a solid,capsulated,brown-black lesion.Immunohistochemistry showed that the tumor cells were positive for human melanoma black-45(HMB-45),melanoma antigen(MelanA),S100,SOX10,and BRAF,confirming the final diagnosis of meningeal melanocytoma.Ultimately,no signs of radiological local recurrence were observed during the two-year follow-up.Collectively,meningeal melanocytoma is difficult to distinguish from common tumors in the CPA region before operation due to the lack of specificity in imaging and symptoms.Complete surgical resection is the best therapeutic option for this tumor.Although the tumor is commonly considered as a benign lesion,recurrence and metastasis are common,and pathogenesis remains unclear.

Clinical Benefits of Facial Nerve Monitoring during Cerebellopontine Angle Surgery

Background: The surgery of cerebellopontine angle tumours has remarkably progressed over the last 2 decades due to improved microsurgical techniques. The primary operative goals are microscopic total removal of the tumour while securing the adjacent cranial nerves. Facial Nerve plays a critical role in facial muscles function and one’s cosmetic appearance, and its weakness can have profound implications on a patient’s quality of life. Aim of the Study: To assess the impact of monitoring techniques on the preservation of facial nerve function during cerebellopontine angle tumours surgery. Patients and Methods: This is a prospective study. This study was conducted on 30 cases (2 groups, each had 15 patients) with CPA lesions that had undergone surgical excision of these lesions performed by retrosigmoid approach (Group A: the patients were operated under continuous intraoperative facial nerve monitoring (IOFNM) and Group B: the patients were operated without IOFNM). They were operated upon in neurosurgery departments at Al-Azhar university hospitals between August 2019 and August 2021. Results: This study showed that excellent facial nerve function (HB Grade I and II) was higher in group A than group B, immediately and at 6-month post op (80% and 93% VS 53.3% and 66.7%). Intermediate (HB Grade III and VI) and Poor (HB Grade V and VI) facial nerve function was higher in group B than group A;both immediately and 6-month postop (46.7% and 33.3% VS 20% and 6.6%). However, no statistically significant P-Value between both groups. Conclusion: We concluded that IOFNM can help, but cannot guarantee, the preservation of facial nerve. Furthermore, it is merely a technical adjunct and does not replace surgical skills, knowledge of anatomy and experience.

Anatomic structural study of cerebellopontine angle via endoscope

Background Minimally invasive surgery in skull base relying on searching for possible anatomic basis for endoscopic technology is controversial. The objective of this study was to observe the spatial relationships between main blood vessels and nerves in the cerebellopontine angle area and provide anatomic basis for lateral and posterior skull base minimally invasive surgery via endoscopic retrosigmoid keyhole approach.Methods This study was conducted on thirty dried adult skulls to measure the spatial relationships among the surface bony marks of posterior cranial fossa, and to locate the most appropriate drilling area for retrosigmoid keyhole approach. In addition, we used 10 formaldehyde-fixed adult cadaver specimens for simulating endoscopic retrosigmoid approach to determine the visible scope.Results The midpoint between the mastoid tip and the asterion was the best drilling point for retrosigmoid approach. A hole centered on this point with the 2.0 cm in diameter was suitable for exposing the related structures in the cerebellopontine angle. Retrosigmoid keyhole approach can decrease the pressure on the cerebellum and expose the related structures effectively which include facial nerve, vestibulocochlear nerve, trigeminal nerve, glossopharyngeal nerve, vagus nerve, accessory nerve, hypoglossal nerve, anterior inferior cerebellar artery, posterior inferior cerebellar artery and labyrinthine artery, etc.Conclusions Exact location on endoscope retrosigmoid approach can avoid dragging cerebellum during the minimally invasive surgery. The application of retrosigmoid keyhole approach will extend the application of endoscopic technology.

Gastrointestinal Symptoms—A Rare Complication of Untreated CPA Tumor

Cerebellopontine angle (CPA) lesions account for up to 10% of all intracranial tumors. Most CPA tumors are benign, but can cause nerve damage or compress the surrounding structures if left untreated. The typical presentation is with adult-onset sensorineural hearing loss or non-pulsatile tinnitus. In some patients, this goes unnoticed, and presentation is delayed until the lesion is much larger and presents with symptoms related to mass effect. We present the case study of 63 years old gentleman, who had suspected left CPA lesion on CT head done few years ago for dizziness and left-sided facial numbness. MRI could not be done at that time due to his MRI incompatible pacemaker leading to delay in his management eventually causing loss of patient to the follow up. He later developed progressive difficulty in walking which was initially attributed to as secondary to vasovagal syncope and postural hypotension. He eventually presented to us with intractable nausea and vomiting, worsening headache and ataxia. He had an urgent CT head which showed significant growth in the lesion with compression of the surrounding structures and obstructive hydrocephalus. He was given steroids which improved his nausea and vomiting, followed by undergoing surgery in regional center leading to significant improvement in his gait within few days of surgery. He unfortunately continued to have a degree of ataxia and facial numbness. This case illustrates a rare presentation of CPA tumor with symptoms of nausea and vomiting as a result of mass effect of the growing tumor. In addition, this review also shows the importance of regularly following up the patients with suspected CPA lesions on initial scans which will help with identifying the increase in size of lesion promptly and potentially preventing advanced complications of CPA tumors. We suggest regular monitoring of these patients to timely manage the lesion and avoid the potential life-threatening complications.