A Case of Trigeminal Neuralgia Due to Cerebellopontine Epidermoid Cyst: Discrepancy between Intraoperative and Radiological Findings of Constructive Interference in Steady State (CISS)

Cerebellopontine angle epidermoid cyst masquerading as trigeminal neuralgia: A rare presentation and surgical outcome

Cerebellopontine (CP) angle epidermoid cysts are rare, benign, slow-growing intracranial lesions that arise from ectodermal inclusions during embryogenesis. They often present with symptoms caused by compression of adjacent structures, with trigeminal neuralgia being an uncommon presentation. A 19-year-old female presented with a 1-month history of tingling sensation on the right side of her face. MRI of the brain revealed an extra-axial cystic lesion at the right CP angle extending into the ambient cistern. The lesion appeared hypointense on T1-weighted imaging, hyperintense on T2-weighted imaging, and dirty hyperintense on FLAIR, with diffusion restriction on DWI and no blooming on SWI. It caused a mass effect with compression of the right pons and trigeminal nerve. The patient underwent microsurgical resection of the cyst, and histopathological findings confirmed the diagnosis of an epidermoid cyst. Postoperatively, the patient showed symptomatic improvement and was advised long-term follow-up. This case emphasizes the importance of advanced imaging in diagnosing rare intracranial lesions and highlights surgical resection as an effective treatment for CP angle epidermoid cysts presenting with atypical symptoms.

Trigeminal neuralgia revealing an epidermoid cyst impinging on the Vth cranial nerve: A case report

Intracranial epidermoid cysts, also referred to as intracranial primary cholesteatomas, are uncommon, benign tumors characterized by slow, linear growth patterns akin to normal epidermal tissue. They typically become symptomatic around age 43, with a slight female predominance, and are most frequently located in the cerebellopontine angle. This summary presents the case of a 62-year-old woman suffering from paroxysmal excruciating pain of the right hemiface, indicative of trigeminal neuralgia, linked to an intracranial epidermoid cyst in the cerebellopontine angle. Radiological assessment, through magnetic resonance imaging, was instrumental in identifying the cyst. Total surgery resection is the most effective treatment, but it can be challenging due to tumor adherence to important neurovascular structures, therefore responsible for an incomplete removal of the proliferative capsule causing a higher risk of recurrence. The case also raises questions about treatment options, as the patient opted against surgical intervention. Managing intracranial epidermoid cysts requires a careful weighing of potential benefits against associated risks.

Erenumab in the Treatment of Comorbid Trigeminal Neuralgia in Patients With Migraine

Background Surgical treatment for trigeminal neuralgia (TN) sometimes becomes difficult. Erenumab, an anti-calcitonin gene-related peptide (CGRP)-receptor monoclonal antibody, is used for migraine and potentially has efficacy for TN. Method We retrospectively investigated six migraine patients with comorbidity treated with 70 mg of erenumab. Monthly headache days and a numerical rating scale (NRS) of TN were evaluated before, one, and three months after erenumab administration. Results Before being treated with 70 mg of erenumab, the six migraine patients with comorbid TN had taken at least one sort of preventative medication, but it had been ineffective. During the three-month erenumab use, previous medications were continued. The median age was 71 years (range 59-87). The six patients (five females and one male) had episodic migraine. Three had TN due to vessels, one had TN due to a tumor, one had TN without neurovascular compression, and one had an undetermined etiology. Five (83%) of the six patients reported improved NRS of TN. The median NRS of TN before, one, and three months after treatment were 8 (7-10), 3.5 (0-10), and 2 (0-5, n=4). Monthly headache days were 4 (4-10), 2.5 (0-4), and 1 (1-2, n=4). There were no side effects of erenumab. Conclusion Surgical treatment sometimes cannot be performed for those with TN. Our findings were preliminary and a bigger sample size is required for this study to draw firmer conclusions. However, it is possible, although rare, that there are migraine patients for whom the NRS of comorbid TN improves with the use of erenumab, an anti-CGRP receptor monoclonal antibody.