Mallur Pavan S, Wisoff Jeffrey H, Lalwani Anil K
Department of Otolaryngology, New York University School of Medicine, New York, NY 10016, United States.
Int J Pediatr Otorhinolaryngol. 2008 Apr;72(4):529-34. doi: 10.1016/j.ijporl.2007.12.010. Epub 2008 Feb 5.
Tumors of the cerebellopontine angle (CPA) are common and represent up to 10% of all intracranial tumors. Rarely, intrinsic brainstem tumors can involve the CPA and present with auditory symptoms typical of CPA tumors such as hearing loss, vertigo and tinnitus. We report on a rare case of an intrinsic brainstem neoplasm presenting with steroid responsive fluctuating sensorineural hearing loss in a child. The patient initially presented with an acute worsening of an unilateral sensorineural hearing loss, without additional symptoms, that responded to oral steroids. Otoacoustic emission testing demonstrated normal outer hair cell function suggesting retrocochlear pathology. Magnetic resonance imaging with contrast enhancement revealed an intrinsic neoplasm of the middle cerebellar peduncle impinging on the 7th/8th neurovascular bundle within the CPA. The patient underwent gross total resection of the juvenile pilocytic astrocytoma via retrosigmoid craniotomy and remains disease free at 2 years postoperatively. This case highlights that suspicion of central nervous system pathology should be heightened in the presence of steroid responsive, fluctuating sensorineural hearing loss with normal outer hair cell function.
桥小脑角（CPA）肿瘤很常见，占所有颅内肿瘤的10%。极少数情况下，脑干原发性肿瘤可累及CPA，并表现出CPA肿瘤典型的听觉症状，如听力丧失、眩晕和耳鸣。我们报告了一例罕见的脑干原发性肿瘤病例，该病例表现为一名儿童出现对类固醇有反应的波动性感音神经性听力损失。患者最初表现为单侧感音神经性听力损失急性加重，无其他症状，对口服类固醇有反应。耳声发射测试显示外毛细胞功能正常，提示蜗后病变。增强磁共振成像显示小脑脚中部原发性肿瘤压迫CPA内的第7/8神经血管束。患者通过乙状窦后开颅术接受了幼年型毛细胞星形细胞瘤的全切除，术后2年无疾病复发。该病例强调，当出现对类固醇有反应、波动性感音神经性听力损失且外毛细胞功能正常时，应提高对中枢神经系统病变的怀疑。
