An 11-year-old male, neutered Cavalier King Charles spaniel is presented for an episode of acute collapse with inability to support himself on the hind limbs and disorientation. Based on the radiographs and history, which one of the following tests would be next indicated?
一只11岁的查理士王猎犬由于突发昏迷,后肢无法站立以及失去方向感前来就诊。根据病史和下面的x光片,提示你需要进行的下一步检查是什么?