Abstract:
Pupillary assessment is a quintessential part of the clinical examination in neuro-intensive care patients because it provides insight into the integrity of midbrain reflex arcs. Abnormal pupils, particularly anisocoria and later bilateral fixed mydriasis, are classically used to assess expansive intracranial processes because they are frequently considered early indicators of transtentorial midbrain compression due to elevated intracranial pressure. Complex ocular motor deficits mapping to the midbrain are rarely described in the setting of high transtentorial pressure. This is likely because ocular motor deficits typically occur in conjunction with decreased consciousness and corticospinal tract dysfunction reflecting advanced midbrain compromise. We present a case of left midbrain compression due to downward herniation in a patient with acute-on-chronic bilateral subdural hematoma. Ocular motor assessment demonstrated left internuclear ophthalmoplegia (INO) and an ocular tilt reaction, termed INO plus. However, pupillary, mental status, and sensorimotor examinations were unremarkable. Head magnetic resonance imaging revealed acute perforator ischemia in the left pontomesencephalic tegmentum, localizing to the ipsilateral medial longitudinal fasciculus and graviceptive oculocephalic circuits. Microvascular compromise secondary to mechanical pressure is discussed as a causative mechanism. We caution against overreliance on \"telltale pupils\" in suspected brainstem compression and recommend checking for other oculomotor signs.
摘要:
瞳孔评估是神经重症监护患者临床检查的重要组成部分,因为它可以深入了解中脑反射弧的完整性。异常瞳孔,尤其是不适和后来的双侧固定散瞳,通常用于评估扩张性颅内过程,因为它们通常被认为是由于颅内压升高而引起的经中脑压迫的早期指标。在高幕压力的背景下,很少描述映射到中脑的复杂眼运动缺陷。这可能是因为眼运动缺陷通常与意识下降和皮质脊髓束功能障碍一起发生,反映了中脑晚期损害。我们介绍了一例急性慢性双侧硬膜下血肿患者由于下疝引起的左中脑压迫。眼球运动评估显示左核间眼肌麻痹(INO)和眼球倾斜反应,称为INOplus。然而,瞳孔,精神状态,感觉运动检查并不显著。头部磁共振成像显示左桥中脑被盖急性穿支缺血,定位到同侧内侧纵向束和妊娠性眼指路。讨论了继发于机械压力的微血管损害作为成因机制。我们告诫不要在怀疑脑干压迫中过度依赖“有告状的瞳孔”,并建议检查其他动眼体征。