Stead Gavin A, Cresswell Fiona V, Jjunju Samuel, Oanh Pham K N, Thwaites Guy E, Donovan Joseph
Infectious Diseases Institute, Kampala, Uganda.
Clinical Research Department London School of Hygiene and Tropical Medicine, London, United Kingdom.
eNeurologicalSci. 2021 Feb 22;23:100330. doi: 10.1016/j.ensci.2021.100330. eCollection 2021 Jun.
Brain infections cause significant morbidity and mortality worldwide, especially in resource-limited settings with high HIV co-infection rates. Raised intracranial pressure [ICP] may complicate brain infection and worsen neurological injury, yet invasive ICP monitoring is often unavailable. Optic nerve sheath diameter [ONSD] ultrasound may allow detection of raised ICP at the bedside; however, pathology in brain infection is different to traumatic brain injury, in which most studies have been performed. The use of ONSD ultrasound has been described in tuberculous meningitis, cryptococcal meningitis and cerebral malaria; however correlation with invasive ICP measurement has not been performed. Normal optic nerve sheath values are not yet established for most populations, and thresholds for clinical intervention cannot be assumed to match those used in non-infective brain pathology. ONSD ultrasound may be suitable for use in resource-limited settings by clinicians with limited ultrasound training. Standardisation of scanning technique, consensus on normal ONSD values, and action on abnormal results, are areas for future research. This scoping review examines the role of ONSD ultrasound in brain infection. We discuss pathophysiology, and describe the rationale, practicalities, and challenges of utilising ONSD ultrasound for brain infection monitoring and management. We discuss the existing evidence base for this technique, and identify knowledge gaps and future research priorities.
脑部感染在全球范围内导致了严重的发病率和死亡率，尤其是在艾滋病毒合并感染率高的资源有限地区。颅内压升高可能使脑部感染复杂化并加重神经损伤，但通常无法进行有创颅内压监测。视神经鞘直径（ONSD）超声检查或许能在床边检测到颅内压升高；然而，脑部感染的病理情况与创伤性脑损伤不同，大多数相关研究都是在创伤性脑损伤中进行的。已有文献报道在结核性脑膜炎、隐球菌性脑膜炎和脑型疟疾中使用ONSD超声检查；但尚未将其与有创颅内压测量结果进行相关性研究。大多数人群的正常视神经鞘值尚未确定，临床干预阈值也不能假定与非感染性脑部病变中使用的阈值相同。对于超声检查培训有限的临床医生而言，ONSD超声检查可能适用于资源有限的环境。扫描技术的标准化、正常ONSD值的共识以及对异常结果采取的措施，都是未来的研究方向。本综述探讨了ONSD超声检查在脑部感染中的作用。我们讨论了病理生理学，并描述了利用ONSD超声检查进行脑部感染监测和管理的基本原理、实用性及挑战。我们讨论了该技术的现有证据基础，并确定了知识空白和未来的研究重点。
