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OBJECTIVES: Critically ill patients are at high risk of acute brain injury. Bedside multimodality neuromonitoring techniques can provide a direct assessment of physiologic interactions between systemic derangements and intracranial processes and offer the potential for early detection of neurologic deterioration before clinically manifest signs occur. Neuromonitoring provides measurable parameters of new or evolving brain injury that can be used as a target for investigating various therapeutic interventions, monitoring treatment responses, and testing clinical paradigms that could reduce secondary brain injury and improve clinical outcomes. Further investigations may also reveal neuromonitoring markers that can assist in neuroprognostication. We provide an up-to-date summary of clinical applications, risks, benefits, and challenges of various invasive and noninvasive neuromonitoring modalities. DATA SOURCES: English articles were retrieved using pertinent search terms related to invasive and noninvasive neuromonitoring techniques in PubMed and CINAHL. STUDY SELECTION: Original research, review articles, commentaries, and guidelines. DATA EXTRACTION: Syntheses of data retrieved from relevant publications are summarized into a narrative review. DATA SYNTHESIS: A cascade of cerebral and systemic pathophysiological processes can compound neuronal damage in critically ill patients. Numerous neuromonitoring modalities and their clinical applications have been investigated in critically ill patients that monitor a range of neurologic physiologic processes, including clinical neurologic assessments, electrophysiology tests, cerebral blood flow, substrate delivery, substrate utilization, and cellular metabolism. Most studies in neuromonitoring have focused on traumatic brain injury, with a paucity of data on other clinical types of acute brain injury. We provide a concise summary of the most commonly used invasive and noninvasive neuromonitoring techniques, their associated risks, their bedside clinical application, and the implications of common findings to guide evaluation and management of critically ill patients. CONCLUSIONS: Neuromonitoring techniques provide an essential tool to facilitate early detection and treatment of acute brain injury in critical care. Awareness of the nuances of their use and clinical applications can empower the intensive care team with tools to potentially reduce the burden of neurologic morbidity in critically ill patients. [ABSTRACT FROM AUTHOR]

BACKGROUND AND PURPOSE: Patients with acute ischemic stroke receive computed tomography angiogram (CTA) and digital subtraction angiogram (DSA) for clinical evaluation. Current guidelines lack in defining indications for transcranial Doppler (TCD) and/or carotid duplex ultrasonography (CUS) in acute stroke evaluation or follow‐up cerebrovascular imaging after reperfusion. We investigated the clinical utility of performing additional TCD/CUS after reperfusion in guiding postacute care stroke management. METHODS: Retrospective review of acute ischemic stroke patients admitted to a comprehensive stroke center with CTA head and neck and/or DSA followed by TCD/CUS. Cases were reviewed by two authors to determine if TCD/CUS provided additional diagnostic information to aid management. A nominal group process, using a third author, achieved consensus in cases of disagreements. RESULTS: Only 25 of 198 patients had CTA or DSA followed by TCD/CUS. Ten (40%) cases showed new clinical information from CUS aiding management. Of those with TCD, 5 patients (22.7%) had findings that impacted management. These clinical scenarios included detection of mobile thrombus requiring anticoagulation; distinguishing carotid near‐occlusion from occlusion; confirming hemodynamic significance of intra/extracranial stenosis helping emergent stenting/endarterectomy; detecting hyperperfusion on TCDs causing symptoms; and establishing chronicity of carotid stenosis based on collateral flow patterns, which deferred further intervention. DISCUSSION: Our experience shows that TCD/CUS may offer additional diagnostic information assisting postacute care management in small subset of patients with acute ischemic stroke. Larger studies are needed to research the clinical impact and cost‐effectiveness of additional imaging and inform clinical guidelines for selecting patients who will benefit from these additional studies. [ABSTRACT FROM AUTHOR]

Background and Purpose: Ischemic stroke can occur in 20-55% of patients with infective endocarditis (IE) with 75% occurring during the first 2 weeks of treatment. CT or MRI brain can diagnose the sequelae of stroke but transcranial Doppler (TCD) can document active embolization. We undertook a retrospective review of our patient cohort and a systematic review of literature to assess the role of TCD in early diagnosis and management of ischemic stroke in IE.Methods: Retrospective chart review and literature review.Results: We found 89 patients with stroke caused by IE at our institution from December 2011 to April 2018. TCDs were obtained on 26 patients; 16 were abnormal for cerebrovascular abnormalities. Only 4 patients had 30-minute emboli monitoring performed, of which one revealed emboli. We found 3 studies investigating the role of TCDs in IE that showed promise in its use as a predictive tool in stroke risk stratification.Conclusions: Presence of embolization in the form of high-intensity transient signals (HITS) detected on TCDs can be used for early diagnosis of IE, assessing efficacy of antibiotic therapy, and stratification of stroke risk in IE. This can aid further research into testing preventative interventions for reducing stroke burden in IE such as earlier valvular surgery or vacuum-assisted vegetation extraction. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) independently increases the risk of stroke and small vessel disease (SVD). This study compared SVD and a transcranial Doppler (TCD)-based marker of intracranial vascular resistance (pulsatility index, PI) in post-stroke patients with and without CKD. Between January 2015 and December 2017, 118 individuals with stable eGFR (50 with CKD) had cerebral MRI and TCD within three months of a stroke. The means of bilateral PI in anterior (anterior cerebral [ACA] and middle cerebral arteries [MCA]) and posterior vessels (posterior cerebral [PCA] and vertebral arteries [VA]) were computed. CKD strongly correlated with higher distal resistance (median CKD ACA PI 1.2, IQR 1.0 to 1.35 vs. controls 0.91 IQR 0.79 to 1.1 [ p < 0.0001]; median MCA PI 1.14 IQR 1.03 to 1.39 vs. controls 0.93 IQR 0.79 to 1.1 [ p < 0.0001]) and MRI SVD burden (median CKD SVD 4.98 × 104 IQR 2.66 to 7.76 × 104 voxels vs. controls median SVD 6.7 × 103 IQR 2.4 to 24.0 × 103 [ p < 0.0001]). In conclusion, in patients with recent stroke, CKD is an independent determinant of increased intracranial vascular resistance in both anterior and posterior cerebral circulations. MRI SVD volume is significantly associated with anterior and posterior circulation PI. [ABSTRACT FROM AUTHOR]