Role of Epileptic Activity in Older Adults With Delirium, a Prospective Continuous EEG Study

Prevalence of clinical electroencephalography findings in stroke patients with delirium

OBJECTIVE

Delirium is an acute cognitive disorder associated with multiple electroencephalographic (EEG) abnormalities in non-neurological patients, though specific EEG characteristics in patients with stroke remain unclear. We aimed to compare the prevalence of EEG abnormalities in stroke patients during delirium episodes with periods that did not correspond to delirium.

METHODS

We retrospectively analyzed clinical EEG reports for stroke patients who received daily delirium assessments as part of a prospective study. We compared the prevalence of EEG features corresponding to patient-days with vs. without delirium, including focal and generalized slowing, and focal and generalized epileptiform abnormalities (EAs).

RESULTS

Among 58 patients who received EEGs, there were 192 days of both EEG and delirium monitoring (88% [n = 169] corresponding to delirium). Generalized slowing was significantly more prevalent on days with vs. without delirium (96% vs. 57%, p = 0.03), as were bilateral or generalized EAs (38% vs. 13%, p = 0.03). In contrast, focal slowing (53% vs. 74%, p = 0.11) and focal EAs were less prevalent on days with delirium (38% vs. 48%, p = 0.37), though these differences were not statistically significant.

CONCLUSIONS

We found a higher prevalence of generalized but not focal EEG abnormalities in stroke patients with delirium.

SIGNIFICANCE

These findings may reinforce the diffuse nature of delirium-associated encephalopathy, even in patients with discrete structural lesions.

Tranexamic Acid and the Risk of Delirium after Off-Pump Surgery

We investigated whether in patients undergoing off-pump coronary artery bypass grafting surgery a single bolus of 1 g tranexamic acid (TXA) impacts the risk of postoperative delirium using the propensity score matching approach. In 2,757 pairs, the risk of delirium was 4.2% (TXA group) and 5.0% (non-TXA group), with a relative risk in the TXA versus the non-TXA group of 0.83 (95% confidence interval: 0.65-1.07; p = 0.16). There was no significant interaction between TXA administration and renal function on the risk of delirium (p = 0.12). Data indicate that a single bolus of 1 g TXA does not increase the risk of delirium in patients undergoing off-pump surgery.

Electroencephalography in delirium assessment: a scoping review

Background

Delirium is a common disorder affecting around 31% of patients in the intensive care unit (ICU). Delirium assessment scores such as the Confusion Assessment Method (CAM) are time-consuming, they cannot differentiate between different types of delirium and their etiologies, and they may have low sensitivities in the clinical setting. While today, electroencephalography (EEG) is increasingly being applied to delirious patients in the ICU, a lack of clear cut EEG signs, leads to inconsistent assessments.

Methods

We therefore conducted a scoping review on EEG findings in delirium. One thousand two hundred thirty-six articles identified through database search on PubMed and Embase were reviewed. Finally, 33 original articles were included in the synthesis.

Results

EEG seems to offer manifold possibilities in diagnosing delirium. All 33 studies showed a certain degree of qualitative or quantitative EEG alterations in delirium. Thus, normal routine (rEEG) and continuous EEG (cEEG) make presence of delirium very unlikely. All 33 studies used different research protocols to at least some extent. These include differences in time points, duration, conditions, and recording methods of EEG, as well as different patient populations, and diagnostic methods for delirium. Thus, a quantitative synthesis and common recommendations are so far elusive.

Conclusion

Future studies should compare the different methods of EEG recording and evaluation to identify robust parameters for everyday use. Evidence for quantitative bi-electrode delirium detection based on increased relative delta power and decreased beta power is growing and should be further pursued. Additionally, EEG studies on the evolution of a delirium including patient outcomes are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02557-w.

Understanding Disorders of Consciousness: Opportunities for Critical Care Nurses

BACKGROUND

Disorders of consciousness are powerful predictors of outcomes including mortality among critically ill patients. Encephalopathy, delirium, and coma are disorders of consciousness frequently encountered by critical care nurses but often classified incorrectly.

OBJECTIVE

To provide a greater understanding of disorders of consciousness and to provide standardized assessments and nursing interventions for these disorders.

METHODS

A literature search was conducted by using the terms consciousness, mental status, awareness, arousal, wakefulness, assessment, disorders of consciousness, delirium, encephalopathy, coma, vegetative state, and minimal consciousness. Articles were published in the past 10 years in CINAHL and PubMed. Articles were excluded if they were not in English or directly related to caring for patients with a disorder of consciousness. The remaining 142 articles were evaluated for inclusion; 81 articles received full review.

RESULTS

A disorder of consciousness signifies that the threshold for compensation has been surpassed with potentially irreversible damage. Altered thalamocortical interactions and reduced cortical activity impair communication networks across the various parts of the brain, causing a disturbance in consciousness.

DISCUSSION

The cue-response theory is a model that describes the process and impact of nursing care on recovery from acute brain injury. Appropriate standardized assessments and interventions must be used to manage altered levels of consciousness in critically ill patients.

CONCLUSIONS

Paying close attention to neurological changes and monitoring them with standardized assessments are critical to implementing early measures to prevent complications.

Evaluation and Management of Delirium

Delirium, sometimes referred to as encephalopathy, is an acute confusional state that is both common in hospitalized patients and associated with poor outcomes. For patients, families, and caregivers, delirium can be a traumatic experience. While delirium is one of the most common diagnoses encountered by the consulting neurologist, the majority of the time it will have been previously unrecognized as such by the care team. Neurologic syndromes such as dementia or aphasia can either be misdiagnosed as delirium or may coexist with it, necessitating careful neurologic assessment. Once the diagnosis of delirium has been established, a careful evaluation for predisposing and precipitating factors can help uncover modifiable contributors, which should be addressed as part of a multicomponent, primarily nonpharmacologic intervention. Importantly, delirium management, which begins with comprehensive prevention, should emphasize the humanity of the delirious patient and the challenges of caring for this vulnerable population. When considered, delirium represents an important opportunity for the neurologist to substantially enhance patient care.

Electroencephalography of mechanically ventilated patients at high risk of delirium

Objective

Neurophysiological exploration of ICU delirium is limited. Here, we examined EEG characteristics of medical‐surgical critically ill patients with new‐onset altered consciousness state at high risk for ICU delirium.

Materials and methods

Pre‐planned analysis of non‐neurological mechanically ventilated medical‐surgical ICU subjects, who underwent a prospective multicenter randomized, controlled EEG study (NCT03129438, April 2017–November 2018). EEG characteristics, according to the 2012 ACNS nomenclature, included background activity, rhythmic periodic patterns/epileptic activity, amplitude, frequency, stimulus‐induced discharges, triphasic waves, reactivity, and NREM sleep. We explored EEG findings in delirious versus non‐delirious patients, specifically focusing on the presence of burst‐suppression and rhythmic periodic patterns (ictal‐interictal continuum), and ictal activity.

Results

We analyzed 91 patients (median age, 66 years) who underwent EEG because of new‐onset altered consciousness state at a median 5 days from admission; 42 patients developed delirium (46%). Burst‐suppression (10 vs 0%, p = .02), rhythmic/periodic patterns (43% vs 22%, p = .03) and epileptiform activity (7 vs 0%, p = .05) were more frequent in delirious versus non‐delirious patients. The presence of at least one of these abnormal EEG findings (32/91 patients; 35%) was associated with a significant increase in the likelihood of delirium (42 vs 15%, p = .006). Cumulative dose of sedatives and analgesics, as well as all other EEG characteristics, did not differ significantly between the two groups.

Conclusion

In mechanically ventilated non‐neurological critically ill patients with new‐onset alteration of consciousness, EEG showing burst‐suppression, rhythmic or periodic patterns, or seizures/status epilepticus indicate an increased risk of ICU delirium.

Nonconvulsive status epilepticus manifesting as rapidly progressive dementia and infarction in the splenium of the corpus callosum: A case report

RATIONALE

Nonconvulsive status epilepticus (NCSE) is a heterogeneous disease with multiple subtypes. NCSE poses great diagnostic and therapeutic challenges due to the lack of typical symptoms. Here, we report a case of NCSE manifesting as rapidly progressive dementia (RPD) and infarction in the splenium of the corpus callosum. Additionally, the relevant literature was reviewed.

PATIENT CONCERNS

A 63-year-old man presented with RPD. Electroencephalogram (EEG) revealed NCSE, and brain magnetic resonance imaging (MRI) showed an isolated infarction in the splenium of the corpus callosum. Mini-mental state examination showed moderate cognitive impairment (14/30 points).

DIAGNOSIS

A diagnosis of NCSE with RPD and infarction in the splenium of the corpus callosum was made.

INTERVENTIONS

The patient was treated with intravenous diazepam (10 mg), oral levetiracetam (1.0g twice daily), oral sodium valproate (0.2g twice daily), and intramuscular phenobarbital sodium (0.2g once daily).

OUTCOMES

After the treatment, the symptoms were improved. The patient could answer questions. Repeated EEG showed that the background a rhythm was slightly overdeveloped, and no clinical or electrical seizures were observed. After discharge, the patient was treated with oral levetiracetam (1.0g twice daily) and oral sodium valproate (0.2g twice daily) for 6 months. At the last follow-up, the patient had clear consciousness, sensitive response, and fluent answering ability. Repeated mini-mental state examination showed that his cognitive function was significantly improved (28/30 points); nevertheless, the lesion in the splenium of corpus callosum remained unchanged on MRI.

LESSONS

NCSE manifesting as RPD and infarction in the splenium of the corpus callosum is extremely rare. Epileptic events and focal infarction are usually overlooked in patients with dementia, and the diagnostic value of MRI and EEG should be highlighted.

Does continuous electroencephalography influence therapeutic decisions in neurocritical care?

OBJECTIVES

In the neurocritical care unit (neuro-ICU), the impact of continuous EEG (cEEG) on therapeutic decisions and prognostication, including outcome prediction using the Status Epilepticus Severity Score (STESS), is poorly investigated. We studied to what extent cEEG contributes to treatment decisions, and how this relates to clinical outcome and the use of STESS in neurocritical care.

METHODS

We included patients admitted to the neuro-ICU or neurological step-down unit of a tertiary referral hospital between 05/2013 and 06/2015. Inclusion criteria were ≥20 h of cEEG monitoring and age ≥15 years. Exclusion criteria were primary epileptic and post-cardiac arrest encephalopathies.

RESULTS

Ninety-eight patients met inclusion criteria, 80 of which had status epilepticus, including 14 with super-refractory status. Median length of cEEG monitoring was 50 h (range 21-374 h). Mean STESS was lower in patients with favorable outcome 1 year after discharge (modified Rankin Scale [mRS] 0-2) compared to patients with unfavorable outcome (mRS 3-6), albeit not statistically significant (mean STESS 2.3 ± 2.1 vs 3.6 ± 1.7, p = 0.09). STESS had a sensitivity of 80%, a specificity of 42%, and a negative predictive value of 93% for outcome. cEEG results changed treatment decisions in 76 patients, including escalation of antiepileptic treatment in 65 and reduction in 11 patients.

CONCLUSION

Status Epilepticus Severity Score had a high negative predictive value but low sensitivity, suggesting that STESS should be used cautiously. Of note, cEEG results altered clinical decision-making in three of four patients, irrespective of the presence or absence of status epilepticus, confirming the clinical value of cEEG in neurocritical care.

Challenges of Delirium Management in Patients with Traumatic Brain Injury: From Pathophysiology to Clinical Practice

Traumatic brain injury (TBI) can initiate a very complex disease of the central nervous system (CNS), starting with the primary pathology of the inciting trauma and subsequent inflammatory and CNS tissue response. Delirium has long been regarded as an almost inevitable consequence of moderate to severe TBI, but more recently has been recognized as an organ dysfunction syndrome with potentially mitigating interventions. The diagnosis of delirium is independently associated with prolonged hospitalization, increased mortality and worse cognitive outcome across critically ill populations. Investigation of the unique problems and management challenges of TBI patients is needed to reduce the burden of delirium in this population. In this narrative review, possible etiologic mechanisms behind post-traumatic delirium are discussed, including primary injury to structures mediating arousal and attention and secondary injury due to progressive inflammatory destruction of the brain parenchyma. Other potential etiologic contributors include dysregulation of neurotransmission due to intravenous sedatives, seizures, organ failure, sleep cycle disruption or other delirium risk factors. Delirium screening can be accomplished in TBI patients and the presence of delirium portends worse outcomes. There is evidence that multi-component care bundles including an analgesia-prioritized sedation algorithm, regular spontaneous awakening and breathing trials, protocolized delirium assessment, early mobility and family engagement can reduce the burden of ICU delirium. The aim of this review is to summarize the approach to delirium in TBI patients with an emphasis on pathogenesis and management. Emerging CNS-active drug therapies that show promise in preclinical studies are highlighted.