Diagnostic yield of cerebral imaging in patients with acute confusion

Neurological diagnostic tests for patients with and without delirium: a prospective observational study

Since most of the precipitating factors of delirium are not due to neurological disorders, neurological diagnostic tests (NDTs) may be of limited value. We hypothesized that delirium has a high burden of NDTs with a low diagnostic yield. All patients admitted to the internal medicine wards of a single secondary teaching hospital between November 2019 and January 2020 were eligible. Within the first 48 h of their admission, they had a formal evaluation by a neuropsychologist to screen for presence of delirium. NDTs (brain MRI, brain CT, electroencephalography (EEG), and lumbar puncture) performed during the hospital stay were compared between patients with and without delirium using a logistic regression model stratified by a propensity score. The proportions of diagnostic yield (acute anomalies that changed the treatment management) provided by each type of examination were compared. Of 217 patients included, 19/32 patients (61%) with delirium had one or more NDTs, compared to 48/185 (26%) without delirium (adjusted OR 2.7; 95%CI 1.1-6.7; p = 0.027). The proportions of NDT results affecting management for patients with and without delirium were 13 and 20% for brain CT scans (p = 0.71), 29 and 38% for brain MRI (p = 0.99), and 20 and 10% for EEGs (p = 0.99), respectively. The higher proportion of NDTs performed on patients with delirium was associated with a low diagnostic yield, although not statistically different from those performed among inpatients without delirium. There is a need for restrictive, evidence-based guidelines to help with the work-up for patients with delirium.

Head computed tomography for elderly patients with acute altered mental status in the emergency setting: value for decision-making and predictors of abnormal findings

OBJECTIVE

This study evaluated the impact of head computed tomography (CT) on clinical decision-making about older adults with acute altered mental status (AMS) in the emergency department in terms of CT's diagnostic yield, emergency department length of stay, and changes in medical strategy. It also attempted to find predictors of an acute imaging abnormality.

METHODS

This was a 1-year, retrospective, single-center observational study of patients aged ≥75 years who underwent noncontrast head CT because of an isolated episode of AMS. The acute positive CT findings were ischemic strokes, hemorrhages, tumors, demyelinating lesions, hydrocephalus, and intracranial infections.

RESULTS

A total of 594 CTs were performed, of which 38 (6.4%) were positive. The main etiology of AMS was sepsis (29.1%). Changes in medical strategy were more common in patients with a positive CT, and the major changes were ordering additional neuro exams (odds ratio [OR], 95.3; 95% confidence interval [CI], 38.4-233.8; P<0.001), adjusting treatments (OR, 12.2; 95% CI, 5.0-29.5; P<0.001), and referral to a neurologic unit (OR, 7.3; 95% CI, 3.0-17.5; P<0.01). Three factors were significantly associated with a positive outcome: Glasgow Coma Scale <13 (OR, 8.5; 95% CI, 2.3-28.9; P<0.001), head wound (OR, 3.1; 95% CI, 1.1-8.2; P=0.025), and dehydration (OR, 0.3; 95% CI, 0.1-0.4; P=0.021). For elderly patients with a Glasgow Coma Scale ≥13 and no head wound or clinical dehydration, the probability of a positive CT was 0.02 (95% CI, 0.01-0.04). Considering only those patients, the diagnostic yield fell to 1.7%.

CONCLUSION

In elderly patients, the causes of AMS are primarily extracerebral. Randomized clinical trials are needed to validate a clinical pathway for selecting patients who require emergent neuroimaging.

Current Challenges in the Recognition and Management of Delirium Superimposed on Dementia

Delirium occurring in a patient with preexisting dementia is referred to as delirium superimposed on dementia (DSD). DSD commonly occurs in older hospitalized patients and is associated with worse outcomes, including higher rates of mortality and institutionalization, compared to inpatients with delirium or dementia alone. This narrative review summarizes the screening, diagnosis, management, and pathophysiology of DSD and concludes by highlighting opportunities for future research. Studies were identified via Medline and PsycINFO keyword search, and handsearching reference lists. Conceptually, DSD could be considered an "acute exacerbation" of dementia precipitated by a noxious insult akin to an acute exacerbation of heart failure or acute on chronic renal failure. However, unlike other organ systems, there are no established biomarkers for delirium, so DSD is diagnosed and monitored clinically. Because cognitive dysfunction is common to both delirium and dementia, the diagnosis of DSD can be challenging. Inattention, altered levels of arousal, and motor dysfunction may help distinguish DSD from dementia alone. An informant history suggestive of an acute change in cognition or alertness should be investigated and managed as delirium until proven otherwise. The key management principles include prevention, identifying and treating the underlying precipitant(s), implementing multicomponent interventions to create an ideal environment for brain recovery, preventing complications, managing distress, and monitoring for resolution. Informing and involving family members or caregivers throughout the patient journey are essential because there is significant prognostic uncertainty, including the risk of persistent cognitive and functional decline following DSD and relapse. Furthermore, informal carers can provide significant assistance in management. Emerging evidence demonstrates that increased exposure to delirium is associated with neuronal injury and worse cognitive outcomes although the mechanisms through which this occurs remain unclear. Given the clinical overlap between delirium and dementia, studying shared pathophysiological pathways may uncover diagnostic tests and is an essential step in therapeutic innovation.

ACR Appropriateness Criteria® Acute Mental Status Change, Delirium, and New Onset Psychosis

Acute changes in mental status represent a broad collection of symptoms used to describe disorders in mentation and level of arousal, including the more narrowly defined diagnoses of delirium and psychosis. A wide range of precipitating factors may be responsible for symptom onset including infection, intoxication, and metabolic disorders. Neurologic causes that may be detected on neuroimaging include stroke, traumatic brain injury, nonconvulsive seizure, central nervous system infection, tumors, hydrocephalus, and inflammatory disorders. Not infrequently, two or more precipitating factors may be found. Neuroimaging with CT or MRI is usually appropriate if the clinical suspicion for an acute neurological cause is high, where the cause of symptoms is not found on initial assessment, and for patients whose symptoms do not respond appropriately to management. There was disagreement regarding the appropriateness of neuroimaging in cases where a suspected, nonneurologic cause is found on initial assessment. Neuroimaging with CT is usually appropriate for patients presenting with delirium, although the yield may be low in the absence of trauma or a focal neurological deficit. Neuroimaging with CT or MRI may be appropriate in the evaluation of new onset psychosis, although the yield may be low in the absence of a neurologic deficit. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Delirium Screening and Management in Inpatient Rehabilitation Facilities

Delirium is an acute and fluctuating disturbance in cognition attention and awareness that is often a reflection of abnormal physiological condition of an individual. Delirium is highly prevalent among an older population and is associated with high mortality, poor medical and functional outcomes, and high healthcare cost. Delirium often has iatrogenic triggers, and it has been recognized as a quality indicator of healthcare organizations. Despite its high prevalence and significance, more than 50% of the delirium cases are underrecognized by healthcare professionals and remained untreated. Most patients in inpatient rehabilitation facilities are older adults with multiple risk factors for delirium including operation, intensive care stay, multiple co-morbidities, and impaired mobility. Early detection, intervention, and primary prevention of delirium will allow patients to avoid additional morbidities and reach their maximum functional potential during their rehabilitation stay. After the systematic implementation of delirium screening in our inpatient rehabilitation facility, we found that 10.3% of patients were screened positive for delirium at admission. This review discusses the systematic implementation of screening and intervention for delirium as well as the epidemiology of delirium to increase the awareness and guide clinical practice for clinicians in inpatient rehabilitation facilities.

An update on postoperative delirium: Clinical features, neuropathogenesis, and perioperative management

PURPOSE OF REVIEW

We present a focused review on postoperative delirium for anesthesiologists, encompassing clinical features, neuropathogenesis, and clinical identification and management strategies based on risk factors and current delirium treatments.

RECENT FINDINGS

The literature on postoperative delirium is dominated by non-experimental studies. We review delirium phenotypes, diagnostic criteria, and present standard nomenclature based on current literature. Disruption of cortical integration of complex information (CICI) may provide a framework to understand the neuropathogenesis of postoperative delirium, as well as risk factors and clinical modifiers in the perioperative period. We further divide risk factors into patient factors, surgical factors, and medical/pharmacological factors, and present specific considerations for each in the preoperative, intraoperative, and postoperative periods.

SUMMARY

Postoperative delirium is prevalent, poorly understood, and often missed with current screening techniques. Proper identification of risk factors is useful for perioperative interventions and can help tailor patient-specific management strategies.

The use of cerebral imaging for investigating delirium aetiology

BACKGROUND

This study aims to investigate the frequency and patterns of use of cerebral imaging in delirium and to describe pathological changes associated with delirium using computed tomography (CT) and magnetic resonance imaging (MRI).

METHODS

This retrospective observational study included patients with delirium admitted to a tertiary hospital (The Royal Melbourne Hospital, Australia) between January 2015 and August 2016. Data on cerebral imaging was collected and positive imaging findings were defined as: Acute or subacute infarct, haemorrhage, abscess, neoplasm, vasculitis, posterior reversible encephalopathy syndrome, encephalitis, acute demyelination, or fat embolism.

RESULTS

There were 1653 (5% of 32,725) patients with delirium (median age 80 years, inter-quartile range 71-86, 54% male). Thirty-three percent (N = 538) had cerebral imaging (CT only: N = 457, MRI only: N = 10, both: N = 71). In 11% (N = 57) of patients, CT brain scans were positive. MRI brain was completed in 17 patients with a positive CT (17/57), changing the diagnosis in two cases. Fifty-four patients with negative CT scans also had MRI brain; 33% (N = 18) of these were positive. Younger patients were more likely to have MRI compared to CT brain scan. Patients admitted to a neurology unit were more likely to have cerebral imaging.

CONCLUSION

Use of CT brain was common in delirium patients, with an 11% rate of positive findings. Fewer patients had MRI brain scans, which added diagnostic information in some cases. Future studies are needed to define the significance of cerebral imaging in delirium management and establish guidelines for its use.

Thermoregulation and age

The thermoregulatory functions may vary with age. Thermosensitivity is active in neonates and children; both heat production and heat loss effector mechanisms are functional but easily exhaustable. Proportional and lasting defense against thermal challenges is difficult, and both hypothermia and hyperthermia may easily develop. Febrile or hypothermic responses to infections or endotoxin can also develop, together with confusion. In small children febrile convulsions may be dangerous. In old age the resting body temperature may be lower than in young adults. Further, thermosensitivity decreases, the thresholds for activating skin vasomotor and evaporative responses or metabolism are shifted, and responses to thermal challenges are delayed or insufficient: both hypothermia and hyperthermia may develop easily. Infection-induced fevers are often limited or absent, or replaced by hypothermia. Various types of brain damage may induce special forms of hypothermia, hyperthermia, or severe fever. Impaired mental state often accompanies hypothermia and hyperthermia, and may occasionally be a dominant feature of infection (instead of the most commonly observed fever). Aging brings about a turning point in women's life: the menopause. The well-known influence of regular hormonal cycles on the thermoregulation of a woman of fertile age gives way to menopausal hot flushes caused by estrogen withdrawal. Not all details of this thermoregulatory anomaly are fully understood yet.

Cerebral blood flow MRI in the nondemented elderly is not predictive of post-operative delirium but is correlated with cognitive performance

Three-dimensional Arterial Spin Labeling (ASL) MRI was performed before surgery in a cohort of 146 prospectively enrolled subjects ≥ 70 years old scheduled to undergo elective surgery. We investigated the prospective association between ASL-derived measures of cerebral blood flow (CBF) before surgery with postoperative delirium incidence and severity using whole-brain and globally normalized voxel-wise analysis. We also investigated the cross-sectional association of CBF with patients' baseline performance on specific neuropsychological tests, and with a composite general cognitive performance measure (GCP). Out of 146 subjects, 32 (22%) developed delirium. We found no significant association between global and voxel-wise CBF with delirium incidence or severity. We found the most significant positive associations between CBF of the posterior cingulate and precuneus and the Hopkins Verbal Learning Test - Revised total score, Visual Search and Attention Test (VSAT) score and the GCP composite. VSAT score was also strongly associated with right parietal lobe CBF. ASL can be employed in a large, well-characterized older cohort to examine associations between CBF and age-related cognitive performance. Although ASL CBF measures in regions previously associated with preclinical Alzheimer's Disease were correlated with cognition, they were not found to be indicators of baseline pathology that may increase risk for delirium.

Comparing consultation-liaison psychiatrist's and neurologist's approaches to delirium - A retrospective analysis

OBJECTIVE

To compare the diagnostic, management, and treatment recommendations made by consultation-liaison psychiatrists (CLP) and neurologists (CLN) for suspected delirium and to investigate factors that may have influenced the choice for a particular consultation service.

METHOD

In this retrospective case analysis, we screened the files of 1882 (CLP: 1112, CLN: 770) inpatients seen by CLP and CLN at the Charité - University Medicine, Berlin, Germany, in 2013. This revealed a total of 148 (CLP: 99, CLN: 49) delirium patients. Information found on the consultation form and in the patients' files was used for data collection and subsequently analyzed.

RESULTS

Intensive care and surgical units preferably called CLP, while internists consulted more CLN and patients suffering from neurological or psychiatric preconditions were more often seen by the respective specialist. Despite no significant difference between psychomotor activity levels among the groups, CLP recommended significantly more pharmacological interventions (p = 0.000) and CLN ordered significantly more diagnostic procedures (p = 0.000).

CONCLUSION

Our results show considerable differences between CLP and CLN treatment recommendations, which may indicate a conflicting approach to delirium work-up, not accountable to unequal patient characteristics. These preliminary results are not conclusive and should be followed up by high evidence level research.

Utility of Head CT Scan for Acute Inpatient Delirium

 Delirium is a common occurrence in hospitalized patients, especially in the geriatric age group. Data was retrospectively reviewed for patients who developed delirium during hospitalization. Acute intracranial changes on imaging were noted only in four patients (11%) and all had preimaging clinical symptoms and signs, which warranted imaging. Imaging should be considered only in the presence of head injury, fall, history of anticoagulation, focal neurological signs, fever, and raised intracranial pressure. Development of more clear guidelines will result in decreased ordering of unnecessary neuroimaging, substantial cost savings, and less radiation exposure for patients.

Diagnostic yield of head computed tomography for the hospitalized medical patient with delirium

BACKGROUND

Delirium is common in hospitalized patients and warrants early diagnosis and treatment. Often the evaluation of delirium includes head computed tomography imaging. However, in hospitalized medical patients, the yield of head computed tomography is unknown.

OBJECTIVE

To determine the diagnostic yield of head computed tomography when evaluating a hospitalized medical patient with delirium in the absence of a recent fall, head trauma, or new neurologic deficit.

DESIGN AND SETTING

Retrospective medical record review at a large academic medical center in Boston, Massachusetts.

PARTICIPANTS

We reviewed all medical records for head computed tomography scans performed from January 2010 through November 2012 in patients on the general medicine or medical subspecialties units.

MAIN OUTCOMES

A "positive" head computed tomography was defined as an intracranial process that could explain delirium. An "equivocal" head computed tomography was defined as the presence of a finding of unclear significance in relation to delirium.

RESULTS

There were 398 patients hospitalized for >24 hours who underwent head computed tomography for delirium. Two hundred twenty head computed tomography studies met eligibility criteria, with 6 (2.7%) positive and 4 (1.8%) equivocal results. All positive and equivocal findings resulted in change in management.

CONCLUSIONS

The diagnostic yield of head computed tomography in determining the cause of delirium in hospitalized patients is low. Due to the low rate of positive findings, head imaging is unnecessary in the majority of cases of delirium. However, there may be a subset of high-risk individuals in which head imaging is indicated.

[Delirium in patients with neurological diseases: diagnosis, management and prognosis]

Delirium is a common acute neuropsychiatric syndrome. It is characterized by concurrent disturbances of consciousness and attention, perception, reasoning, memory, emotionality, the sleep-wake cycle as well as psychomotor symptoms. Delirium caused by alcohol or medication withdrawal is not the subject of the current review. Specific predisposing and precipitating factors have been identified in delirium which converge in a common final pathway of global brain dysfunction. The major predisposing factors are older age, cognitive impairment or dementia, sensory deficits, multimorbidity and polypharmacy. Delirium is always caused by one or more underlying pathologies which need to be identified. In neurology both primary triggers of delirium, such as stroke or epileptic seizures and also secondary triggers, such as metabolic factors or medication side effects play a major role. Nonpharmacological interventions are important in the prevention of delirium and lead to an improvement in prognosis. Delirium is associated with increased mortality and in the long term the development of cognitive deficits and functional impairment.

Delirium in elderly people

Delirium is an acute disorder of attention and cognition in elderly people (ie, those aged 65 years or older) that is common, serious, costly, under-recognised, and often fatal. A formal cognitive assessment and history of acute onset of symptoms are necessary for diagnosis. In view of the complex multifactorial causes of delirium, multicomponent non-pharmacological risk factor approaches are the most effective strategy for prevention. No convincing evidence shows that pharmacological prevention or treatment is effective. Drug reduction for sedation and analgesia and non-pharmacological approaches are recommended. Delirium offers opportunities to elucidate brain pathophysiology--it serves both as a marker of brain vulnerability with decreased reserve and as a potential mechanism for permanent cognitive damage. As a potent indicator of patients' safety, delirium provides a target for system-wide process improvements. Public health priorities include improvements in coding, reimbursement from insurers, and research funding, and widespread education for clinicians and the public about the importance of delirium.

Development of a risk score to guide brain imaging in older patients admitted with falls and confusion

OBJECTIVES

CT scanning of the brain is commonly performed in older people admitted to hospital with a fall, but the yield of positive findings is low. We used audit data to develop a risk-stratification score to guide more efficient use of CT scanning.

METHODS

12 potential predictors of positive CT findings were derived from a literature review. Case notes of consecutive patients presenting with falls and confusion who had undergone brain imaging were reviewed as part of an ongoing audit. Correlation of each factor with positive CT findings was undertaken and a final risk score was developed. Receiver-operating characteristic analysis was undertaken, an optimum cut-off identified, and positive and negative predictive values were calculated.

RESULTS

66 patients with a mean age of 74.8 years were included. 13 of the 66 (20%) brain imaging studies revealed a new pathology. Previous history of falls, atrial fibrillation, head or face trauma, focal neurological signs, warfarin use and a Glasgow coma score of <14 were significant univariate positive predictors. Antecedent dementia was included as a negative predictor. The final weighted score (range -1 to 8 points) gave an area under the curve of 0.83 (95% confidence interval 0.70 to 0.96, p<0.001). When using a cut-off of 3 points, sensitivity for significant new pathology on brain imaging was 83%, specificity was 89%, positive predictive value was 63% and negative predictive value was 96%.

CONCLUSION

A simple weighted risk score may be able to guide the need for brain imaging in older people presenting to hospital with falls. The score requires validation in a larger, prospectively collected cohort.

Drug-induced confusional states: the usual suspects?

BACKGROUND

Acute confusional state (ACS) is a frequent reason for hospital admission. This study examines retrospectively the frequency by which individual drugs were found responsible for ACS.

RESULTS

Drug-induced ACS was found in 65 (18.8%) of 346 hospital admissions for acute confusion. The most frequent causative substances were dopaminergic drugs in Parkinsonian patients (24.2%), diuretics (15.1%), tricyclic or tetracyclic antidepressants (13.6%) and benzodiazepines (13.6%). Almost half of the patients were demented, and in one-third of these, dementia had not been diagnosed hitherto.

CONCLUSION

The data suggest that diuretics by way of causing hyponatraemia are as relevant a cause of ACS as dopaminergic or anticholinergic substances.

Delirium in elderly adults: diagnosis, prevention and treatment

Delirium is a common and serious acute neuropsychiatric syndrome with core features of inattention and global cognitive dysfunction. The etiologies of delirium are diverse and multifactorial and often reflect the pathophysiological consequences of an acute medical illness, medical complication or drug intoxication. Delirium can have a widely variable presentation, and is often missed and underdiagnosed as a result. At present, the diagnosis of delirium is clinically based and depends on the presence or absence of certain features. Management strategies for delirium are focused on prevention and symptom management. This article reviews current clinical practice in delirium in elderly individuals, including the diagnosis, treatment, outcomes and economic impact of this syndrome. Areas of future research are also discussed.

Delirium in elderly adults: diagnosis, prevention and treatment

Delirium is a common and serious acute neuropsychiatric syndrome with core features of inattention and global cognitive dysfunction. The etiologies of delirium are diverse and multifactorial and often reflect the pathophysiological consequences of an acute medical illness, medical complication or drug intoxication. Delirium can have a widely variable presentation, and is often missed and underdiagnosed as a result. At present, the diagnosis of delirium is clinically based and depends on the presence or absence of certain features. Management strategies for delirium are focused on prevention and symptom management. This article reviews current clinical practice in delirium in elderly individuals, including the diagnosis, treatment, outcomes and economic impact of this syndrome. Areas of future research are also discussed.

Delirium in a 74-year-old man: correct imaging revealed the truth

Delirium is a cognitive disorder. DSM-IV criteria for delirium must include both acute onset and fluctuating symptoms; disturbance of consciousness (including inattention); at least one of the following: disorganised thinking, disorientation, memory impairment or perceptual disturbance; and evidence of a putative causal medical condition. Traditionally, the course has been described as transient in which recovery is likely to be complete if the underlying aetiological factor is promptly corrected or is self-limited. The most common precipitating causes in elderly include sepsis, dehydration and drugs. Work-up for delirium is limited to septic screening, baseline investigations and imaging. Patients with delirium without focal signs and with either evidence for a medical aetiology of delirium or pre-diagnosed dementia are at a very low risk of having focal lesions in their contrast-enhanced CT or MRI. We are presenting an interesting case of delirium with urosepsis whose imaging revealed milliary brain tuberculomas on contrast-enhanced MRI.