Neuropsychological profile of persons with anoxic brain injury: Differences regarding physiopathological mechanism

Acute hypoxia impairs posterior cerebral bioenergetics and memory in man

Hypoxia has the potential to impair cognitive function; however, it is still uncertain which cognitive domains are adversely affected. We examined the effects of acute hypoxia (∼7 h) on central executive (Go/No-Go) and non-executive (memory) tasks and the extent to which impairment was potentially related to regional cerebral blood flow and oxygen delivery (CDO2 ). Twelve male participants performed cognitive tasks following 0, 2, 4 and 6 h of passive exposure to both normoxia and hypoxia (12% O2 ), in a randomized block cross-over single-blinded design. Middle cerebral artery (MCA) and posterior cerebral artery (PCA) blood velocities and corresponding CDO2 were determined using bilateral transcranial Doppler ultrasound. In hypoxia, MCA DO2 was reduced during the Go/No-Go task (P = 0.010 vs. normoxia, main effect), and PCA DO2 was attenuated during memorization (P = 0.005 vs. normoxia) and recall components (P = 0.002 vs. normoxia) in the memory task. The accuracy of the memory task was also impaired in hypoxia (P = 0.049 vs. normoxia). In contrast, hypoxia failed to alter reaction time (P = 0.19 vs. normoxia) or accuracy (P = 0.20 vs. normoxia) during the Go/No-Go task, indicating that selective attention and response inhibition were preserved. Hypoxia did not affect cerebral blood flow or corresponding CDO2 responses to cognitive activity (P > 0.05 vs. normoxia). Collectively, these findings highlight the differential sensitivity of cognitive domains, with memory being selectively vulnerable in hypoxia. NEW FINDINGS: What is the central question of this study? We sought to examine the effects of acute hypoxia on central executive (selective attention and response inhibition) and non-executive (memory) performance and the extent to which impairments are potentially related to reductions in regional cerebral blood flow and oxygen delivery. What is the main finding and its importance? Memory was impaired in acute hypoxia, and this was accompanied by a selective reduction in posterior cerebral artery oxygen delivery. In contrast, selective attention and response inhibition remained well preserved. These findings suggest that memory is selectively vulnerable to hypoxia.

Which training methods are effective for learning new smartphone memory apps after acquired brain injury? A pilot randomized controlled trial comparing trial and error, systematic instruction and error-based learning

This study aimed to compare the efficacy of three skills training methods (Trial and error TEL; systematic instruction SI; and error-based learning EBL) for training the use of a smartphone reminder app in individuals with an acquired brain injury. Participants (N = 38, M_age = 61.21 years, 71.1% stroke) were randomly allocated to one of three training conditions and trained over one two-hour session. Proficiency of performance with the trained app (primary outcome) was assessed immediately post-training, one- and six-weeks post-intervention. Secondary outcomes included generalization of skills, error commission, smartphone use frequency and confidence, and subjective memory complaints. Proficiency with the trained app after TEL was higher than SI immediately after the training (d = 0.87) and EBL at the one-week follow-up (d = 0.98). No differences were found six-weeks post-training. Smartphone use confidence increased at the six-week follow-up after TEL (d = 1.12) and EBL training (d = 0.91) but not after SI (d = 0.26). Self-reported memory complaints decreased across time for all groups (η_p² = 0.30). There was no clearly superior training method for optimizing proficiency with the reminder app. The expected benefits of SI and EBL may not have emerged due to the single-session format of the training. However, smartphone training via TEL or EBL has the potential to address confidence-related barriers to smartphone use.

Long-term Neuropsychiatric Complications and 18F-FDG-PET Hypometabolism in the Brain From Prolonged Infection of COVID-19

It is becoming increasingly clear that the worldwide outbreak of severe acute respiratory syndrome coronavirus 2 will have long-term negative consequences. Some patients report functional complaints long after recovery from coronavirus disease-2019 (COVID-19), which include fatigue, breathlessness, heart palpitations, loss or alteration of taste and smell, and problems with attention, memory, and cognition. However, the long-term complications for those patients who had severe symptoms and prolonged hypoxia during their course of their hospital stay is still unknown. We report 2 patients with confirmed diagnoses of COVID-19 who experienced prolonged infection and developed rapid progressive dementia following COVID-19 pneumonia after a follow-up period of 5 to 10 months. As these cases may become more prevalent over time, we should learn to recognize the early signs of long-term COVID-19 complications in those who are especially vulnerable to neurocognitive decline.

Preliminary construct validity of a memory concerns scale derived from a PROMIS® item bank in a spanish-speaking sample

This study examined preliminary evidence of construct validity in a stand-alone memory concerns scale constructed from the Patient-Reported Outcomes Measurement Information System (PROMIS®) Cognitive Function item bank. A sample of 396 individuals, ages 18-75 (M = 33.7, SD = 12.7), from Spain and Latin America completed an online survey regarding lifetime exposure to factors associated with neurological compromise. The sample was 69.4% female. Respondents completed 8 items from the PROMIS® Cognitive Function item bank v1.0 dealing with memory concerns (MCS-8) along with the PROMIS® 8-item short form reflecting general cognitive concerns (CCS-8). The MCS-8 had high internal consistency reliability (Cronbach's alpha = 0.90), and represented a factor distinct from general cognitive concerns items on the CCS-8 in confirmatory factor analysis. Analysis of covariance controlling for sex, age, and education, showed that individuals endorsing history of exposure to sources of neurological compromise scored significantly lower T-scores on the MCS-8 than those who did not report any such history, F(1,390) = 6.4, p = 0.012. Older age was significantly associated with greater memory concerns, a relationship with age not observed with the CCS-8. As a stand-alone self-report measure, the MCS-8 appears to measure a construct distinct from general cognitive concerns that may be of interest for further research in clinical populations.

Cognitive Impairment in Convalescent COVID-19 Patients Undergoing Multidisciplinary Rehabilitation: The Association with the Clinical and Functional Status

BACKGROUND

Cognitive impairment has been reported in the aftermath of severe acute respiratory syndrome due to coronavirus 2 (SARS-CoV-2) infection. We investigated the possible association between cognitive impairment and the main clinical and functional status variables in a cohort of convalescent COVID-19 patients without premorbid diseases potentially affecting cognition.

METHODS

We consecutively screened for inclusion of convalescent COVID-19 patients referring to a post-acute care facility for pulmonary rehabilitation. All the enrolled patients were assessed for cognitive functions. We also investigated features of psychological distress (anxiety, depression, symptoms of posttraumatic stress disorder and quality of life) and cardiac and pulmonary functional status.

RESULTS

The 63 enrolled patients (mean age 59.82 ± 10.78, male gender = 47) showed a high frequency of depressive symptoms (76.2%) and anxiety (55.5%), and a high prevalence of symptoms of posttraumatic stress disorder (PTSD, 44.4%). About half of the total sample showed reduced cognitive efficiency (RCE, 44.4%) in the domains of spatial and verbal long-term memory and executive functions. Patients with RCE more frequently showed alteration of blood pressure (BP) circadian rhythm (p = 0.01), higher levels of D-Dimer (p = 0.03), had experienced a severe illness (p = 0.02), had longer disease duration (p = 0.04), more clinically relevant symptoms of PTSD (p = 0.02), more frequent cognitive complaints (p = 0.002), higher anxiety scores (p = 0.01) and lower quality of life (p = 0.02) than patients with normal cognitive efficiency.

CONCLUSIONS

Our findings indicated a possible association between the RCE after COVID-19 and some cardiological variables, including some indirect measures of a residual autonomic disorder, such as the presence of an altered BP circadian rhythm. Future research studies with large samples are needed to provide valid conclusions.

Frequency and profile of objective cognitive deficits in hospitalized patients recovering from COVID-19

Early reports and case series suggest cognitive deficits occurs in some patients with COVID-19. We evaluated the frequency, severity, and profile of cognitive dysfunction in patients recovering from prolonged COVID-19 hospitalization who required acute inpatient rehabilitation prior to discharge. We analyzed cross-sectional scores from the Brief Memory and Executive Test (BMET) in a cohort of N = 57 COVID-19 patients undergoing inpatient rehabilitation, calculating the frequency of impairment based on neuropsychologist diagnosis and by age-normed BMET subtests. In total, 43 patients (75%) were male, 35 (61%) were non-white, and mean age was 64.5 (SD = 13.9) years. In total, 48 (84%) were previously living at home independently. Two patients had documented preexisting cognitive dysfunction; none had known dementia. Patients were evaluated at a mean of 43.2 (SD = 19.2) days after initial admission. In total, 50 patients (88%) had documented hypoxemic respiratory failure and 44 (77%) required intubation.  Forty-six patients (81%) had cognitive impairment, ranging from mild to severe. Deficits were common in working memory (26/47 [55%] of patients), set-shifting (21/44 [47%]), divided attention (18/39 [46%]), and processing speed (14/35 [40%]). Executive dysfunction was not significantly associated with intubation length or the time from extubation to assessment, psychiatric diagnosis, or preexisting cardiovascular/metabolic disease. Attention and executive functions are frequently impaired in COVID-19 patients who require acute rehabilitation prior to discharge. Though interpretation is limited by lack of a comparator group, these results provide an early benchmark for identifying and characterizing cognitive difficulties after COVID-19. Given the frequency and pattern of impairment, easy-to-disseminate interventions that target attention and executive dysfunctions may be beneficial to this population.

Neuronal Death in the CNS Autonomic Control Center Comes Very Early after Cardiac Arrest and Is Not Significantly Attenuated by Prompt Hypothermic Treatment in Rats

Autonomic dysfunction in the central nervous system (CNS) can cause death after recovery from a cardiac arrest (CA). However, few studies on histopathological changes in animal models of CA have been reported. In this study, we investigated the prevalence of neuronal death and damage in various brain regions and the spinal cord at early times after asphyxial CA and we studied the relationship between the mortality rate and neuronal damage following hypothermic treatment after CA. Rats were subjected to 7-8 min of asphyxial CA, followed by resuscitation and prompt hypothermic treatment. Eight regions related to autonomic control (the cingulate cortex, hippocampus, thalamus, hypothalamus, myelencephalon, and spinal cord) were examined using cresyl violet (a marker for Nissl substance) and Fluoro-Jade B (a marker for neuronal death). The survival rate was 44.5% 1 day post-CA, 18.2% 2 days post-CA and 0% 5 days post-CA. Neuronal death started 12 h post-CA in the gigantocellular reticular nucleus and caudoventrolateral reticular nucleus in the myelencephalon and lamina VII in the cervical, thoracic, lumbar, and sacral spinal cord, of which neurons are related to autonomic lower motor neurons. In these regions, Iba-1 immunoreactivity indicating microglial activation (microgliosis) was gradually increased with time after CA. Prompt hypothermic treatment increased the survival rate at 5 days after CA with an attenuation of neuronal damages and death in the damaged regions. However, the survival rate was 0% at 12 days after CA. Taken together, our study suggests that the early damage and death of neurons related to autonomic lower motor neurons was significantly related to the high mortality rate after CA and that prompt hypothermic therapy could increase the survival rate temporarily after CA, but could not ultimately save the animal.

Factors predicting rehabilitation outcomes after severe acquired brain injury in trauma, stroke and anoxia populations: A cohort study

Severe acquired brain injury has long-term physical and cognitive effects. Identifying patient variables predictive of recovery in different brain injury populations would generate improved prognostic information and help rehabilitation teams set appropriate therapeutic goals. This cohort study of 447 NHS neurorehabilitation inpatients aimed to identify functional and cognitive predictors of recovery following severe acquired brain injury caused by trauma, stroke and anoxia. Motor and cognitive impairment ratings were collected at admission and discharge using the Functional Independence Measure and Functional Assessment Measure (FIM+FAM), and injury-related and demographic data were collated from medical records. Predictors of physical, cognitive and overall recovery were identified via hierarchical regression analyses. Several key findings emerged. Firstly, on-admission motor skills predicted functional and overall outcomes across groups. Secondly, on-admission social interaction skills predicted cognitive discharge outcomes in stroke and trauma, and overall outcomes for stroke, but did not predict anoxia outcomes. Thirdly, age predicted all forms of recovery for stroke only. Further group-specific factors were also identified as predicting motor and cognitive recovery, indicating that factors key to the rehabilitation trajectory may differ between populations. These variables should be considered in rehabilitation goal planning, although further research is required to explore their contributions to recovery.

Number Processing Error as a Clinical Manifestation of Hemispatial Neglect Following Hypoxic Brain Injury: a Case Report

Hemispatial neglect is a symptom where patients do not show response to stimuli on the contralesional side of their brain lesion. Although it is most common in the context of hemispheric stroke, several pathological processes including neurodegenerative disease, neoplasia, and trauma may cause this. Prevalence of hemispatial neglect is unknown and rarely reported among patients with hypoxic brain injury. Also, hemispatial neglect accompanying neglect dyslexia is rather hard to be recognized and symptoms involving numbers are exceptionally rare. We report a patient with hypoxic brain injury following cardiac arrest who showed signs of neglect dyslexia for numbers that provided a primary clue for the diagnosis of left hemispatial neglect. Early detection of different forms of cognitive dysfunction of hypoxic brain injury is highly essential in providing early neurorehabilitation for better prognosis.

A comparison of systematic instruction, error-based learning and trial and error to train the use of smartphone memory apps after acquired brain injury: A three-armed phase II randomised controlled trial study protocol

Background:

The uptake of smartphones as external compensatory memory aids following an acquired brain injury (ABI) in rehabilitation settings is low. Potential reasons for this include professionals not having evidence-based guidelines regarding the best methods to train smartphone use and prospective users not being familiar with technology and/or having memory and learning difficulties. This paper describes the protocol of a study that aims to compare the efficacy of three training methods (Systematic Instruction, Error-based Learning and Trial-and-Error) for training the use of a smartphone reminder app, in people with ABI presenting with memory complaints.

Methods/Design:

This is a three-armed, assessor-blinded, Phase II randomised controlled trial. The estimated sample size is 51 participants aged >18 years, who are equally randomised to one of the three training groups. They are seen across four sessions: one to conduct baseline measures; one for training the use of an app and two for follow-up assessments (1- and 6-weeks post-training). The main outcome measure is proficiency of performance in tasks with the trained app. Secondary outcomes include generalisation of skills to other apps, number of errors committed while attempting the tasks, frequency of smartphone usage in general and as a memory aid and confidence in smartphone use and memory self-efficacy. Outcome measures are collected by an independent blinded assessor. Proficiency of performance, generalisation of skills and error commission are measured immediately post-training and at the two follow-up sessions. The other secondary measures are taken pre-intervention and at the two follow-up sessions.

Discussion:

This study will provide initial evidence regarding the efficacy of three different methods to train ABI survivors with memory difficulties in how to use smartphone apps as compensatory memory aids. The results could inform a larger Phase III trial and advance knowledge concerning the advantages or disadvantages of using error-reducing and trial-and-error techniques. Further, the findings could determine the potential of error-based learning as an emerging training method for people with memory impairment within rehabilitation.

Communicative and swallowing disorders in anoxic patients: A retrospective study on clinical outcomes and performance measures

BACKGROUND

Anoxic brain injury (ABI) is a neurological condition associated to a severe deterioration of brain functioning, whose symptomatology and clinical outcomes may be heterogeneous: cognitive deficits, language disorders like dysarthria and swallowing impairments. Nevertheless, there is still a lack of information on the rehabilitation outcomes.

OBJECTIVE

To confirm the occurrence of communication and swallowing deficits in 37 ABI patients and to examine whether intensive rehabilitation may contribute to any improvements and its relation to ABI severity and functional autonomy.

METHODS

37 patients, hospitalized at IRCCS San Camillo Hospital from 2011 to 2018 were analyzed retrospectively. All patients completed a functional evaluation and a language and swallowing assessment, within one week from hospital admission (T0). The assessment was repeated after an intensive rehabilitation treatment (T1).

RESULTS

Results show that dysphagia is a frequent and severe outcome in anoxic patients, whereas communication disorders (aphasia and dysarthria) are less severe. Moreover, ABI patients seem to be positively sensitive to an intensive rehabilitation program.

CONCLUSIONS

An early multidisciplinary management of communicative-linguistic and swallowing functions is crucial in order to prevent adverse events and to plan a tailored rehabilitation pathway.

Validity of early-onset dementia diagnoses in VA electronic medical record administrative data

OBJECTIVE

To determine the validity of diagnoses indicative of early-onset dementia (EOD) obtained from an algorithm using administrative data, we examined Veterans Health Administration (VHA) electronic medical records (EMRs).

METHOD

A previously used method of identifying cases of dementia using administrative data was applied to a random sample of 176 cases of Post-9/11 deployed veterans under 65 years of age. Retrospective, cross-sectional examination of EMRs was conducted, using a combination of administrative data, chart abstraction, and review/consensus by board-certified neuropsychologists.

RESULTS

Approximately 73% of EOD diagnoses identified using existing algorithms were identified as false positives in the overall sample. This increased to approximately 76% among those with mental health conditions and approximately 85% among those with mild traumatic brain injury (TBI; i.e. concussion). Factors related to improved diagnostic accuracy included more severe TBI, diagnosing clinician type, presence of neuroimaging data, absence of a comorbid mental health condition diagnosis, and older age at time of diagnosis.

CONCLUSIONS

A previously used algorithm for detecting dementia using VHA administrative data was not supported for use in the younger adult samples and resulted in an unacceptably high number of false positives. Based on these findings, there is concern for possible misclassification in population studies using similar algorithms to identify rates of EOD among veterans. Further, we provide suggestions to develop an enhanced algorithm for more accurate dementia surveillance among younger populations.

Cognitive performance in transient global hypoxic brain injury due to moderate drowning

INTRODUCTION

Drowning is a serious and frequently neglected public health threat. Primary respiratory impairment after submersion often leads to brain dysfunction. Depending on the period of global hypoxia (respiratory failure), clinical aspects of neurological dysfunction are evident on the first evaluation after the water rescue. Nowadays, many neuropsychological assessments after drowning are inconclusive, with some studies reporting only minor neurological or cognitive impairments. The aim of this study is to identify measures in neuropsychological tests that most contribute to classify volunteers as moderate drowning subjects or healthy controls. To the best of our knowledge, this study is the first neuropsychological prospective case-control study of moderate drowning in a country with large coastal cities.

METHOD

Fifteen moderate drowning patients (DP), who met the inclusion criteria, were compared with 18 healthy controls (HC). All subjects were assessed on memory, learning, visual spatial ability, executive function, attention, and general intellectual functioning and underwent structural magnetic resonance (MR) imaging of the brain at 3.0 T, in order to exclude subjects with anatomic abnormalities.

RESULTS

Neuropsychological tests assessing learning, execution function, and verbal fluency-Rey Auditory Verbal Learning Test (RAVLT) general learning ability, Digit Span total, Phonological Verbal Fluency (total FAS correct), and Brief Visuospatial Memory Test Revised (BVMT) correct recognition-have the strongest discriminating ability, using predictive models via the partial least squares (PLS) approach for data classification, while the other tests have shown similar predictive values between groups.

CONCLUSIONS

Learning, execution function, and verbal fluency domains were the most critically affected domains. Serious impairments in the same domains have already been reported in severe drowning cases, and we hypothesize that subtle alterations found in moderate drowning cases, although not sufficient to be detected in daily routine, may possibly have a negative impact on cognitive reserve.

Bilateral Hippocampal Restricted Diffusion: Same Picture Many Causes

With some regularity, we have encountered the unusual imaging abnormality of bilateral hippocampal restricted diffusion, either in isolation or in combination with other coincident abnormalities. In this retrospective case series, we examine clinical and imaging data to explore potential etiologies and clinical implications of this imaging finding. Sixteen cases with the imaging abnormality are presented, with etiologies including hypoxemia, hypoxemia-ischemia, and seizures.

Reading as a Nursing Intervention for Agitation in Patients With Anoxic Brain Injury

PURPOSE

The purpose of this article is to describe and recommend reading as a nursing intervention for agitated patients with anoxic brain injury.

DESIGN

The design of this study is a case report of the results from reading to an agitated patient with anoxic brain injury.

METHODS

Observation of the effects of reading to an agitated patient.

FINDINGS

Fifteen minutes of reading to an agitated patient during the evening hours had a calming effect.

CONCLUSIONS

Reading to agitated patients is an additional nursing intervention with little risk and represents efficient, patient-centered care.

CLINICAL RELEVANCE

Reading is a successful nursing intervention that has a calming effect on agitated patients.