Procedural Learning and Memory Rehabilitation in Korsakoff's Syndrome - a Review of the Literature

Transcranial electrical stimulation for procedural learning and rehabilitation

Procedural learning is the acquisition of motor and non-motor skills through a gradual process that increases with practice. Impairments in procedural learning have been consistently demonstrated in neurodevelopmental, neurodegenerative, and neuropsychiatric disorders. Considering that noninvasive brain stimulation modulates brain activity and boosts neuroplastic mechanisms, we reviewed the effects of coupling transcranial direct current stimulation (tDCS) with training methods for motor and non-motor procedural learning to explore tDCS potential use as a tool for enhancing implicit learning in healthy and clinical populations. The review covers tDCS effects over i. motor procedural learning, from basic to complex activities; ii. non-motor procedural learning; iii. procedural rehabilitation in several clinical populations. We conclude that targeting the primary motor cortex and prefrontal areas seems the most promising for motor and non-motor procedural learning, respectively. For procedural rehabilitation, the use of tDCS is yet at an early stage but some effectiveness has been reported for implicit motor and memory learning. Still, systematic comparisons of stimulation parameters and target areas are recommended for maximising the effectiveness of tDCS and its robustness for procedural rehabilitation.

Neuropsychiatric and Neuropsychological Aspects of Alcohol-Related Cognitive Disorders: An In-Depth Review of Wernicke's Encephalopathy and Korsakoff's Syndrome

Alcohol-related cognitive disorders have long been an area of study, yet they continue to pose challenges in the diagnosis, treatment, and understanding of underlying neuropsychiatric mechanisms. The present article offers a comprehensive review of Wernicke's Encephalopathy and Korsakoff's Syndrome, two conditions often seen on a continuum of alcohol-related brain damage. Drawing on current medical literature, neuroimaging studies, and clinical case reports, we explore the neuropsychiatric and neuropsychological profiles, symptomatology, and differential diagnoses of these disorders. We delve into the biochemical pathways implicated in the development of WE and KS, notably thiamine deficiency and its impact on neurotransmitter systems and neural networks. The article also addresses the challenges in early diagnosis, often complicated by non-specific symptoms and co-occurring psychiatric conditions. Furthermore, we review the current state of treatment protocols, including pharmacological and non-pharmacological interventions. Finally, the article highlights gaps in current knowledge and suggests directions for future research to improve diagnosis, treatment, and patient outcomes. Understanding the nuanced interplay between the neuropsychiatric and neuropsychological aspects of WE and KS is crucial for both clinicians and researchers alike, in order to provide effective treatment and to advance our understanding of these complex conditions.

Procedural learning and retention relative to explicit learning and retention in mild cognitive impairment and Alzheimer's disease using a modification of the trail making test

Amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD) dementia are characterized by pathological changes to the medial temporal lobes, resulting in explicit learning and retention reductions. Studies demonstrate that implicit/procedural memory processes are relatively intact in these populations, supporting different anatomical substrates for differing memory systems. This study examined differences between explicit and procedural learning and retention in individuals with aMCI and AD dementia relative to matched healthy controls. We also examined anatomical substrates using volumetric MRI. Results revealed expected difficulties with explicit learning and retention in individuals with aMCI and AD with relatively preserved procedural memory. Explicit verbal retention was associated with medial temporal cortex volumes. However, procedural retention was not related to medial temporal or basal ganglia volumes. Overall, this study confirms the dissociation between explicit relative to procedural learning and retention in aMCI and AD dementia and supports differing anatomical substrates.

Music Therapy and Korsakoff's Syndrome: The State of the Art

In this perspective article, the authors give insight into the beneficial effects and the current developments in music therapy for patients with Korsakoff's syndrome (KS) in the Netherlands. Music may be the key to distracting patients from negative moods, to help them express emotions and to teach them new skills on physical, psychosocial and cognitive levels. This may lead to improving the quality of life of patients with KS. Emphasis is placed on the personal experience of the authors and on the future directions in the field. Their experience, as well as the experience of music therapy colleagues working in the field with the same target population (joined together in the Music Therapy Korsakoff Expertise Group), is situated in the context of existing literature and showcases current developments in the specific field of music therapy and KS. Since literature on this specific topic is limited, the authors allowed themselves to delve into somewhat older but still leading and representative literature. There is still little knowledge on how music therapy may contribute to reducing the impairments patients with KS suffer and to improving their quality of life in general. Using the Empathic Directive Approach (EDA) as the starting point, the authors elaborate on different potential approaches and interventions. With this article, the authors aim to gain more insight into the potential role of the music therapist by highlighting music-therapeutic micro-interventions and to provide recommendations for future directions on how to integrate music therapy in the treatment of patients with Korsakoff's syndrome.

Eye Movements as Proxy for Visual Working Memory Usage: Increased Reliance on the External World in Korsakoff Syndrome

In the assessment of visual working memory, estimating the maximum capacity is currently the gold standard. However, traditional tasks disregard that information generally remains available in the external world. Only when to-be-used information is not readily accessible, memory is taxed. Otherwise, people sample information from the environment as a form of cognitive offloading. To investigate how memory deficits impact the trade-off between sampling externally or storing internally, we compared gaze behaviour of individuals with Korsakoff amnesia (n = 24, age range 47-74 years) and healthy controls (n = 27, age range 40-81 years) on a copy task that provoked different strategies by having information freely accessible (facilitating sampling) or introducing a gaze-contingent waiting time (provoking storing). Indeed, patients sampled more often and longer, compared to controls. When sampling became time-consuming, controls reduced sampling and memorised more. Patients also showed reduced and longer sampling in this condition, suggesting an attempt at memorisation. Importantly, however, patients sampled disproportionately more often than controls, whilst accuracy dropped. This finding suggests that amnesia patients sample frequently and do not fully compensate for increased sampling costs by memorising more at once. In other words, Korsakoff amnesia resulted in a heavy reliance on the world as 'external memory'.

The Use of an Errorless Learning Application to Support Re-Learning of (Instrumental) Activities for People Living with Korsakoff Syndrome

Korsakoff syndrome (KS) is a severe neuropsychiatric syndrome derived from acute thiamine deficiency and concomitant alcohol use disorders. KS patients need lifelong assistance because of the severity of their cognitive problems. In clinical practice and research, errorless learning has proven to be an effective cognitive rehabilitation method for patients with KS. Our study focused on optimizing errorless learning by introducing new software technology to support the training process of errorless learning. Although the benefits of errorless learning for patients with Korsakoff's syndrome have been thoroughly investigated, it is currently unclear whether new technology could contribute to better learning and maintenance of everyday tasks. Therefore, an errorless learning application was built. This device is a web application and can be used on a tablet, laptop, or smartphone. The application allows clinicians and researchers to insert pictures, videoclips, timers, and audio fragments in the different steps of an errorless learning training plan. This way, the different steps are visible and easy to follow for patients. Moreover, it ensures as a learning method that the training is executed exactly the same way for each and every training. The aim of this study was twofold: to examine whether the use of the errorless learning application is effective, and whether it leads to better results than a regular errorless learning of everyday activities. In total, 13 patients with KS were trained in instrumental activities of daily living by means of the application, and 10 patients were trained with traditional instructions. Results showed an equal improvement for both training methods. Importantly, the technology group could better remember the training when probed at a later moment than the traditional errorless learning group. These results are promising for further development of novel technology to support errorless learning applications in clinical practice.

Patients With Severe Alcohol-Related Cognitive Impairment Improve in Flexibility When Abstinence Is Maintained: A Comparative Study With Alzheimer’s Disease

The disease progression of severe alcohol-related cognitive impairment (ARCI) is debated. The aim of this study was to compare the cognitive change of patients with severe ARCI in inpatient setting to that of patients with Alzheimer’s disease (AD). Fifteen consecutive patients with severe ARCI were recruited between 2013 and 2015. They received inpatient detoxification, neurological assessment, and inpatient cognitive rehabilitation in specialized facilities. Twelve patients, with documented AD matched on sex and initial cognitive impairment severity, were selected. All have benefited from two neuropsychological assessments. The neurocognitive change was tested in both groups with pair-wised Wilcoxon tests. ARCI and AD patients’ time course was compared with Mann–Whitney–Wilcoxon test. In ARCI group, first assessment occurred at 2.9 (± 2.2) months of abstinence and follow-up 6.5 (± 2.9) months later, the mean age was 56.5 (± 7.4) years, and 12 were men. In AD group, follow-up occurred at 12.8 (± 2.9) months (p < 10–3), the mean age was 72.3 (± 8.4) years (p < 10–3), and 10 were men. ARCI patients significantly improved on one executive function test (TMT-B; p < 0.05), while AD patients have worsened memory subtests on Free-and-Cued-Selective-Reminding Test (p < 0.05). These tests showed a statistically different change between severe ARCI and AD group (p < 0.05). Severe ARCI patients have improved in executive functioning, discernible on the TMT-B test, in specific care setting, including abstinence maintenance and rehabilitation. The disease progression was different from that observed in AD patients.

Construction of complex memories via parallel distributed cortical-subcortical iterative integration

The construction of complex engrams requires hippocampal-cortical interactions. These include both direct interactions and ones via often-overlooked subcortical loops. Here, we review the anatomical organization of a hierarchy of parallel 'Papez' loops through the hypothalamus that are homologous in mammals from rats to humans. These hypothalamic loops supplement direct hippocampal-cortical connections with iterative reprocessing paced by theta rhythmicity. We couple existing anatomy and lesion data with theory to propose that recirculation in these loops progressively enhances desired connections, while reducing interference from competing external goals and internal associations. This increases the signal-to-noise ratio in the distributed engrams (neocortical and cerebellar) necessary for complex learning and memory. The hypothalamic nodes provide key motivational input for engram enhancement during consolidation.

Smartwatch reminders are as effective as verbal reminders in patients with Korsakoff's syndrome: three case studies

Korsakoff's syndrome (KS) is a neurocognitive disorder caused by severe malnutrition. KS patients typically show severe impairments in prospective memory (PM), thus, have difficulties with remembering to perform delayed intentions. The current study investigated the possible benefits of a smartwatch aid for PM tasks in patients with KS and compared its efficacy with verbal in-person reminders. Three patients participated in the present study and were asked to complete everyday PM tasks. The results of each patient were analyzed as a single-case study. The results highlight the great potential of using smartwatches as external memory aids in KS patients in everyday life.

"Vascular" Korsakoff Syndrome With Bilaterally Damaged Mammillothalamic Tracts: Insights Into the Pathogenesis of "Acute" Korsakoff Syndrome As Acute-Onset Irreversible Anterograde Amnesia

The structural pathogenesis of Wernicke-Korsakoff syndrome remains debatable. Wernicke encephalopathy is acute and often reversible whereas Korsakoff syndrome (KS) is chronic and may be irreversible. The cognitive deficits observed in KS are considered to be primarily due to damage to the anterior nucleus of the thalamus, mammillary bodies, and corpus callosum. We present an extremely rare case of non-alcoholic “vascular” KS (vKS) as acute-onset amnesia. A 97-year-old man living alone was brought to our hospital, complaining of sudden-onset behavioral changes with amnesia. Diffusion-weighted images (DWIs) showed fresh cerebral infarction in the right thalamus involving the right mammillothalamic tract (MTT). T2*-weighted images (T2*WIs), in addition, revealed a microbleed scar over the left MTT. This case supports the hypothesis that bilateral MTT dysfunction can lead to KS. Furthermore, in collaboration with a prior report about non-alcoholic “acute” KS due to cerebral infarction, this case supports the existence of vascular KS as an acute-onset amnestic syndrome, as well as insight into the pathogenesis of KS as an irreversible amnestic syndrome.

Korsakoff syndrome: An overlook (Review)

This review aimed to analyze the latest neurobiological findings regarding Korsakoff syndrome, since alcoholism is the most prevalent addiction worldwide. In addition, we analyzed the optimal treatment that can be administered in order to minimize the symptoms and improve the outcome of these patients. The disruption of memory circuits within the brain of alcoholic patients results in the amnestic syndrome known as Korsakoff syndrome. It is generally characterized by a chronic neuropsychiatric syndrome caused by vitamin B1 (thiamine) deficiency. Other categories of patients can develop Korsakoff syndrome without consuming alcohol such as AIDS patients, terminally ill cancer patients, or patients with chronic infections and malnutrition. Vitamin B1 is required in the Krebs cycle for production of adenosine triphosphate (ATP). It is also a cofactor in the production of acetylcholine and certain neurotransmitters. Alcohol consumption can decrease the intake, gastrointestinal absorption and cellular utilization of vitamin B1. Treatment of alcohol withdrawal along with high doses of vitamin B1 can improve the general outcome of patients. A small percentage of patients can recover from Wernicke's encephalopathy with no permanent brain damage. The onset of Korsakoff syndrome darkens the prognosis. Alcohol abstinence is an absolute recommendation and prevents the extension of neural damage.

Wernicke-Korsakoff Syndrome in Hyperemesis Gravidarum: A Case Report and Literature Review

BACKGROUND

Wernicke-Korsakoff syndrome (WKS) is a triad of ophthalmoplegia, ataxia and memory deficits due to thiamine insufficiency resulting from under- or untreated Wernicke's encephalopathy (WE), which may be associated with hyperemesis gravidarum (HEG).

CASE PRESENTATION

We present a case of a 36-year-old Filipino woman in her first trimester with HEG, along with the WKS triad and abnormal hyperintense signals in the bilateral thalami and midbrain, left occipital lobe, periaqueductal gray matter and pontine periventricular areas. Neurologic deficits partially improved but persisted despite intravenous thiamine administration.

EVIDENCE REVIEW

A review of current treatments for WE, and the prevention and neurocognitive recovery of WKS was done. The beneficial effects of thiamine for acute WKS are supported by several case reports and clinical experience. Evidence from one randomized controlled trial wherein thiamine was given in various doses for treating WE or preventing WKS in an alcohol-dependent population is limited by methodological issues. Rehabilitation and pharmacotherapy for neurocognitive recovery seems promising, but they have inadequate evidentiary support. More robust studies on multi-modal strategies are warranted to facilitate the neurocognitive recovery of patients with WKS.

Recognition of younger and older faces in Korsakoff's syndrome

The own-age bias refers to the observation that face recognition is typically superior for own-age faces compared with other-age faces. We investigated this bias in Korsakoff patients, as well as its relationship with social contact and episodic memory. Korsakoff patients and age-matched controls were exposed to older faces (own-age faces) and younger faces (other-age faces). In the recognition phase, they were invited to decide whether faces had been exposed in the encoding phase or not. Results revealed an own-age bias in control participants (i.e., high recognition of older than for younger faces), but not in Korsakoff patients (i.e., similar recognition of older and younger faces). Furthermore, both Korsakoff's syndrome and controls reported more social contact with old than with young individuals. Recognition of younger and older faces in Korsakoff patients was significantly correlated with episodic performance but not with social contact with younger and older people. We conclude that the lack of own-age bias in Korsakoff's syndrome is related rather to compromise of episodic memory than to diminished social contact with younger adults.

Memantine Usage for Management of Korsakoff Syndrome in the Setting of Chronic Alcohol Use and Unspecified Eating Disorder

Korsakoff syndrome is a neuropsychiatric condition frequently seen as a progression of Wernicke’s encephalopathy and is often associated with long-term alcohol abuse. It is characterized by further cognitive impairments, such as indiscriminate anterograde and retrograde amnesia, in addition to executive function deficits. As the syndrome is a result of severe thiamine deficiency, its management primarily focuses on nutritional replenishment and electrolyte maintenance. In recent years, a few published reports have detailed the off-label use of Food and Drug Administration (FDA) approved drugs for Alzheimer’s in an attempt to treat neurocognitive deficits associated with Korsakoff patients. In this particular case, we note subjective improvement in cognition after initiating memantine, an N-Methyl-d-aspartate (NMDA) receptor antagonist.

Behavioural effects of light intervention in people with Korsakoff Syndrome: A pilot study

Korsakoff Syndrome (KS) is commonly associated with behavioural symptoms such as agitation, apathy, and disinhibition. People with KS often reside in long-term care facilities, which reduces their exposure to natural light. Little is known regarding positive effects of light intervention in KS. Our objective was to evaluate the influence of a dawn simulation therapy on behavioural symptoms in KS. 38 patients residing in a 24-hour care facility were exposed for 6 weeks to a dawn simulation system in their bedrooms, which gradually increased from 0 lux to 290 lux. Behavioural symptoms were measured over 9 weeks. Weeks 1-3 consisted of the baseline phase and weeks 3-9 consisted of the light intervention phase. Our study showed that total severity of neuropsychiatric symptoms was less prominent during light intervention. More specifically, a decrease on the apathy, disinhibition, behaviour at night and appetite and eating behaviour subscales was found during the light intervention phase compared to the baseline phase. Additionally, a significant effect was found on decreasing emotional distress for caregivers. Results suggest that light intervention therapy has a positive effect on reducing behavioural symptoms in KS as well as the levels of stress experienced by the patients' caregivers.

High emotional experience during autobiographical retrieval in women with Korsakoff syndrome

INTRODUCTION

In this exploratory study, we investigated gender differences regarding autobiographical memory in KS.

METHOD

We invited 33 patients with KS and 35 matched control participants to retrieve autobiographical memories and, afterward, to rate mental time travel during retrieval, emotional value and importance of memories.

RESULTS

Analysis demonstrated lower specificity (i.e., lower ability to retrieve memories situated in a specific time and space), mental time travel, and importance in patients with KS compared to control participants. Analysis also demonstrated no significant difference between patients with KS and control participants regarding emotion. Critically, analysis demonstrated no significant differences neither women and men with KS, nor between women and men in the control group, regarding autobiographical specificity, mental time travel, or importance. However, women with KS attributed higher emotional value for memories compared to men with KS, and the same results were observed in the control group.

DISCUSSION

These findings demonstrate that the higher emotional experience during autobiographical retrieval, as observed in the general population, can also be observed in KS.

Unraveling Apathy in Korsakoff Syndrome Patients Receiving Long-Term Care With and Without Cerebrovascular Comorbidity

BACKGROUND

Korsakoff syndrome (KS) is a severe neuropsychiatric disorder caused by acute deficiency of vitamin B1 and concomitant alcoholism. Patients with KS are particularly vulnerable for cerebrovascular comorbidity. KS is characterized by cognitive and neuropsychiatric symptoms, one of which is apathy. Apathy is a pathological lack of goal-directed behaviors, goal-directed cognitions, and goal-directed emotions. Cerebrovascular accidents are known to carry a risk for developing apathy. Apathy has a dramatic effect on the autonomy and daily lives of patients suffering from this condition.

METHODS

We assessed general apathy and related subconstructs in fifteen patients with KS, fifteen patients with KS and cerebrovascular comorbidity who reside in a 24-hour care facility, and fifteen healthy controls.

RESULTS

Compared with healthy controls, both KS patient groups showed higher levels of apathy as rated by a close informant. We found no difference between both KS patient groups and the healthy control group on the self-report section of the Pleasant Activities List, suggesting that motivation is still intact in KS patients. It is important to note a discrepancy was found between self-reporting and proxy reporting on this list. KS patients with cerebrovascular comorbidity showed more severe emotional blunting compared to both KS patients without cerebrovascular comorbidity and healthy controls. The competency to consent was lower in patients compared with healthy controls, but no difference was found between KS patients with cerebrovascular comorbidity and those without.

CONCLUSIONS

Our results suggest that KS patients show increased levels of general apathy compared with healthy controls. Patients show a diminished competency to consent and increased emotional blunting, while motivation is not compromised. Cerebrovascular comorbidity in KS forms a high risk for emotional blunting. The results of this study suggest that apathy is a severe problem in KS. More attention in both the literature and clinical practice would benefit this complex patient population.

Domains of cognition and their assessment

Cognitive performance is typically conceptualized in terms of domains of functioning. These domains are hierarchical in nature, with the bottom referring to more basic sensory and perceptual processes and the top referring to elements of executive functioning and cognitive control. Domains are not independent of each other and executive functioning exerts control over the utilization of more basic processes. Assessments are typically targeted at subdomains of each ability area and careful combination of tasks can reveal patterns of performance consistent with a variety of different neurological and neuropsychiatric conditions. This review covers the general structures of domains, the patterns of impairments across domains seen in common neuropsychiatric conditions, and use of assessment strategies to differentiate, to the extent possible, between different types of conditions manifesting cognitive impairment.


Chunking to improve verbal forward spans in Korsakoff's syndrome

Chunking is a mnemonic strategy that involves organizing information into appropriate units. Our article examined the use of this strategy on forward and backward span performance in Korsakoff's syndrome. Fifteen patients with Korsakoff's syndrome and 17 age-and-education matched healthy controls participated to the study. Digit span performance (both forward and backward) was tested before and after chunking training. Results demonstrated an increased performance on the forward spans after chunking training in the patients with Korsakoff's syndrome, but no beneficial effect was observed on the backward spans in these participants. Controls demonstrated a chunking effect on both forward and backward span performance. Our findings suggest that a simple training in chunking may be useful as part of a cognitive strategy training for improving working memory performance in patients with Korsakoff's syndrome.

The effects of strategy training on spatial memory in diencephalic amnesia: a randomized controlled study

Alcoholic Korsakoff’s syndrome is characterized by severe amnesia, also affecting spatial memory. To date, research on cognitive rehabilitation in these patients is scarce. Aim of the present study is to examine the efficacy of a mnemonic strategy training in patients with Korsakoff’s syndrome. A randomized controlled exploratory study was performed. A convenience sample of 14 patients with amnesia due to alcoholic Korsakoff’s syndrome was included and randomized into a mnemonic strategy training group (n = 7) and a control group (n = 7). The training group completed a 3-day 45–60 min mnemonic strategy training that focused on specific strategies to encode and retrieve information about specific objects and their locations in virtual rooms, using labeling, verbal reasoning and mental imagery. The control group only received care as usual. Outcome measure was an object-location memory task consisting of novel, untrained object locations administered 1 day before the intervention, as well as 1 day and 1 week after completing the intervention. Patients in the intervention group were able to acquire and use the strategies, but no significant differences were found between the intervention group and the control group, and no significant change in performance was demonstrated compared to baseline 1 day and 1 week after the intervention. To conclude, the mnemonic strategy training in KS patients did not result in a better spatial memory performance 1 day or 1 week after training completion compared to participation in the regular non-cognitive treatment program that focused on occupational therapy, music therapy and exercise.

A Computerized Functional Skills Assessment and Training Program Targeting Technology Based Everyday Functional Skills

Today, many functional skills are technology-based, so development of a technology-based training program has broad importance. Here we present a computerized functional skills training program that was paired in half of the participants with a commercially available cognitive training (CCT) program. Non-impaired older individuals (NC) aged 60+ (n=45) and similarly aged individuals with mild cognitive impairment (MCI; n=50) were randomized to receive 12 weeks of twice-weekly computerized functional skills training (CFST) or 12 weeks of twice-weekly sessions split between CCT and CFST. Skills trained were use of an ATM; internet banking; ticket kiosk; telephone and internet prescription refill; medication management; and internet shopping. As with previous functional capacity assessments, we focus on completion time for each simulation. 51 participants completed the training program, either by mastering all 6 tasks (34) or completing 12 weeks of training. 44 more participants completed 4 or more training sessions so they were also analyzed for improvement up to their last training session. Completion time for all 6 tests significantly improved from the baseline assessment to the final training session in both groups of participants (all p<0.001 with an average improvement in task completion time of 45%). Further, there was no differential improvement in MCI and NC in the 6 tests from baseline to end of training (all t<1.66, all p>0.12). Finally, combined CCT plus CFST did not differ from CSFT alone on any of the percent-change score measures (all t<1.64, all p>0.11). Both NC and MCI groups evidenced substantial improvements in performance. CCT supplementation led to similar functional gains with half as many training sessions. The NC participants proceeded through the training fairly rapidly even without CCT supplementation; MCI participants required more training but learned equivalently. These findings suggest that even in cases with memory impairments, functional skills can be efficiently learned with training.

Executive Dysfunction in Patients With Korsakoff's Syndrome: A Theory-Driven Approach

Aims

In addition to amnesia, executive deficits are prominent in Korsakoff's syndrome (KS), yet poorly studied. This study investigates the degree of executive dysfunction in patients with KS for the three main executive subcomponents shifting, updating and inhibition using novel, theory-driven paradigms.

Short summary

Compared to healthy controls, patients with KS show impairments on the executive subcomponents shifting and updating, but not on inhibition.

Methods

Executive functions were measured with six carefully designed tasks in 36 abstinent patients with KS (mean age 62.3; 28% woman) and compared with 30 healthy non-alcoholic controls (mean age 61.8; 40% woman). ANOVAs were conducted to examine group differences and effect sizes were calculated.

Results

Compared to healthy controls, patients with KS were impaired on the executive subcomponents shifting and updating. No statistically significant group difference was found on the factor inhibition.

Conclusions

Executive dysfunction in long-abstinent patients with alcoholic KS shows a profile in which shifting and updating ability are affected most. It also highlights that executive dysfunction is an important feature of KS and requires more attention in scientific and clinical practice, as these deficits may also affect daily functioning.

Smartwatch aids time-based prospective memory in Korsakoff syndrome: a case study

Prospective memory (PM) is the ability to remember to carry out an intention in the future. PM is particularly impaired in Korsakoff syndrome (KS). We investigated the benefit of a smartwatch and smartphone compared to no aid in supporting time accuracy and PM task performance in KS. Time accuracy was improved with a smartwatch compared to the other conditions. Furthermore, the smartwatch and phone conditions were more effective than no aid in assisting memory for task content. Together these results suggest that using an external memory aid is beneficial for successful PM in KS.

Identification and Evaluation of Neuropsychological Tools Used in the Assessment of Alcohol-Related Cognitive Impairment: A Systematic Review

Background: Neuropsychological assessment is central to identifying and determining the extent of Alcohol-Related Cognitive Impairment (ARCI). The present systematic review aimed to synthesize and discuss the evidence appraising the neuropsychological tests used to assess ARCI in order to support clinicians and researchers in selecting appropriate tests for use with this population. Methods: We searched for studies investigating the psychometric, diagnostic and practical values of tools used in the screening, diagnosis, and assessment of Korsakoff's Syndrome (KS), Alcohol-Related Dementia (ARD), and those with a specific diagnosis of Alcohol-Related Brain Damage (ARBD). The following databases were searched in March 2016 and again in August 2018: MEDLINE, EMBASE, Psych-INFO, ProQuest Psychology, and Science Direct. Study quality was assessed using a checklist designed by the authors to evaluate the specific factors contributing to robust and clearly reported studies in this area. A total of 43 studies were included following the screening of 3646 studies by title and abstract and 360 at full-text. Meta-analysis was not appropriate due to heterogeneity in the tests and ARCI samples investigated in the studies reviewed. Instead, review findings were narratively synthesized and divided according to five domains of assessment: cognitive screening, memory, executive function, intelligence and test batteries, and premorbid ability. Effect sizes (d) were calculated to supplement findings. Results: Overall, several measures demonstrated sensitivity to the cognitive deficits associated with chronic alcoholism and an ability to differentiate between gradations of impairment. However, findings relating to the other psychometric qualities of the tests, including those important for the accurate assessment and monitoring of ARCI (e.g., test-retest reliability), were entirely absent or limited. Additionally, the synthesis of neuropsychological outcomes presented here supports the recent impetus for a move away from discrete diagnoses (e.g., KS, ARD) and the distinctions between them toward more broad and inclusive diagnostic conceptualizations of ARCI, thereby recognizing the heterogeneity in presentation. Conclusions: Based on the evidence reviewed, provisional recommendations for appropriate tests in each domain of assessment are presented, though further validation of most tests is warranted. Review findings can support efficient and evidenced-based test-selection and guide future research in this area.

Social and emotional loneliness in Korsakoff's syndrome

INTRODUCTION

Loneliness is the subjective negative evaluation of social participation and isolation. Emotional loneliness reflects the absence of close relationships, and social loneliness the absence of a social network. Although loneliness is a growing problem in modern society, studies about loneliness in patients with Korsakoff's syndrome (KS) in need of chronic care are currently missing.

METHODS

Sixty-three KS patients in long-term care and their primary caregivers reported loneliness of the patients on the De Jong Gierveld Loneliness Scale.

RESULTS

A majority of KS patients reliably reported to feel lonely on both a social and emotional level of loneliness. The caregiving professionals rated loneliness of the patients even higher. Patients that had stayed in the clinic for a longer time tended to report less social loneliness, while caregivers reported less emotional loneliness in those patients. The KS-specific neuropsychiatric symptom of confabulations and a lack of social visits had a negative impact on social loneliness as perceived by the caregivers.

CONCLUSION

Loneliness is a large problem in patients with KS that live in a long term care facility. Social loneliness can be positively influenced by creating possibilities to interact with other people, although the severity of the neuropsychiatric aspects of KS could compromise the presence of those interactions.

Forgetting the new locations of one's keys: spatial-memory interference in Korsakoff's amnesia

The present study focused on interference in a group of patients with amnesia due to Korsakoff's syndrome (KS) within the domain of spatial memory. An object-location memory task was used in which participants first learned an array of objects on a computer screen, followed by a reconstruction of the object positions. Next a trial was given in which the same objects were presented only now in different locations. Participants had to place the objects a second time but at the new locations. This was repeated for seven pairs of baseline/interference trials. Both Korsakoff patients and matched controls did worse on the interference trials than on the baseline trials, indicating that it is difficult to relearn new spatial locations for objects that previously were remembered in other locations. When computing relative interference effects (that is the percentage change from baseline in the interference trials), Korsakoff patients were less affected than controls. It is discussed in how far interference depends on the strength of the original memories, which are markedly lower in KS patients.

Long-term cognitive and neuroanatomical stability in patients with anoxic amnesia: A Case Report

BACKGROUND

Anoxia can result in selective hippocampal damage with associated impairments in declarative memory. Whilst memory impairments and brain structures are thought to be stable, there are little data regarding the effects of ageing or change over time in patients with amnesia from anoxic brain injury.

METHODS

To assess change over time, we compared structural magnetic resonance imaging (MRI) with data obtained over ten years previously in two well-characterized patients with amnesia (JRW and RS) who experienced an anoxic brain injury. Six healthy, age-matched control participants were recruited to compare brain volumes with the patients at Time 2. Wechsler adult intelligence scale-revised and Wechsler memory scale-revised scores were compared to scores on the same tests administered 13 and 19 years prior.

RESULTS

Patients with amnesia had significantly smaller hippocampal volumes than controls, but comparable medial temporal lobe and ventricular volumes. Memory, intellectual function and brain volumes were stable over time.

CONCLUSION

Patients with an amnesia due to anoxia have memory impairments and smaller hippocampal volumes compared to controls; however, memory, intelligence and structural volumes remain stable over time. At ages 50 and 57, they do not appear to have early age-associated cognitive decline that is sometimes observed in patients with traumatic brain injury.

Visuospatial declarative learning despite profound verbal declarative amnesia in Korsakoff's syndrome

Korsakoff's syndrome (KS) is a neuropsychiatric disorder characterised by severe amnesia. Although the presence of impairments in memory has long been acknowledged, there is a lack of knowledge about the precise characteristics of declarative memory capacities in order to implement memory rehabilitation. In this study, we investigated the extent to which patients diagnosed with KS have preserved declarative memory capacities in working memory, long-term memory encoding or long-term memory recall operations, and whether these capacities are most preserved for verbal or visuospatial content. The results of this study demonstrate that patients with KS have compromised declarative memory functioning on all memory indices. Performance was lowest for the encoding operation compared to the working memory and delayed recall operation. With respect to the content, visuospatial memory was relatively better preserved than verbal memory. All memory operations functioned suboptimally, although the most pronounced disturbance was found in verbal memory encoding. Based on the preserved declarative memory capacities in patients, visuospatial memory can form a more promising target for compensatory memory rehabilitation than verbal memory. It is therefore relevant to increase the number of spatial cues in memory rehabilitation for KS patients.

Korsakoff's syndrome: a critical review

In this review, we present a survey on Korsakoff's syndrome (KS), a residual syndrome in patients who suffered from a Wernicke encephalopathy (WE) that is predominantly characterized by global amnesia, and in more severe cases also by cognitive and behavioral dysfunction. We describe the history of KS and its definition, its epidemiology, and the lack of consensus criteria for its diagnosis. The cognitive and behavioral symptoms of KS, which include anterograde and retrograde amnesia, executive dysfunction, confabulation, apathy, as well as affective and social-cognitive impairments, are discussed. Moreover, recent insights into the underlying neurocognitive mechanisms of these symptoms are presented. In addition, the evidence so far on the etiology of KS is examined, highlighting the role of thiamine and alcohol and discussing the continuity hypothesis. Furthermore, the neuropathology of KS is reviewed, focusing on abnormalities in the diencephalon, including the mammillary bodies and thalamic nuclei. Pharmacological treatment options and nonpharmacological interventions, such as those based on cognitive rehabilitation, are discussed. Our review shows that thiamine deficiency (TD) is a crucial factor in the etiology of KS. Although alcohol abuse is by far the most important context in which TD occurs, there is no convincing evidence for an essential contribution of ethanol neurotoxicity (EN) to the development of WE or to the progression of WE to KS. Future research on the postmortem histopathological analysis of brain tissues of KS patients is crucial for the advancement of our knowledge of KS, especially for associating its symptoms with lesions in various thalamic nuclei. A necessary requirement for the advancement of studies on KS is the broad acceptance of a comprehensive definition and definite diagnostic criteria. Therefore, in this review, we propose such a definition of KS and draft outlines for prospective diagnostic criteria.

The effect of errorless learning on quality of life in patients with Korsakoff's syndrome

BACKGROUND

Errorless learning (EL) is a promising rehabilitation principle for (re)learning instrumental activities in patients with amnesia, including patients with Korsakoff's syndrome (KS). Successfully (re)learning tasks might improve the sense of competence and independence, and subsequently the quality of life. Quality of life in patients with KS has received limited attention, and no studies have been conducted to experimentally examine the effect of EL on quality of life in patients in this patient group.

MATERIALS AND METHODS

The QUALIDEM, an observation scale for quality of life, was completed by professional nurses before and after EL training in a group of fifty-one patients with KS. This scale was also completed for a group of thirty-one control patients receiving care as usual but no EL training.

RESULTS

Quality of life was significantly increased on eight of the nine subscales in the Korsakoff group who participated in an EL training. There was a trend toward a significant increase in "positive affect" (ie, the ninth subscale). In contrast, no changes over time were found on any of the subscales in the control group that did not participate in any EL training.

CONCLUSION

Despite severe memory impairments, patients with KS still have the potential to (partially) (re)learn tasks using EL. This potential should be exploited, as the successes of (re)-learning might improve the quality of life of Korsakoff patients in nursing homes.

Behavioral/Nonpharmacological Approaches to Addressing Cognitive-Linguistic Symptoms in Individuals With Dementia

Despite current barriers to developing and implementing nonpharmacological or behavioral cognitive-linguistic treatments for dementia, a growing evidence base indicates that individuals with dementia may indeed benefit from a range of nonpharmacological intervention approaches in terms of helping them maintain and/or improve their language and cognitive abilities as well as general functioning and emotional well being. With respect to the current dementia literature, this article describes restorative and compensatory approaches for cognitive symptoms, including direct stimulation of cognitive functions and internal and external strategies to maximize use of residual cognitive skills. We also summarize various language treatment techniques designed to address word retrieval deficits or functional communication issues in a range of dementia types and severity. Broader stimulation approaches such as Montessori-based treatment, reminiscence therapy, and exercise/movement therapy are also reviewed given their potential to benefit not only the cognitive-linguistic symptoms of individuals with dementia, but also other aspects of physical, emotional, and behavioral functioning. Last, we conclude by highlighting limitations in the current research literature along with factors to consider for maximizing nonpharmacological treatment effects (i.e., generalization and maintenance of treatment gains) in clinical or research settings.