Child development and the role of visual experience in the use of spatial and non-spatial features in haptic object perception

Previous work has suggested a different developmental timeline and role of visual experience for the use of spatial and non-spatial features in haptic object recognition. To investigate this conjecture, we used a haptic ambiguous odd-one-out task in which one object needed to be selected as being different from two other objects. The odd-one-out could be selected based on four characteristics: size, shape (spatial), texture, and weight (non-spatial). We tested sighted children from 4 to 12 years of age; congenitally blind, late blind, and adult participants with low vision; and normally sighted adults. Given the protracted developmental time course for spatial perception, we expected a shift from a preference for non-spatial features toward spatial features during typical development. Due to the dominant influence of vision for spatial perception, we expected congenitally blind adults to show a similar preference for non-spatial features as the youngest children. The results confirmed our first hypothesis; the 4-year-olds demonstrated a lower dominance for spatial features for object classification compared with older children and sighted adults. In contrast, our second hypothesis was not confirmed; congenitally blind adults' preferred categorization criteria were indistinguishable from those of sighted controls. These findings suggest an early development, but late maturation, of spatial processing in haptic object recognition independent of visual experience.

Personality traits and personality problems in Korsakoff syndrome patients

Personality research is of relevance because it provides insights into the psychological strengths and vulnerabilities of a person. Korsakoff's syndrome (KS) is a severe neuropsychiatric disorder following acute thiamine deficiency, usually as a consequence of alcohol-use disorders. Research on personality traits of KS patients is currently limited. The aim of the current exploratory study was therefore to examine the personality traits and problems of KS patients. We assessed self-reported and informant-reported personality traits and problems in institutionalized KS patients (n = 30). Results indicate that the psychotic personality organization was more frequently present in KS patients compared to a psychiatric reference population, leading to increased vulnerability for the development of severe psychiatric issues. Informants observed more premorbid and current cluster B ("emotional") and C ("anxious") personality behavior in comparison to the general population. Also, rigid- and socially avoidant behavior in KS patients was observed to increase over the years. They also observed personality problems such as emotional-, unpredictable-, dramatic-, anxious and fearful behavior in the present and in the past. KS patients reported themselves as healthy individuals, indicating a lack of self-awareness. We recommend training programs for the medical team focussed on psycho-education and supportive interventions for patients with complex personality problems concomitant to KS.

Is there selective retroactive memory enhancement in humans?: a meta-analysis

Memory is an adaptive and flexible system that preferentially stores motivationally relevant information. However, in some cases information that is initially irrelevant can become relevant at a later time. The question arises whether and to what extent the memory system can retroactively boost memories of the initially irrelevant information. Experimental studies in animals and humans have provided evidence for such retroactive memory boosting. Additionally, these studies suggest that retroactive memory enhancement (RME) can be selective to the semantic meaning of the material. Nonetheless, recent experimental work could not replicate these findings, posing the question whether the selective RME effect is reliable. To synthesize the available evidence, we conducted meta-analyses of 14 experiments. Although the classical meta-analytic procedure suggested a small selective RME effect, Cohen's dz = 0.16, when accounting for small-study bias using robust Bayesian meta-analysis the null hypothesis was supported, Cohen's dz = 0.02, BF01 = 3.03. Furthermore strong evidence was found for a bias due to small-study effects, BF10 = 11.39. Together, this calls the reliability of a selective RME effect into question.

Alcohol use disorder and muscle weakness: Original study of the effect of vitamin D supplementation in ambulatory participants with alcohol use disorder

INTRODUCTION

Chronic alcohol-related myopathy presents with proximal muscle weakness. We studied the effect of vitamin D supplementation on muscle weakness in adults with alcohol use disorder.

METHOD

Randomized controlled trial. Participants were community-dwelling adults with alcohol use disorder. Participants allocated to VIDIO, vitamin D intensive outreach, received bimonthly oral doses of 50,000‒100,000 IU cholecalciferol for 12 months. Participants allocated to CAU, care as usual, received prescriptions of once-a-day tablets containing 800 IU cholecalciferol and 500 mg calcium carbonate. Data included demographic variables, laboratory tests, alcohol use, and rating scales of help-seeking and support. Main outcomes were the participants' quadriceps maximum voluntary contractions (qMVC) and serum-25(OH)vitamin D concentrations, 25(OH)D.

RESULTS

In 66 participants, sex ratio 50/16, mean age 51 year, alcohol use was median 52 [IQR 24‒95] drinks per week. Baseline qMVC values were 77% (SD 29%) of reference values. Laboratory tests were available in 44/66 participants: baseline 25(OH)D concentrations were 39.4 (SD 23.7) nmol/L. Thirty-one participants with 25(OH)D concentrations <50 nmol/L received either VIDIO or CAU and improved in qMVC, respectively with mean 51 (P<0.05) and 62 Newton (no P-value because of loss of follow-up) after one year of treatment. Vitamin D status increased with mean +56.1 and +37.4 nmol/L, respectively in VIDIO and CAU.

CONCLUSION

The qMVC values improved during vitamin supplementation in adults with vitamin D deficiency and alcohol use disorder. Despite higher 25(OH)D concentrations in VIDIO, in terms of muscle health no advise could be given in favor of one vitamin strategy over the other.

TRIAL REGISTRATION

Netherlands Trial Register (NTR) identifier: NTR4114.

Wernicke's Encephalopathy in Acute and Chronic Kidney Disease: A Systematic Review

Thiamine (vitamin B1) deficiency is relatively common in patients with kidney disease. Wernicke's encephalopathy (WE) is caused by vitamin B1 deficiency. Our aim was to systematically review the signs and symptoms of WE in patients with kidney disease. We conducted a systematic literature review on WE in kidney disease and recorded clinical and radiographic characteristics, treatment and outcome. In total 323 manuscripts were reviewed, which yielded 46 cases diagnosed with acute and chronic kidney disease and WE published in 37 reports. Prodromal characteristics of WE were loss of appetite, vomiting, weight loss, abdominal pain, and diarrhea. Parenteral thiamine 500 mg 3 times per day often led to full recovery, while Korsakoff's syndrome was found in those receiving low doses. To prevent WE in kidney failure, we suggest administering high doses of parenteral thiamine in patients with kidney disease who present with severe malnutrition and (prodromal) signs of thiamine deficiency.

When Do Korsakoff Patients Justify Immoral Behaviors? The Influence of Premorbid Delinquency and Self-Other Perspectives in Moral Decision-Making and Moral Reasoning

Korsakoff's syndrome (KS) is a chronic neuropsychiatric disorder caused by a vitamin B1 deficiency. KS is characterized by profound amnesia and often accompanied by poor executive functioning, decreased social-cognitive abilities, and difficulties in behavioral regulation. As moral behaviors and attitudes may provide insight in socio-behavioral interactions, the current study aimed to evaluate everyday moral maturity by administering self- versus other-oriented moral dilemmas in a group of KS patients (n = 20) and healthy controls (n = 20). Responses were scored according to the Kohlberg stages of moral reasoning. Furthermore, we assessed premorbid delinquency and current neurocognitive functioning as possible relevant factors. Our results show that KS patients were prone to lower levels of moral maturity when confronted with moral dilemmas relating to themselves, compared to dilemmas relating to (un)personal others in KS patients, while healthy subjects showed an opposite pattern. Moral immaturity could find its origin already before the onset of the KS diagnosis, as suggested by the elevated premorbid levels of delinquent behavior and correlation between premorbid delinquency and moral maturity in KS. Lower moral maturity could therefore be a possible predisposing factor to both delinquency and later development of Korsakoff's syndrome.

Gastrointestinal and eating problems in SCN1A-related seizure disorders

OBJECTIVE

Our study aimed to describe the prevalence and characteristics of gastrointestinal and eating problems in Dravet syndrome (DS) and other SCN1A-related seizure disorders and to determine the association between the occurrence of gastrointestinal and eating problems and core features of DS.

METHODS

Gastrointestinal and eating problems were assessed with a questionnaire in a Dutch cohort of participants with an SCN1A-related seizure disorder. Associations between the number of gastrointestinal and eating problems and core features of DS, seizure severity, level of intellectual disability, impaired mobility, behavioral problems, and use of anti-seizure medication, were explored by multivariate ordinal regression analyses. Symptoms were divided into the categories dysphagia-related, behavioral, and gastrointestinal, and were assessed separately.

RESULTS

One hundred sixty-nine participants with an SCN1A-related seizure disorder, of whom 118 (69.8%) with DS and 51 (30.2%) with Generalized Epilepsy with Febrile Seizures Plus / Febrile Seizures (GEFS+/FS), the non-DS phenotype, were evaluated. Gastrointestinal and eating problems were highly prevalent in DS participants, 50.8% had more than three symptoms compared to 3.9% of non-DS participants. Of participants with DS, 17.8% were fully or partly fed by a gastric tube. Within the three different symptom categories, the most prevalent dysphagia-related symptom was drooling (60.7%), distraction during mealtimes (61.4%) the most prevalent behavioral symptom, and constipation and loss of appetite (both 50.4%) the most prevalent gastrointestinal symptoms. DS participants who use a wheelchair (odds ratio (OR) 4.9 95%CI (1.9-12.8) compared to walking without aid), who use ≥3 anti-seizure medications (ASM) (OR 5.9 95%CI (1.9-18.2) compared to <3 ASM) and who have behavioral problems (OR 3.0 95%CI (1.1-8.1) compared to no behavioral problems) had more gastrointestinal and eating problems.

CONCLUSION

Gastrointestinal and eating problems are frequently reported symptoms in DS. Distinguishing between symptom categories will lead to tailored management of patients at risk, will improve early detection, and enable a timely referral to a dietitian, behavioral expert, and/or speech therapist, ultimately aiming to improve the quality of life of both patients and caregivers.

Self-Reported Pain and Pain Observations in People with Korsakoff's Syndrome: A Pilot Study

Korsakoff's syndrome (KS) is a chronic neuropsychiatric disorder. The large majority of people with KS experience multiple comorbid health problems, including cardiovascular disease, malignancy, and diabetes mellitus. To our knowledge pain has not been investigated in this population. The aim of this study was to investigate self-reported pain as well as pain behavior observations reported by nursing staff. In total, 38 people diagnosed with KS residing in a long-term care facility for KS participated in this research. The Visual Analogue Scale (VAS), Pain Assessment in Impaired Cognition (PAIC-15), Rotterdam Elderly Pain Observation Scale (REPOS), and the McGill Pain Questionnaire-Dutch Language Version (MPQ-DLV) were used to index self-rated and observational pain in KS. People with KS reported significantly lower pain levels than their healthcare professionals reported for them. The highest pain scores were found on the PAIC-15, specifically on the emotional expression scale. Of importance, the patient pain reports did not correlate with the healthcare pain reports. Moreover, there was a high correlation between neuropsychiatric symptoms and observational pain reports. Specifically, agitation and observational pain reports strongly correlated. In conclusion, people with KS report less pain than their healthcare professionals indicate for them. Moreover, there is a close relationship between neuropsychiatric symptoms and observation-reported pain in people with KS. Our results suggest that pain is possibly underreported by people with KS and should be taken into consideration in treating neuropsychiatric symptoms of KS as a possible underlying cause.

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'.

Korsakoff syndrome and altered pain perception: a search of underlying neural mechanisms

OBJECTIVES

Patients with Korsakoff syndrome (KS) may have a diminished pain perception. Information on KS and pain is scarce and limited to case descriptions. The present study is the first to investigate the underlying neural mechanisms of altered pain perception in patients with KS more systematically.

METHODS

We conducted a literature search on neural correlates of pain perception in other neurocognitive disorders in which extensive research was done.

RESULTS

The brain areas that are affected in KS showed considerable overlap with the neural correlates of pain perception in other neurocognitive disorders. We discussed which different aspects of disturbed pain perception could play a role within KS, based on distinct neural damage and brain areas involved in pain perception.

CONCLUSIONS

Combining current knowledge, we hypothesize that diminished pain perception in KS may be related to lesioned neural connections between cerebral cortical networks and relays of mainly the thalamus, the periaqueductal gray, and possibly lower brain stem regions projecting to the cerebellum. Based on these neural correlates of altered pain perception, we assume that increased pain thresholds, inhibition of pain signals, and disturbed input to cerebral and cerebellar cortical areas involved in pain processing, all are candidate mechanisms in cases of diminished pain perception in KS. We recommend that clinicians need to be alert for somatic morbidity in patients with KS. Due to altered neural processing of nociceptive input the clinical symptoms of somatic morbidity may present differently (i.e. limited pain responses) and therefore are at risk of being missed.

The era of our lives: The memory of Korsakoff patients for the first Covid-19 pandemic lockdown in the Netherlands

Memories for worldwide and emotional events (such as 9/11) are more vividly relived and recalled than memories for everyday events. Previous studies have shown that flashbulb memories of a single event enhanced the memory strength in severe amnesia. It is currently unknown whether macro-events that stretch out over longer periods of time (weeks, months) strengthen memory even further. Our aim was therefore to investigate to what extent patients with severe amnesia, due to Korsakoff's syndrome (KS), were able to relive the first Covid-19 lockdown in the Netherlands, and whether experienced emotions enhanced reliving of the participants. We included 22 KS patients and 24 age-, education-, and gender-matched healthy controls. Covid-19 related memories were assessed by measures of autobiographical memory specificity, phenomenological reliving, emotional intensity and semantic-and episodic knowledge about the first lockdown in March 2020 - May 2020 in the Netherlands. Although amnesia patients remembered significantly fewer autobiographical details regarding the Covid-19 lockdown than healthy controls, one fourth of the KS patients recalled specific events. Amnesia patients reported levels of emotional intensity equivalent to those in the control group. Stronger autobiographical reliving was associated with higher emotional intensity. Both amnesia patients and healthy controls had higher recall of episodic than semantic lockdown related information. In conclusion, results demonstrate that information for macro-events can still be memorized and relived, most specifically when emotional valence is high, even by highly amnestic patients.

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.

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.

Short Digital Spatial Memory Test Detects Impairment in Alzheimer's Disease and Mild Cognitive Impairment

BACKGROUND

Impairment in navigation abilities and object location memory are often seen in early-stage Alzheimer's Disease (AD), yet these constructs are not included in standard neuropsychological assessment. We investigated the differential ability of a short digital spatial memory test in mild AD dementia and mild cognitive impairment (MCI).

METHODS

21 patients with AD dementia (66.9 ± 6.9; 47% female), 22 patients with MCI (69.6 ± 8.3; 46% female) and 21 patients with subjective cognitive decline (SCD) (62.2 ± 8.9; 48% female) from the Amsterdam Dementia Cohort performed the Object Location Memory Test (OLMT), consisting of a visual perception and memory trial, and the Virtual Tübingen (VT) test, consisting of a scene recognition, route continuation, route ordering and distance comparison task. The correlations with other cognitive domains were examined.

RESULTS

Patients with mild AD dementia (Z: -2.51 ± 1.15) and MCI (Z: -1.81 ± 0.92) performed worse than participants with SCD (Z: 0.0 ± 1.0) on the OLMT. Scene recognition and route continuation were equally impaired in patients with AD dementia (Z: -1.14 ± 0.73; Z: -1.44 ± 1.13) and MCI (Z: -1.37 ± 1.25; Z: -1.21 ± 1.07). Route ordering was only impaired in patients with MCI (Z: -0.82 ± 0.78). Weak to moderate correlations were found between route continuation and memory (r(64) = 0.40, p < 0.01), and between route ordering and attention (r(64) = 0.33, p < 0.01), but not for the OLMT.

CONCLUSION

A short digital spatial memory test battery was able to detect object location memory and navigation impairment in patients with mild AD dementia and MCI, highlighting the value of incorporating such a test battery in standard neuropsychological assessment.

Lifelogging as a rehabilitation tool in patients with amnesia: A narrative literature review on the effect of lifelogging on memory loss

Visual lifelogging is the procedure that enables individuals to visually record daily life activities by means of small wearable cameras, which can be worn around the neck or on the clothing. Lifelogging devices automatically take pictures or videos after pre-set time intervals or after dynamic input changes. Although some studies have shown effectivity of reviewing lifelogging images in brain-damaged individuals with forms of amnesia as a rehabilitation tool, systematic endeavours to overview this literature is yet missing. The aim of this narrative literature review was to review all the available case-studies, experimental studies and group studies in brain-damaged individuals applying lifelogging devices in a clinical context. The included studies showed efficacy for both subjective and objective measures of memory. In mild to severe amnesia, reviewing images recorded by the lifelogging device was beneficial to subjective and objective measures of memory. Lifelogging is demonstrated to have a great potential in helping people who are suffering from memory loss. It can offer an excellent alternative to currently more frequently used memory rehabilitation techniques and can be applied more in clinical settings.

Wernicke Encephalopathy in schizophrenia: a systematic review

INTRODUCTION

In schizophrenia, patients can experience delusions or hallucinations regarding their food or health status, leading to diminished intake. Fasting or not eating a balanced diet can cause neurological complications after severe vitamin B1 malnourishment. The precise signs and symptoms of Wernicke's Encephalopathy (WE) in schizophrenia are not clear. Our aim, therefore, was to conduct a systematic review of the characteristics of WE in patients with schizophrenia.

METHODS

We conducted our search from inception using Mesh terms schizophrenia, Wernicke Encephalopathy, Korsakoff's syndrome. We searched Pubmed, ISI Web of Science, and Scopus. We defined WE as mental, oculomotor, and motoric alterations and thiamine deficiency; schizophrenia was defined as psychosis, hallucinations and/or delusions; adequate WE treatment as >500 mg/day intramuscular or intravenous. Our search yielded 15 WE cases.

RESULTS

WE is characterised by a triad of mental status change, ocular signs and ataxia. In alcohol use disorder, this triad is present in 16% of the cases, but 12 out of the 15 published schizophrenia cases presented themselves with a full triad. Importantly, as an additional characteristic, patients often lost weight within a short period of time.

CONCLUSIONS

The development of a full triad and additional symptomatology suggests a late recognition of signs and symptoms of WE in schizophrenia. Prophylactic thiamine checks and treatment in patients with schizophrenia are relevant, and if WE is suspected adequate parenteral thiamine supplementation is necessary.Key pointsOnly few cases of schizophrenia-related WE have been published in the literature, though challenges in diagnosing and recognising WE suggest that the vast majority of cases go undetected.Acute thiamine deficiency leads to Wernicke's Encephalopathy.Patients diagnosed with schizophrenia are at risk to develop Wernicke's Encephalopathy.Timely treatment with high doses of thiamine can adequately treat Wericke's Encephalopathy.

Anatomy of phonemic and semantic fluency: A lesion and disconnectome study in 1231 stroke patients

Disturbances of semantic and phonemic fluency are common after brain damage, as a manifestation of language, executive, or memory dysfunction. Lesion-symptom mapping (LSM) studies can provide fundamental insights in shared and distinct anatomical correlates of these cognitive functions and help to understand which patients suffer from these deficits. We performed a multivariate support vector regression-based lesion-symptom mapping and structural disconnection study on semantic and phonemic fluency in 1231 patients with acute ischemic stroke. With the largest-ever LSM study on verbal fluency we achieved almost complete brain lesion coverage. Lower performance on both fluency types was related to left hemispheric frontotemporal and parietal cortical regions, and subcortical regions centering on the left thalamus. Distinct correlates for phonemic fluency were the anterior divisions of middle and inferior frontal gyri. Distinct correlates for semantic fluency were the posterior regions of the middle and inferior temporal gyri, parahippocampal and fusiform gyri and triangular part of the inferior frontal gyrus. The disconnectome-based analyses additionally revealed phonemic fluency was associated with a more extensive frontoparietal white matter network, whereas semantic fluency was associated with disconnection of the fornix, mesiotemporal white matter, splenium of the corpus callosum. These results provide the most detailed outline of the anatomical correlates of phonemic and semantic fluency to date, stress the crucial role of subcortical regions and reveal a novel dissociation in the left temporal lobe.

Wernicke-Korsakoff syndrome despite no alcohol abuse: A summary of systematic reports

BACKGROUND

Wernicke-Korsakoff syndrome (WKS) is a neurological disorder typically found in alcohol use disorder. The fact that it also occurs in nonalcoholic patients is less well known and often ignored. For the first time, this review offers a systematic investigation of the frequency and associated features of nonalcoholic WKS in the published literature.

METHOD

We included 11 recent systematic reports, with a total of 586 nonalcoholic WKS cases following hyperemesis gravidarum (n = 177), cancer (n = 129), bariatric surgery (n = 118), hunger strike (n = 41), soft drink diet in children (n = 33), depression (n = 21), Crohn's disease (n = 21), schizophrenia (n = 15), anorexia nervosa (n = 12), ulcerative colitis (n = 10), and incidental thiamine-deficient infant formula (n = 9).

FINDINGS

Vomiting and extreme weight loss were strong predictors of nonalcoholic WKS in adults. Blurred vision was a common presenting sign in about one-fourth of the patients. The classic triad of WKS is characterized by confusion, ataxia, and eye-movement disorders. All reviewed studies reported high percentages of patients presenting with an altered mental status, while both motor symptoms were variably present.

INTERPRETATION

The foregoing observations led to several important conclusions. First, we can see that nutritional impoverishment leads to profound brain damage in the form of WKS. Second, it seems that physicians are either unaware of or underestimate the risks for nonalcoholic WKS. Physicians must be specifically vigilant in detecting and treating WKS in patients with sudden and severe weight loss and vomiting. Third, lower doses of thiamine frequently lead to chronic Wernicke-Korsakoff syndrome. We noticed that when thiamine treatment for WKS was administered, in many cases doses were too low. In line with proven interventions we therefore recommend a parenteral thiamine treatment of 500 mg 3 times per day in adults.

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.

The Road More Travelled: The Differential Effects of Spatial Experience in Young and Elderly Participants

Our spatial mental representations allow us to give refined descriptions of the environment in terms of the relative locations and distances between objects and landmarks. In this study, we investigated the effects of familiarity with the everyday environment, in terms of frequency of exploration and mode of transportation, on categorical and coordinate spatial relations, on young and elderly participants, controlling for socio-demographic factors. Participants were tested with a general anamnesis, a neuropsychological assessment, measures of explorations and the Landmark Positioning on a Map task. The results showed: (a) a modest difference in performance with categorical spatial relations; (b) a larger difference in coordinate spatial relations; (c) a significant moderating effect of age on the relationship between familiarity and spatial relations, with a stronger relation among the elderly than the young. Ceteris paribus, the role of direct experience with exploring their hometown on spatial mental representations appeared to be more important in the elderly than in the young. This advantage appears to make the elderly wiser and likely protects them from the detrimental effects of aging on spatial mental representations.

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.

More mental rotation time does not imply more mental effort: Pupillary diameters do not change with angular distance

The ability to mentally rotate objects in space is a fundamental cognitive capacity. Previous studies showed that the time to rotate the image of a figure to match another increases progressively with angular disparity. It remains unclear whether this increase in response time with angular disparity could reflect increased processing operations or more cognitive effort instead of a sustained use of a 'rotate' mechanism without a change in workload. We collected response times as well as pupillary responses that index cognitive workload and activity in the brainstem's locus coeruleus, from a sample of 38 young adults performing a chronometric mental rotations task. The results showed the expected increase in response times but no increase in pupil diameters between 60, 120, and 180 degrees of rotation, suggesting no significant changes in arousal levels when rotating figures near and far. This indicates that during mental rotation the load on cognitive resources remains constant irrespective of angular distance.

Moral reasoning, moral decision-making, and empathy in Korsakoff's syndrome

Korsakoff's syndrome (KS) is a neuropsychiatric disorder, caused by a vitamin B1 deficiency. Although it is known that patients with KS display diminished theory of mind functioning and frequently exhibit marked antisocial interactions little attention has so far focused on the integrity of moral decision-making abilities, moral reasoning, and empathy. In an experimental cross-sectional design, 20 patients diagnosed with KS, and twenty age-, education-, and gender-equivalent healthy participants performed tests assessing moral decision-making, moral reasoning maturity, empathy, and executive functioning. Participants were administered the Moral Behaviour Inventory (MBI) for everyday moral dilemmas, and ten cartoons of abstract moral dilemmas. Responses were scored according to the Kohlberg stages of moral reasoning. Empathy and executive functioning were assessed with the Interpersonal Reactivity Index (IRI) and the Frontal Assessment Battery (FAB). In contrast to frontal traumatic brain injury patients, KS patients did not display a utilitarian bias, suggesting preserved moral decision-making abilities. Of interest, KS patients had significantly lower levels of moral reasoning maturity on everyday moral dilemmas, and abstract moral dilemmas. In patients, empathy was moderately related to the level of moral maturity on both tasks, while executive functioning was not. In conclusion, KS patients have preserved moral decision-making abilities, but their moral reasoning abilities are poorer in everyday and abstract situations. Lower moral reasoning abilities and lower levels of empathy together may be responsible for adverse social functioning in KS.

Studying Individual Differences in Spatial Cognition Through Differential Item Functioning Analysis

Background: In the field of spatial cognition, the study of individual differences represents a typical research topic. Gender and age have been prominently investigated. A promising statistical technique used to identify the different responses to items in relation to different group memberships is the Differential Item Functioning Analysis (DIF). The aim of the present study was to investigate the DIF of the Landmark positioning on a Map (LPM) task, across age groups (young and elderly) and gender, in a sample of 400 healthy human participants. Methods: LPM is a hometown map completion test based on well-known and familiar landmarks used to assess allocentric mental representations. DIF was assessed on LPM items two times: on categorical (i.e., positions) and coordinate (i.e., distances) scores, separately. Results: When positions and distances were difficult to assess with respect to the intended reference point, the probability to endorse the items seemed to get worse for the elderly compared to the younger participants. Instead other features of landmarks (high pleasantness, restorativeness) seemed to improve the elderly performance. A gender-related improvement of probability to endorse distance estimation of some landmarks, favoring women, emerged, probably associated with their repeated experiences with those landmarks. Overall, the complexity of the task seemed to have a differential impact on young and elderly people while gender-oriented activities and places seemed to have a differential impact on men and women. Conclusions: For the first time DIF was applied to a spatial mental representation task, based on the schematic sketch maps of the participants. The application of DIF to the study of individual differences in spatial cognition should become a systematic routine to early detect differential items, improving knowledge, as well as experimental control, on individual differences.

Health problems and care needs in patients with Korsakoff's syndrome: A systematic review

WHAT IS KNOWN ON THE SUBJECT?: Patients with Korsakoff's syndrome suffer from a broad range of comorbid somatic and/or psychiatric conditions. The various health problems in patients with Korsakoff's syndrome limit their ability to perform daily activities and also negatively affect their social functioning. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE?: Patients with Korsakoff's syndrome have complex somatic and psychiatric comorbid conditions co-occurring with behavioural and functional problems. They are compounded by patients' poor self-awareness regarding their health status and functioning. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: This review demonstrates that patients with Korsakoff's syndrome should receive integrated care. Integrated care for patients with Korsakoff's syndrome should be based on accurate multidimensional and multidisciplinary diagnostics in which nurses and nurse assistants have a prominent role due to their central position in the care process patients with Korsakoff's syndrome. ABSTRACT: Introduction The literature shows that Korsakoff's syndrome is associated with a wide range of severe comorbid somatic and psychiatric health problems that lead to care needs in several domains of functioning. Aim To provide a comprehensive overview of Korsakoff patients' health conditions and related care needs. Method Following the PRISMA guidelines, we searched MEDLINE, PsycInfo, Cochrane Library and CINAHL up to January 2019. After applying our inclusion criteria, two reviewers independently selected the studies, extracted the data and assessed methodological quality. Results Twelve articles were included. The commonest somatic comorbid conditions were liver disease, cardiovascular disease, COPD and diabetes mellitus. The commonest psychiatric comorbid conditions were mood disorder, personality disorder and psychotic disorder. Anxiety, aggressive/agitated behaviour, depressive symptoms and care needs in social functioning and (instrumental) activities of daily living were also very commonly reported. Discussion In patients with Korsakoff's syndrome, somatic and psychiatric comorbid conditions co-occur with behavioural and functional problems. They are compounded by patients' poor self-awareness regarding their health status and functioning. Adequate responses to their care needs require high-quality integrated care. Implications for practice Patients with Korsakoff's syndrome should receive integrated care based on accurate multidimensional and multidisciplinary diagnostics in which nurses have a prominent role.

Episodic future thinking together with observational learning benefits prospective memory in high-functioning Korsakoff's syndrome patients

Objective

Patients with Korsakoff’s syndrome (KS) have difficulty carrying out tasks which rely on prospective memory (PM). Since remembering to carry out an action in the future is crucial for living independently, it is of primary interest to develop strategies that improve PM performance in KS patients.

Design

The study employed a computer categorization task as an ongoing activity into which a PM task was embedded. We included episodic future thinking (EFT) and observational learning (Experiment 2) to boost PM.

Methods

Experiment 1 evaluated the efficacy of EFT following written PM task instructions in ten KS patients. Due to floor‐level PM performance in Experiment 1, Experiment 2 included an instructional video demonstrating the PM intention. In Experiment 2, twenty‐six KS patients performed both conditions (EFT and no‐EFT) at least 1 week apart, while twelve controls with alcohol use disorder without KS performed the no‐EFT condition. In Experiment 2, the PM instructions were also shown through video (observational learning component). Mild cognitive impairment was assessed in a short test battery.

Results

Experiment 1 showed overall floor performance in both conditions. Experiment 2 showed that KS patients performed PM tasks less accurately than the control group in the no‐EFT condition. In Experiment 2, where the observational learning component was included, EFT improved PM performance in KS patients. This effect was driven by a sub‐group of high‐functioning KS patients.

Conclusions

This study showed the value of an observational learning component together with EFT in improving PM performance, in relatively high‐functioning KS patients.

Practitioner points

KS patients performed the PM task less accurately than non‐KS controls with alcohol use disorder, confirming PM impairment in this patient population.

Controls with alcohol use disorder performed the PM task at ceiling level.

Showing an instructional video demonstrating the PM intention improved PM performance and later recall of PM task instructions in KS patients.

Episodic future thinking strategy improved PM performance in KS patients with relatively intact cognitive functioning.

Visual working memory capacity in Korsakoff's amnesia

Introduction: Despite the interest in memory functioning in Korsakoff's syndrome (KS), visual working memory capacity in KS is still poorly understood. Results from the last decades on working memory limitations in KS appear to be mixed, clearly calling for further investigations.Method: We investigated visual working memory storage capacity of patients diagnosed with KS using a change detection paradigm. Nine patients diagnosed with KS and thirty age- and education- matched healthy controls were presented twice with 2, 3, 4, or 6 bars with different orientations and had to detect whether the orientation of the target bar had changed.Results: As a group, KS patients performed significantly worse than controls on all set sizes, with an average capacity of 1.13 items, compared to 1.75 items in the control participants. In case study analysis, 4 out of 9 patients performed significantly worse than control participants, while 5 had relatively intact visual working memory capacity. In patients, deficits in visual working memory could not be explained by other cognitive deficits.Conclusion: Based on these results, we conclude that visual working memory deficits are a prominent characteristic in some, but not all KS patients. Training visual working memory capacity could possibly optimize other cognitive difficulties in this population.

Preventing Wernicke Encephalopathy After Bariatric Surgery

Half a million bariatric procedures are performed annually worldwide. Our aim was to review the signs and symptoms of Wernicke's encephalopathy (WE) after bariatric surgery. We included 118 WE cases. Descriptions involved gastric bypass (52%), but also newer procedures like the gastric sleeve. Bariatric WE patients were younger (median = 33 years) than those in a recent meta-analysis of medical procedures (mean = 39.5 years), and often presented with vomiting (87.3%), ataxia (84.7%), altered mental status (76.3%), and eye movement disorder (73.7%). Younger age seemed to protect against mental alterations and higher BMI against eye movement disorders. The WE treatment was often insufficient, specifically ignoring low parenteral thiamine levels (77.2%). In case of suspicion, thiamine levels should be tested and treated adequately with parenteral thiamine supplementation.

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.

Preventing Wernicke's encephalopathy in anorexia nervosa: A systematic review

Anorexia nervosa (AN) is a common eating disorder that affects 2.9 million people worldwide. Not eating a balanced diet or fasting can cause neurological complications after severe vitamin B1 malnourishment, although the precise signs and symptoms of Wernicke's encephalopathy (WE) are not clear. Our aim was to review the signs and symptoms of WE in patients with AN. We searched MEDLINE, EMBASE, Scopus, and PiCarta on all case descriptions of WE following AN. All case descriptions of WE in AN, irrespective of language, were included. Twelve WE cases were reviewed, suggesting that WE following AN is still a relatively rare neuropsychiatric disorder. WE is characterized by a triad of: mental status change, ocular signs, and ataxia. In alcoholism, this triad is present in 16% of cases, but eight out of 12 AN cases presented themselves with a full triad of symptomatology. Importantly, patients often had a more complex triad than has been previously described, involving vertigo, diplopia, and the consequences of refeeding syndrome. The development of a full triad and additional symptomatology suggests a late recognition of signs and symptoms of WE in AN. A complicating factor is the overlap between symptoms of thiamine deficiency and the symptoms of WE. Specifically, patients who show rapid weight loss are vulnerable for the development of WE. Eating disorders, such as AN, can lead to WE. Prophylactic thiamine checks and treatment in patients with AN are relevant, and in case of suspicion of WE, adequate parenteral thiamine supplementation is necessary.

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.

Microstructure of Strategic White Matter Tracts and Cognition in Memory Clinic Patients with Vascular Brain Injury

BACKGROUND

White matter injury is an important factor for cognitive impairment in memory clinic patients. We determined the added value of diffusion tensor imaging (DTI) of strategic white matter tracts in explaining variance in cognition in memory clinic patients with vascular brain injury.

METHODS

We included 159 patients. Conventional MRI markers (white matter hyperintensity volume, lacunes, nonlacunar infarcts, brain atrophy, and microbleeds), and fractional anisotropy and mean diffusivity (MD) of the whole brain white matter and of 18 white matter tracts were related to cognition using linear regression and Bayesian network analysis.

RESULTS

On top of all conventional MRI markers combined, MD of the whole brain white matter explained an additional 3.4% (p = 0.014), 7.8% (p < 0.001), and 1.2% (p = 0.119) variance in executive functioning, speed, and memory, respectively. The Bayesian analyses of regional DTI measures identified strategic tracts for executive functioning (right superior longitudinal fasciculus), speed (left corticospinal tract), and memory (left uncinate fasciculus). MD within these tracts explained an additional 3.4% (p = 0.012), 3.8% (p = 0.007), and 2.1% (p = 0.041) variance in executive functioning, speed, and memory, respectively, on top of all conventional MRI and global DTI markers combined.

CONCLUSION

In memory clinic patients with vascular brain injury, DTI of strategic white matter tracts has a significant added value in explaining variance in cognitive functioning.

Development and Test of an Extendable Endoprosthesis for Bone Reconstruction in the Leg

A malignant bone tumour may develop in the femur of a child. In the majority of cases it will be necessary to resect the bone involved, growth plate and adjacent tissues. A modular endoprosthetic system has been developed which can be extended non-invasively to bridge the defect resulting from such a resection. Elongation is achieved by using an external magnetic field. In vitro tests with a prototype showed that the lengthening element met all requirements. Six animal experiments showed that the lengthening element also functioned in vivo.

Radiant star nanoparticle prodrugs for the treatment of intracellular alveolar infections

Radiant star nanoparticle prodrugs were synthesized in a two-step process by first homopolymerizing RAFT transmers followed by copolymerization from the hyperbranched polymer core.

Egocentric and Exocentric Spatial Judgements of Visual Displacement

The role of changes in ego- and exocentric spatial relationships on perceptual judgements about visual displacement was investigated in this study. Subjects were asked to indicate whether a dot in a test stimulus was displaced compared to a dot in a reference stimulus. Subjects were given explicit instructions to report displacement relative to themselves (egocentric) or relative to a circle surrounding the dot (exocentric). Four types of test stimuli were used in which object-circle (exocentric) and object-observer (egocentric) relations were systematically varied. It was found that for test stimuli that reveal conflicting ego- and exocentric spatial information, subjects performed poorly in both instruction conditions. This suggests that ego- and exocentric representations cannot be used independently and are probably interconnected.

The cost of making an eye movement: A direct link between visual working memory and saccade execution

To facilitate visual continuity across eye movements, the visual system must presaccadically acquire information about the future foveal image. Previous studies have indicated that visual working memory (VWM) affects saccade execution. However, the reverse relation, the effect of saccade execution on VWM load is less clear. To investigate the causal link between saccade execution and VWM, we combined a VWM task and a saccade task. Participants were instructed to remember one, two, or three shapes and performed either a No Saccade-, a Single Saccade- or a Dual (corrective) Saccade-task. The results indicate that items stored in VWM are reported less accurately if a single saccade-or a dual saccade-task is performed next to retaining items in VWM. Importantly, the loss of response accuracy for items retained in VWM by performing a saccade was similar to committing an extra item to VWM. In a second experiment, we observed no cost of executing a saccade for auditory working memory performance, indicating that executing a saccade exclusively taxes the VWM system. Our results suggest that the visual system presaccadically stores the upcoming retinal image, which has a similar VWM load as committing one extra item to memory and interferes with stored VWM content. After the saccade, the visual system can retrieve this item from VWM to evaluate saccade accuracy. Our results support the idea that VWM is a system which is directly linked to saccade execution and promotes visual continuity across saccades.

A systematic investigation of navigation impairment in chronic stroke patients: Evidence for three distinct types

OBJECTIVE

In a recent systematic review, Claessen and van der Ham (2017) have analyzed the types of navigation impairment in the single-case study literature. Three dissociable types related to landmarks, locations, and paths were identified. This recent model as well as previous models of navigation impairment have never been verified in a systematic manner. The aim of the current study was thus to investigate the prevalence of landmark-based, location-based, and path-based navigation impairment in a large sample of stroke patients.

METHOD

Navigation ability of 77 stroke patients in the chronic phase and 60 healthy participants was comprehensively evaluated using the Virtual Tübingen test, which contains twelve subtasks addressing various aspects of knowledge about landmarks, locations, and paths based on a newly learned virtual route. Participants also filled out the Wayfinding Questionnaire to allow for making a distinction between stroke patients with and without significant subjective navigation-related complaints.

RESULTS

Analysis of responses on the Wayfinding Questionnaire indicated that 33 of the 77 participating stroke patients had significant navigation-related complaints. An examination of their performance on the Virtual Tübingen test established objective evidence for navigation impairment in 27 patients. Both landmark-based and path-based navigation impairment occurred in isolation, while location-based navigation impairment was only found along with the other two types.

CONCLUSIONS

The current study provides the first empirical support for the distinction between landmark-based, location-based, and path-based navigation impairment. Future research relying on other assessment instruments of navigation ability might be helpful to further validate this distinction.

Patients' and parents' views regarding supportive care in childhood cancer

Purpose

Intensive therapies in pediatric malignancies increased survival rates but also occurrence of treatment-related morbidities. Therefore, supportive care fulfills an increasingly important role. In planning development of guidelines with incorporation of shared decision making, we noticed that little is known about the needs and preferences of patients and their parents. Our goals were therefore to investigate (1) which supportive care topics patients and parents regard as most important and (2) the preferred role they wish to fulfill in decision making.

Methods

This qualitative study consisted of three focus groups (two traditional, one online) with patients and parents of two Dutch pediatric oncology centers. Data were transcribed as simple verbatim and analyzed using thematic analysis.

Results

Eleven adolescent patients and 18 parents shared detailed views on various aspects of supportive care. Themes of major importance were communication between patient and physician (commitment, accessibility, proactive attitude of physicians), well-timed provision of information, and the suitability and accessibility of psychosocial care. In contrast to prioritized supportive care topics by medical professionals, somatic issues (e.g., febrile neutropenia) were infrequently addressed. Patients and parents preferred to be actively involved in decision making in selected topics, such as choice of analgesics and anti-emetics, but not in, e.g., choice of antibiotics.

Conclusions

Children with cancer and parents were provided a valuable insight into their views regarding supportive care and shared decision making. These results have important implications towards improving supportive care, both in selecting topics for guideline development and incorporating preferences of patients and parents herein.

Electronic supplementary material

The online version of this article (doi:10.1007/s00520-017-3723-7) contains supplementary material, which is available to authorized users.

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.

Impact of Strategically Located White Matter Hyperintensities on Cognition in Memory Clinic Patients with Small Vessel Disease

BACKGROUND AND PURPOSE

Studies on the impact of small vessel disease (SVD) on cognition generally focus on white matter hyperintensity (WMH) volume. The extent to which WMH location relates to cognitive performance has received less attention, but is likely to be functionally important. We examined the relation between WMH location and cognition in a memory clinic cohort of patients with sporadic SVD.

METHODS

A total of 167 patients with SVD were recruited from memory clinics. Assumption-free region of interest-based analyses based on major white matter tracts and voxel-wise analyses were used to determine the association between WMH location and executive functioning, visuomotor speed and memory.

RESULTS

Region of interest-based analyses showed that WMHs located particularly within the anterior thalamic radiation and forceps minor were inversely associated with both executive functioning and visuomotor speed, independent of total WMH volume. Memory was significantly associated with WMH volume in the forceps minor, independent of total WMH volume. An independent assumption-free voxel-wise analysis identified strategic voxels in these same tracts. Region of interest-based analyses showed that WMH volume within the anterior thalamic radiation explained 6.8% of variance in executive functioning, compared to 3.9% for total WMH volume; WMH volume within the forceps minor explained 4.6% of variance in visuomotor speed and 4.2% of variance in memory, compared to 1.8% and 1.3% respectively for total WMH volume.

CONCLUSIONS

Our findings identify the anterior thalamic radiation and forceps minor as strategic white matter tracts in which WMHs are most strongly associated with cognitive impairment in memory clinic patients with SVD. WMH volumes in individual tracts explained more variance in cognition than total WMH burden, emphasizing the importance of lesion location when addressing the functional consequences of WMHs.

The Wayfinding Questionnaire as a Self-report Screening Instrument for Navigation-related Complaints After Stroke: Internal Validity in Healthy Respondents and Chronic Mild Stroke Patients

OBJECTIVE

In current stroke care, cognitive problems are usually diagnosed in a stepwise manner. More specifically, screening instruments are first applied to support healthcare professionals in deciding whether a second step (an extensive assessment) would be appropriate. None of the existing screening instruments, however, takes navigation ability into account. This is problematic, as navigation impairment after stroke has been shown to be common, more so than previously thought. The Wayfinding Questionnaire (WQ) is therefore presented as a screening instrument for navigation-related complaints after stroke. The internal validity of the WQ was investigated in two samples of participants to establish the final version.

METHOD AND RESULTS

In Study 1, the WQ was administered in a representative sample of 356 healthy participants. Its factor structure was investigated using a principal component analysis. This procedure resulted in deletion of four items and revealed a three-factor structure: "Navigation and Orientation," "Spatial Anxiety," and "Distance Estimation". In Study 2, a confirmatory analysis was performed to directly verify the factor structure as obtained in Study 1 based on data of 158 chronic mild stroke patients. Fit indices of the confirmatory analysis indicated acceptable model fit. The reliability of the three subscales was found to be very good in both healthy participants and patients.

CONCLUSIONS

These studies allowed us to determine the final version of the WQ. The results indicated that the WQ is an internally valid and reliable instrument that can be interpreted using a three-factor structure in both healthy respondents and chronic mild stroke patients.