Aging effects on dual-route speech processing networks during speech perception in noise.

Healthy aging leads to complex changes in the functional network of speech processing in a noisy environment. The dual-route neural architecture has been applied to the study of speech processing. Although evidence suggests that senescent increases activity in the brain regions across the dorsal and ventral stream regions to offset reduced periphery, the regulatory mechanism of dual-route functional networks underlying such compensation remains largely unknown. Here, by utilizing functional near-infrared spectroscopy (fNIRS), we investigated the compensatory mechanism of the dual-route functional connectivity, and its relationship with healthy aging by using a speech perception task at varying signal-to-noise ratios (SNR) in healthy individuals (young adults, middle-aged adults, and older adults). Results showed that the speech perception scores showed a significant age-related decrease with the reduction of the SNR. The analysis results of dual-route speech processing networks showed that the functional connection of Wernicke's area and homolog Wernicke's area were age-related increases. Further to clarify the age-related characteristics of the dual-route speech processing networks, graph-theoretical network analysis revealed an age-related increase in the efficiency of the networks, and the age-related differences in nodal characteristics were found both in Wernicke's area and homolog Wernicke's area under noise environment. Thus, Wernicke's area might be a key network hub to maintain efficient information transfer across the speech process network with healthy aging. Moreover, older adults would recruit more resources from the homologous Wernicke's area in a noisy environment. The recruitment of the homolog of Wernicke's area might provide a means of compensation for older adults for decoding speech in an adverse listening environment. Together, our results characterized dual-route speech processing networks at varying noise environments and provided new insight for the compensatory theories of how aging modulates the dual-route speech processing functional networks.

More widespread functionality of posterior language area in patients with brain tumors.

Damage to the posterior language area (PLA), or Wernicke's area causes cortical reorganization in the corresponding regions of the contralateral hemisphere. However, the details of reorganization within the ipsilateral hemisphere are not fully understood. In this context, direct electrical stimulation during awake surgery can provide valuable opportunities to investigate neuromodulation of the human brain in vivo, which is difficult through the non-invasive approaches. Thus, in this study, we aimed to investigate the characteristics of the cortical reorganization of the PLA within the ipsilateral hemisphere. Sixty-two patients with left hemispheric gliomas were divided into groups depending on whether the lesion extended to the PLA. All patients underwent direct cortical stimulation with a picture-naming task. We further performed functional connectivity analyses using resting-state functional magnetic resonance imaging (MRI) in a subset of patients and calculated betweenness centrality, an index of the network importance of brain areas. During direct cortical stimulation, the regions showing positive (impaired) responses in the non-PLA group were localized mainly in the posterior superior temporal gyrus (pSTG), whereas those in the PLA group were widely distributed from the pSTG to the posterior supramarginal gyrus (pSMG). Notably, the percentage of positive responses in the pSMG was significantly higher in the PLA group (47%) than in the non-PLA group (8%). In network analyses of functional connectivity, the pSMG was identified as a hub region with high betweenness centrality in both the groups. These findings suggest that the language area can spread beyond the PLA to the pSMG, a hub region, in patients with lesion progression to the pSTG. The change in the pattern of the language area may be a compensatory mechanism to maintain efficient brain networks.

tDCS of right-hemispheric Wernicke's area homologue affects contextual learning of novel lexicon.

Numerous studies have shown robust evidence of the right hemisphere's involvement in the language function, for instance in the processing of intonation, grammar, word meanings, metaphors, etc. However, its role in lexicon acquisition remains obscure. We applied transcranial direct current stimulation (tDCS) over the right-hemispheric homologue of Wernicke's area to assess its putative involvement in the processing of different types of novel semantics. After receiving 15 min of anodal, cathodal, or sham (placebo) tDCS, three groups of healthy participants learnt novel concrete and abstract words in the context of short stories. Learning outcomes were assessed using a battery of tests immediately after this contextual learning session and 24 h later. As a result, an inhibitory effect of cathodal tDCS and a facilitatory effect of anodal tDCS were found for abstract word acquisition only. We also found a significant drop in task performance on the second day of the assessment for both word types in all the stimulation groups, suggesting no significant influence of tDCS on the post-learning consolidation of new memory traces. The results suggest an involvement of Wernicke's right-hemispheric counterpart in initial encoding (but not consolidation) of abstract semantics, which may be explained either by the right hemispheres direct role in processing lexical semantics or by an indirect impact of tDCS on contralateral (left-hemispheric) cortical areas through cross-callosal connections.

Transcranial direct-current stimulation of core language areas facilitates novel word acquisition.

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that can alter the state of the stimulated brain area and thereby affect neurocognitive processes and resulting behavioural performance. Previous studies have shown disparate results with respect to tDCS effects on language function, particularly with respect to language learning and word acquisition. To fill this gap, this study aimed at systematically addressing the effects of tDCS of core left-hemispheric language cortices on the brain mechanisms underpinning two main neurocognitive strategies of word learning: implicit inference-based Fast Mapping (FM) and direct instruction-based Explicit Encoding (EE). Prior to a word-learning session, 160 healthy participants were given 15 min of either anodal or cathodal tDCS of Wernicke's or Broca's areas, or a control sham (placebo) stimulation, using a between-group design. Each participant then learned 16 novel words (8 through FM and 8 through EE) in a contextual word-picture association session. Moreover, these words were learnt either perceptually via auditory exposure combined with a graphical image of the novel object, or in an articulatory mode, where the participants additionally had to overtly articulate the novel items. These learning conditions were fully counterbalanced across participants, stimuli and tDCS groups. Learning outcomes were tested at both lexical and semantic levels using two tasks: recognition and word-picture matching. EE and FM conditions produced similar outcomes, indicating comparable efficiency of the respective learning strategies. At the same time, articulatory learning produced generally better results than non-articulatory exposure, yielding higher recognition accuracies and shorter latencies in both tasks. Crucially, real tDCS led to global outcome improvements, demonstrated by faster (compared to sham) reactions, as well as some accuracy changes. There was also evidence of more specific tDCS effects: better word-recognition accuracy for EE vs. FM following cathodal stimulation as well as more expressed improvements in recognition accuracy and reaction times for anodal Broca's and cathodal Wernicke's stimulation, particularly for unarticulated FM items. These learning mode-specific effects support the notion of partially distinct brain mechanisms underpinning these two learning strategies. Overall, numerically largest improvements were observed for anodal Broca's tDCS, whereas the least expressed benefits of tDCS for learning were measured after anodal Wernicke stimulation. Finally, we did not find any inhibitory effects of either tDCS polarity in any of the comparisons. We conclude that tDCS of core language areas exerts a general facilitatory effect on new word acquisition with some limited specificity to learning protocols - the result that may be of potential applied value for future research aimed at ameliorating learning deficits and language disorders.

Stem Cell Therapy and Thiamine Deficiency-Induced Brain Damage.

Wernicke's encephalopathy (WE) is a major central nervous system disorder resulting from thiamine deficiency (TD) in which a number of brain regions can develop serious damage including the thalamus and inferior colliculus. Despite decades of research into the pathophysiology of TD and potential therapeutic interventions, little progress has been made regarding effective treatment following the development of brain lesions and its associated cognitive issues. Recent developments in our understanding of stem cells suggest they are capable of repairing damage and improving function in different maladys. This article puts forward the case for the potential use of stem cell treatment as a therapeutic strategy in WE by first examining the effects of TD on brain functional integrity and its consequences. The second half of the paper will address the future benefits of treating TD with these cells by focusing on their nature and their potential to effectively treat neurodegenerative diseases that share some overlapping pathophysiological features with TD. At the same time, some of the obstacles these cells will have to overcome in order to become a viable therapeutic strategy for treating this potentially life-threatening illness in humans will be highlighted.

Wernicke's encephalopathy with pinpoint pupils and diplopia.

This case report presents the clinical findings of a female patient diagnosed with Wernicke's encephalopathy, characterized by pinpoint pupils. While pupillary changes can occur in Wernicke's encephalopathy, the presence of pinpoint pupils is exceedingly rare. In this report, we aim to document and discuss this unusual presentation, as well as speculate on the potential mechanisms underlying this atypical manifestation of the disease.

The role of CT brain findings in the early diagnosis of infantile encephalitic beriberi.

BACKGROUND: Thiamine deficiency disease may occur in infants from thiamine-deficient mothers in developing countries, as well as in infants fed solely with soy-based formula. Thiamine deficiency in infants may present with acute neurological manifestations of infantile encephalitic beriberi. OBJECTIVE: To review the role of noncontrast CT brain findings in infantile encephalitic beriberi in early diagnosis. MATERIALS AND METHODS: A retrospective review of noncontrast CT scans of the brain in 21 infants with acute-onset infantile encephalitic beriberi was carried out. RESULTS: On noncontrast-enhanced CT brain, hypodense lesions were seen symmetrically in the putamen in all the babies; symmetric hypodensities were seen in the caudate nuclei in 14/21 (67%), in dorsomedial thalami/hypothalamic/subthalamic area in 4/21 (19%), and in the globi pallidi in 2/21 (9.5%) of the infants. CONCLUSION: Recognition of symmetrical hypodense lesions in the basal ganglia and medial thalami/hypothalamic/subthalamic area on noncontrast CT scan of the brain are important early features to recognize in encephalitic beriberi in at-risk infants. ADVANCES IN KNOWLEDGE: IEBB is a cause of hypodense bilateral basal ganglia and may be identified by this finding in the appropriate clinical settings.

Bilateral hearing loss as the initial presentation of reversible Wernicke's encephalopathy with splenial lesion.

BACKGROUND: Wernicke's encephalopathy (WE) is an acute neurological syndrome resulting from thiamine (vitamin B1) deficiency. It has been recognized increasingly in non-alcoholic patients, such as in the condition of malnutrition. Recent literature has shed light on uncommon symptoms and neuroimaging findings. CASE REPORT: We reported a case of a 44-year-old male who initially presented with bilateral hearing loss, and exhibited abnormality in the splenium of the corpus callosum on magnetic resonance imaging (MRI) diffusion-weighted imaging sequence. On the following day the patient developed new symptoms, including unstable walking, double vision and hallucination. The subsequent brain MRI demonstrated lesions involving periaqueductal grey matter and bilateral medial thalamus, indicating the diagnosis of WE. Empirical treatment with intravenous thiamine resulted in complete clinical and radiological resolution. CONCLUSION: To the best of our knowledge, the current case is the first report of WE in literature with uncommon but reversible manifestations. This case warns us to maintain a heightened level of suspicion for WE in malnourished patients with neurological deficits, despite the possibility of atypical presentations encompassing bilateral hearing disturbances and unusual neuroradiological results. Early diagnosis and timely administration of thiamine in WE are likely to lead to a favorable outcome and full recovery.

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.

Using Academic Consultation-Liaison Telepsychiatry to Meet the Mental Health Needs of Complex, Medically Ill Patients in Underserved Areas: A Case Report.

Background: The nationwide shortage of mental health resources often disproportionately affects rural areas. As innovative strategies are required to address mental health resource shortages in rural areas, telepsychiatry consultation (TPC) may represent a population health-oriented approach to bridge this gap. In this case report, we examine the use of TPC from an academic consultation-liaison psychiatry service to a rural community hospital. Case Report: We describe the case of a woman with Wernicke encephalopathy seeking to leave the hospital against medical advice and the role that the TPC service played in the patient's evaluation and management, including assessing decision-making capacity. Discussion: We then examine benefits and limitations of the service, including a narrative review of the relevant, but limited, available literature as well as suggestions for how the service may be improved and incorporated into psychiatry residency and fellowship training in the future.

What can cause cancer patients to attempt suicide? Thiamine deficiency mimicking the symptoms of major depressive disorder.

OBJECTIVES: Thiamine deficiency (TD) presents with various physical and psychiatric symptoms, but no cases with depression-like symptoms have been reported. METHODS: We report a patient with cancer who appeared to attempt suicide as a consequence of depressive mood likely related to TD. RESULTS: The patient was a 58-year-old woman diagnosed with recurrent endometrial cancer, with lung metastasis and pelvic dissemination. The patient apparently attempted suicide was referred to the psycho-oncology department. At the time of the examination, major depressive disorder was suspected based on her mental symptoms, but when thiamine was administered intravenously in response to her poor dietary intake, her palpitations, dyspnea, anorexia, and insomnia improved, and her suicidal ideation disappeared at her reexamination 1 hour later after thiamine administration. SIGNIFICANCE OF RESULTS: It is likely that the observed palpitations, dyspnea, anorexia, and insomnia, as well as the severe depression and the attempted suicide, which were thought to be physical symptoms associated with depression, were actually related to TD. Suicidal ideation and attempted suicide are conspicuous as psychiatric symptoms. However, in such cases, rather than simply starting treatment for depression, it is necessary to consider reversible TD as a cause of these symptoms and perform differential diagnosis to confirm the physical illness.

Thiamine deficiency as a differential diagnosis for severe fatigue in terminally ill cancer patients.

OBJECTIVES: Patients with advanced cancer present various symptoms as their disease progresses. Among these, fatigue is a frequent symptom in patients with advanced cancer and is associated with decreased quality of life (QOL). However, there are few reports regarding its association with thiamine deficiency (TD). METHODS: We report a case in which we found TD in a patient with advanced lung cancer who presented with weight loss, significant fatigue, and appeared to have a worsening general condition, for whom symptoms were dramatically improved within a short period of time by intravenous administration of thiamine. RESULTS: The patient was a 76-year-old woman who had been diagnosed with lung cancer and liver metastases 6 months earlier. Due to interstitial pneumonia, she was not a candidate for chemotherapy and so palliative care was started. At 8 months after initial diagnosis, the patient complained of fatigue during a medical examination, so a blood sample was taken. A week later, she visited the hospital with a cane. She felt extremely fatigued and was unable to stand, but results from the previous blood test revealed that a TD. The fatigue disappeared 15 minutes after intravenous administration of thiamine and she was able to return home without the cane. SIGNIFICANCE OF RESULTS: Fatigue is a frequent symptom in advanced cancer patients, and TD may be the underlying cause. Inclusion of TD in the differential diagnosis may contribute to improving patient QOL.

Vitamin B1 Deficiency Identified from Incidental Detection of Hyperlactatemia: A Case Report.

Introduction: Vitamin B1 deficiency poses a significant risk of impaired consciousness, with manifestations ranging from anorexia and fatigue to severe neurological and cardiovascular disturbances. Wernicke's encephalopathy, a neurological disorder stemming from vitamin B1 deficiency, presents as the triad of ophthalmoplegia, altered mental state, and cerebellar ataxia. However, these symptoms are not consistently present, complicating the diagnosis. In addition, subclinical vitamin B1 deficiency can progress unnoticed until severe complications arise. Studies indicate a high rate of undiagnosed cases, emphasizing the need for early detection and intervention. Case presentation: We present the case of a 65-year-old man in whom hyperlactatemia was incidentally detected, leading to the diagnosis of vitamin B1 deficiency. The patient, presenting with vertigo and vomiting, had been eating boxed lunches bought from convenience stores following the death of his wife 3 years earlier. Vertigo gradually improved with rest, but the persistence of hyperlactatemia prompted further investigation, revealing low vitamin B1 levels and high pyruvate levels. Treatment with dietary adjustments and supplements significantly improved his symptoms. Discussion: In this case, hyperlactatemia was found in a vertigo patient, revealing asymptomatic vitamin B1 deficiency. Elevated lactate is often linked with conditions like sepsis but can also stem from overlooked factors such as low vitamin B1 levels due to poor diet habits like consuming fried foods. Conclusion: This case highlights the importance of considering vitamin B1 deficiency in patients with unexplained hyperlactatemia, even in high-income countries. Early detection can prevent progression to the severe complications associated with Wernicke's encephalopathy. Proactive measurement of lactate levels in at-risk populations may facilitate early diagnosis and intervention, ultimately improving patient outcomes.

[Wernicke encephalopathy : a neuro-ophthalmological side effect of bariatric surgery]. / L'encéphalopathie de Gayet-Wernicke : une complication neuro-ophtalmologique de la chirurgie bariatrique.

Due to an increase in the worldwide prevalence of obesity and the efficiency of bariatric surgery, this procedure is more often performed. Besides its benefits, it has also disadvantages and may be the cause of nutritional deficiencies. Thiamin deficiency is particularly important to diagnose and to treat early as it can lead to major sequelae and even to death. Wernicke's encephalopathy is the most frequent presentation associating confusion, ataxia, ophtalmoplegia and nystagmus. The full triad is not usually observed, which may lead to sub-diagnosis of this affection. The diagnosis is clinical, biological and radiologic thanks to the brain MRI. Intravenous thiamin supplementation therapy must be administered as fast as possible in order to avoid long-term damages. In the ophthalmological field, the potential sequelae are ophthalmoplegia, nystagmus and optic neuropathy. Therapeutics for nystagmus are pharmacological, surgical and/or optical. We illustrate this condition with a case report of an 18-year-old man developing Wernicke's encephalopathy as early as six weeks after a sleeve gastrectomy.

Suite à une augmentation de la prévalence de l'obésité dans le monde et à l'efficacité de la chirurgie bariatrique, cette technique est pratiquée de plus en plus fréquemment. Malgré ses avantages, elle n'est pas sans risque et peut être responsable de déficits nutritionnels multiples. Le déficit en vitamine B1 ou thiamine est particulièrement important à connaître et, à rapidement diagnostiquer en raison des nombreuses séquelles invalidantes, voire le décès du patient, dont il peut être responsable. Le tableau classique est l'encéphalopathie de Gayet-Wernicke associant confusion, ataxie et troubles oculomoteurs. Néanmoins, il n'est pas toujours complet, ce qui participe au sous-diagnostic de cette pathologie. Le diagnostic est clinique, biologique et/ou radiologique grâce à l'IRM cérébrale. La supplémentation vitaminique intraveineuse doit être instaurée le plus rapidement possible afin d'éviter des séquelles à long terme. D'un point de vue ophtalmologique, les séquelles potentielles sont les ophtalmoplégies, les nystagmus et les neuropathies optiques. Les thérapies envisageables du nystagmus, outre la supplémentation en thiamine en aigu, sont pharmacologiques, chirurgicales et/ou optiques. Nous illustrons cette pathologie par un cas clinique d'encéphalopathie de Gayet-Wernicke dès la 6ème semaine post-opératoire d'une chirurgie bariatrique de type «sleeve¼ chez un patient de 18 ans.

Acute hearing and visual loss caused by thiamine deficiency.

BACKGROUND: Wernicke encephalopathy (WE) is a devastating acute or subacute neurological disorder caused by thiamine deficiency. Wernicke encephalopathy is characterized by the triad of ocular signs, cerebellar dysfunction, and confusion. Visual loss and hearing loss are less common findings in WE. Here, we report a case of Wernicke encephalopathy in a nonalcoholic liver cirrhosis patient who presented with acute bilateral deafness and bilateral blindness. CASE PRESENTATION: A 60-year-old Chinese man presented with a history of bilateral blindness and bilateral hypoacousia for 3 days. He had a history of liver cirrhosis and chronic hepatitis C virus infection and did not have a habit of alcohol consumption. Ophthalmologic and otologic examinations showed no obvious abnormalities. MRI findings revealed symmetric fluid-attenuated inversion recovery (FLAIR) hyperintensities in the bilateral medial dorsal thalamus, periventricular region around the third ventricle and tectum, and dorsal medulla oblongata. One day after hospitalization, the patient developed a mild coma. Based on the laboratory and neuroimaging findings, we diagnosed the patient with Wernicke encephalopathy. He soon regained consciousness after administration of thiamine. Both his visual acuity and his hearing function improved gradually. CONCLUSIONS: We suggest that Wernicke encephalopathy can present with bilateral blindness and bilateral deafness.

The Wernicke conundrum revisited: evidence from connectome-based lesion-symptom mapping.

Wernicke's area has been assumed since the 1800s to be the primary region supporting word and sentence comprehension. However, in 2015 and 2019, Mesulam and colleagues raised what they termed the 'Wernicke conundrum', noting widespread variability in the anatomical definition of this area and presenting data from primary progressive aphasia that challenged this classical assumption. To resolve the conundrum, they posited a 'double disconnection' hypothesis: that word and sentence comprehension deficits in stroke-based aphasia result from disconnection of anterior temporal and inferior frontal regions from other parts of the brain due to white matter damage, rather than dysfunction of Wernicke's area itself. To test this hypothesis, we performed lesion-deficit correlations, including connectome-based lesion-symptom mapping, in four large, partially overlapping groups of English-speaking chronic left hemisphere stroke survivors. After removing variance due to object recognition and associative semantic processing, the same middle and posterior temporal lobe regions were implicated in both word comprehension deficits and complex non-canonical sentence comprehension deficits. Connectome lesion-symptom mapping revealed similar temporal-occipital white matter disconnections for impaired word and non-canonical sentence comprehension, including the temporal pole. We found an additional significant temporal-parietal disconnection for non-canonical sentence comprehension deficits, which may indicate a role for phonological working memory in processing complex syntax, but no significant frontal disconnections. Moreover, damage to these middle-posterior temporal lobe regions was associated with both word and non-canonical sentence comprehension deficits even when accounting for variance due to the strongest anterior temporal and inferior frontal white matter disconnections, respectively. Our results largely agree with the classical notion that Wernicke's area, defined here as middle superior temporal gyrus and middle-posterior superior temporal sulcus, supports both word and sentence comprehension, suggest a supporting role for temporal pole in both word and sentence comprehension, and speak against the hypothesis that comprehension deficits in Wernicke's aphasia result from double disconnection.

Controversy over the temporal cortical terminations of the left arcuate fasciculus: a reappraisal.

The arcuate fasciculus has been considered a major dorsal fronto-temporal white matter pathway linking frontal language production regions with auditory perception in the superior temporal gyrus, the so-called Wernicke's area. In line with this tradition, both historical and contemporary models of language function have assigned primacy to superior temporal projections of the arcuate fasciculus. However, classical anatomical descriptions and emerging behavioural data are at odds with this assumption. On one hand, fronto-temporal projections to Wernicke's area may not be unique to the arcuate fasciculus. On the other hand, dorsal stream language deficits have been reported also for damage to middle, inferior and basal temporal gyri that may be linked to arcuate disconnection. These findings point to a reappraisal of arcuate projections in the temporal lobe. Here, we review anatomical and functional evidence regarding the temporal cortical terminations of the left arcuate fasciculus by incorporating dissection and tractography findings with stimulation data using cortico-cortical evoked potentials and direct electrical stimulation mapping in awake patients. First, we discuss the fibres of the arcuate fasciculus projecting to the superior temporal gyrus and the functional rostro-caudal gradient in this region where both phonological encoding and auditory-motor transformation may be performed. Caudal regions within the temporoparietal junction may be involved in articulation and associated with temporoparietal projections of the third branch of the superior longitudinal fasciculus, while more rostral regions may support encoding of acoustic phonetic features, supported by arcuate fibres. We then move to examine clinical data showing that multimodal phonological encoding is facilitated by projections of the arcuate fasciculus to superior, but also middle, inferior and basal temporal regions. Hence, we discuss how projections of the arcuate fasciculus may contribute to acoustic (middle-posterior superior and middle temporal gyri), visual (posterior inferior temporal/fusiform gyri comprising the visual word form area) and lexical (anterior-middle inferior temporal/fusiform gyri in the basal temporal language area) information in the temporal lobe to be processed, encoded and translated into a dorsal phonological route to the frontal lobe. Finally, we point out surgical implications for this model in terms of the prediction and avoidance of neurological deficit.

Seizures in eating disorders.

OBJECTIVE: To complete a descriptive study of seizure etiology in a large population of eating disorder (ED) patients and to better understand whether malnutrition itself, in those with EDs, is associated with seizure development. METHOD: In this retrospective study, 75 patients with documented seizures met inclusion criteria from a total of 1664 charts. RESULTS: Prevalence of seizures in this ED cohort was found to be 4.5%, with 29.3% of individuals experiencing seizures due to psychogenic nonepileptic seizures (PNES). Other common causes of seizures included substance abuse/withdrawal (18.7%), primary seizure disorder (12%), and electrolyte abnormalities/hypoglycemia (10.7%). Three patients (4%) also developed their seizures presumably due to Wernicke's encephalopathy (WE). DISCUSSION: Several etiologies of seizures are reported from this large sample of ED patients, and this is also the first study to report on a possible association of WE as a cause of seizures in ED patients. The contribution of WE and malnutrition toward the development of seizures in this population remains to be determined, and future studies should also seek to better understand the inter-relationship between malnutrition and the other variables discussed in this article, such as hypomagnesemia, toward seizure development. PUBLIC SIGNIFICANCE: The medical complications of EDs are myriad but seizures have not historically been considered one of those direct complications of malnutrition. The findings of this retrospective study suggest that seizure development may be a direct and indirect complication associated with EDs. The presentation of Wernicke's encephalopathy, which can also be associated with development of seizures, requires further investigation in those with EDs.

Can thiamine substitution restore cognitive function in alcohol use disorder?

AIMS: While clinical consequences of thiamine deficiency in alcohol use disorder (AUD) are severe, evidence-based recommendations on dosage, type of administration and duration of thiamine substitution (TS), and its' target levels remain sparse. This study aimed to compare the effect of two best practice TS regimens on thiamine blood levels (i.e. thiamine pyrophosphate, TPP) and cognitive function. METHODS: In 50 patients undergoing in-patient alcohol-withdrawal treatment, TPP levels were determined at baseline and end of weeks 1, 2 and 8 following administration of oral TS (3 × 100 mg/day for 7 days followed by 1 × 100 mg/day thereafter) either with or without preceding intravenous TS (3 × 100 mg/day for 5 days). An extensive psychiatric assessment was conducted at baseline, including an evaluation of AUD severity and depressive symptoms. Additionally, cognitive function and depressive symptoms were repeatedly evaluated. RESULTS: Relevant increases (mean increase by 100.2 nmol/l [CI 76.5-123.8], P < 0.001) in peripheral blood TPP levels were observed in all patients at the end of weeks 1 and 2. Furthermore, no relevant difference between the intravenous and the oral group was found (average difference between increases: 2.3 nmol/l, P = 0.912). Importantly, an association between the 'extent of the response' to TS and the performance in a memory task was revealed in secondary analyses. CONCLUSION: TS was associated with improving cognitive function in patients with AUD, independently of the substitution regime. Thus, in clinical practice, oral TS might be a sufficient but obligatory medication to prevent cognitive decline in AUD in the absence of Wernicke-Korsakoff Syndrome.

Is there a time window for MRI in Wernicke encephalopathy - a decade of experience from a tertiary hospital.

OBJECTIVE: Wernicke encephalopathy (WE) is a neuropsychiatric syndrome caused by thiamine deficiency. Despite its low sensitivity, brain magnetic resonance imaging (MRI) is the most useful diagnostic technique. Our aim was to investigate whether the timing of the imaging study, and thiamine replacement can influence brain MRI findings in these patients. METHODS: Retrospective observational study of hospitalized patients between January/2008 and December/2020 with a clinical diagnosis of WE. Data from clinical presentation, diagnostic features, therapeutic approach, and outcomes were collected. RESULTS: We identified 41 patients (55 ± 13.3 years) with WE. Brain MRI was performed in 36 patients, and one third had T2/FLAIR hyperintensities suggestive of WE. We found an association between a history of poor diet and periventricular hyperintensities (p = 0.023), especially on the ventral surface of the thalamus and the periaqueductal region. It was found that the odds of having a typical imaging of WE decreased by 5.3% for each additional unit (100 mg) of thiamine administered (p = 0.046) (95% CI [0.89, 0.99]). On the other hand, the number of days from clinical presentation was not found to be a viable predictor (p = 0.254) (95% CI [0.88, 1.03]) Recovery was positively correlated with the total dose of thiamine received until discharge (p = 0.020). CONCLUSIONS: MRI hyperintensities seem to be dependent on the timing of thiamine correction and, particularly, on the thiamine dosage prescribed at admission. Nevertheless, thiamine replacement should not be delayed, as its timely prescription is associated with a better prognosis at discharge.