Unusual encephalopathy with Wernicke-Korsakoff syndrome-like features due to adjuvant nivolumab for malignant melanoma.

INTRODUCTION: Autoimmune encephalitis is a rare immune-related adverse event of PD-1 inhibitors, nivolumab and pembrolizumab. Autoimmune hypophysitis can also be seen with the use of these agents. The relationship between these two phenomena is currently unknown. CASE REPORT: We describe a 79-year-old man with anterior scalp melanoma who received adjuvant nivolumab therapy. Sixteen weeks after the completion of nivolumab therapy, the patient presented to the hospital with altered mental status, anterograde amnesia, and symptoms of nausea and vomiting. The patient's encephalopathy was associated with confabulations. Workup identified increased CSF protein without increased cellularity, along with decreased serum cortisol and ACTH levels. This was consistent with encephalitis and central adrenal insufficiency. MANAGEMENT AND OUTCOME: The patient had a robust clinical response to steroids, with resolution of mental status changes and normalization of blood pressure. He continues to receive maintenance steroid therapy without any further symptoms six months later. CONCLUSIONS: We report herein a unique case of encephalopathy in the setting of nivolumab use for the treatment of melanoma. The condition resembled Korsakoff psychosis seen in the setting of alcoholism and was associated with central adrenal insufficiency. A prompt response to steroids was both diagnostic and therapeutic in our case, suggesting the resolution of autoimmune phenomena related to nivolumab.

Protocatechuic Acid Prevents Some of the Memory-Related Behavioural and Neurotransmitter Changes in a Pyrithiamine-Induced Thiamine Deficiency Model of Wernicke-Korsakoff Syndrome in Rats.

The purpose of this research was to investigate the effects of protocatechuic acid (PCA) at doses of 50 and 100 mg/kg on the development of unfavourable changes in cognitive processes in a pyrithiamine-induced thiamine deficiency (PTD) model of the Wernicke-Korsakoff syndrome (WKS) in rats. The effects of PCA were assessed at the behavioural and biochemical levels. Behavioural analysis was conducted using the Foot Fault test (FF), Bar test, Open Field test, Novel Object Recognition test (NOR), Hole-Board test and Morris Water Maze test (MWM). Biochemical analysis consisting of determination of concentration and turnover of neurotransmitters in selected structures of the rat CNS was carried out using high-performance liquid chromatography. PTD caused catalepsy (Bar test) and significantly impaired motor functions, leading to increased ladder crossing time and multiplied errors due to foot misplacement (FF). Rats with experimentally induced WKS showed impaired consolidation and recall of spatial reference memory in the MWM test, while episodic memory related to object recognition in the NOR was unimpaired. Compared to the control group, rats with WKS showed reduced serotonin levels in the prefrontal cortex and changes in dopamine and/or norepinephrine metabolites in the prefrontal cortex, medulla oblongata and spinal cord. PTD was also found to affect alanine, serine, glutamate, and threonine levels in certain areas of the rat brain. PCA alleviated PTD-induced cataleptic symptoms in rats, also improving their performance in the Foot Fault test. In the MWM, PCA at 50 and 100 mg/kg b.w. improved memory consolidation and the ability to retrieve acquired information in rats, thereby preventing unfavourable changes caused by PTD. PCA at both tested doses was also shown to have a beneficial effect on normalising PTD-disrupted alanine and glutamate concentrations in the medulla oblongata. These findings demonstrate that certain cognitive deficits in spatial memory and abnormalities in neurotransmitter levels persist in rats that have experienced an acute episode of PTD, despite restoration of thiamine supply and long-term recovery. PCA supplementation largely had a preventive effect on the development of these deficits, to some extent also normalising neurotransmitter concentrations in the brain.

Hyperemesis-induced Wernicke-Korsakoff Syndrome due to Hypergastrinemia during Long-term Treatment with Proton Pump Inhibitors.

We herein report a patient with Wernicke-Korsakoff syndrome (WKS) who had neither a history of alcoholism or of history of gastric surgery. A 56-year-old woman was transferred to our hospital because of the loss of consciousness and she was diagnosed to have Wernicke encephalopathy. She showed proton pump inhibitor-induced refractory hypergastrinemia with the subsequent development of hyperemesis and a vitamin B1 deficiency.

Thiamine deficiency degrades the link between spatial behavior and hippocampal synapsin I and phosphorylated synapsin I protein levels.

The links between spatial behavior and hippocampal levels of synapsin I and phosphosynapsin I were assessed in normal rats and in the pyrithiamine-induced thiamine deficiency (PTD) rat model of Wernicke-Korsakoff's syndrome. Synapsin I tethers small synaptic vesicles to the actin cytoskeleton in a phosphorylation-dependent manner, is involved in neurotransmitter release and has been implicated in hippocampal-dependent learning. Positive correlations between spontaneous alternation behavior and hippocampal levels of both synapsin I and phosphorylated synapsin I were found in control rats. However, spontaneous alternation performance was impaired in PTD rats and was accompanied by a significant reduction (30%) in phosphorylated synapsin I. Furthermore, no correlations were observed between either form of synapsin I and behavior in PTD rats. These data suggest that successful spontaneous alternation performance is related to high levels of hippocampal synapsin I and phosphorylated synapsin I. These results not only support the previous findings that implicate impaired hippocampal neurotransmission in the spatial learning and memory deficits associated with thiamine deficiency, but also suggest a presynaptic mechanism.

Clinical and pathological features of alcohol-related brain damage.

One of the sequelae of chronic alcohol abuse is malnutrition. Importantly, a deficiency in thiamine (vitamin B(1)) can result in the acute, potentially reversible neurological disorder Wernicke encephalopathy (WE). When WE is recognized, thiamine treatment can elicit a rapid clinical recovery. If WE is left untreated, however, patients can develop Korsakoff syndrome (KS), a severe neurological disorder characterized by anterograde amnesia. Alcohol-related brain damage (ARBD) describes the effects of chronic alcohol consumption on human brain structure and function in the absence of more discrete and well-characterized neurological concomitants of alcoholism such as WE and KS. Through knowledge of both the well-described changes in brain structure and function that are evident in alcohol-related disorders such as WE and KS and the clinical outcomes associated with these changes, researchers have begun to gain a better understanding of ARBD. This Review examines ARBD from the perspective of WE and KS, exploring the clinical presentations, postmortem brain pathology, in vivo MRI findings and potential molecular mechanisms associated with these conditions. An awareness of the consequences of chronic alcohol consumption on human behavior and brain structure can enable clinicians to improve detection and treatment of ARBD.

The Korsakoff syndrome: clinical aspects, psychology and treatment.

AIMS: The Korsakoff syndrome is a preventable memory disorder that usually emerges (although not always) in the aftermath of an episode of Wernicke's encephalopathy. The present paper reviews the clinical and scientific literature on this disorder. METHODS: A systematic review of the clinical and scientific literature on Wernicke's encephalopathy and the alcoholic Korsakoff syndrome. RESULTS: The Korsakoff syndrome is most commonly associated with chronic alcohol misuse, and some heavy drinkers may have a genetic predisposition to developing the syndrome. The characteristic neuropathology includes neuronal loss, micro-haemorrhages and gliosis in the paraventricular and peri-aqueductal grey matter. Lesions in the mammillary bodies, the mammillo-thalamic tract and the anterior thalamus may be more important to memory dysfunction than lesions in the medial dorsal nucleus of the thalamus. Episodic memory is severely affected in the Korsakoff syndrome, and the learning of new semantic memories is variably affected. 'Implicit' aspects of memory are preserved. These patients are often first encountered in general hospital settings where they can occupy acute medical beds for lengthy periods. Abstinence is the cornerstone of any rehabilitation programme. Korsakoff patients are capable of new learning, particularly if they live in a calm and well-structured environment and if new information is cued. There are few long-term follow-up studies, but these patients are reported to have a normal life expectancy if they remain abstinent from alcohol. CONCLUSIONS: Although we now have substantial knowledge about the nature of this disorder, scientific questions (e.g. regarding the underlying genetics) remain. More particularly, there is a dearth of appropriate long-term care facilities for these patients, given that empirical research has shown that good practice has beneficial effects.

Development and resolution of brain lesions caused by pyrithiamine- and dietary-induced thiamine deficiency and alcohol exposure in the alcohol-preferring rat: a longitudinal magnetic resonance imaging and spectroscopy study.

Wernicke's encephalopathy (WE) is characterized by lesions in thalamus, hypothalamus (including mammillary nuclei), and inferior colliculi, results in serious disabilities, has an etiology of thiamine deficiency, is treatable with thiamine, and occurs most commonly with alcoholism. Despite decades of study, whether alcohol exposure exacerbates the neuropathology or retards its resolution remains controversial. To examine patterns of brain damage and recovery resulting from thiamine deprivation with and without alcohol exposure, we conducted in vivo magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) at 3 T in alcohol-preferring (P) rats, which had voluntarily consumed large amounts of alcohol before thiamine manipulation. A total of 18 adult male P rats (nine alcohol-exposed) received a thiamine-deficient diet for 2 weeks: 10 (five alcohol-exposed) received intraperitoneal (i.p.) pyrithiamine (PT) and eight (four alcohol-exposed) received i.p. thiamine supplementation. Neurological signs developed by day 14. Rats were scanned before thiamine depletion and 18 and 35 days after thiamine repletion. Two-dimensional J-resolved MRS single-voxel spectra with water reference were collected in a voxel subtending the thalamus; metabolite quantification was corrected for voxel tissue content. MRI identified significant enlargement of dorsal ventricles and increase in signal intensities in thalamus, inferior colliculi, and mammillary nuclei of PT compared with thiamine-treated (TT) groups from MRI 1-2, followed by significant normalization from MRI 2-3 in thalamus and colliculi, but not mammillary nuclei and lateral ventricles. Voxel-by-voxel analysis revealed additional hyperintense signal clusters in the dorsal and ventral hippocampus and enlargement of the fourth ventricle. MRS showed a significant decline and then partial recovery in thalamic N-acetylaspartate, a marker of neuronal integrity, in PT compared with TT rats, with no change detected in creatine, choline, or glutamate. PT rats with prior alcohol exposure exhibited attenuated recovery in the thalamus and arrested growth of the corpus callosum; further, two of the five alcohol-exposed PT rats died prematurely. Parenchymal and ventricular changes with thiamine manipulation concur with human radiological signs of WE. The enduring macrostructural and neurochemical abnormalities involving critical nodes of Papez circuit carry liabilities for development of amnesia and incomplete recovery from other cognitive and motor functions subserved by the affected neural systems.

Cholinergic parameters and the retrieval of learned and re-learned spatial information: a study using a model of Wernicke-Korsakoff Syndrome.

This is a factorial (2 x 2 x 2) spatial memory and cholinergic parameters study in which the factors are chronic ethanol, thiamine deficiency and naivety in Morris water maze task. Both learning and retention of the spatial version of the water maze were assessed. To assess retrograde retention of spatial information, half of the rats were pre-trained on the maze before the treatment manipulations of pyrithiamine (PT)-induced thiamine deficiency and post-tested after treatment (pre-trained group). The other half of the animals was only trained after treatment to assess anterograde amnesia (post-trained group). Thiamine deficiency, associated to chronic ethanol treatment, had a significant deleterious effect on spatial memory performance of post-trained animals. The biochemical data revealed that chronic ethanol treatment reduced acetylcholinesterase (AChE) activity in the hippocampus while leaving the neocortex unchanged, whereas thiamine deficiency reduced both cortical and hippocampal AChE activity. Regarding basal and stimulated cortical acetylcholine (ACh) release, both chronic ethanol and thiamine deficiency treatments had significant main effects. Significant correlations were found between both cortical and hippocampal AChE activity and behaviour parameters for pre-trained but not for post-trained animals. Also for ACh release, the correlation found was significant only for pre-trained animals. These biochemical parameters were decreased by thiamine deficiency and chronic ethanol treatment, both in pre-trained and post-trained animals. But the correlation with the behavioural parameters was observed only for pre-trained animals, that is, those that were retrained and assessed for retrograde retention.

Age-related vulnerability to diencephalic amnesia produced by thiamine deficiency: the role of time of insult.

Age is a risk factor for the development of many neurological disorders, including alcohol-related neurological disorders. A rodent model of Wernicke-Korsakoff Syndrome (WKS), acute pyrithiamine-induced thiamine deficiency (PTD), produces diencephalic damage and impairments of memory similar to what is seen in WKS patients. Advanced age increases the vulnerability to the cascade of acute and some chronic neurological events caused by PTD treatment. Interactions between PTD treatment and age at the time of treatment (3, 10, or 21 months), in addition to the effects of an increased recovery period, were examined relative to spatial memory impairment and neuropathology in Fischer 344 rats. Although acute neurological disturbances and medial thalamic brain lesions were more prevalent in middle-aged and senescent rats exposed to PTD treatment, relative to young rats, behavioral data did not support the view that PTD and aging have synergistic effects. In addition, both advanced age and PTD treatment result in a loss of basal forebrain cholinergic neurons, though there was no interaction. Despite the fact that no convincing evidence was found for an effect of extended recovery time on neuropathology measures, young rats given an extensive recovery period displayed less working memory impairment. In summary, these data provide evidence for an increased susceptibility of the aged rat to the acute neurological consequences and diencephalic pathology associated with PTD treatment and indicated a similar vulnerability of the middle-aged rat. However, the synergistic interaction between aging and PTD treatment in thalamic tissue loss did not express behaviorally.

Aging potentiates the acute and chronic neurological symptoms of pyrithiamine-induced thiamine deficiency in the rodent.

The present study aimed to assess the role of advanced age in the development and manifestation of thiamine deficiency using an animal model of Wernicke-Korsakoff syndrome (WKS). Interactions between pyrithiamine-induced thiamine deficiency (PTD) and age were examined relative to working memory impairment and neuropathology in Fischer 344 rats. Young (2-3 months) and aged (22-23 months) F344 rats were assigned to one of two treatment conditions: PTD or pair-fed control (PF). Rats in the former group were further divided into three groups according to duration of PTD treatment. Working memory was assessed with an operant matching-to-position (MTP) task; after testing, animals were sacrificed and both gross and immunocytochemical measures of brain pathology were obtained. Aged rats exhibited acute neurological disturbances during the PTD treatment regime earlier than did young rats, and also developed more extensive neuropathology with a shorter duration of PTD. Aged rats displayed increased brain shrinkage (smaller frontal cortical and callosal thickness) as well as enhanced astrocytic activity in the thalamus and a decrease in ChAT-positive cell numbers in the medial septum; the latter two measures of neuropathology were potentiated by PTD. In both young and aged rats, and to a greater degree in the latter group, PTD reduced thalamic volume. Behaviorally, aged rats displayed impaired choice accuracy on the delayed MTP task. Regardless of age, rats with lesions centered on the internal medullary lamina of the thalamus also displayed impaired choice accuracy. Moreover, increased PTD treatment duration led to increased response times on the delayed MTP task. These results suggest that aging does indeed potentiate the neuropathology associated with experimental thiamine deficiency, supporting an age coupling hypothesis of alcohol-related neurological disorders.