Visual loss and optic nerve head swelling in thiamine deficiency without prolonged dietary deficiency

Xeropthalmia and optic neuropathy secondary to ARFID: a case report

BACKGROUND

Patients with avoidant/restrictive food intake disorder (ARFID) commonly present with loss of weight or faltering growth in the setting of poor nutrition. However, patients with ARFID can present with micronutrient deficiencies without weight loss. In patients with ARFID, clinicians should be vigilant for micronutrient deficiencies and their presentations.

CASE PRESENTATION

We report a unique case of ARFID in a twelve-year-old girl, who developed micronutrient deficiencies and presented with acute visual loss with a preceding history of impaired night vision. Ophthalmic examination revealed xerophthalmia and bilateral optic neuropathy. Investigations showed severe Vitamin A and folate deficiencies which accounted for her clinical findings. In addition, she was also found to have low Vitamin B12, copper, and Vitamin D levels. She had a history of selective eating from a young age with a diet consisting largely of carbohydrates, with no regular intake of meat, dairy, fruit and vegetables. This was not driven by weight or body image concerns. The patient's symptoms improved significantly with appropriate vitamin replacement and continued multidisciplinary care.

CONCLUSIONS

This report describes a patient with ARFID presenting with visual complaints. In this case, the selective eating behaviours resulted in xeropthalmia and optic neuropathy. Micronutrient deficiencies are uncommon in developed countries. When these deficiencies are suspected, eating disorders, such as ARFID, should be considered. Similarly, clinicians caring for patients with restrictive eating disorders including ARFID should be familiar with the clinical presentations of various micronutrient deficiencies and consider evaluation and treatment for micronutrient deficiencies when clinically indicated.

Optic Nerve Neuroprotection in Glaucoma: A Narrative Review

In recent years, researchers have been interested in neuroprotective therapies as a cutting-edge therapeutic strategy to treat neurodegenerative disorders by shielding the brain system from harmful events. Millions of individuals worldwide suffer from glaucoma, an ocular neurodegenerative disease characterized by gradual excavation of the optic nerve head, retinal axonal damage, and consequent visual loss. The pathology's molecular cause is still mostly unknown, and the current treatments are not able to alter the disease's natural progression. Thus, the modern approach to treating glaucoma consists of prescribing medications with neuroprotective properties, in line with the treatment strategy suggested for other neurodegenerative diseases. For this reason, several naturally derived compounds, including nicotinamide and citicoline, have been studied throughout time to try to improve glaucoma management by exploiting their neuroprotective properties. The purpose of this review is to examine the naturally derived compounds that are currently utilized in clinical practice for neuroprotection in glaucomatous patients based on scientific data, emphasizing these compounds' pivotal mechanism of action as well as their proven therapeutic and neuroprotective benefits.

Wernicke Syndrome: Case Report and Literature Review of Contributing Factors-Can Malpractice Dynamics Be Identified?

Wernicke Encephalopathy (WE) is a neurological acute syndrome related to vitamin B1 deficiency and is relatively common in patients with chronic alcoholism. In the case of Hyperemesis Gravidarum, thiamine body stores become unable to meet the increased demand, resulting in acute deficiency. WE is associated with typical clinical and radiological findings. Treatment pathways rely on thiamine replacement. The case herein reported is centered around a 33-year-old diabetic patient at 12 weeks of gestation, with WE due to hyperemesis gravidarum. The disease manifested itself with weakness, mental confusion, headache, and impaired vision. The diagnosis was established after the detection of typical findings by MRI. Thirty days after therapy was started, most of the patient's neurological disorders were resolved. The patient was discharged 40 days later with instructions to continue daily thiamine supplementation. The pregnancy outcome was good. Unfortunately, mild ataxia persisted in 2-year follow-up as a long-term consequence. When diagnosed and treated, WE has a favorable prognosis. However, roughly 80% of patients experience memory loss, which may continue for a long time, while gait disorders reportedly affect about 35% of patients. Mild ataxia and dysmetria may persist, too. We reviewed the scientific literature on WE in women with HG until February 2023. Hardly any authors report data on long-term sequelae. Our report emphasizes how important it is to take into consideration this complication in clinical practice, referring to published guidelines and recommendations. Neurological maternal sequelae can demonstrably persist despite early diagnosis and appropriate management. For this reason, a long-term follow-up is recommended. Wernicke syndrome management cannot yet rely on well-established conclusive guidelines; hence, a cautionary approach ought to be prioritized in order to ensure medicolegal soundness.

Ocular Manifestations of Wernicke's Encephalopathy in a Patient with Hyperemesis Gravidarum Complicating Pregnancy

Wernicke's encephalopathy (WE) is a condition resulting from thiamine deficiency and has been linked to conditions such as hyperemesis gravidarum, anorexia nervosa, hemodialysis, and chronic alcoholism. The aim of the report is to outline the ocular manifestations of WE. We present the case of a 33-year-old woman, who presented in her second trimester of pregnancy with persistent vomiting, nystagmus, ataxia, global confusion as well as hypotonia, and tremors. She was subsequently diagnosed with WE complicating pregnancy. Ophthalmoscopy showed asymmetric superficial retinal hemorrhages at the peripapillary area in both eyes with associated retinal exudates. On treatment with thiamine supplementation, her systemic condition as well as ocular symptoms resolved. This is a rare case outlining the ocular manifestations of WE. This condition may cause serious, lasting neurologic impairments or death if not properly treated. Only 50% of these pregnancies end in the delivery of healthy offspring. Early diagnosis and treatment of these cases can prevent avertable consequences.

Bilateral papilledema with vision loss due to post-COVID-19-induced thiamine deficiency: illustrative case

BACKGROUND

Bilateral papilledema with vision loss is considered a neurosurgical emergency due to high intracranial pressure. However, it may not be the only cause of papilledema. The authors reported an association among coronavirus disease 2019 (COVID-19), bilateral papilledema, blindness, and Wernicke's encephalopathy (WE).

OBSERVATIONS

An 18-year-old woman presented to the neurosurgery service with rapid profound vision loss and bilateral papilledema. She had COVID-19 3 months earlier with subsequent loss of smell (anosmia) and taste (ageusia), which resulted in hyperemesis and a 43-lb weight loss. Examination revealed ataxia, horizontal nystagmus, and blindness. Magnetic resonance imaging and magnetic resonance venography of her brain were normal. Presumptive diagnosis of WE was made, and she was treated with intravenous thiamine with restoration of vision within 48 hours. Patient's thiamine level was less than half the normal value.

LESSONS

Neurosurgeons should be aware of this unique correlation between papilledema and vision loss and its association with WE due to post-COVID-19 hyperemesis and weight loss from anosmia and ageusia.

Micronutrient Deficiencies Presenting with Optic Disc Swelling Associated with or without Intracranial Hypertension: A Systematic Review

Idiopathic intracranial hypertension (IIH) is a neurological disorder characterised by optic disc swelling secondary to raised intracranial pressure (ICP) of unknown cause. Obesity is the most established and prevalent risk factor in developed countries. As obesogenic diets are high in calories and nutrient-poor, there may be associated nutritional deficiencies that contribute to the clinical presentation of IIH. Yet none, aside from iron deficiency, are currently included in the inclusion or exclusion criteria for the diagnosis of IIH. Our primary aim was to determine which micronutrient deficiencies, aside from iron deficiency, could present with optic disc swelling associated with or without intracranial hypertension that could potentially meet current IIH diagnostic criteria. To this end, we conducted a systematic search of articles published between 1 January 1980 and 18 December 2020 reporting cases of optic disc swelling associated with micronutrient deficiencies. In total, 65 cases met the eligibility criteria from initial searches: all were case reports and case series with a high risk of bias. Our findings suggest that patients with IIH or unexplained optic disc swelling ought to be screened, investigated, and treated for associated micronutrient deficiencies in vitamin A, B1 and B12; and weight loss interventions in IIH patients ought to promote better nutrition in addition to overall calorie restriction.

Thiamine supplementation holds neurocognitive benefits for breastfed infants during the first year of life

Women reliant on mostly rice‐based diets can have inadequate thiamine intake, placing breastfed infants at risk of thiamine deficiency and, in turn, physical and cognitive impairments. We investigated the impact of maternal thiamine supplementation doses on infants’ cognitive, motor, and language development across the first year. In this double‐blind, four‐parallel‐arm, randomized controlled trial, healthy mothers of exclusively breastfed newborn infants were recruited in Kampong Thom, Cambodia. At 2 weeks postnatal, women (n = 335) were randomized to one of four treatment groups to consume one capsule/day with varying amounts of thiamine for 22 weeks: 0, 1.2, 2.4, and 10 mg. At 2, 12, 24, and 52 weeks of age, infants were assessed with the Mullen Scales of Early Learning (MSEL) and the Caregiver Reported Early Development Instrument (CREDI). Multiple regression and mixed effects modeling suggest that by 6 months of age, the highest maternal thiamine dose (10 mg/day) held significant benefits for infants’ language development, but generally not for motor or visual reception development. Despite having achieved standardized scores on the MSEL that approximated U.S. norms by 6 months, infants showed a significant drop relative to these norms in both language domains following trial completion, indicating that nutritional interventions beyond 6 months may be necessary.

Konzo risk factors, determinants and etiopathogenesis: What is new? A systematic review

Konzo is a toxico-nutritional upper motor neuron disease causing a spastic paraparesis in schoolchildren and childbearing women in some African countries. Almost a century since the first description of konzo, its underlying etiopathogenic mechanisms and causative agent remain unknown. This paper aims at refreshing the current knowledge of konzo determinants and pathogenesis in order to enlighten potential new research and management perspectives. Literature research was performed in PubMed and Web of Science databases according to the PRISMA methodology. Available data show that cassava-derived cyanide poisoning and protein malnutrition constitute two well-documented risk factors of konzo. However, observational studies have failed to demonstrate the causal relationship between konzo and cyanide poisoning. Thiocyanate, the current marker of choice of cyanide exposure, may underestimate the actual level of cyanide poisoning in konzo patients as a larger amount of cyanide is detoxified via other unusual pathways in the context of protein malnutrition characterizing these patients. Furthermore, the appearance of konzo may be the consequence of the interplay of several factors including cyanide metabolites, nutritional deficiencies, psycho-emotional and geo-environmental factors, resulting in pathophysiologic phenomena such as excitotoxicity or oxidative stress, responsible for neuronal damage that takes place at sparse cellular and/or subcellular levels.

Natural Products: Evidence for Neuroprotection to Be Exploited in Glaucoma

Glaucoma, a leading cause of irreversible blindness worldwide, is an optic neuropathy characterized by the progressive death of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) is recognized as the main risk factor. Despite effective IOP-lowering therapies, the disease progresses in a significant number of patients. Therefore, alternative IOP-independent strategies aiming at halting or delaying RGC degeneration is the current therapeutic challenge for glaucoma management. Here, we review the literature on the neuroprotective activities, and the underlying mechanisms, of natural compounds and dietary supplements in experimental and clinical glaucoma.

Nutritional Optic Neuropathies: State of the Art and Emerging Evidences

Nutritional optic neuropathy is a cause of bilateral, symmetrical, and progressive visual impairment with loss of central visual acuity and contrast sensitivity, dyschromatopsia, and a central or centrocecal scotoma. The clinical features are not pathognomonic, since hereditary and toxic forms share similar signs and symptoms. It is becoming increasingly common due to the widespread of bariatric surgery and strict vegetarian or vegan diets, so even the scientific interest has recently increased. In particular, recent studies have focused on possible pathogenetic mechanisms, and on novel diagnostic and therapeutic strategies in order to prevent the onset, make a prompt diagnosis and an accurate nutritional supplementation, and to avoid irreversible optic nerve atrophy. Nowadays, there is clear evidence of the role of cobalamin, folic acid, thiamine, and copper, whereas further studies are needed to define the role of niacin, riboflavin, and pyridoxine. This review aims to summarize the etiology, diagnosis, and treatment of nutritional optic neuropathy, and it is addressed not only to ophthalmologists, but to all physicians who could come in contact with a patient with a possible nutritional optic neuropathy, being a fundamental multidisciplinary approach.

Neuro-ophthalmic Manifestations of Wernicke Encephalopathy

Wernicke encephalopathy (WE) is a life-threatening but reversible syndrome resulting from acute thiamine deficiency that is frequently overlooked and underdiagnosed. It is classically characterized by a triad of ocular dysfunction, ataxia, and altered mental status. However, less than 1/3 patients have the complete triad, so it is crucial to have a high index of suspicion. Awareness of the early signs of WE is essential to prevent clinical progression, as patients with the full triad already have a profoundly thiamine-deficient state. This review highlights the neuro-ophthalmic manifestations of WE to guide the clinician in identifying the condition. In addition, we provide an update regarding the clinical characteristics, pathophysiology, neuroimaging and laboratory findings, treatment options, and prognosis of WE.

The effects of thiamine pyrophosphate on ethanol induced optic nerve damage

Background

We aimed to determine the protective effects of thiamine pyrophosphate on ethanol induced optic neuropathy in an experimental model.

Methods

The rats were assigned into 4 groups, with 6 rats in each group as follows: healthy controls (HC group), only ethanol administered group (EtOH group), ethanol + thiamine pyrophosphate (20 mg/kg) administered group (TEt-20 group), and only thiamine pyrophosphate (20 mg/kg) (TPG group) administered group. To the rats in TEt-20 and TPG groups, 20 mg/kg thiamine pyrophosphate was administered via intraperitoneal route. To the rats in HC and EtOH groups, the same volume (0.5 ml) of distilled water as solvent was applied in the same manner. To the rats in TEt-20 and EtOH groups, one hour after application of thiamine pyrophosphate or distilled water, 32% ethanol with a dose of 5 g/kg was administered via oral gavage. This procedure was repeated once a day for 6 weeks. From the blood samples and tissues obtained from the rats, Malondialdehyde (MDA), reduced glutathione (GSH), interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) levels were studied. Histopathological evaluations were performed to the optic nerve tissue.

Results

Serum and tissue IL-1β, TNF-α and MDA levels were the highest in EtOH group which were significantly lower in thiamine pyrophosphate administered group (TEt-20 group) (p: 0.001). Serum and tissue reduced GSH levels were the lowest in EtOH group which were also significantly higher in TEt-20 group (p:0.001). In histopathological evaluations, in EtOH group there was obvious destruction and edema with hemorrhage and dilated blood vessels which were not present in any other groups.

Conclusions

There was an apparent destruction in ethanol administered group in histopathological analyses with an augmented level of oxidative stress markers and all those alterations were prevented with concomitant thiamine pyrophosphate administration. These protective effects of thiamine pyrophosphate are extremely important in chronic ethanol consumption. Clinical studies are warranted to define the exact role of thiamine pyrophosphate in prevention of ethanol induced optic neuropathy.

Visual loss and optic neuropathy associated with Wernicke's encephalopathy in hyperemesis gravidarum

Wernicke's encephalopathy (WE) is a potentially fatal neuropsychiatric syndrome precipitated by thiamine deficiency due to a variety of causes such as chronic severe alcoholism, starvation, and prolonged intravenous feeding. WE has also been observed rarely in the clinical setting of hyperemesis gravidarum. Here, we report the case of a 34-year-old pregnant woman who presented with reduced vision, gaze-evoked nystagmus, and postural imbalance preceded by 2 weeks of hyperemesis. Fundus examination showed features consistent with papillitis. Magnetic resonance imaging (MRI) showed T2WI, FLAIR, and diffusion-weighted imaging MR images showing hyperintensity in dorsomedial thalami and periaqueductal grey matter with diffusion restriction. She was diagnosed with WE based on history, clinical examination findings, and MRI findings and was treated with injectable thiamine. She showed marked improvement in vision and nystagmus within 3 days. Our case is a rare presentation of WE in a pregnant woman with hyperemesis gravidarum.

Treatment and Outcomes in Nutritional Optic Neuropathy

PURPOSE OF REVIEW

Nutritional optic neuropathy is a potential cause of severe visual loss; however, appropriate and timely management can result in excellent visual outcomes. The purpose of this review is to outline our current understanding of the treatment and outcomes for nutritional optic neuropathy.

RECENT FINDINGS

Current understanding of nutritional optic neuropathy has been greatly aided by some well-reported and investigated epidemics of the condition, most notably the Cuban epidemic optic neuropathy of the early 1990s. More recently, there is an emerging literature surrounding nutritional deficiencies that can occur in patients who have undergone bariatric surgery. There also continues to be a stream of case reports in the literature that add to our understanding. Nutritional optic neuropathy has a great deal of overlap with toxic optic neuropathies and hereditary optic neuropathies and should not be thought of in isolation from these conditions. The mainstay of treatment for nutritional optic neuropathy involves identifying and replacing deficient nutrients as well as identifying and eliminating contributory toxins. It is also important to identify contributory genetic factors and to consider the broader social, economic and societal factors which may contribute.

Visual Loss, Retinal Hemorrhages, and Optic Disc Edema Resulting From Thiamine Deficiency Following Bariatric Surgery Complicated by Prolonged Vomiting

BACKGROUND

Vision loss resulting from thiamine deficiency is a recognized complication of bariatric surgery. Most patients with such vision loss have Wernicke encephalopathy with characteristic changes seen on neuroimaging. Other patients may have retinal hemorrhages, optic disc edema, and peripheral neuropathy without Wernicke encephalopathy. The risk for thiamine deficiency is potentiated by the presence of prolonged vomiting.

CASE REPORT

A 37-year-old female presented with abrupt onset of vision loss and peripheral neuropathy following bariatric surgery. She had a history of prolonged vomiting postoperatively. Examination of the posterior segment of the eye revealed optic disc edema and large retinal hemorrhages bilaterally. Metabolic workup demonstrated thiamine deficiency. She responded quickly to parenteral thiamine therapy with recovery of normal vision and resolution of ophthalmologic findings.

CONCLUSION

Patients who undergo bariatric surgery and have a thiamine deficiency can present with visual symptoms and ophthalmologic findings only visible by fundoscopy prior to developing more severe and potentially irreversible complications from the vitamin deficiency. Early detection of intraocular changes resulting from thiamine deficiency and initiation of therapy could prevent more devastating neurologic manifestations. Our case supports the consideration of a prospective study aimed at determining the true incidence of ocular and visual changes such as retinal hemorrhage, optic disc edema, and peripapillary telangiectasia in patients following bariatric surgery.

Fulminant high altitude blindness

Prolonged altitude exposure even with acclimatization continues to present a physiological challenge to all organ systems including the central nervous system. We describe a case of a 41-year-old Caucasian female climber who suffered severe visual loss that was due to possible optic nerve pathology occurring during a high altitude expedition in the Himalayas. This case is atypical of classic high altitude cerebral oedema and highlights yet another danger of prolonged sojourn at extreme altitudes.

Nerve Fiber Layer Infarcts in Thiamine Deficiency

Thiamine deficiency classically manifests as the triad of Wernicke encephalopathy: acute confusional state, ataxic gait, and ocular motor dysfunction. However, most patients do no present with this classic triad. Optic neuropathy in thiamine deficiency is a rare manifestation and is usually associated with fundus appearances of optic disc swelling or optic disc pallor. We present 2 unique cases of thiamine deficiency where the fundus demonstrated peripapillary retinal nerve fiber layer thickening without florid disc swelling or pallor.

Thiamine and magnesium deficiencies: keys to disease

Thiamine deficiency (TD) is accepted as the cause of beriberi because of its action in the metabolism of simple carbohydrates, mainly as the rate limiting cofactor for the dehydrogenases of pyruvate and alpha-ketoglutarate, both being critical to the action of the citric acid cycle. Transketolase, dependent on thiamine and magnesium, occurs twice in the oxidative pentose pathway, important in production of reducing equivalents. Thiamine is also a cofactor in the dehydrogenase complex in the degradation of the branched chain amino acids, leucine, isoleucine and valine. In spite of these well accepted facts, the overall clinical effects of TD are still poorly understood. Because of the discovery of 2-hydroxyacyl-CoA lyase (HACL1) as the first peroxisomal enzyme in mammals found to be dependent on thiamine pyrophosphate (TPP) and the ability of thiamine to bind with prion protein, these factors should improve our clinical approach to TD. HACL1 has two important roles in alpha oxidation, the degradation of phytanic acid and shortening of 2-hydroxy long-chain fatty acids so that they can be degraded further by beta oxidation. The downstream effects of a lack of efficiency in this enzyme would be expected to be critical in normal brain metabolism. Although TD has been shown experimentally to produce reversible damage to mitochondria and there are many other causes of mitochondrial dysfunction, finding TD as the potential biochemical lesion would help in differential diagnosis. Stresses imposed by infection, head injury or inoculation can initiate intermittent cerebellar ataxia in thiamine deficiency/dependency. Medication or vaccine reactions appear to be more easily initiated in the more intelligent individuals when asymptomatic marginal malnutrition exists. Erythrocyte transketolase testing has shown that thiamine deficiency is widespread. It is hypothesized that the massive consumption of empty calories, particularly those derived from carbohydrate and fat, results in a high calorie/thiamine ratio as a major cause of disease. Because mild to moderate TD results in pseudo hypoxia in the limbic system and brainstem, emotional and stress reflexes of the autonomic nervous system are stimulated and exaggerated, producing symptoms often diagnosed as psychosomatic disease. If the biochemical lesion is recognized at this stage, the symptoms are easily reversible. If not, and the malnutrition continues, neurodegeneration follows and results in a variety of chronic brain diseases. Results from acceptance of the hypothesis could be tested by performing erythrocyte transketolase tests to pick out those with TD and supplementing the affected individuals with the appropriate dietary supplements.