Porphyria and its neurologic manifestations

Targeting Platelet Activating Factor Signaling for Therapeutic Benefits in Neurodegenerative Disorders

Neurodegenerative disorders (NDs), including dementia, Alzheimer's disease (AD), and Parkinson's disease (PD), are age-related diseases closely associated with chronic inflammation, oxidative stress, gene mutations, autoimmune-derived inflammation, and other external risk factors. They are characterized by progressive neuronal loss, cognitive decline, and/or motor dysfunction, with chronic inflammation being a key player in intensifying NDs' occurrence. One of the most important molecular inflammatory mediators linking inflammation to NDs is the platelet-activating factor (PAF) and its pivotal signaling for regulating neuroinflammation, apoptosis, and neuronal damage. Dysregulation of PAF activity and metabolism/levels, along with overexpression of its receptor (PAF-R) have been associated with exacerbated inflammatory responses, further aggravating neurodegeneration. This article highlights the role of PAF in neurodegeneration, with a particular focus on novel insights into the potential medicinal use of PAF inhibitors for the prevention and treatment of neurodegenerative diseases. We evaluate the recently proposed concept of targeting the PAF signaling pathway through either natural and/or synthetic inhibitors or a combination of both. It explores the potential of these inhibitors to offer significant preventative and therapeutic benefits against NDs, likely through anti-inflammatory anti-aging effects and by slowing down the disease progression and preserving cognitive and motor dysfunction. Current status and future perspectives of such therapeutic approaches are also discussed.

Contaminant Exposure Profiles Demonstrate Similar Physiological Effects Across Environments Despite Unique Profile Composition in Formosa, Argentina, and Connecticut, USA

OBJECTIVE

Exposure to environmental contaminants is globally universal. However, communities vary in the specific combination of contaminants to which they are exposed, potentially contributing to variation in human health and creating "locally situated biologies." We investigated how environmental exposures differ across environments by comparing exposure profiles between two contexts that differ markedly across political, economic, and sociocultural factors-Namqom, Formosa, Argentina, and New Haven, Connecticut, United States.

METHODS

We collected infant urine, maternal urine, and human milk samples from mother-infant dyads in Formosa (n = 13) and New Haven (n = 21). We used untargeted liquid chromatography with high-resolution mass spectrometry (LC-HRMS) to annotate environmental contaminants and endogenous metabolites in these samples, and we analyzed the data using exposome-wide association studies (EWAS) followed by pathway enrichment.

RESULTS

We found statistically significant differences between the chemical exposure profiles of the Argentinian and US mothers, mostly involving pesticides; however, we observed similarities in the infant urine and human milk environmental contaminant profiles, suggesting that the maternal body may buffer infant exposure through human milk. We also found that infants and mothers were exposed to contaminants that were associated with alterations in amino acid and carbohydrate metabolism. Infants additionally showed alterations in vitamin metabolism, including vitamins B1, B3, and B6.

CONCLUSIONS

Differences in chemical exposure profiles may be related to structural factors. Despite variation in the composition of exposure profiles between the two study sites, environmental contaminant exposure was associated with similar patterns in human physiology when we considered contaminants comprehensively rather than individually, with implications for metabolic and cardiovascular disease risk as well as infant cognitive development.

Acute Intermittent Porphyria in a Burn Patient: Case Study and Review of the Literature

Healthcare providers evaluating patients presenting with neurological, visceral, or cutaneous symptoms that are disproportionate to the expected severity may need to consider porphyria in the differential. Porphyria is an inherited condition in which toxic metabolites of the heme pathway are increased. Carriers of porphyrias are asymptomatic and will not present with classical symptoms, nor will levels be elevated, until the disease is induced by certain drugs, hormones, or idiopathic causes such as the stress of trauma. Acute intermittent porphyria (AIP), a form of acute porphyria, is a rare autosomal dominant disease that results in a dysfunctional porphobilinogen deaminase. This consequently increases neurotoxic porphobilinogen and subsequent increase in δ-aminolevulinic acid. Both of these metabolites cause neurovisceral symptoms that afflict the patient in acute attacks. We present a rare case of AIP manifested in a burn patient suffering a burn injury. The patient presented with symptoms indicative of AIP, including altered mental status and abdominal pain accompanied with a chronic history of alcoholism and smoking. A negative work-up, including imaging and findings of associated manifestations consistent with AIP led to a discovery of elevated porphyrins. The patient's course and death due to his injuries gives insight into the presentation of AIP in a burn patient.

Clinical Reasoning: A 54-Year-Old Woman With Progressive Headache and Neurologic Decline

A 54-year-old woman presented with headache and vasculopathy. She was treated for reversible cerebral vasoconstriction syndrome but continued to have clinicoradiographic decline with headache, seizures, systemic symptoms, and progression of vasculopathy on imaging. We present the diagnosis of a rare genetic disease with its various neurologic complications and systemic manifestations. Our case also illustrates the importance of differences in the metabolism of various antiseizure medications, recognition of which may avoid precipitating the disease.

Novel Therapeutic Approaches in Inherited Neuropathies: A Systematic Review

The management of inherited neuropathies relies mostly on the treatment of symptoms. In recent years, a better understanding of the pathogenic mechanisms that underlie neuropathies has allowed for the development of disease-modifying therapies. Here, we systematically review the therapies that have emerged in this field over the last five years. An updated list of diseases with peripheral neuropathy as a clinical feature was created based on panels of genes used clinically to diagnose inherited neuropathy. This list was extended by an analysis of published data by the authors and verified by two experts. A comprehensive search for studies of human patients suffering from one of the diseases in our list yielded 28 studies that assessed neuropathy as a primary or secondary outcome. Although the use of various scales and scoring systems made comparisons difficult, this analysis identified diseases associated with neuropathy for which approved therapies exist. An important finding is that the symptoms and/or biomarkers of neuropathies were assessed only in a minority of cases. Therefore, further investigation of treatment efficacy on neuropathies in future trials must employ objective, consistent methods such as wearable technologies, motor unit indexes, MRI or sonography imaging, or the use of blood biomarkers associated with consistent nerve conduction studies.

Porphyria: a case report

BACKGROUND

Prompt diagnosis of metabolic disorders in a resource-limited country like Nepal is daunting. Acute intermittent porphyria is a rare but common hepatic porphyria mostly seen in females of the reproductive age group. As its incidence is quite uncommon, conjectures about porphyria diagnosis are often duped into a diagnostic conundrum.

CASE PRESENTATION

Here we unravel a case of a 15-year-old Hindu Nepalese girl distraught by the myriad of symptoms in the setting of severe abdominal pain accompanied by constipation and limb pain as the chief complaints. She presented with acute severe hypertension with marked persistent hyponatremia (up to 109 mEq/L). Despite conservative management of hypertension and electrolytes, unresolved electrolyte imbalance led us to the speculation of disturbance in the renin-angiotensin-aldosterone system. Due to her exacerbating neurovisceral status, she also required intensive care during the disease course. After thorough investigations and exemption of presumed provisional diagnoses, based on sustained symptomatic presentation, the clinical suspicion was driven towards a diagnosis of porphyria-related disorders. Positive Watson-Schwartz test substantiated the diagnosis of acute intermittent porphyria. Her symptoms gradually abated after the consumption of high carbohydrate diets.

CONCLUSION

This case highlights the baffling amalgamation of symptoms that simulate common diseases of concern yet are buried in the realm of porphyric disorders. Porphyria can be diagnosed using simple screening tools and timely treatment can diminish serious consequences.

Clinical Challenges of Acute Porphyria in the Young Adult

Porphyria is a metabolic disorder caused by a mutation in the heme biosynthetic pathway, with vague symptomatology and rare prevalence. A triad of hyponatremia, intermittent seizures, and abdominal pain should raise suspicion for porphyria. The diagnosis is based on increased blood porphobilinogen levels and genetic mutations. Treatment involves Dextrose-10 administration followed by hematin infusions as soon as possible. A maintenance dose of hematin is required in some cases. Here, we report a delayed diagnosis of acute intermittent porphyria (AIP) in an 18-year-old female, who first presented with severe anemia attributed to iron deficiency from menstrual blood loss. After discharge, she was readmitted with bilateral lower extremity and abdominal pain, hyponatremia, and seizure attributed to polypharmacy. During this second hospitalization, she was transferred to our hospital complaining of chest pain, shortness of breath, markedly decreased weakness, dysphagia, and hallucinations. After an extensive workup, she was diagnosed with AIP, and Dextrose-10 and hemin infusion were started. Our patient was found to have a missense mutation in the Hydroxymethylbilane synthase gene. She recovered after an extended ICU stay of 45 days and was discharged with a moderate improvement of weakness. Early diagnosis is necessary to prevent severe manifestations and long-term sequelae, such as axonal neuropathy, which occurred in the presented case.

A Neurologist's Practical Approach to Cognitive Impairment

The global prevalence of dementia is expected to triple by the year 2050. This impending health care crisis has led to new heights of public awareness and general concern regarding cognitive impairment. Subsequently, clinicians are seeing more and more people presenting with cognitive concerns. It is important that clinicians meet these concerns with a strategy promoting accurate diagnoses. We have diagramed and described a practical approach to cognitive impairment. Through an algorithmic approach, we determine the presence and severity of cognitive impairment, systematically evaluate domains of function, and use this information to determine the next steps in evaluation. We also discuss how to proceed when cognitive impairment is associated with motor abnormalities or rapid progression.

Profiling of Serum Metabolites of Acute Intermittent Porphyria and Asymptomatic HMBS Mutation Carriers

This study aims to present the serum metabolite profiles of patients with acute intermittent porphyria (AIP) and identify specific metabolites that could potentially discriminate between AIP, asymptomatic HMBS mutation carriers, and healthy individuals. The study cohort included 46 female participants: 21 AIP patients, 5 asymptomatic carriers, and 20 ‘normal’ participants (without HMBS gene mutation). Serum samples were analyzed for 157 selected metabolites or clinical variables using an assay combining liquid chromatography MS/MS and direct flow injection. AUC analysis was used to distinguish unique variables between the three groups. A total of 15 variables differed significantly between the AIP and normal control group (VIP score > 1.0 and p < 0.05 with FDR correction). In AIP patients, the levels tyrosine, valine, and eGFR were significantly lower, and the levels of sphingomyelin C16:0, C24:0, C24:1, phosphatidylcholine diacyl C32:1, C36:1, C36:3, ornithine, sarcosine, citrulline, blood urea nitrogen AST, and ALT were significantly higher. The AUC of these 15 variables in discriminating between normal and AIP patients ranged between 0.73 and 0.94 (p < 0.05). In conclusion, serum metabolic profiles differ between normal individuals and patients carrying the HMBS mutation. The unique metabolites associated with AIP identified in this study may be useful for monitoring the development of AIP symptoms.

Recurrent Seizures in an Adolescent Female-A Daunting Puzzle

Acute porphyrias are metabolic disorders resulting from deficiency of a specific enzyme involved in heme biosynthetic pathway. These deficiencies also affect normal renal physiology, as kidneys are also involved in heme synthesis. Sometimes, this could even lead to end stage renal disease. Acute Intermittent Porphyria, an autosomal dominant disorder arising from half-normal activity of hydroxymethylbilane synthase, is characterized by occurrence of vague neurovisceral attacks (abdominal pain, nausea, vomiting, constipation and neuropsychiatric symptoms), with urinary excretion of porphyrin precursors, such as 5-Amino-levulinic acid (ALA) and Porphobilinogen (PBG). Acute attacks are triggered by dehydration, diarrhea, steroids, low calorie diets. Treatment includes avoidance of precipitating factors, adequate hydration, high carbohydrate diet and heme replacement. Here, we present an adolescent female who had presented with recurrent abdominal pain, dyselectrolyemia with associated seizures, was diagnosed with Acute Intermittent Porphyria and recovered well with symptomatic management.

Genodermatoses with behavioural sequelae

Children with genodermatoses are at an increased risk of developing behavioural disorders which may impart lasting damage on the individual and their family members. As such, early recognition of childhood mental health disorders via meticulous history taking, thorough physical examination, and disorder-specific testing is of paramount importance for timely and effective intervention. If carried out properly, prompt psychiatric screening and intervention can effectively mitigate, prevent or even reverse, the psychiatric sequela in question. To that end, this review aims to inform the concerned physician of the manifestations and treatment strategies relevant to the psychological sequelae of genodermatoses.

The "Dangles" - Wrist, Finger and Thumb Drop: A Case Report of Saturday Night Palsy and a Historical and Molecular Detour

Saturday night palsy refers to neuropraxia of the radial nerve following prolonged compression against the spiral groove of the humerus. The pattern of weakness is unique with wrist, thumb, and finger drop, and recovery is universal by six months. What makes this clinical entity fascinating are the toxic and metabolic diseases that can manifest similarly, namely, plumbism (Saturnism) and acute porphyrias. The acute porphyrias (heme biosynthetic inborn errors of metabolism) are well known to cause motor neuropathy, with upper more than lower limb weakness, with wrist, thumb and finger drop a frequent manifestation. Intriguingly, lead neurotoxicity (plumbism), which has historically been tightly associated with wrist, thumb, and finger drop, is associated with the inhibition of at least three enzymes of heme biosynthesis. Mechanistically, interference with heme ring synthesis interferes with electron transport chain protein synthesis, which leads to oxidative phosphorylation defects, energy failure, axonal transport impairment, and, subsequently, an axonopathy. The lead atom has a valence of two (giving up two electrons) similar to that of the calcium atom, allowing lead to bind to spongy and cortical bone and interfering with the presynaptic voltage-gated calcium channel (VGCC) neurons. We list the salient features and similarities of these two very rare entities, hence, the term plumboporphyric neuropathy for one of the genetic variants of heme biosynthesis. Lastly, we briefly outline the spectacular history of plumbism and adumbrate on the similarity of the bacchanalian ecstasy of Roman festivals (Saturnism), over-indulgence in lead-sweetened and lead-laden barrels of wine, and the syncretism between the Saturnine palsy and Saturday night palsy. We present a case of wrist, thumb, and finger drop due to compressive neuropraxia as a platform to segue into the historical simulacra.

Metabolic epilepsies amenable to ketogenic therapies: Indications, contraindications, and underlying mechanisms

Metabolic epilepsies arise in the context of rare inborn errors of metabolism (IEM), notably glucose transporter type 1 deficiency syndrome, succinic semialdehyde dehydrogenase deficiency, pyruvate dehydrogenase complex deficiency, nonketotic hyperglycinemia, and mitochondrial cytopathies. A common feature of these disorders is impaired bioenergetics, which through incompletely defined mechanisms result in a wide spectrum of neurological symptoms, such as epileptic seizures, developmental delay, and movement disorders. The ketogenic diet (KD) has been successfully utilized to treat such conditions to varying degrees. While the mechanisms underlying the clinical efficacy of the KD in IEM remain unclear, it is likely that the proposed heterogeneous targets influenced by the KD work in concert to rectify or ameliorate the downstream negative consequences of genetic mutations affecting key metabolic enzymes and substrates-such as oxidative stress and cell death. These beneficial effects can be broadly grouped into restoration of impaired bioenergetics and synaptic dysfunction, improved redox homeostasis, anti-inflammatory, and epigenetic activity. Hence, it is conceivable that the KD might prove useful in other metabolic disorders that present with epileptic seizures. At the same time, however, there are notable contraindications to KD use, such as fatty acid oxidation disorders. Clearly, more research is needed to better characterize those metabolic epilepsies that would be amenable to ketogenic therapies, both experimentally and clinically. In the end, the expanded knowledge base will be critical to designing metabolism-based treatments that can afford greater clinical efficacy and tolerability compared to current KD approaches, and improved long-term outcomes for patients.

Therapeutic strategies for acute intermittent porphyria

Acute intermittent porphyria (AIP) is an autosomal dominant disease caused by mutations in porphobilinogen deaminase (PBGD), the third enzyme of the heme synthesis pathway. Symptoms of AIP usually manifest as intermittent acute attacks with occasional neuropsychiatric crises. The management of AIP includes treatment of acute attacks, prevention of attacks, long-term monitoring and treatment of chronic complications. Intravenous injection of heme is the most effective method of treating acute attacks. Carbohydrate loading is used when heme is unavailable or in the event of mild attacks. Symptomatic treatment is also needed during attacks. Prevention of attacks includes eliminating precipitating factors, heme prophylaxis and liver transplantation. New treatment options include givosiran (siRNA) to down-regulate ALA synthase-1 (ALAS1) and the messenger RNA of PBGD (PBGD mRNA) delivered to the liver cells of patients with AIP. Long-term monitoring of chronic complications includes regular liver-kidney function and hepatocellular carcinoma (HCC) screening.

Acute intermittent porphyria: focus on possible mechanisms of acute and chronic manifestations

Porphyrias are a group of inherited metabolic diseases that include eight types, each of which is caused by a mutation that affects an enzyme of the heme biosynthetic pathway. When an enzyme defect has physiological significance, it leads to overproduction of pathway precursors prior to the defective step. The partial absence of the third enzyme in the heme biosynthetic pathway, porphobilinogen deaminase (PBGD) also known as hydroxymethylbilane synthase (HMBS), results in acute intermittent porphyria (AIP), which affects mainly women. Subjects who had AIP symptoms were deemed to have manifest AIP (MAIP). Clinical manifestations are usually diverse and non-specific. Acute AIP episodes may present with abdominal pain, nausea, and vomiting, and repeated episodes may result in a series of chronic injuries. Therefore, studying the mechanisms of acute and chronic manifestations of AIP is of great significance. This review aims to summarize the possible mechanisms of acute and chronic manifestations in patients with AIP.

Effects of early and recent mercury and lead exposure on the neurodevelopment of children with elevated mercury and/or developmental delays during lactation: A follow-up study

This follow-up study of 82 children investigated the potential impact of early and recent exposure to mercury and lead on their neurodevelopmental performance at 5-8 years of age (2017-2018). Early exposure of these children to mercury, methylmercury, and lead was assessed during lactation at 3-12 months old, as well as their mother's exposure using measurements from a cross-sectional study (2011-2013). Only infants who failed to pass the neurodevelopment screening tools and/or had elevated mercury were included in this study. Urine and hair were sampled during the follow-up study to assess the children's recent exposure to mercury, methylmercury, and lead. Their cognitive performance and visual-motor integration were also measured using the Test of Non-Verbal Intelligence (TONI) and the Beery-Visual-Motor Integration (Beery VMI), respectively. The association between alterations in urinary porphyrins excretion and exposure to metals was analyzed and their influence on the children's neurodevelopment was explored. Linear regression models revealed a significant negative association between the infants' mercury exposure during lactation and the TONI Quotient (β = -0.298, 95%CI = -4.677, -0.414) and Beery VMI Age Equivalent scores at age 5-8 (β = -0.437, 95%CI = -6.383, -1.844). The mothers' blood methylmercury was inversely and significantly associated with their children's TONI Quotient (β = -0.231, 95%CI = -8.184, -0.331). In contrast, the children's Beery VMI Age Equivalent scores were positively and significantly associated with the hair methylmercury of the mothers (β = 0.214, 95%CI = 0.088, 3.899) and their infants (β = 0.256, 95%CI = 0.396, 4.488). These relationships suggest the presence of negative confounding that we did not take into account. Unlike mercury, there was some evidence that lead in breast milk had an inverse relationship with the children's visual-motor coordination skills. Our study did not show a clear association between children's recent exposure to metals and neurodevelopment. However, a significant inverse association was observed between the TONI Quotient and the interaction of hair methylmercury × ∑porphyrins (ß = -0.224, 95%CI = -0.86, -0.049), implying that porphyrins are a sensitive measure of low body-mercury burden. Although lead induced higher ∑porphyrins excretion in urine (β = 0.347, 95%CI = 0.107, 0.525), their interaction did not influence children's neurodevelopmental scores. The interactions between metals and porphyrins might provide insights into their potential contributory role in the pathogenesis associated with neurological disorders or other diseases. Despite the small sample size of the present study, its findings about the association between toxic metal exposure and the high risk of poor neurodevelopmental performance are worrying, particularly at an early age, and additional research is needed using larger sample sizes.

The Multifaceted Role of Heme in Cancer

Heme, an iron-containing porphyrin, is of vital importance for cells due to its involvement in several biological processes, including oxygen transport, energy production and drug metabolism. Besides these vital functions, heme also bears toxic properties and, therefore, the amount of heme inside the cells must be tightly regulated. Similarly, heme intake from dietary sources is strictly controlled to meet body requirements. The multifaceted nature of heme renders it a best candidate molecule exploited/controlled by tumor cells in order to modulate their energetic metabolism, to interact with the microenvironment and to sustain proliferation and survival. The present review summarizes the literature on heme and cancer, emphasizing the importance to consider heme as a prominent player in different aspects of tumor onset and progression.

Acute Intermittent Porphyria: Current Perspectives And Case Presentation

Acute intermittent porphyria (AIP) is an autosomal dominant metabolic disorder characterized by a deficiency in heme biosynthesis. Heme biosynthesis occurs throughout the body, but it is most prominent in the erythroblastic system and liver. AIP is a hepatic porphyria whereby the liver is the source of toxic heme metabolites. Clinical manifestations of AIP result from a genetic mutation that leads to partial function of porphobiliogen deaminase (PBGD). This causes an accumulation of upstream, neurotoxic metabolites. Symptoms include but are not limited to peripheral neuropathies, autonomic neuropathies and psychiatric manifestations. AIP can be life threatening and clinical signs and symptoms are often heterogeneous and non-specific. Therefore, it is important to be able to recognize these patients to make a prudent diagnosis and offer appropriate therapy. Here, we review the epidemiology, pathophysiology, clinical presentation, diagnosis, and management of AIP including the role of liver transplantation.

Lifestyle factors including diet and biochemical biomarkers in acute intermittent porphyria: Results from a case-control study in northern Norway

BACKGROUND

Lifestyle factors, including a low intake of carbohydrates, dieting, alcohol consumption, cigarette smoking and stress are some of the possible triggers of attacks in acute intermittent porphyria (AIP). The influence of lifestyle factors, including energy intake, diet and alcohol consumption on the biochemical disease activity in AIP and biochemical nutritional markers were examined.

METHODS

A case-control study with 50 AIP cases and 50 controls matched for age, sex and place of residence was performed. Dietary intake was registered using a food diary in 46 matched pairs. Symptoms, alcohol intake, stress and other triggering factors of the last AIP attack were recorded on questionnaires. Porphyrin precursors, liver and kidney function markers, vitamins, diabetogenic hormones and other nutritional biomarkers were analyzed by routine methods. The Wilcoxon matched-pairs signed rank test was used to compare the cases vs. controls. The Spearman's rank correlation coefficient was used on the cases.

RESULTS

Increasing total energy intake was negatively correlated with the biochemical disease activity. The intake of carbohydrates was lower than recommended, i.e., 40 and 39% of total energy intake in the AIP cases and controls, respectively. The plasma resistin level was significantly higher (p = .03) in the symptomatic than asymptomatic cases. Plasma insulin was lower in those with high porphobilinogen levels. The intake of sugar and candies were higher in the AIP cases with low U-delta aminolevulinic acid (ALA) levels (p = .04). Attacks were triggered by psychological stress (62%), physical strain (38%), food items (24%) and alcohol (32%) in the 34 symptomatic cases. Alcohol was used regularly by 88% of the cases (3.2 g ethanol/day) and 90% of the controls (6.3 g/day), but the intake was significantly lower in symptomatic than in asymptomatic cases (p = .045).

CONCLUSION

A high intake of energy, sugar and candies and a higher insulin level were associated with a lower biochemical disease activity. The resistin level was higher in the symptomatic than the asymptomatic cases. AIP patients drink alcohol regularly, but the intake was significantly lower in the symptomatic cases.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01617642.

Systematically Analyzing the Pathogenic Variations for Acute Intermittent Porphyria

The rare autosomal dominant disorder acute intermittent porphyria (AIP) is caused by the deficient activity of hydroxymethylbilane synthase (HMBS). The symptoms of AIP are acute neurovisceral attacks which are induced by the dysfunction of heme biosynthesis. To better interpret the underlying mechanism of clinical phenotypes, we collected 117 HMBS gene mutations from reported individuals with AIP and evaluated the mutations' impacts on the corresponding protein structure and function. We found that several mutations with most severe clinical symptoms are located at dipyromethane cofactor (DPM) binding domain of HMBS. Mutations on these residues likely significantly influence the catalytic reaction. To infer new pathogenic mutations, we evaluated the pathogenicity for all the possible missense mutations of HMBS gene with different bioinformatic prediction algorithms, and identified 34 mutations with serious pathogenicity and low allele frequency. In addition, we found that gene PPARA may also play an important role in the mechanisms of AIP attacks. Our analysis about the distribution frequencies of the 23 variations revealed different distribution patterns among eight ethnic populations, which could help to explain the genetic basis that may contribute to population disparities in AIP prevalence. Our systematic analysis provides a better understanding for this disease and helps for the diagnosis and treatment of AIP.

Porphyrias: A clinically based approach

BACKGROUND

Porphyrias are a group of metabolic diseases, individually rare but with an important combined prevalence. Because of their pathological complexity and clinical heterogeneity, they present a challenging diagnosis. The present review aims to provide a clinically based approach to the recognition and treatment of these disorders.

METHODS

We carried out a search in PubMed, with the keyword "porphyria", for reviews published in English from 2010 until 2017.

RESULTS

The research yielded 196 papers, of which 64 were included in the final narrative review.

CONCLUSIONS

Porphyrias can be divided based on clinical presentation in acute neurovisceral, chronic cutaneous bullous, chronic cutaneous non-bullous and acute neurovisceral/chronic cutaneous bullous. Each individual porphyria presents a characteristic pattern of porphyrins in plasma, urine, stool and red blood cells. As such, diagnosis is easily obtained by following a simple diagnostic algorithm. Early recognition is key in managing these diseases. Neurovisceral porphyrias require acute support therapy and chronic eviction of precipitating factors. Cutaneous prophyrias, as photosensitivity disorders, rely on sunlight avoidance and, in some cases, specific therapeutic interventions. Given the rarity of these conditions, physician awareness is crucial.

Porfiria intermitente aguda como desencadenante de síndrome de Guillain-Barre

Introducción. La porfiria es un conjunto de enfermedades metabólicas que tienen como base fisiopatológica la acumulación de precursores tóxicos. Su similitud clínica con enfermedades como el síndrome de Guillain-Barre puede retrasar el diagnostico, aumentando la posibilidad de complicaciones.Presentación del caso. Paciente femenino quien presentó síntomas inespecíficos de porfiria y síndrome de Guillain-Barre. La mujer fue evaluada de manera integral y recibió tratamiento para ambas patologías, respondiendo de manera inusual.Conclusión. La respuesta farmacológica atípica encontrada y la relación causa-efecto entre ambas entidades se justifica a la luz de sus procesos fisiopatológicos y la respuesta inmune desencadenada por los mismos.

Nonconvulsive status epilepticus secondary to acute porphyria crisis

Both variegate and acute intermittent porphyria can manifest with various neurological symptoms. Although acute symptomatic seizures have been previously described, they are typically tonic–clonic and focal impaired awareness seizures. Convulsive status epilepticus and epilepsia partialis continua are rare and have been described on a case report basis. To our knowledge, there are no previously reported cases describing non-convulsive status epilepticus (NCSE) with electroencephalogram (EEG) documentation in the setting of acute porphyria crisis. We report a unique presentation of NCSE, which resolved after administering levetiracetam in a patient with variegate porphyria, without a known seizure disorder.

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Seizures among acute intermittent porphyria (AIP) patients are not uncommon with prevalence being as high as 10%–20%.

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Non-convulsive status epilepticus (NCSE) in variegate porphyria (VP) patients should be considered in patients with altered mental status and acute porphyric crisis.

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Recognition and avoidance of prophyrogenic anti-seizure medications is important in the treatment of these patients.

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Levetiracetam and hemin are potential treatment combinations for nonconvulsive status epilepticus in acute porphyria crisis patients.

Unraveling the Role of Heme in Neurodegeneration

Heme (iron-protoporphyrin IX) is an essential co-factor involved in several biological processes, including neuronal survival and differentiation. Nevertheless, an excess of free-heme promotes oxidative stress and lipid peroxidation, thus leading to cell death. The toxic properties of heme in the brain have been extensively studied during intracerebral or subarachnoid hemorrhages. Recently, a growing number of neurodegenerative disorders have been associated to alterations of heme metabolism. Hence, the etiology of such diseases remains undefined. The aim of this review is to highlight the neuropathological role of heme and to discuss the major heme-regulated pathways that might be crucial for the survival of neuronal cells. The understanding of the molecular mechanisms linking heme to neurodegeneration will be important for therapeutic purposes.

Mitochondrial Targeting in Neurodegeneration: A Heme Perspective

Mitochondrial dysfunction has achieved an increasing interest in the field of neurodegeneration as a pathological hallmark for different disorders. The impact of mitochondria is related to a variety of mechanisms and several of them can co-exist in the same disease. The central role of mitochondria in neurodegenerative disorders has stimulated studies intended to implement therapeutic protocols based on the targeting of the distinct mitochondrial processes. The review summarizes the most relevant mechanisms by which mitochondria contribute to neurodegeneration, encompassing therapeutic approaches. Moreover, a new perspective is proposed based on the heme impact on neurodegeneration. The heme metabolism plays a central role in mitochondrial functions, and several evidences indicate that alterations of the heme metabolism are associated with neurodegenerative disorders. By reporting the body of knowledge on this topic, the review intends to stimulate future studies on the role of heme metabolism in neurodegeneration, envisioning innovative strategies in the struggle against neurodegenerative diseases.

A rare case of acute intermittent porphyria with ichthyosis vulgaris in a young boy

Acute intermittent porphyria (AIP) and ichthyosis vulgaris both are autosomal dominant disorders with incomplete penetrance caused by the deficiency of porphobilinogen deaminase enzyme and filaggrin protein, respectively. We report a rare case of a 9-year-old boy having two genetic diseases with an unclear association. An acute attack of AIP is characterized by gastrointestinal symptoms and neuropsychiatric manifestations. Although rare in the first decade of life, the presence of reddish urine with a typical presentation such as abdominal pain, hypertension, seizure, and paresthesias lead us to the diagnosis of AIP. The precipitating factor in the present case was prolonged fasting in Ramadan.

A case of hereditary coproporphyria with posterior reversible encephalopathy and novel coproporphyrinogen oxidase gene mutation c.863T>G (p.Leu288Trp)

A 21-year-old female had recurrent presentations to the emergency department with myalgia, vomiting, abdominal pain and subsequently developed generalized seizures. She was volume depleted with a plasma sodium of 125 mmol/L (reference interval: 135-145) and she had fluctuating hypertension. Acute porphyria was suspected and confirmed with raised urine porphobilinogen/creatinine ratio of 12:4 μmol/mmoL (reference interval < 1:5) and she was treated with intravenous haem arginate. Urinary porphyrin/creatinine ratio was 673 nmol/mmoL (reference interval <35) and faecal porphyrins 2430 μmol/kg dry weight (reference interval: <200) were markedly elevated, with raised faecal CIII:CI ratio, consistent with acute coproporphyria. Diagnosis was confirmed by the demonstration of a novel missense variant in the coproporphyrinogen oxidase gene c.863T > G (p.Leu288Trp) predicted to be deleterious and which segregated with three other affected family members. Although CT head was normal, magnetic resonance imaging scan revealed symmetrical signal abnormalities and swelling in the parietal and occipital lobes consistent with posterior reversible encephalopathy. Over several days, her seizures ceased and sodium and blood pressure normalized. The aetiology of the acute porphyric attack was likely multifactorial with contributions from a recent viral illness and caloric deprivation. No drug precipitant was identified. We postulate that untreated hypertension played a key role in the development of posterior reversible encephalopathy. Early clinical suspicion and urine porphobilinogen testing are the key components in preventing morbidity and mortality in acute porphyrias.

Peripheral neuropathy in complex inherited diseases: an approach to diagnosis

Peripheral neuropathy is a common finding in patients with complex inherited neurological diseases and may be subclinical or a major component of the phenotype. This review aims to provide a clinical approach to the diagnosis of this complex group of patients by addressing key questions including the predominant neurological syndrome associated with the neuropathy, for example, spasticity, the type of neuropathy and the other neurological and non-neurological features of the syndrome. Priority is given to the diagnosis of treatable conditions. Using this approach, we associated neuropathy with one of three major syndromic categories: (1) ataxia, (2) spasticity and (3) global neurodevelopmental impairment. Syndromes that do not fall easily into one of these three categories can be grouped according to the predominant system involved in addition to the neuropathy, for example, cardiomyopathy and neuropathy. We also include a separate category of complex inherited relapsing neuropathy syndromes, some of which may mimic Guillain-Barré syndrome, as many will have a metabolic aetiology and be potentially treatable.

A Unique Neuropsychiatric Syndrome in Variant Hereditary Coproporphyria: Case Report and Review of the Literature

Hereditary coproporphyria (HCP) is the third most common of the acute porphyrias, after acute intermittent porphyria and variegate porphyria. It is caused by decreased activity of the sixth step in the heme biosynthetic pathway. Here we present a case of a woman with HCP who has experienced a wide variety of symptoms over several years. Most interesting among these is a unique neuropsychiatric syndrome marked by severe confusion, disorientation, and abnormal behavior. The literature is reviewed regarding the pathophysiology and management of neuropsychiatric manifestations of porphyria. As many other diagnoses are often considered before the diagnosis of porphyria is made, clinicians should keep in mind the highly variable neurological and psychiatric symptoms of porphyria.

Systemic inflammation in acute intermittent porphyria: a case-control study

This study aimed to examine whether acute intermittent porphyria (AIP) is associated with systemic inflammation and whether the inflammation correlates with disease activity. A case-control study with 50 AIP cases and age-, sex- and place of residence-matched controls was performed. Plasma cytokines, insulin and C-peptide were analysed after an overnight fast using multiplex assay. Long pentraxin-3 (PTX3) and complement activation products (C3bc and TCC) were analysed using enzyme-linked immunosorbent assay (ELISA). Urine porphobilinogen ratio (U-PBG, µmol/mmol creatinine), haematological and biochemical tests were performed using routine methods. Questionnaires were used to register AIP symptoms, medication and other diseases. All 27 cytokines, chemokines and growth factors investigated were increased significantly in symptomatic AIP cases compared with controls (P < 0·0004). Hierarchical cluster analyses revealed a cluster with high visfatin levels and several highly expressed cytokines including interleukin (IL)-17, suggesting a T helper type 17 (Th17) inflammatory response in a group of AIP cases. C3bc (P = 0·002) and serum immunoglobulin (Ig)G levels (P = 0·03) were increased significantly in cases with AIP. The U-PBG ratio correlated positively with PTX3 (r = 0·38, P = 0·006), and with terminal complement complex (TCC) levels (r = 0·33, P = 0·02). PTX3 was a significant predictor of the biochemical disease activity marker U-PBG in AIP cases after adjustment for potential confounders in multiple linear regression analyses (P = 0·032). Prealbumin, C-peptide, insulin and kidney function were all decreased in the symptomatic AIP cases, but not in the asymptomatic cases. These results indicate that AIP is associated with systemic inflammation. Decreased C-peptide levels in symptomatic AIP cases indicate that reduced insulin release is associated with enhanced disease activity and reduced kidney function.

Experiences and concerns of patients with recurrent attacks of acute hepatic porphyria: A qualitative study

BACKGROUND

The acute hepatic porphyrias (AHPs) are rare inborn errors of heme biosynthesis, characterized clinically by life-threatening acute neurovisceral attacks. Patients with recurrent attacks have a decreased quality of life (QoL); however, no interactive assessment of these patients' views has been reported. We conducted guided discussions regarding specific topics, to explore patients' disease experience and its impact on their lives.

METHODS

Sixteen AHP patients experiencing acute attacks were recruited to moderator-led online focus groups. Five groups (3-4 patients each) were conducted and thematic analyses to identify, examine, and categorize patterns in the data was performed.

RESULTS

All patients identified prodromal symptoms that began days prior to acute severe pain; the most common included confusion ("brain fog"), irritability, and fatigue. Patients avoided hospitalization due to prior poor experiences with physician knowledge of AHPs or their treatment. All patients used complementary and alternative medicine treatments to avoid hospitalization or manage chronic pain and 81% reported varying degrees of effectiveness. All patients indicated their disease impacted personal relationships due to feelings of isolation and difficulty adjusting to the disease's limitations.

CONCLUSION

Patients with recurrent attacks recognize prodromal warning symptoms, attempt to avoid hospitalization, turn to alternative treatments, and have markedly impaired QoL. Counseling and individualized support is crucial for AHP patients with recurrent attacks.

Acute porphyria in a patient with Arnold Chiari malformation

Patient: Female, 33

Final Diagnosis: Acute porphyria

Symptoms: Abdominal pain • alternating bowel habits

Medication: Metronidazole • bactrim • oxybutynin

Clinical Procedure: EMG • porhyria workup

Specialty: Neurology

Medical conditions with neuropsychiatric manifestations

Medical disease sometimes affects patients through neuropsychiatric manifestations. When neuropsychiatric symptoms are predominant, identifying medical disease early in the illness course is imperative because many of these conditions are reversible with appropriate treatment. A high index of suspicion is required on the part of clinicians, particularly when patients also present with physical signs or unexplained symptoms that might suggest a broader, systemic process. The processes that most commonly cause neuropsychiatric symptoms include infectious, autoimmune, endocrinologic, metabolic, and neoplastic diseases. This article focuses on the most common of these conditions, and conditions for which early diagnosis and treatment are particularly important.