The neuropsychiatry of inborn errors of metabolism

Psychiatric Manifestations in Children and Adolescents with Inherited Metabolic Diseases

Background: Inherited metabolic disorders (IEMs) can be represented in children and adolescents by psychiatric disorders. The early diagnosis of IEMs is crucial for clinical outcome and treatment. The aim of this review is to analyze the most recurrent and specific psychiatric features related to IEMs in pediatrics, based on the onset type and psychiatric phenotypes. Methods: Following the PRISMA Statement, a systematic literature review was performed using a predefined algorithm to find suitable publications in scientific databases of interest. After removing duplicates and screening titles and abstracts, suitable papers were analyzed and screened for inclusion and exclusion criteria. Finally, the data of interest were retrieved from the remaining articles. Results: The results of this study are reported by type of symptoms onset (acute and chronic) and by possible psychiatric features related to IEMs. Psychiatric phenomenology has been grouped into five main clinical manifestations: mood and anxiety disorders; schizophrenia-spectrum disorders; catatonia; eating disorders; and self-injurious behaviors. Conclusions: The inclusion of a variety of psychiatric manifestations in children and adolescents with different IEMs is a key strength of this study, which allowed us to explore the facets of seemingly different disorders in depth, avoiding possible misdiagnoses, with the related delay of early and appropriate treatments.

When rare meets common: Treatable genetic diseases are enriched in the general psychiatric population

Mental illnesses are one of the biggest contributors to the global disease burden. Despite the increased recognition, diagnosis and ongoing research of mental health disorders, the etiology and underlying molecular mechanisms of these disorders are yet to be fully elucidated. Moreover, despite many treatment options available, a large subset of the psychiatric patient population is nonresponsive to standard medications and therapies. There has not been a comprehensive study to date examining the burden and impact of treatable genetic disorders (TGDs) that can present with neuropsychiatric features in psychiatric patient populations. In this study, we test the hypothesis that TGDs that present with psychiatric symptoms are more prevalent within psychiatric patient populations compared to the general population by performing targeted next-generation sequencing of 129 genes associated with 108 TGDs in a cohort of 2301 psychiatric patients. In total, 48 putative affected and 180 putative carriers for TGDs were identified, with known or likely pathogenic variants in 79 genes. Despite screening for only 108 genetic disorders, this study showed a two-fold (2.09%) enrichment for genetic disorders within the psychiatric population relative to the estimated 1% cumulative prevalence of all single gene disorders globally. This strongly suggests that the prevalence of these, and most likely all, genetic diseases is greatly underestimated in psychiatric populations. Increasing awareness and ensuring accurate diagnosis of TGDs will open new avenues to targeted treatment for a subset of psychiatric patients.

Presenilin Gene Mutation-associated Psychosis: Phenotypic Characteristics and Clinical Implications

Although psychotic symptoms have been described in association with rare presenilin ( PSEN ) gene mutations underlying early-onset Alzheimer disease (AD), no contemporary reviews on this topic exist. The purpose of this review is to characterize the psychiatric phenotype (specifically with respect to psychosis) of PSEN1 and PSEN2 variant-associated AD. A PubMed search was completed in July 2023. Only articles that described individuals harboring a PSEN1 or PSEN2 mutation who experienced symptoms of psychosis were included in the review. Thirty-three articles describing 52 individuals were included in the review, as well as one other study that provided limited information pertaining to an additional 21 cases. While visual hallucinations were the most common psychotic symptom, followed by persecutory delusions, auditory hallucinations occurred in ~17% of individuals. In ~33% of the reviewed cases psychotic symptoms were present at or near disease onset, and 9 of these individuals experienced auditory hallucinations and/or delusions in the absence of visual hallucinations (~17% of all cases). In many cases, symptoms developed at a relatively young age. As presenilin gene variant-associated psychosis may resemble a primary psychotic disorder, clinicians should be vigilant with respect to screening for signs/symptoms suggestive of neurodegeneration in first-episode psychosis.

Long-term outcomes in two adult siblings with Fucosidosis - Diagnostic odyssey and clinical manifestations

Fucosidosis (OMIN# 230000) is a rare lysosomal storage disorder (LSDs) caused by mutations in the FUCA1 gene, leading to alpha-L-fucosidase deficiency; it is inherited as an autosomal recessive trait. Fucosidosis represents a disease spectrum with a wide variety of clinical features, but most affected patients have slow neurologic deterioration. Many patients die young and the long-term clinical outcomes in adult patients are poorly documented. Here, we report the long-term follow up of two Caucasian siblings, a 31-year-old man and 25-year-old woman. We describe the clinical, biochemical, radiological and genetic findings in two siblings affected by Fucosidosis and the differences between them after 19-years follow up. The dermatological features of the younger sibling have been reported previously by Bharati et al. (2007). Both patients have typical features of Fucosidosis, such as learning difficulties, ataxia, and angiokeratomas with differing severity. Case 1 presents severe ataxia with greater limitation of mobility, multiple dysostoses, angiokeratomas on his limbs, retinal vein enlargement and increased tortuosity in the eye and gastrointestinal symptoms. Biochemical analysis demonstrated a deficiency of alpha-fucosidase in leucocytes. Case 2 has a greater number of angiokeratomas and has suffered three psychotic episodes. The diagnosis of Fucosidosis was confirmed in cultured skin fibroblast at the age of 12 years. Molecular analysis of the FUCA1 gene showed a heterozygous mutation c.998G > A p.(Gly333Asp), with a pathogenic exon 4 deletion in the other allele in both patients. Conclusion. Fucosidosis presents a wide clinical heterogeneity and intrafamilial variability of symptoms. Psychosis and gastrointestinal symptoms have not been reported previously in Fucosidosis.

Insight into adult-onset metachromatic leukodystrophy with optic atrophy: A comprehensive case report

This abstract provides an overview of metachromatic leukodystrophy (MLD), an autosomal recessive disorder stemming from arylsulfatase A deficiency. MLD leads to cerebroside sulfate accumulation, causing central and peripheral demyelination. Clinical manifestations vary by age group: late-infantile (rapid progression), juvenile (slower progression), and adult-onset (psychiatric symptoms). A case study details a 23-year-old with progressive vision impairment, motor weakness, and cognitive changes. Examination and MRI findings led to suspicion of MLD, later confirmed by enzyme testing. Optic nerve involvement is emphasized, along with diagnostic criteria involving enzyme assays, imaging, and urinary sulfatide excretion tests. While no cure exists, symptomatic and supportive care, including hematopoietic stem cell transplantation, remains key in MLD management.

Metabolomic disorders: confirmed presence of potentially treatable abnormalities in patients with treatment refractory depression and suicidal behavior

BACKGROUND

Refractory depression is a devastating condition with significant morbidity, mortality, and societal cost. Approximately 15% of patients with major depressive disorder are refractory to currently available treatments. We hypothesized metabolic abnormalities contributing to treatment refractory depression are associated with distinct findings identifiable in the cerebrospinal fluid (CSF). Our hypothesis was confirmed by a previous small case-controlled study. Here we present a second, larger replication study.

METHODS

We conducted a case-controlled, targeted, metabolomic evaluation of 141 adolescent and adult patients with well-characterized history of depression refractory to three maximum-dose, adequate-duration medication treatments, and 36 healthy controls. Plasma, urine, and CSF metabolic profiling were performed by coupled gas chromatography/mass spectrometry, and high-performance liquid chromatography, electrospray ionization, tandem mass spectrometry.

RESULTS

Abnormalities were identified in 67 of 141 treatment refractory depression participants. The CSF abnormalities included: low cerebral folate (n = 20), low tetrahydrobiopterin intermediates (n = 11), and borderline low-tetrahydrobiopterin intermediates (n = 20). Serum abnormalities included abnormal acylcarnitine profile (n = 12) and abnormal serum amino acids (n = 20). Eighteen patients presented with two or more abnormal metabolic findings. Sixteen patients with cerebral folate deficiency and seven with low tetrahydrobiopterin intermediates in CSF showed improvement in depression symptom inventories after treatment with folinic acid and sapropterin, respectively. No healthy controls had a metabolite abnormality.

CONCLUSIONS

Examination of metabolic disorders in treatment refractory depression identified an unexpectedly large proportion of patients with potentially treatable abnormalities. The etiology of these abnormalities and their potential roles in pathogenesis remain to be determined.

The impact of liver transplantation on health-related quality of life in (acute) intoxication-type inborn errors of metabolism

Organic acidurias (OAs), urea-cycle disorders (UCDs), and maple syrup urine disease (MSUD) belong to the category of intoxication-type inborn errors of metabolism (IT-IEM). Liver transplantation (LTx) is increasingly utilized in IT-IEM. However, its impact has been mainly focused on clinical outcome measures and rarely on health-related quality of life (HRQoL). Aim of the study was to investigate the impact of LTx on HrQoL in IT-IEMs. This single center prospective study involved 32 patients (15 OA, 11 UCD, 6 MSUD; median age at LTx 3.0 years, range 0.8-26.0). HRQoL was assessed pre/post transplantation by PedsQL-General Module 4.0 and by MetabQoL 1.0, a specifically designed tool for IT-IEM. PedsQL highlighted significant post-LTx improvements in total and physical functioning in both patients' and parents' scores. According to age at transplantation (≤3 vs. >3 years), younger patients showed higher post-LTx scores on Physical (p = 0.03), Social (p < 0.001), and Total (p =0.007) functioning. MetabQoL confirmed significant post-LTx changes in Total and Physical functioning in both patients and parents scores (p ≤ 0.009). Differently from PedsQL, MetabQoL Mental (patients p = 0.013, parents p = 0.03) and Social scores (patients p = 0.02, parents p = 0.012) were significantly higher post-LTx. Significant improvements (p = 0.001-0.04) were also detected both in self- and proxy-reports for almost all MetabQoL subscales. This study shows the importance of assessing the impact of transplantation on HrQoL, a meaningful outcome reflecting patients' wellbeing. LTx is associated with significant improvements of HrQol in both self- and parent-reports. The comparison between PedsQL-GM and MetabQoL highlighted that MetabQoL demonstrated higher sensitivity in the assessment of disease-specific domains than the generic PedsQL tool.

Psychosis Caused by a Somatic Condition: How to Make the Diagnosis? A Systematic Literature Review

BACKGROUND

First episode of psychosis (FEP) is a clinical condition that usually occurs during adolescence or early adulthood and is often a sign of a future psychiatric disease. However, these symptoms are not specific, and psychosis can be caused by a physical disease in at least 5% of cases. Timely detection of these diseases, the first signs of which may appear in childhood, is of particular importance, as a curable treatment exists in most cases. However, there is no consensus in academic societies to offer recommendations for a comprehensive medical assessment to eliminate somatic causes.

METHODS

We conducted a systematic literature search using a two-fold research strategy to: (1) identify physical diseases that can be differentially diagnosed for psychosis; and (2) determine the paraclinical exams allowing us to exclude these pathologies.

RESULTS

We identified 85 articles describing the autoimmune, metabolic, neurologic, infectious, and genetic differential diagnoses of psychosis. Clinical presentations are described, and a complete list of laboratory and imaging features required to identify and confirm these diseases is provided.

CONCLUSION

This systematic review shows that most differential diagnoses of psychosis should be considered in the case of a FEP and could be identified by providing a systematic checkup with a laboratory test that includes ammonemia, antinuclear and anti-NMDA antibodies, and HIV testing; brain magnetic resonance imaging and lumbar puncture should be considered according to the clinical presentation. Genetic research could be of interest to patients presenting with physical or developmental symptoms associated with psychiatric manifestations.

Eine Kinderkrankheit wird erwachsen

Zusammenfassung: Die Untersuchung von seltenen Erkrankungen ist aufgrund der geringen Anzahl an Patient_innen sowie einem häufig heterogenen, multisymptomatischen Erscheinungsbild deutlich erschwert. Als Beispiel für eine solche seltene Krankheit dient im Folgenden die progrediente, neurodegenerative Erbkrankheit Niemann-Pick Typ C (NPC), die lange Zeit als „Kinderkrankheit“ galt. Im Verlauf des letzten Jahrzehnts wurde jedoch auch ein substanzieller Anteil an erwachsenen NPC-Patient_innen diagnostiziert. Da zum klinischen Erscheinungsbild von erwachsenen NPC-Patient_innen wenig Umfassendes bekannt ist, widmet sich der Artikel diesem Thema und zeigt, inwieweit die Erkenntnisse zu Manifestationen sowie zur Krankheitsentwicklung von pädiatrischen auf erwachsene NPC-Patient_innen übertragbar sind. Die Darstellung von Erkrankungsmerkmalen der Subpopulationen pädiatrischer gegenüber jugendlicher bzw. erwachsener NPC-Patient_innen basiert auf der verfügbaren Literatur sowie Expertenmeinungen hinsichtlich der Epidemiologie, des genetischen Mutationsmusters, des klinischen Bildes einschließlich der Prodromalsymptome, der Progressionsrate, dem allgemeinen Behandlungsregime und den Therapieeffekten. Insgesamt erweist sich NPC als ein Krankheitskontinuum, basierend auf weitestgehend ähnlichen genetischen Mutationsmustern sowie einer sich in den Altersgruppen entsprechenden Pathophysiologie. Pädiatrische und jugendliche bzw. erwachsene Patient_innen sind durch diverse Facetten fortschreitender neuropsychologischer Manifestationen wie bspw. kognitive Defizite und deutliche Einschränkungen ihrer motorischen Fähigkeiten (einschließlich der Berücksichtigung von prodromalen Symptomen) gekennzeichnet. NPC verläuft bei Kindern sowie bei jugendlichen bzw. erwachsenen Patient_innen auf die ähnliche Weise – jedoch mit einer beschleunigten Progressionsrate und einer somit verkürzten Lebenserwartung, je jünger die Patient_innen bei erstmaligem Auftreten neurologischer Symptome sind. Jedoch weist die hohe Krankheitslast aller NPC-Patient_innen auf die Schwere dieser seltenen Stoffwechselkrankheit hin. Die Behandlung von NPC erfolgt altersunabhängig interdisziplinär. Es besteht bisher keine kausale Therapieoption.

Psychiatric manifestations of inborn errors of metabolism: A systematic review

Inborn errors of metabolism (IEMs) are characterized by deficits in metabolic enzymes as a result of an inherited disease, leading to the accumulation or decreased excretion of proteins, carbohydrates and lipids. Although IEMs are often diagnosed during childhood, adolescent and adult onset variants may be accompanied by less somatic and more psychiatric manifestations, which often hampers recognition by psychiatrists of the distinction between a primary and secondary psychiatric disorder. To help clinicians in the diagnostic process, we aimed to provide an overview of psychiatric manifestations in IEMs. Our literature search yielded 4380 records in total, of which 88 studies were included in the qualitative synthesis. Reported psychiatric disorders in adolescent and adult IEMs included depression, anxiety disorder, psychosis, attention deficit hyperactivity disorder, autism spectrum disorder, bipolar disorder and obsessive-compulsive disorder as assessed by semi-structured diagnostic interviews and validated questionnaires. A diagnostic screener and multidisciplinary IEM clinics are proposed to help clinicians during the diagnostic process, to prevent diagnostic delay and to raise awareness of the psychiatric manifestations among IEMs.

Exposure to leucine alters glutamate levels and leads to memory and social impairment in zebrafish

Maple Syrup Urine Disease (MSUD) is a metabolic disorder characterized by high levels in blood and urine of branched-chain amino acids leucine, isoleucine, and valine and their alpha-ketoacids, by a partial or total blockade in the activity of branched-chain complex alpha-keto acids dehydrogenase. The main symptoms in MSUD occur in the central nervous system, including cognitive deficits, locomotor, poor feeding, seizures, psychomotor delay, and mental retardation, but the mechanisms of neurotoxicity and behavior alteration due to this disease are poorly understood, thus this study aimed at showing the effects of leucine exposure on glutamate levels and behavior in zebrafish. For this, we analyzed the behavior using the social preference test and novel object recognition test, moreover, we analyse the glutamate levels and uptake using scintillation and high-performance liquid chromatography methods. Our results demonstrated a decrease in glutamate levels and uptake, accompanied by memory and social impairment. In conclusion, these results suggest that alterations in glutamate levels can be associated with behavior impairment, however, more studies are necessary to understand the mechanisms for brain damage in MSUD.

Catatonia in autism and other neurodevelopmental disabilities: a state-of-the-art review

Individuals with neurodevelopmental disabilities (NDDs) may be at increased risk for catatonia, which can be an especially challenging condition to diagnose and treat. There may be symptom overlap between catatonia and NDD-associated behaviors, such as stereotypies. The diagnosis of catatonia should perhaps be adjusted to address symptom overlap and to include extreme behaviors observed in patients with NDDs, such as severe self-injury. Risk factors for catatonia in individuals with NDDs may include trauma and certain genetic variants, such as those that disrupt SHANK3. Common etiologic features between neurodevelopmental disabilities and catatonia, such as excitatory/inhibitory imbalance and neuroimmune dysfunction, may partially account for comorbidity. New approaches leveraging genetic testing and neuroimmunologic evaluation may allow for more precise diagnoses and effective treatments.

Quantification of monoamine biomarkers in cerebrospinal fluid: comparison of a UHPLC-MS/MS method to a UHPLC coupled to fluorescence detection method

Inborn errors of monoamine neurotransmitter metabolism are rare genetic diseases classified as catecholamine and serotonin metabolism disorders or neurotransmitter transportopathies. To diagnose these orphan diseases, monoamine metabolites have been identified and validated as cerebrospinal fluid (CSF) biomarkers: 5-hydroxy-tryptophane, 5-hydroxy-indol-acetic acid, 3-ortho-methyl-DOPA, homovanillic acid, and 3-methoxy-4-hydroxyphenylglycol. The present work presents a UHPLC-MS/MS method developed for the quantification of these metabolites in CSF and compares it to a previously described UHPLC-FD method. MS/MS detection was performed in positive electrospray ionization and multiple reaction monitoring (MRM) mode. The UHPLC-MS/MS and UHPLC-FD methods were validated in terms of accuracy, linearity, precision, and matrix effect. The lower limits of quantification (LLOQ) were ranging between 0.5 nM and 10 nM and between 1 and 5 nM for the UHPLC-MS/MS method and the UHPLC-FD one, respectively. We verified the applicability of both methods by analyzing 30 CSF samples. The measured concentrations were comparable to the reference values described in the literature. The two methods allowed to distinguish pathological samples from healthy ones for clinical diagnosis. UHPLC-MS/MS and UHPLC-FD methods exhibit very close LLOQs. As UHPLC-MS/MS method is more selective, it allows faster analysis with 6 minutes per run versus 10 minutes for the UHPLC-FD method.

Determinants of Quality of Life in Children with Inborn Errors of Metabolism Receiving a Restricted Diet

OBJECTIVE

To investigate the determinants of quality of life (QoL) in children with inborn errors of metabolism with restricted diet (IEMRDs) using a single theory-based multidimensional model.

STUDY DESIGN

In this multicenter cross-sectional study, data from children aged 8-17 years with IEMRDs (except phenylketonuria) and their parents were collected from January 2015 to December 2017. Measurements included a child's self-reported QoL, self-rated behavioral problems and anxiety, and parental anxiety. Based on hypotheses from a literature-built theoretical model linking demographic, clinical, family environment, and psychosocial characteristics to QoL either directly or indirectly, associations of these factors with a child's self-rated QoL were examined using a structural equation modeling approach.

RESULTS

A total of 312 children (mean [SD] age, 12.2 [2.6] years; 51% boys [n = 160]) were included. Higher levels of trait anxiety and behavioral problems in children were the most important factors associated with poorer QoL (standardized path coefficients, -0.71 and -0.23, respectively). In addition, higher parent trait anxiety, younger age at diagnosis, and a disease requiring an emergency diet were associated with poorer QoL in these children. The final model fit the data closely according to conventional goodness-of-fit statistics and explained 86% of the QoL variance.

CONCLUSIONS

Psychosocial factors appear to be major determinants of QoL impairment in children with IEMRDs. These factors should be addressed in clinical practice as part of the global treatment plan for a child with IEMRD. Future studies based on a longitudinal design should consider coping strategies when exploring potential predictive factors of QoL.

Screening for inborn errors of metabolism in psychotic patients using Next Generation Sequencing

Inborn errors of metabolism (IEMs) are a group of rare genetic disorders which, when emerging later in life, are often characterized by neuropsychiatric manifestations including psychosis. This study aimed to determine whether it would be useful to screen patients presenting with a psychotic disorder for IEMs by a single blood sample using Next Generation Sequencing (NGS), in order to detect rare, treatable causes of psychotic disorders. Blood was drawn from 60 patients with a psychotic disorder, with a duration of illness of less than 5 years. Blood samples were screened for 67 genes using NGS (Illumina® MiSeq sequencing technique). The results were compared to the human reference genome (GoNL, n = 498). The identified variants were classified according to the ACMG classification. For the psychotic patients, 6 variants of a likely pathogenic (class 4, n = 2) or pathogenic (class 5, n = 4) origin were found. As all variants were heterozygous, no patients were considered to be affected by an IEM. For the GoNL control group, 73 variants of a likely pathogenic (class 4, n = 31) or pathogenic (class 5, n = 42) origin were found. All of these found variants were heterozygous. Therefore, these individuals from the control group were considered to be a carrier only. Thus, no patients were identified to have an IEM as an underlying disease using this approach. However, NGS may be useful to detect variants of genes associated with IEMs in an enriched subgroup of psychotic patients.

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.

HEME: a neglected player in nociception?

Despite increasing progress in the understanding of the pathophysiology of pain, current management of pain syndromes is still unsatisfactory. The recent discovery of novel pathways associated with pain insensitivity in humans represents a unique opportunity to improve our knowledge on the pathophysiology of pain. Heme metabolism recently emerged as a crucial regulator of nociception. Of note, alteration of heme metabolism has been associated with pain insensitivity as well as with acute and chronic pain in porphyric neuropathy and hemolytic diseases. However, the molecular mechanisms linking heme to the pain pathways still remain unclear. The review focuses on the major heme-regulated processes relevant for sensory neurons' maintenance, peripheral and central sensitization as well as for pain comorbidities, like anxiety and depression. By discussing the body of knowledge on the topic, we provide a novel perspective on the molecular mechanisms linking heme to nociception.

Administration of branched-chain amino acids alters epigenetic regulatory enzymes in an animal model of Maple Syrup Urine Disease

Maple Syrup Urine Disease (MSUD) is an autosomal recessive inherited disorder that affects the activity of the branched-chainα-keto acid dehydrogenase complex (BCDK). This deficiency on BCDK complex results in the accumulation of branched-chain amino acids (BCAA) leucine, isoleucine, valine, and their corresponding α-keto acids. Epigenetic changes can negatively affect the metabolism of BCAA. These changes are catalyzed by the epigenetic regulatory enzymes, e.g., DNA methyltransferase (DNMT), histone deacetylases (HDAC), and histone acetyltransferases (HAT). However, the impacts of BCAA administration on the activity of epigenetic regulatory enzymes in the brain of MSUD patients are still unknown. In this study, we aimed to demonstrate the impact of BCAA administration on the activity of DNMT, HDAC, and HAT in the brain structures of infant rats, an animal model of MSUD. For that, we administered a BCAA pool to infant rats for 21 days. We demonstrated that BCAA administration significantly increased the DNMT and HDAC activities in the hippocampus and striatum, but not in the cerebral cortex of MSUD infant rats. A positive correlation was observed between HDAC and DNMT activities in the hippocampus and striatum of animals exposed to BCAA injections. Our results showed that the BCAA administration could modulate epigenetic regulatory enzymes, mainly DNMT and HDAC, in the brains of infant rats. Therefore, we suggest that the increase in the activity of DNMT and HDAC in the hippocampus and striatum could partially explain the neurological impairments presented in animal models of MSUD.

Health-related quality of life in paediatric patients with intoxication-type inborn errors of metabolism: Analysis of an international data set

Acute intoxication-type inborn errors of metabolism (IT-IEM) such as urea cycle disorders and non-acute IT-IEM such as phenylketonuria have a major impact on paediatric patients' life. Patients have to adhere to a strict diet but may face neurocognitive impairment and - in acute diseases - metabolic decompensations nevertheless. Research on the subjective burden of IT-IEM remains sparse. Studies with appropriate sample sizes are needed to make valid statements about health-related quality of life (HrQoL) in children and adolescents with IT-IEM. Six international metabolic centres contributed self-reports and proxy reports of HrQoL (assessed with the Paediatric Quality of Life Inventory) to the final data set (n = 251 patients; age range 2.3-18.8 years). To compare HrQoL of the patient sample with norm data and between acute and non-acute IT-IEM, t tests were conducted. To examine the influence of child age, sex, diagnosis and current dietary treatment on HrQoL, multiple linear regression analyses were conducted. Self-reports and proxy reporst showed significantly lower HrQoL total scores for children with IT-IEM compared to healthy children. Current dietary treatment significantly predicted lower proxy reported total HrQoL. Children with non-acute IT-IEM reported significantly lower psychosocial health and emotional functioning than children with acute IT-IEM. The patient sample showed significantly impaired HrQoL and a diet regimen remains a risk factor for lower HrQoL. Differences in HrQoL between acute and non-acute IT-IEM subgroups indicate that factors beyond symptom severity determine the perception of disease burden. Identifying these factors is of crucial importance to develop and implement appropriate interventions for those in need.

Case Report: "Niemann-Pick Disease Type C in a Catatonic Patient Treated With Electroconvulsive Therapy"

We describe a case of an adolescent male with Niemann-Pick Type C (NP-C), a neurodegenerative lysosomal lipid storage disorder, who presented with recurrent catatonia which required repeated treatment with electroconvulsive therapy (ECT). During the ECT-course, seizure threshold increased substantially, leading to questions about the influence of NP-C on neuronal excitability. In this exemplary ECT-patient, NP-C was diagnosed not until after the first ECT-course when initial psychopharmacology for catatonia had failed and antipsychotics and benzodiazepines showed significant side-effects. Clinicians should be aware of NP-C in patients referred for ECT, especially in the case of treatment resistance, neurological symptoms and intolerance of psychopharmacological drugs. As was shown in our NP-C patient, ECT can be repeatedly effective for catatonic features. In the literature, effectiveness of ECT in patients with NP-C has sparsely been reported. This case demonstrates that detection of NP-C is beneficial for patients because more optimal treatment with ECT can be provided earlier without further exposure to side-effects.

The characterization of psychotic symptoms in succinic semialdehyde dehydrogenase deficiency: a review

Succinic semialdehyde dehydrogenase (SSADH) deficiency is an ultra-rare inborn error of metabolism that results in disrupted gamma-amino butyric acid (GABA) catabolism. In addition to developmental delay, intellectual disability, hypotonia, ataxia, and seizures, a variety of neuropsychiatric symptoms may occur, including psychosis. By highlighting all available and relevant case reports/series, this qualitative review seeks to characterize the prevalence, clinical manifestation, pathophysiology, and treatment of psychotic symptoms in this population. Psychosis occurs in a minority of SSADH-deficient individuals, and most commonly presents as auditory or visual hallucinations with an onset in adolescence or young adulthood. Although the pathophysiology underlying the development of psychosis in this context is not fully understood, it likely in part relates to increased GABA and/or gamma hydroxybutyric acid activity. Although antipsychotic medications should be used cautiously in SSADH deficiency, they may be effective at treating emergent psychotic symptoms.

Brain Branched-Chain Amino Acids in Maple Syrup Urine Disease: Implications for Neurological Disorders

Maple syrup urine disease (MSUD) is an autosomal recessive disorder caused by decreased activity of the branched-chain α-ketoacid dehydrogenase complex (BCKDC), which catalyzes the irreversible catabolism of branched-chain amino acids (BCAAs). Current management of this BCAA dyshomeostasis consists of dietary restriction of BCAAs and liver transplantation, which aims to partially restore functional BCKDC activity in the periphery. These treatments improve the circulating levels of BCAAs and significantly increase survival rates in MSUD patients. However, significant cognitive and psychiatric morbidities remain. Specifically, patients are at a higher lifetime risk for cognitive impairments, mood and anxiety disorders (depression, anxiety, and panic disorder), and attention deficit disorder. Recent literature suggests that the neurological sequelae may be due to the brain-specific roles of BCAAs. This review will focus on the derangements of BCAAs observed in the brain of MSUD patients and will explore the potential mechanisms driving neurologic dysfunction. Finally, we will discuss recent evidence that implicates the relevance of BCAA metabolism in other neurological disorders. An understanding of the role of BCAAs in the central nervous system may facilitate future identification of novel therapeutic approaches in MSUD and a broad range of neurological disorders.

Lysosomal Diseases and Neuropsychiatry: Opportunities to Rebalance the Mind

The brain is the physical organ of the mind but efforts to understand mental illness within a neurobiological context have hitherto been unavailing. Mental disorders (anxiety, depression, bipolar disorder, and schizophrenia) affect about one fifth of the population and present an almost endless societal challenge at the frontier of human sciences. Prodigious technological advances in functional neuroimaging and large-scale genetics have not yet delivered the prospect of refined molecular understanding of mental illness beyond early anatomical descriptions of brain metabolism. However, intensive clinical phenotyping and quantitative metabolic studies using sophisticated radio-ligands in positron-emission tomography, persistently favor the neurobiological approach. This Perspective pursues a familiar maxim in Medicine, aptly summarized in the words of Arthur Koestler: “Nature is generous in her senseless experiments on mankind.” Hitherto, studies in neuropsychiatry have largely ignored rare genetic disorders but derangements of specific components within the cerebral laboratory offer rich opportunities for mechanistic exploration. Aberrant psychic behavior is characteristic of many inborn errors of metabolism and although each disorder represents a universe of its own, we are at a threshold for understanding, since contemporary genetics and cell biology furnish abundant materials to take on the perturbing enigma of mental derangement. A further development relates to orphan drugs with actions on defined molecular targets: these represent new ways to study the pathogenesis of psychiatric phenomena associated with rare diseases and in a manner not formerly possible. Here we introduce the frontier of schizophrenia and its strong association with late-onset Tay-Sachs disease as a paradigm to explore.

A novel heterozygous mutation in the HMBS gene in a patient with acute intermittent porphyria and posterior reversible encephalopathy syndrome

Acute intermittent porphyria (AIP) is a rare inherited disorder, which is caused by the partial deficiency of hydroxymethylbilane synthase (HMBS), an enzyme of the heme biosynthetic pathway. Abdominal pain, neuropsychiatric disturbance and neuropathy are the typical manifestations of the disease. Complications such as posterior reversible encephalopathy syndrome (PRES), a rare type of brain lesion present on MRI, are also observed in patients with AIP. The present study reports on the case of a 36‑year‑old Chinese female patient with AIP and PRES. Genomic DNA were obtained from peripheral blood leukocytes and genomic regions of the HMBS gene were amplified as 2 fragments, which together contained all the exons and flanking intronic regions. Sanger sequencing of the amplified DNA fragments from the patient and the patient's family revealed a novel frameshift deletion (c.405‑406delAA) in exon 8 of the HMBS gene. This mutation leads to a subsequent truncated protein (p.Glu135AspfsX74). The recombinant mutant protein had 62% activity relative to the wild‑type protein but similar thermostability. It was confirmed that this novel mutation was the cause of AIP. Accumulation of D‑aminolevulinic acid (ALA) due to HMBS dysfunction is a potential mechanism of PRES. The manifestation of PRES may be associated with ALA‑induced cytotoxicity and the destruction of the blood‑brain barrier. In summary, in the present study, a novel pathogenic HMBS mutation was identified, expanding on the molecular heterogeneity of AIP.

Clinical and biochemical footprints of inherited metabolic diseases. III. Psychiatric presentations

Psychiatric symptoms are common manifestations in many inborn errors of metabolism (IEMs), ranging from attention deficit, anxiety and mood and behavioral disorders to psychosis. Furthermore, IEMs represent a significant percentage of all autism cases. We reviewed and updated the list of metabolic disorders known to be associated with various psychiatric manifestations and found more than 100 relevant IEMs. This represents the third of a series of articles attempting to create and maintain a comprehensive list of clinical and metabolic differential diagnoses according to organ system involvement.

Clues and challenges in the diagnosis of intermittent maple syrup urine disease

BACKGROUND

Maple syrup urine disease is a rare autosomal-recessive aminoacidopathy, caused by deficient branched-chain 2-keto acid dehydrogenase (BCKD), with subsequent accumulation of branched-chain amino acids (BCAAs): leucine, isoleucine and valine. While most cases of MSUD are classic, some 20% of cases are non-classic variants, designated as intermediate- or intermittent-types. Patients with the latter form usually develop normally and are cognitively intact, with normal BCAA levels when asymptomatic. However, intercurrent febrile illness and catabolism may cause metabolic derailment with life-threatening neurological sequelae. Thus, early detection and dietary intervention are warranted in intermittent MSUD.

PATIENTS AND METHODS

We describe eight patients from four unrelated families, diagnosed with intermittent MSUD. Their presenting symptoms during metabolic crises varied from confusion and decreased consciousness, to ataxia, and acute psychosis. Molecular confirmation of MSUD was pursued via sequencing of the BCKDHA, BCKDHB and DBT genes.

RESULTS

All affected individuals were found to harbor bi-allelic pathogenic variants in either BCKDHB or DBT. Of the seven variants, four variants in BCKDHB (p.G101D, p. V103A, p. A221D, p. Y195C) and one variant in DBT (p.K427E) were not previously described.

CONCLUSIONS

While newborn screening programs allow for early detection of classic MSUD, cases of the intermittent form might go undetected, and present later in childhood following metabolic derailment, with an array of non-specific symptoms. Our experience with the families reported herein adds to the current knowledge regarding the phenotype and mutational spectrum of this unique inborn error of branched-chain amino acid metabolism, and underscore the high index of suspicion required for its diagnosis.

Nosology and Phenomenology of Psychosis in Movement Disorders

Background

Psychotic symptoms, such as delusions and hallucinations, are part of the clinical picture of several conditions presenting movement disorders. Phenomenology and epidemiology of psychosis in Parkinson's disease have received wide attention; however, the presence of psychosis in other movement disorders is, comparatively, less well known.

Objectives

To review psychotic symptoms present in different movement disorders.

Methods

A comprehensive and structured literature search was performed to identify and analyze data on patients with movement disorders and comorbid psychosis.

Results

In monogenic parkinsonisms, such as PARK-GBA, PARK-LRRK2, and PARK-SNCA, visual hallucinations related to dopamine replacement therapy are frequent as well as are delusions in PARK-LRRK2 and PARK-SNCA, but not in PARK-GBA. Different types of delusions and hallucinations are found in Huntington's disease and other choreic disorders. In Tourette's syndrome, paranoid delusions as well as visual, olfactory, and auditory hallucinations have been described, which usually develop after an average of 10 years of disease. Delusions in ataxias are more frequent in ATX-TBP, ATX-ATN1, and ATX-ATXN3, whereas it is rare in Friedreich's ataxia. Psychosis is also a prominent and frequent clinical feature in Fahr's disease, Wilson's disease, neurodegeneration with brain iron accumulation, and some lysosomal storage disorders, whereas it is uncommon in atypical parkinsonisms and dystonia. Psychosis usually occurs at late disease stages, but may appear as onset symptoms of the disease, especially in Wilson's disease, Huntington's disease, late-onset Tays-Sachs, and Niemann-Pick.

Conclusion

Psychosis is a frequent comorbidity in most hyper- and hypokinetic movement disorders. Appropriate recognition is relevant both in the early and late disease stages.

Challenges in diagnosing and managing adult patients with urea cycle disorders

Urea cycle disorders (UCD) are a group of rare inherited metabolic conditions of amino acid catabolism caused by an enzyme deficiency within the hepatic ammonia detoxification pathway. The presentation of these disorders ranges from life-threatening intoxication in the neonate to asymptomatic status in adults. Late-onset UCDs can present for the first time in adulthood and may mimic other causes of acute confusion or psychiatric diseases, and are often associated with neurological symptoms. Late-onset UCDs may become apparent during periods of metabolic stress such as rapid weight loss, gastric bypass surgery, chronic starvation or the postpartum period. Early diagnosis is critical for effective treatment and to prevent long-term complications of hyperammonemia. The challenges of management of adults include for example: (a) poor compliance to dietary and medical treatment which can result in recurrent hospital admissions; (b) severe neurological dysfunction; (c) the management of pregnancy and the postpartum period; and (d) access to multidisciplinary care peri-operatively. In this review, we highlight a number of challenges in the diagnosis and management of adult patient with late-onset UCDs and suggest a systematic management approach.

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.

Discovery of Biomarker Panels for Neural Dysfunction in Inborn Errors of Amino Acid Metabolism

Patients with inborn errors of amino acid metabolism frequently show neuropsychiatric symptoms despite accurate metabolic control. This study aimed to gain insight into the underlying mechanisms of neural dysfunction. Here we analyzed the expression of brain-derived neurotrophic factor (BDNF) and 10 genes required for correct brain functioning in plasma and blood of patients with Urea Cycle Disorders (UCD), Maple Syrup Urine Disease (MSUD) and controls. Receiver-operating characteristic (ROC) analysis was used to evaluate sensitivity and specificity of potential biomarkers. CACNA2D2 (α2δ2 subunit of voltage-gated calcium channels) and MECP2 (methyl-CpG binding protein 2) mRNA and protein showed an excellent neural function biomarker signature (AUC ≥ 0,925) for recognition of MSUD. THBS3 (thrombospondin 3) mRNA and AABA gave a very good biomarker signature (AUC 0,911) for executive-attention deficits. THBS3, LIN28A mRNA, and alanine showed a perfect biomarker signature (AUC 1) for behavioral and mood disorders. Finally, a panel of BDNF protein and at least two large neural AAs showed a perfect biomarker signature (AUC 1) for recognition of psychomotor delay, pointing to excessive protein restriction as central causative of psychomotor delay. To conclude, our study has identified promising biomarker panels for neural function evaluation, providing a base for future studies with larger samples.

Alexithymia, Suicide Ideation and Homocysteine Levels in Drug Naïve Patients with Major Depression: A Study in the "Real World" Clinical Practice

Objective

This study was performed to elucidate relationships between alexithymia, suicide ideation and homocysteine levels in drug-naïve outpatients with major depressive disorder (MDD).

Methods

Sixty seven outpatients with MDD with melancholic features were evaluated by the means of the Hamilton Depression Rating Scale, the Toronto Alexithymia Scale (TAS–20), the Scale of Suicide Ideation, and homocysteine levels.

Results

Alexithymic subjects showed higher scores on all scales and higher homocysteine levels. Regression analysis shown higher homocysteine levels and TAS-20’ “Difficulty in Describing Feelings” dimension, in turn being associated with higher suicide ideation.

Conclusion

In conclusion, alexithymic MDD outpatients may characterize for homocysteine dysregulation that may be linked to suicide ideation, regardless depression’ severity. However, study limitations are discussed and must be considered.

Systematic review of psychiatric signs in Niemann-Pick disease type C

Objectives: We conducted the first systematic literature review and analysis of psychiatric manifestations in Niemann-Pick disease type C (NPC) to describe: (1) time of occurrence of psychiatric manifestations relative to other disease manifestations; and (2) frequent combinations of psychiatric, neurological and visceral disease manifestations. Methods: A systematic EMBase literature search was conducted to identify, collate and analyze published data from patients with NPC associated with psychiatric symptoms, published between January 1967 and November 2015. Results: Of 152 identified publications 40 were included after screening that contained useable data from 58 NPC patients (mean [SD] age at diagnosis of NPC 27.8 [15.1] years). Among patients with available data, cognitive, memory and instrumental impairments were most frequent (90% of patients), followed by psychosis (62%), altered behavior (52%) and mood disorders (38%). Psychiatric manifestations were reported before or at neurological disease onset in 41 (76%) patients; organic signs (e.g., hepatosplenomegaly, hearing problems) were reported before psychiatric manifestations in 12 (22%). Substantial delays to diagnosis were observed (5-6 years between psychiatric presentation and NPC diagnosis). Conclusions: NPC should be considered as a possible cause of psychiatric manifestations in patients with an atypical disease course, acute-onset psychosis, treatment failure, and/or certain combinations of psychiatric/neurological/visceral symptoms.

Biomarkers for major depressive and bipolar disorders using metabolomics: A systematic review

Major depressive disorder (MDD) and bipolar disorder (BD) lack robust biomarkers useful for screening purposes in a clinical setting. A systematic review of the literature was conducted on metabolomic studies of patients with MDD or BD through the use of analytical platforms such as in vivo brain imaging, mass spectrometry, and nuclear magnetic resonance. Our search identified a total of 7,590 articles, of which 266 articles remained for full-text revision. Overall, 249 metabolites were found to be dysregulated with 122 of these metabolites being reported in two or more of the studies included. A list of biomarkers for MDD and BD established from metabolites found to be abnormal, along with the number of studies supporting each metabolite and a comparison of which biological fluids they were reported in, is provided. Metabolic pathways that may be important in the pathophysiology of MDD and BD were identified and predominantly center on glutamatergic metabolism, energy metabolism, and neurotransmission. Using online drug registries, we also illustrate how metabolomics can facilitate the discovery of novel candidate drug targets.

Psychiatric and Cognitive Symptoms Associated with Niemann-Pick Type C Disease: Neurobiology and Management

Niemann-Pick disease type C (NPC) is a lysosomal storage disorder that presents with a spectrum of clinical manifestations from infancy and childhood or in early or mid-adulthood. Progressive neurological symptoms including ataxia, dystonia and vertical gaze palsy are a hallmark of the disease, and psychiatric symptoms such as psychosis and mood disorders are common. These latter symptoms often present early in the course of NPC and thus these patients are often diagnosed with a major psychotic or affective disorder before neurological and cognitive signs present and the diagnosis is revised. The commonalities and characteristics of psychotic symptoms in both NPC and schizophrenia may share neuronal pathways and mechanisms and provide potential targets for research in both disorders. The neurobiology of NPC and its relationship to the pattern of neuropsychiatric and cognitive symptoms is described in this review. A number of neurobiological models are proposed as mechanisms by which NPC causes psychiatric and cognitive symptoms, informed from models proposed in schizophrenia and other metabolic disorders. There are a number of symptomatic and illness-modifying treatments for NPC currently available. The current evidence is discussed; focussing on two medications which have shown promise, miglustat and hydroxypropyl-β-cyclodextrin.

Psychosocial Factors in Children and Youth With Special Health Care Needs and Their Families

Children and youth with special health care needs (CYSHCN) and their families may experience a variety of internal (ie, emotional and behavioral) and external (ie, interpersonal, financial, housing, and educational) psychosocial factors that can influence their health and wellness. Many CYSHCN and their families are resilient and thrive. Medical home teams can partner with CYSHCN and their families to screen for, evaluate, and promote psychosocial health to increase protective factors and ameliorate risk factors. Medical home teams can promote protective psychosocial factors as part of coordinated, comprehensive chronic care for CYSHCN and their families. A team-based care approach may entail collaboration across the care spectrum, including youth, families, behavioral health providers, specialists, child care providers, schools, social services, and other community agencies. The purpose of this clinical report is to raise awareness of the impact of psychosocial factors on the health and wellness of CYSHCN and their families. This clinical report provides guidance for pediatric providers to facilitate and coordinate care that can have a positive influence on the overall health, wellness, and quality of life of CYSHCN and their families.

Psychiatric and Cognitive Aspects of Phenylketonuria: The Limitations of Diet and Promise of New Treatments

Phenylketonuria (PKU) is a recessive disorder of phenylalanine metabolism due to mutations in the gene for phenylalanine hydroxylase (PAH). Reduced PAH activity results in significant hyperphenylalaninemia, which leads to alterations in cerebral myelin and protein synthesis, as well as reduced levels of serotonin, dopamine, and noradrenaline in the brain. When untreated, brain development is grossly disrupted and significant intellectual impairment and behavioral disturbance occur. The advent of neonatal heel prick screening has allowed for diagnosis at birth, and the institution of a phenylalanine restricted diet. Dietary treatment, particularly when maintained across neurodevelopment and well into adulthood, has resulted in markedly improved outcomes at a cognitive and psychiatric level for individuals with PKU. However, few individuals can maintain full dietary control lifelong, and even with good control, an elevated risk remains of-in particular-mood, anxiety, and attentional disorders across the lifespan. Increasingly, dietary recommendations focus on maintaining continuous dietary treatment lifelong to optimize psychiatric and cognitive outcomes, although the effect of long-term protein restricted diets on brain function remains unknown. While psychiatric illness is very common in adult PKU populations, very little data exist to guide clinicians on optimal treatment. The advent of new treatments that do not require restrictive dietary management, such as the enzyme therapy Pegvaliase, holds the promise of allowing patients a relatively normal diet alongside optimized mental health and cognitive functioning.

The role of integrated behavioral health in caring for patients with metabolic disorders

This review of integrated behavioral health (IBH) provides a background on IBH models, and the benefits of IBH in pediatric practice with an emphasis on how IBH specialists can collaborate with families and clinicians. An overview of intellectual disability (ID) and psychiatric disorders focused on disorders of inborn errors of metabolism (IEM) highlights issues in assessment and monitoring of these patients with implications for clinical practice and the role of IBH in caring for patients with IEM disorders.

Selective Screening of Fatty Acids Oxidation Defects and Organic Acidemias by Liquid Chromatography/tandem Mass Spectrometry Acylcarnitine Analysis in Brazilian Patients

BACKGROUND

Inborn errors of metabolism (IEM) are diseases which can lead to accumulation of toxic metabolites in the organism.

AIM OF THE STUDY

To investigate, by selective screening, mitochondrial fatty acid oxidation defects (FAOD) and organic acidemias in Brazilian individuals with clinical suspicion of IEM.

METHODS

A total of 7,268 individuals, from different regions of Brazil, had whole blood samples impregnated on filter paper which were submitted to the acylcarnitines analysis by liquid chromatography/tandem mass spectrometry (LC/MS/MS) at the Medical Genetics Service of Hospital de Clínicas de Porto Alegre, Brazil, during July 2008-July 2016.

RESULTS

Our results showed that 68 patients (0.93%) were diagnosed with FAOD (19 cases) and organic acidemias (49 cases). The most prevalent FAOD was multiple acyl CoA dehydrogenase deficiency (MADD), whereas glutaric type I and 3-OH-3-methylglutaric acidemias were the most frequent disorders of organic acid metabolism. Neurologic symptoms and metabolic acidosis were the most common clinical and laboratory features, whereas the average age of the patients at diagnosis was 2.3 years.

CONCLUSIONS

Results demonstrated a high incidence of glutaric acidemia type I and 3-OH-3- methylglutaric acidemia in Brazil and an unexpectedly low incidence of FAOD, particularly medium-chain acyl-CoA dehydrogenase deficiency (MCADD).

Autism spectrum disorders in propionic acidemia patients

Propionic acidemia is the result of a deficiency in propionyl-CoA carboxylase activity. Chronic neurologic and cognitive complications frequently occur, but the psychiatric evolution of the disorder is not well documented. We conducted a pedopsychiatric evaluation of 19 children, adolescents and young adults, aged between 2 and 25 years, using ADI-R, CARS-T, as well as ADOS when autism spectrum disorder was suspected. Previous psychometric examinations were also taken into consideration. Thirteen patients had an IQ < 80. Two patients presented with autism and two additional patients with other autism spectrum disorders. Five patients did not fulfill diagnostic criteria for autism spectrum disorder but showed difficulties indicative of a broader autism phenotype (BAP). Four other patients had severe anxiety manifestations related to their disease. Two patients presented with acute psychotic episodes. The number of decompensations in the first 3 years of life was lower in patients with autism spectrum disorder or related symptoms. These patients were also older when they were assessed (median age of 15 years old versus 11 years old). There was no significant correlation between 3-hydroxypropionate levels during the first 6 years of life and autism spectrum disorder diagnosis. In conclusion, autism spectrum disorder is frequent in patients with propionic acidemia. These patients should undergo in-depth psychiatric evaluation and be screened for autism spectrum disorder. Further studies are needed to understand the underlying mechanisms.

Distinguishing neurocognitive deficits in adult patients with NP-C from early onset Alzheimer's dementia

BACKGROUND

Niemann-Pick disease type C (NP-C) is a rare, progressive neurodegenerative disease caused by mutations in the NPC1 or the NPC2 gene. Neurocognitive deficits are common in NP-C, particularly in patients with the adolescent/adult-onset form. As a disease-specific therapy is available, it is important to distinguish clinically between the cognitive profiles in NP-C and primary dementia (e.g., early Alzheimer's disease; eAD).

METHODS

In a prospective observational study, we directly compared the neurocognitive profiles of patients with confirmed NP-C (n = 7) and eAD (n = 15). All patients underwent neurocognitive assessment using dementia screening tests (mini-mental status examination [MMSE] and frontal assessment battery [FAB]) and an extensive battery of tests assessing verbal memory, visuoconstructive abilities, visual memory, executive functions and verbal fluency.

RESULTS

Overall cognitive impairment (MMSE) was significantly greater in eAD vs. NP-C (p = 0.010). The frequency of patients classified as cognitively 'impaired' was also significantly greater in eAD vs. NP-C (p = 0.025). Patients with NP-C showed relatively preserved verbal memory, but frequent impairment in visual memory, visuoconstruction, executive functions and in particular, verbal fluency. In the eAD group, a wider profile of more frequent and more severe neurocognitive deficits was seen, primarily featuring severe verbal and visual memory deficits along with major executive impairment. Delayed verbal memory recall was a particularly strong distinguishing factor between the two groups.

CONCLUSION

A combination of detailed yet easy-to-apply neurocognitive tests assessing verbal memory, executive functions and verbal fluency may help distinguish NP-C cases from those with primary dementia due to eAD.

Inborn Errors of Metabolism Overview: Pathophysiology, Manifestations, Evaluation, and Management

The specialty of inherited metabolic disease is at the forefront of progress in medicine, with new methods in metabolomics and genomics identifying the molecular basis for a growing number of conditions and syndromes. This review presents an updated pathophysiologic classification of inborn errors of metabolism and a method of clinical screening in neonates, late-onset emergencies, neurologic deterioration, and other common clinical scenarios. When and how to investigate a metabolic disorder is presented to encourage physicians to use sophisticated biochemical investigations and not miss a treatable disorder.

Psychiatric Aspects of Acute Porphyria: a Comprehensive Review

PURPOSE OF REVIEW

The aim of this paper is to review psychiatric manifestations, comorbidities, and psychopharmacological management in individuals with acute porphyria (AP).

RECENT FINDINGS

Recent literature begins to clarify associations between AP, schizophrenia, bipolar disorder, and other psychopathology. Broad psychiatric symptoms have been associated to acute porphyria (AP) and correspond to a spectrum of heterogeneous manifestations such as anxiety, affective alterations, behavioral changes, personality, and psychotic symptoms. These symptoms may be difficult to identify as being related to porphyria since symptoms may arise at any time during the disease process. In addition, these patients may present psychiatric conditions secondary to the disease, such as adjustment disorder and substance use disorders. Timely diagnosis and appropriate treatment of psychiatric manifestations positively impact the course of the disease.

An overview of medical risk factors for childhood psychosis: Implications for research and treatment

OBJECTIVE

Psychotic disorders in childhood and early adolescence often progress to chronic schizophrenia, but in many cases there are diagnosable medical and genetic causes or risk factors. We reviewed our clinical experience and the relevant literature to identify these factors and to define their clinical features, appropriate work-up and treatment.

METHOD

We reviewed the results of comprehensive medical evaluations of 160 psychotic children and adolescents in our center. We also searched the Medline database (January 1994 to December 2015) with the following keywords and combinations: early onset schizophrenia, childhood onset schizophrenia, early onset psychosis, first episode psychosis, inborn errors of metabolism (IEM), genetic syndrome, copy number variants, autoimmune disorders, endocrine diseases, nutritional deficiencies, central nervous system infections, movement disorders, and epilepsy.

RESULTS

In our center, 12.5% of cases had medical disorders likely to be contributing to psychosis. Based on 66 relevant papers and our experience, we describe the clinical features of multiple genetic syndromes, IEM, and autoimmune, neurological, endocrinological and nutritional disorders that increase the risk of psychotic disorders in childhood and adolescence. We propose an algorithm for systematic laboratory evaluation, informed by clinical examination, emphasizing common and/or treatable factors.

CONCLUSIONS

In children and early adolescents with psychotic disorders, systematic medical work-up is warranted to identify medical and genetic factors. Not every rare cause can be worked up, thus careful clinical examinations are required to detect medical, neurological and genetic signs. Comprehensive medical evaluation can detect treatable diseases among cases of early-onset psychosis.

Hemiataxia: A Novel Presentation of Anti-NMDA Receptor Antibody Mediated Encephalitis in an Adolescent

Anti-NMDA receptor antibody associated encephalitis as a cause of new-onset neuropsychiatric manifestations in children and adults can represent a significant diagnostic challenge for clinicians. Clinical signs often include encephalopathy, new-onset psychosis, and movement phenomenon. Although orofacial dyskinesias were initially identified as a characteristic movement phenomenon in this type of encephalitis, an expanded range of abnormalities has recently been reported, including isolated ataxia. We report a case of isolated hemiataxia in a young adult with mild initial psychiatric manifestations. A personal and family history of preceding neuropsychiatric symptoms produced diagnostic confusion and resulted in a significant diagnostic and therapeutic delay. Our case confirms the unilateral movement manifestations that have been emphasized in recent reports. Additionally, it confirms the need for involvement of neurologic as well as psychiatric services in the evaluation of such cases and emphasizes the importance of the neurologic examination in presentations with an initial psychiatric predominance.

Long-term metabolic follow-up and clinical outcome of 35 patients with maple syrup urine disease

BACKGROUND

Maple syrup urine disease (MSUD) is a rare disease that requires a protein-restricted diet for successful management. Little is known, however, about the psychosocial outcome of MSUD patients. This study investigates the relationship between metabolic and clinical parameters and psychosocial outcomes in a cohort of patients with neonatal-onset MSUD.

METHODS

Data on academic achievement, psychological care, family involvement, and biochemical parameters were collected from the medical records of neonatal MSUD patients treated at Necker Hospital (Paris) between 1964 and 2013.

RESULTS

Thirty-five MSUD patients with a mean age of 16.3 (2.1-49.0) years participated. Metabolic decompensations (plasma leucine >380 μmol/L) were more frequent during the first year of life and after 15 years, mainly due to infection and dietary noncompliance, respectively. Leucine levels increased significantly in adulthood: 61.5% of adults were independent and achieved adequate social and professional integration; 56% needed occasional or sustained psychological or psychiatric care (8/19, with externalizing, mood, emotional, and anxiety disorders being the most common). Patients needing psychiatric care were significantly older [mean and standard deviation (SD) 22.6 (7.7) years] than patients needing only psychological follow-up [mean (SD) 14.3 (8.9) years]. Patients with psychological follow-up experienced the highest lifetime number of decompensations; 45% of families had difficulty coping with the chronic disease. Parental involvement was negatively associated with the number of lifetime decompensations.

CONCLUSION

Adults had increased levels of plasma leucine, consistent with greater chronic toxicity. Psychological care was associated with age and number of decompensations. In addition, parental involvement appeared to be crucial in the management of MSUD patients.

Psychiatric adult-onset of urea cycle disorders: A case-series

Adult onset urea cycle disorders (UCD) may present with psychiatric symptoms, occasionally as the initial presentation. We aimed to describe the characteristics of patients presenting with a psychiatric adult-onset of UCDs, to discuss which signs could suggest this diagnosis in such a situation, and to determine which tests should be conducted. A survey of psychiatric symptoms occurring in teenagers or adults with UCD was conducted in 2010 among clinicians involved in the French society for the study of inborn errors of metabolism (SFEIM). Fourteen patients from 14 to 57 years old were reported. Agitation was reported in 10 cases, perseveration in 5, delirium in 4, and disinhibition in 3 cases. Three patients had pre-existing psychiatric symptoms. All patients had neurological symptoms associated with psychiatric symptoms, such as ataxia or dysmetria, psychomotor slowing, seizures, or hallucinations. Fluctuations of consciousness and coma were reported in 9 cases. Digestive symptoms were reported in 7 cases. 9 patients had a personal history suggestive of UCD. The differential diagnoses most frequently considered were exogenous intoxication, non-convulsive status epilepticus, and meningoencephalitis. Hyperammonemia (180-600 μmol/L) was found in all patients. The outcome was severe: mechanical ventilation was required in 10 patients, 5 patients died, and only 4 patients survived without sequelae. Adult onset UCDs can present with predominant psychiatric symptoms, associated with neurological involvement. These patients, as well as patients presenting with a suspicion of intoxication, must have UCD considered and ammonia measured without delay.