A forgotten lethal psychosis: a case report

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.

Cystathionine Beta-Synthase Deficiency: Three Consecutive Cases Detected in 40 Days by Newborn Screening in Emilia Romagna (Italy) and a Comprehensive Review of the Literature

Cysthiatonine beta-synthase (CBS) deficiency (CBSD) is an autosomal recessive rare disorder caused by variations on CBS that leads to impaired conversion of homocysteine (Hcy) to cystathionine. Marked hyperhomocysteinemia is the hallmark of the disease. The administration of pyridoxine, the natural cofactor of CBS, may reduce total plasma Hcy. Patient phenotype is classified on pyridoxine responsivity in two groups: pyridoxine-responsive and non-responsive patients. Ectopia lentis, bone deformities, developmental delay, and thromboembolism are the classic signs and symptoms of the disease. Early diagnosis and treatment impact patients' natural history. Therapy aims to lower promptly and maintain Hcy concentrations below 100 μmol/L. Depending on the patient's phenotype, the treatment goals could be obtained by the administration of pyridoxine and/or betaine associated with a methionine-restricted diet. CBSD could be diagnosed in the early days of life by expanded newborn screening (ENS), however, the risk of false negative results is not negligible. In Emilia-Romagna (Italy), during the first 10 years of screening experience, only three cases of CBSD identified have been diagnosed, all in the last two years (incidence 1:118,000 live births). We present the cases and a comprehensive review of the literature to emphasize the role of ENS for early diagnosis of CBSD and its potential pitfalls, reiterating the need for a more effective method to screen for CBSD.

Psychiatric Disorders Secondary to Neurometabolic Disorders

Some diseases secondary to inborn errors of metabolism are associated with psychiatric disorders or minor neurological symptoms. The existence of some cases with exclusively psychiatric symptoms represents a diagnostic and therapeutic challenge. The aim of this article is to describe seven treatable neurometabolic disorders that should be taken into account in the psychiatric consultation as they manifest with psychiatric symptoms that mask the organic origin of the disorder. Homocysteine metabolism and urea cycle disorders, Wilson's disease, Niemann-Pick disease Type C, acute porphyria and cerebrotendinous xanthomatosis are described. Following an analysis of the literature, a list of psychiatric symptoms associated with these disorders are proposed, ranging from insidious changes in affective state and thought to atypical symptoms such as visual hallucinations, as well as paradoxical effects of antipsychotics or behavioural disorders in children and adolescents associated with loss of autonomy. The most frequently associated neurological signs, such as alterations in the state of consciousness, motor behaviour and balance disorders, catatonia or progressive cognitive deficit are also listed. Emphasis is placed on the importance of considering resistance to antipsychotic treatment as a warning sign to suspect organicity, as well as the significant improvement in psychiatric impairment when effective and early treatment is established.

Oxidative Stress in Homocystinuria Due to Cystathionine ß-Synthase Deficiency: Findings in Patients and in Animal Models

Homocystinuria is an inborn error of amino acid metabolism caused by deficiency of cystathionine ß-synthase (CBS) activity, biochemically characterized by homocysteine (Hcy) and methionine (Met) accumulation in biological fluids and high urinary excretion of homocystine. Clinical manifestations include thinning and lengthening of long bones, osteoporosis, dislocation of the ocular lens, thromboembolism, and mental retardation. Although the pathophysiology of this disease is poorly known, the present review summarizes the available experimental findings obtained from patients and animal models indicating that oxidative stress may contribute to the pathogenesis of homocystinuria. In this scenario, several studies have shown that enzymatic and non-enzymatic antioxidant defenses are decreased in individuals affected by this disease. Furthermore, markers of lipid, protein, and DNA oxidative damage have been reported to be increased in blood, brain, liver, and skeletal muscle in animal models studied and in homocystinuric patients, probably as a result of increased free radical generation. On the other hand, in vitro and in vivo studies have shown that Hcy induces reactive species formation in brain, so that this major accumulating metabolite may underlie the oxidative damage observed in the animal model and human condition. Taken together, it may be presumed that the disruption of redox homeostasis may contribute to the tissue damage found in homocystinuria. Therefore, it is proposed that the use of appropriate antioxidants may represent a novel adjuvant therapy for patients affected by this disease.

Guidelines for the diagnosis and management of cystathionine beta-synthase deficiency

Cystathionine beta-synthase (CBS) deficiency is a rare inherited disorder in the methionine catabolic pathway, in which the impaired synthesis of cystathionine leads to accumulation of homocysteine. Patients can present to many different specialists and diagnosis is often delayed. Severely affected patients usually present in childhood with ectopia lentis, learning difficulties and skeletal abnormalities. These patients generally require treatment with a low-methionine diet and/or betaine. In contrast, mildly affected patients are likely to present as adults with thromboembolism and to respond to treatment with pyridoxine. In this article, we present recommendations for the diagnosis and management of CBS deficiency, based on a systematic review of the literature. Unfortunately, the quality of the evidence is poor, as it often is for rare diseases. We strongly recommend measuring the plasma total homocysteine concentrations in any patient whose clinical features suggest the diagnosis. Our recommendations may help to standardise testing for pyridoxine responsiveness. Current evidence suggests that patients are unlikely to develop complications if the plasma total homocysteine concentration is maintained below 120 μmol/L. Nevertheless, we recommend keeping the concentration below 100 μmol/L because levels fluctuate and the complications associated with high levels are so serious.

A Case of Homocystinuria Misdiagnosed as Moyamoya Disease: A Case Report

Introduction

Homocystinuria is a hereditary disease caused by a defect in the enzymes involved in metabolizing methionine. Homocystinuria can influence many systems and may be mistaken for other diseases, including Moyamoya disease. Here, we report the case of a 10-year-old male patient with a diagnosis of Moyamoya disease who had been monitored for that for an extended period. The patient’s diagnosis was changed to homocystinuria as a result of lens subluxation and cataract findings.

Case Presentation

A 10-year-old male patient presented with vomiting, headache, lethargy, muscular weakness, and eye redness. The patient was mentally retarded, his right pupil was hyperemic, and he had muscle weakness on his left side. In addition, his blood pressure was high. The patient’s history included a diagnosis of Moyamoya. A neck and cranial computed tomography (CT) angiography showed no flow bilaterally past the bifurcation of the carotid artery. The patient’s bilateral internal carotid arteries were determined to be occluded. It was considered that his eye findings could be compatible with a metabolic disease. On metabolic screening, the patient’s homocysteine level was very high. In addition, a heterozygous A1298C mutation was identified in MTHFR. Therefore, the patient was started on a diet free from homocysteine and methionine. In addition, his treatment regimen included vitamins B12 and B6. With these treatments, the patient’s complications regressed.

Conclusions

In cases of unusual vascular lesions, metabolic diseases must be considered. In homocystinuria, early diagnosis and treatment are important. Blood homocysteine levels can be returned to normal, and some complications can be prevented.

Acute psychosis in an adolescent with undiagnosed homocystinuria

Homocystinuria due to cystathionine-β-synthase deficiency (CBS deficiency) usually presents with ectopia lentis, myopia, intellectual disability, skeletal anomalies resembling Marfan syndrome, and thromboembolic events. Whereas neurodevelopment impairments have been often described in untreated homocystinuria adult patients, acute psychosis has rarely been reported as a presenting symptom of the disease. Here, we describe a 17-year-old girl affected by CBS deficiency presenting acute onset of visual hallucinations, behavioral perseverance, psychomotor hyperactivity, and affective inappropriateness. Ectopia lentis, diagnosed several years before, didn't have been considered as possible sign of a metabolic disorder. Psychotic symptoms were unresponsive to the conventional antipsychotic drugs and relieved after pyridoxine and folic acid treatment.

CONCLUSION

A diagnosis of homocystinuria due to CBS deficiency should be considered in patients presenting, as target signs, ectopia lentis with or without learning difficulties, and should also be taken into account as a potentially treatable cause of acute psychosis in childhood and adolescence.

WHAT IS KNOWN

• Homocystinuria frequently present with ectopia lentis, myopia, cognitive impairment, Marfan-like phenotype, osteoporosis, cerebrovascular, or cardiac thrombosis. • Acute psychosis has rarely been reported as a presenting symptom of the disease.

WHAT IS NEW

• The complete psychotic symptoms' remission with pharmacological doses of pyridoxine and folic acid, without antipsychotic drugs.