Porphyria: reexamination of psychiatric implications

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.

Severe hydroxymethylbilane synthase deficiency causes depression-like behavior and mitochondrial dysfunction in a mouse model of homozygous dominant acute intermittent porphyria

Acute intermittent porphyria (AIP) is an autosomal dominant inborn error of heme biosynthesis due to a pathogenic mutation in the Hmbs gene, resulting in half-normal activity of hydroxymethylbilane synthase. Factors that induce hepatic heme biosynthesis induce episodic attacks in heterozygous patients. The clinical presentation of acute attacks involves the signature neurovisceral pain and may include psychiatric symptoms. Here we used a knock-in mouse line that is biallelic for the Hmbs c.500G > A (p.R167Q) mutation with ~ 5% of normal hydroxymethylbilane synthase activity to unravel the consequences of severe HMBS deficiency on affective behavior and brain physiology. Hmbs knock-in mice (KI mice) model the rare homozygous dominant form of AIP and were used as tool to elucidate the hitherto unknown pathophysiology of the behavioral manifestations of the disease and its neural underpinnings. Extensive behavioral analyses revealed a selective depression-like phenotype in Hmbs KI mice; transcriptomic and immunohistochemical analyses demonstrated aberrant myelination. The uncovered compromised mitochondrial function in the hippocampus of knock-in mice and its ensuing neurogenic and neuroplastic deficits lead us to propose a mechanistic role for disrupted mitochondrial energy production in the pathogenesis of the behavioral consequences of severe HMBS deficiency and its neuropathological sequelae in the brain.

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.

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.

Acute Porphyria Presenting as Major Trauma: Case Report and Literature Review

BACKGROUND

Acute porphyria is historically known as "the little imitator" in reference to its reputation as a notoriously difficult diagnosis. Variegate porphyria is one of the four acute porphyrias, and can present with both blistering cutaneous lesions and acute neurovisceral attacks involving abdominal pain, neuropsychiatric features, neuropathy, hyponatremia, and a vast array of other nonspecific clinical features.

CASE REPORT

A 40-year-old man presented to the Emergency Department (ED) as a major trauma call, having been found in an "acutely confused state" surrounded by broken glass. Primary survey revealed: hypertension, tachycardia, abdominal pain, severe agitation, and confusion with an encephalopathy consistent with acute delirium, a Glasgow Coma Scale score of 13, and head-to-toe "burn-like" abrasions. Computed tomography was unremarkable, and blood tests demonstrated hyponatremia, acute kidney injury, and a neutrophilic leukocytosis. The next of kin eventually revealed a past medical history of variegate porphyria. The patient was experiencing an acute attack and received supportive management prior to transfer to intensive care, subsequently making a full recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the importance of recognizing acute medical conditions in patients thought to be suffering from major trauma. Acute porphyria should be considered in any patient with abdominal pain in combination with neuropsychiatric features, motor neuropathy, or hyponatremia. Patients often present to the ED without any medical history, and accurate diagnosis can be essential in the acute setting to minimize morbidity and mortality. The label of the major trauma call must be taken with great caution, and a broad differential diagnosis must be maintained throughout a diligent and thorough primary survey.

Psychiatric signs and symptoms in treatable inborn errors of metabolism

Possible underlying organic causes of psychiatric symptoms can be overlooked in the clinical setting. It is important to increase awareness amongst psychiatric and neurological professionals with regard to certain inborn errors of metabolism as, in some cases, disease-specific therapies are available that can, for instance, treat underlying metabolic causes. The following article describes the basic pathophysiology, clinical and neurological features, and available diagnostic procedures of six treatable metabolic diseases that are associated with neuropsychiatric symptoms: Wilson's disease, cerebrotendinous xanthomatosis, porphyrias, homocysteinemia, urea cycle disorders, and Niemann-Pick disease type C (NP-C). NP-C is taken as a particularly relevant example because, while it is traditionally considered to be a condition that presents with severe neurological and systemic manifestations in children, an increasing number of patients are being detected who have the adolescent- or adult-onset form, which is frequently associated with neuropsychiatric signs. A notable proportion of adult-onset cases have been reported where NP-C has mistakenly been diagnosed and treated as a psychiatric condition, usually based on patients' initial presentation with psychotic or schizophrenia-like symptoms. Underlying organic causes of psychiatric disorders such as psychosis should be considered among patients with atypical symptoms and/or resistance to standard therapy. Alongside improved frameworks for additional multidisciplinary diagnostic work in patients with suspected organic disease, the development of convenient and affordable biochemical screening and/or diagnostic methods has enabled new ways to narrow down differential diagnoses.

Schizoaffective disorder with missed diagnosis of acute porphyria: a case report and overview

Acute porphyrias are often misdiagnosed and most commonly present as atypical neuropsychiatric symptoms or acute abdominal pain. Clinicians should suspect acute porphyrias in patients presenting with variable neuropsychiatric symptoms and unexplained pain. Proper identification can lead to less iatrogenicity associated with porphyrinogenic agents, appropriate management, and a better patient outcome. The case of a patient with hereditary coproporphyria, one of the acute porphyrias, is presented to illustrate the broad manifestations, unsuspected diagnosis, and difficulties in management.

An analysis of six cases of acute intermittent porphyria (AIP)

This analysis describes the diagnosis and psychiatric treatment modalities of 6 patients (5 women, 1 man; mean age 28.5 years) of acute intermittent porphyria (AIP), who presented to the Psychiatry OPD over a period of one year. The mean number of episodes was 2.83. Premorbid personality traits, clinical presentation, urine colour and urinary porphobilinogen titre were recorded. Among the 6 patients, 4 had abdominal pain, 5 had autonomic instability, all 6 had mental symptoms, 3 had depression, 2 came in delirium, and 3 had an episode of seizure.

Anxiety and depression in the acute porphyrias

A previous study of self-rated psychosocial aspects in patients with acute porphyria found that depression, and particularly anxiety, is more common in porphyria patients than in the general population or general medical outpatient attenders. Nearly half of the sample (46%) reported at least some problem with anxiety and/or depression: anxiety caseness was 26% and depression caseness was 13%. This paper extends our previous observations and investigates further the associations between porphyria and anxiety, depression and general mental health in 90 patients (58 acute intermittent porphyria, 32 variegate porphyria). The findings of this study confirm that anxiety is raised in patients with acute intermittent porphyria and with variegate porphyria, in both males and females, compared to the normative population and, using a series of questionnaires exploring the physical and psychosocial features of anxiety, that this anxiety is experienced as a 'relatively stable personality trait', rather than a 'transitory emotional state' (i.e. intrinsic rather than secondary to the porphyria).

General medical considerations in child and adolescent patients who present with psychiatric symptoms

This article has presented a 12-step approach to general medical evaluation in child and adolescent psychiatric emergencies (Box 2). It is hoped that the article, which suggests targeted consideration of key specific issues, will stimulate further interest and work in this area and help optimize child psychiatrists' ability to exclude general medical conditions and work effectively with colleagues in providing children and families with safe medical care.

Porphyria and dementia: a case report

The porphyrias are a group of rare hereditary metabolic disorders where there is an excess formation and excretion of porphyrins or their precursors. Type IIA, acute intermittent porphyria (AIP), has an estimated prevalence of one to eight per 100,000 in the general population but is thought to have a higher prevalence in psychiatric patients. AIP can present with a variety of psychiatric symptoms, often misdiagnosed. Associated neuropathological changes including focal cerebral ischaemic lesions have been found. However, to our knowledge, no case of dementia and AIP has been described. We present the case of a 56 year old man with a five-year history of progressive cognitive decline, diagnosed with AIP at an advanced stage of dementia. Whether AIP contributed to the dementia or is a coincidental finding is unknown. However treatment of AIP in this case resulted in some improvement in the patient's cognitive state.

From King George to neuroglobin: the psychiatric aspects of acute intermittent porphyria

The porphyrias are a heterogeneous group of inherited deficiencies in the heme biosynthetic pathway. Acute intermittent porphyria is both the most prevalent and most severe form of this illness. Psychiatric symptoms are part of the classic presentation of this disorder, and psychiatric patients have a higher rate of porphyria than the general population. Despite this, clinicians often fail to consider this diagnosis in the differential for recalcitrant psychosis or depression. Many patients are asymptomatic until exposed to certain medications, liver damage, or hormonal changes. Diagnosis requires a high index of suspicion and a thorough history, physical examination, and laboratory evaluation. The author reviews historical aspects, diagnostic features, and optimal treatment of acute intermittent porphyria, considers possible etiologies of its psychiatric symptoms, and provides two case histories as examples.

Self-rated psychosocial consequences and quality of life in the acute porphyrias

A battery of self-report psychosocial measures was mailed to 116 patients who had been referred for clinical management (clinic attenders) or laboratory diagnosis (non-clinic attenders) to the London Supraregional Assay Service Centre for Porphyria over the past decade and who tested positive for porphyria. Usable replies were received from 81 (70%) patients. Our interest focused on the prevalence of psychosocial symptoms in acute porphyrias and the perceived effects of porphyria on quality of life and patient experience. Research questions examined included (i), lifestyle factors; (ii) life events; (iii) mental health; (iv) general health; and (v) perceptions of illness of patients receiving specialist clinical management compared to respondents referred for diagnostic investigations, between patients with latent or manifest symptomology and between patients with different types of porphyria. Patients with porphyria have an impaired quality of life, particularly manifest cases, compared to controls and to diabetic patients. Depression, and particularly anxiety, is more common than in the general population or general medical outpatient attenders. Quality oflife is lower in acute intermittent porphyria (AIP) than in other forms of porphyria and a significant number of patients had major life event consequences, e.g. failure to secure, or loss of, employment, limitation of family size. Patients attending a clinic providing specialist porphyria advice, management and counselling received some perceived lifestyle benefits.

Acute porphyric disorders

Acute porphyrias are classified into 3 distinct groups of rare genetic disorders of metabolic enzyme biosynthesis. Acute porphyrias can significantly impact multiple organ systems, which often provides a challenge to the dentist presented with such a patient. A case of hereditary coproporphyria is reported in a patient with many of the classical signs and symptoms. The patient also had complex dental needs that required special medical and pharmacotherapeutic modifications. The acute porphyrias are reviewed by the authors with presentation of this challenging case. Recommendations for other dental health care professionals encountering these patients are then presented.

Psychiatric symptoms of inherited metabolic disease

Inborn errors of metabolism often present with a variety of psychiatric symptoms. With improved diagnosis and treatment options, many patients have increased lifespans; consequently, issues of long-term quality of life are coming to the forefront. Mental health concerns are among these issues. To demonstrate the connection between the course of metabolic disease and its psychiatric manifestations, four different inborn errors of metabolism are reviewed: phenylketonuria, Wilson disease, acute intermittent porphyria, and metachromatic leukodystrophy.

Phenomenology and treatment of psychotic disorders in the psychiatric emergency service

The emergency evaluation of a psychotic patient calls on all of the skills of the psychiatrist. The immediate control of dangerous behavior takes place at the same time that clinicians evaluate patients for delirium. A screening physical examination, a brief mental status examination, and a high index of suspicion for medical diseases are essential tools in the first few minutes of a patient's stay in the psychiatric emergency service. Drugs of abuse are often part of a patient's presentation. Here, too, the first task is to rule out delirium, particularly from sedative or alcohol withdrawal. As soon as a patient's condition is stabilized, the psychiatrist should review all of the available information, develop a working diagnosis, and initiate definitive treatment of the presumed disorder. With fewer emergency patients being hospitalized and with shorter lengths of hospital stay, these initial decisions acquire increasing significance for patient outcome.