Troubles psychiatriques révélateurs d’une maladie de Niemann-Pick de type C à l’âge adulte

Brain anomalies in early psychosis: From secondary to primary psychosis

Brain anomalies are frequently found in early psychoses. Although they may remain undetected for many years, their interpretation is critical for differential diagnosis. In secondary psychoses, their identification may allow specific management. They may also shed light on various pathophysiological aspects of primary psychoses. Here we reviewed cases of secondary psychoses associated with brain anomalies, reported over a 20-year period in adolescents and young adults aged 13-30 years old. We considered age at first psychotic symptoms, relevant medical history, the nature of psychiatric symptoms, clinical red flags, the nature of the brain anomaly reported, and the underlying disease. We discuss the relevance of each brain area in light of normal brain function, recent case-control studies, and postulated pathophysiology. We show that anomalies in all regions, whether diffuse, multifocal, or highly localized, may lead to psychosis, without necessarily being associated with non-psychiatric symptoms. This underlines the interest of neuroimaging in the initial workup, and supports the hypothesis of psychosis as a global network dysfunction that involves many different regions.

[Psychiatric disorders in adult form of Niemann-Pick disease type C]

INTRODUCTION

Niemann-Pick type C disease (NPC) is a rare genetic disease with an extremely heterogeneous clinical presentation. The adult form of this disease is usually expressed with neurological symptoms; however, non-specific psychiatric disorders are often associated. This article presents a retrospective study on a cohort of NPC patients diagnosed in France with the objectives of researching the presence of psychiatric disorders and qualifying these disorders.

METHODS

After carrying out a research within hospital records, a questionnaire was sent to patients or their relatives and their doctors.

RESULTS

The cohort was made up of 22 patients. Fifty-two questionnaires were sent to 47 different doctors. We received 67% of answers from the doctors, with 42% of positive answers. The answer rate of the families was 27%. Among the 22 patients, we found the presence of psychiatric disorders in 86% of cases. Seventy-three percent of the patients presented behavior disorders. Among them, 27% exhibited psychomotor excitation or agitation, 23% aggressiveness, 18% intolerance to frustration, 27% sleep disorders and 23% apathy, listlessness and/or clinophilia. Fifty-five percent of patients presented psychotic symptoms, with 45% with delusions and 36% with hallucinations. Seventy-seven percent of patients presented with mood disorders: 36% suffered from depression and 27% from emotional lability or mood swings. Of the 22 patients, a diagnosis of psychiatric disease was made in 50% of cases. The main diagnoses were schizophrenia (27%) and depression (23%). The other diagnoses identified were acute delirium, dysthymia, infantile psychosis, intellectual disharmonic disability and personality disorder. The average age of emergence of the troubles was 17.1 years old for neurological symptoms and 20.9 years old for psychiatric symptoms. The median age was 18 years old for neurological symptoms and 20 years old for psychiatric ones. In 45% of cases, psychiatric occurred after neurological symptoms; in 27%, they occurred before and they were concomitant in 9%. In 50% of cases, psychiatric symptoms existed before the early diagnosis of NPC; in 9%, they occurred after and in 5%, they occurred during the diagnostic process. Fifty-five percent of the patients were followed by a psychiatrist, 50% of patients had been hospitalized at least once in a psychiatric department. Fifty-five percent of the patients received neuroleptics or antipsychotics, 41% received antidepressants, 41% received mood stabilizers or anticonvulsants, 45% received anxiolytics and 23% hypnotics.

DISCUSSION

Whilst a small cohort, the low incidence of NPC (1/120,000 to 1/150,000) and the scale of a single-center study make the findings important. In our cohort, we found psychiatric disorders in most of the patients. The symptoms were varied and non-specific, and mainly found in late-onset forms of the disease. This incidence of disorder is much higher than the literature suggests, generally describing psychiatric disorders in approximately one third of NPC adult form. On the other hand, our results on schizophrenia are consistent with the updated recommendations for the diagnosis and management of NPC. According to our results, a retrospective study to develop a suspicion index to aid diagnosis of NPC suggests that psychotic symptoms are underestimated in this disease. In our cohort, we also found a significant rate of psychiatric hospitalizations and psychotropic drugs prescription that had not been previously described in the international literature. We did not have sufficient data on the effectiveness of symptomatic treatment in NPC; the literature was contradictory. It should be noted that despite the high rate of psychiatric patients in our cohort, only half of patients consulted a psychiatrist and a few of them have regular follow-up. To conclude, our study is in line with the current literature that suggests an under-estimation of psychiatric disorders in NPC, but also a likely under-diagnosis of NPC in psychiatric departments. All this data encourage us to keep alerting psychiatrists to identifying this disease in order to promote early and optimal care.

[Niemann-Pick type C disease and psychosis: Two siblings]

INTRODUCTION

Niemann-Pick type C disease (NPC) is a rare, neurovisceral, autosomal recessive disease, with an extremely heterogeneous clinical presentation. The adult form of the disease is usually expressed as a neurological form. Non-specific psychiatric symptoms are often associated with NPC. For some cases, it can also be expressed as an isolated psychiatric disorder form. Since 2009, the launching of a medicine called miglustat has helped to improve the disease evolution.

CASE HISTORIES

We report two siblings followed-up in the same department of psychiatry and with an atypical psychotic symptomatology. Case 1 is a 27-year-old French male. He was hospitalised several times due to disordered behaviour, psychomotor excitation, mood instability and wandering. He was originally diagnosed with schizophrenia. However, the patient's psychosis proved refractory to treatment. He also exhibited a number of neurological signs (pyramidal signs and abnormal movements of the hands, head and limbs), which were considered related to his antipsychotic medication. Three years later, a full physical, neurological and neuropsychological examination revealed various neurological and visceral symptoms. He was diagnosed with NPC based on a classical biochemical NPC-phenotype following filipin staining in cultured skin fibroblasts. NPC1 gene sequencing revealed that he was a compound heterozygote for the p.S954L and p.N1156S mutations. The patient's psychiatric and neurological symptoms are currently stabilized by miglustat, allowing the patient to cease antipsychotic medication. Case 2 is the elder sister of Case 1. She was hospitalised several times due to acute delirium, hallucinations and suicidal tendencies. She was diagnosed with paranoid schizophrenia at 22 years of age. She has received a variety of typical and atypical antipsychotics. Many of these drugs proved initially effective but the patient's symptoms repeatedly returned. The patient shows persistent and worsening gait disorder and abnormal arm movements. A follow-up neurological examination at age 29 did not detect any ataxia, cataplexy or vertical supra-nuclear gaze palsy. Direct NPC1 gene sequencing detected a mutant NPC1 allele held in common with her brother, but full sequencing of both the NPC1 and NPC2 genes and multiplex ligation-dependent probe amplification (MLPA) did not detect any other pathogenic mutation or other anomalies.

DISCUSSION

Because NPC is an autosomal recessive condition, heterozygous individuals carrying only one causal gene mutation are usually asymptomatic. Thus, while the accepted wisdom would suggest that patient 2 is not affected by the disease, it is interesting to consider why she has developed neurological and psychiatric disorders like her brother. Several hypotheses are discussed: mental expression in heterozygous genetic factor predisposing to schizophrenia, comorbidity or fortuitous association. It is not currently known whether a patient with a single NPC gene mutation can express NPC in full, partially, or perhaps just to a minimal degree. This case of a patient with a heterozygous "carrier" NPC genotype and neuropsychiatric disorders suggestive of the disease raises the possibility that symptomatic heterozygous NPC patients may exist. On the other hand, if the heterozygous genotype of patient 2 does not give rise to symptomatic disease, it is pertinent to question whether it could be a predisposing factor for the development of psychiatric pathologies. There are currently no published data on the occurrence of heterozygous NPC1 or NPC2 mutations among patients with atypical psychiatric presentations combined with neurological symptoms. Conversely, there are no published data demonstrating an increased frequency of psychiatric disorders in families affected by NPC. Finally, in view of the history of psychiatric disorders in this family, it is possible that psychosis simply occurred concomitantly with symptomatic NPC in patient 1 by chance, and that schizophrenia occurred simultaneously with an asymptomatic NPC carrier genotype in patient 2. To investigate this further, NPC patients' carrier family members (parents and siblings) should be fully screened for signs suggestive of the disease.

Diagnostic and treatment implications of psychosis secondary to treatable metabolic disorders in adults: a systematic review

Objective

It is important for psychiatrists to be aware of certain inborn errors of metabolism (IEMs) as these rare disorders can present as psychosis, and because definitive treatments may be available for treating the underlying metabolic cause. A systematic review was conducted to examine IEMs that often present with schizophrenia-like symptoms.

Data sources

Published literature on MEDLINE was assessed regarding diseases of homocysteine metabolism (DHM; cystathionine beta-synthase deficiency [CbS-D] and homocysteinemia due to methyltetrahydrofolate reductase deficiency [MTHFR-D]), urea cycle disorders (UCD), acute porphyria (POR), Wilson disease (WD), cerebrotendinous-xanthomatosis (CTX) and Niemann-Pick disease type C (NP-C).

Study selection

Case reports, case series or reviews with original data regarding psychiatric manifestations and cognitive impairment published between January 1967 and June 2012 were included based on a standardized four-step selection process.

Data extraction

All selected articles were evaluated for descriptions of psychiatric signs (type, severity, natural history and treatment) in addition to key disease features.

Results

A total of 611 records were identified. Information from CbS-D (n = 2), MTHFR-D (n = 3), UCD (n = 8), POR (n = 12), WD (n = 11), CTX (n = 14) and NP-C publications (n = 9) were evaluated. Six non-systematic literature review publications were also included. In general, published reports did not provide explicit descriptions of psychiatric symptoms. The literature search findings are presented with a didactic perspective, showing key features for each disease and psychiatric signs that should trigger psychiatrists to suspect that psychotic symptoms may be secondary to an IEM.

Conclusion

IEMs with a psychiatric presentation and a lack of, or sub-clinical, neurological signs are rare, but should be considered in patients with atypical psychiatric symptoms.

Recommendations for the diagnosis and management of Niemann-Pick disease type C: an update

Niemann-Pick disease type C (NP-C) is a rare inherited neurovisceral disease caused by mutations in either the NPC1 (in 95% of cases) or the NPC2 gene (in around 5% of cases), which lead to impaired intracellular lipid trafficking and accumulation of cholesterol and glycosphingolipids in the brain and other tissues. Characteristic neurological manifestations of NP-C include saccadic eye movement (SEM) abnormalities or vertical supranuclear gaze palsy (VSGP), cerebellar signs (ataxia, dystonia/dysmetria, dysarthria and dysphagia) and gelastic cataplexy. Epileptic seizures are also common in affected patients. Typically, neurological disease onset occurs during childhood, although an increasing number of cases are being detected and diagnosed during adulthood based on late-onset neurological signs and psychiatric manifestations. Categorization of patients according to age at onset of neurological manifestations (i.e. early-infantile, late-infantile, juvenile and adolescent/adult-onset) can be useful for the evaluation of disease course and treatment responses. The first international guidelines for the clinical management of NP-C in children and adults were published in 2009. Since that time a significant amount of data regarding the epidemiology, detection/diagnosis, and treatment of NP-C has been published. Here, we report points of consensus among experts in the diagnosis and treatment of NP-C based on a follow-up meeting in Paris, France in September 2011. This article serves as an update to the original guidelines providing, among other things, further information on detection/diagnostic methods, potential new methods of monitoring disease progression, and therapy. Treatment goals and the application of disease-specific therapy with miglustat are also re-evaluated.