Interactions between the gut microbiome and the central nervous system and their role in schizophrenia, bipolar disorder and depression

The microbiome co-evolved with its human host over a long time and became essential for many processes. Bacteria play a role in maintaining human health as they digest food, produce vitamins and participate in the regulation of metabolism. By influencing the cytokine balance along with the composition and activity of leukocytes, they constantly interact with the immune system, affecting innate and adaptive immune homeostasis. A growing number of studies indicate that the microbiome in the human intestine may have an impact on the functions of the central nervous system (CNS), through identified pathways called the gut–brain axis. Recent data show that the human microbiome ecosystem interferes with the brain’s development, central signaling systems and behavior. It has been proposed that disruption in the human microbiome may affect the course of psychiatric disorders. The aim of this review is to summarize the recognized pathways of the gut–brain axis that have been thoroughly studied in animal models and to evaluate the role of the dialogue between the microbiota and the central nervous system in schizophrenia, bipolar disorder and depression

Psychiatric illnesses in inflammatory bowel diseases : psychiatric comorbidity and biological underpinnings

Inflammatory bowel disease is a group of chronic medical conditions comprising Crohn’s disease and ulcerative colitis that involves increased frequency of mental disorders. The most common psychiatric disorders in inflammatory bowel disease are depression and anxiety, however, some epidemiologic and biological evidence suggest that other disorders like bipolar disorder occur more often. Biological mechanisms concerning both inflammatory bowel disease and depression or anxiety explain susceptibility to developing mental disorders in inflammatory bowel disease. Interactions of brain gut-axis, immunological disturbances, oxidative stress and vagus nerve dysfunction play a role in pathophysiology of inflammatory bowel disease and mental disorders as well. Significance of these factors was covered in this paper. Psychiatric comorbidity in IBD may affect course of intestinal disease. It can increase frequency and severity of relapses and hinder the treatment so knowledge about relationship between IBD and mental health appears to be vital for proper management of patients with inflammatory bowel disease

Relationship between cerebellar impairments and lexicon retrieval in schizophrenia - preliminary study

Aim of the study. Investigation of relationship between cerebellar motor dysfunctions and language impairments connected with cerebellum during phonological and semantic fluency tasks and verb generation task in schizophrenic patients and healthy control group. Subject or material and methods. 14 schizophrenic patients on olanzapine, clozapine or quetiapine treatment and 13 healthy volunteers were examined. Motor signs were assessed by using the International Co-operative Ataxia Rating Scale (ICARS). Phonological and semantic fluency tasks were performed. All of the words were recorded and counted. Results. Patients with schizophrenia revealed significantly higher ICARS mean score (12.21) than control group (3.92), and lower number of proper generated words in semantic fluency and verb generation tasks. Strong negative correlation (rs(13) = -0.71, p<0.01) was found between ICARS total score and number of proper answers in verb generation task. Discussion. Higher number of total ICARS score in schizophrenia patients in comparison to control group may suggest cerebellar impairments. There is disproportion between semantic and phonological fluency. Significant correlation between verb generation and cerebellar signs supports a hypothesis of cerebellum dysfunction during this task in schizophrenia patients. Conclusions. Schizophrenic patients reveal impairments which may be connected with the cerebellum

Violent behaviour as a result of delirium superimposed on dementia in the course of primary central nervous system lymphoma

Primary central nervous system lymphoma is a rare neoplasm, exceptionally responsible for developing a frontal lobe syndrome. A 71-years-old patient with primary central nervous system lymphoma had undergone frontotemporal craniotomy for tumor removal. Month later, showing syncopies, disorientation and slurred speech, he was transported to Department of Internal Medicine. Neuroimaging revealed numerous tuberous changes in frontal and parietal lobes and frontotemporal area. During hospitalization, patient exhibited inadequate affect, jocular behaviour, was disoriented in the place and time, and unaware of his health state. He took repeated, uncritical attempts to jump out the window and started to exhibit persecutory delusions and hallucinations. Immediate brain radiotherapy was recommended by the oncology specialists. However, the patient did not consent to the recommended method of treatment due to his lack of recollection of the tumor or the craniotomy. The patient was forcibly transferred to Department of Psychiatry. After five weeks of treatment, the patient’s condition improved significantly, and the patient regained memory of the tumor

Peripheral vagus nerve stimulation significantly affects lipid composition and protein secondary structure within dopamine-related brain regions in rats

Recent immunohistochemical studies point to the dorsal motor nucleus of the vagus nerve as the point of departure of initial changes which are related to the gradual pathological developments in the dopaminergic system. In the light of current investigations, it is likely that biochemical changes within the peripheral nervous system may influence the physiology of the dopaminergic system, suggesting a putative role for it in the development of neurodegenerative disorders. By using Fourier transform infrared microspectroscopy, coupled with statistical analysis, we examined the effect of chronic, unilateral electrical vagus nerve stimulation on changes in lipid composition and in protein secondary structure within dopamine-related brain structures in rats. It was found that the chronic vagal nerve stimulation strongly affects the chain length of fatty acids within the ventral tegmental area, nucleus accumbens, substantia nigra, striatum, dorsal motor nucleus of vagus and the motor cortex. In particular, the level of lipid unsaturation was found significantly increasing in the ventral tegmental area, substantia nigra and motor cortex as a result of vagal nerve stimulation. When it comes to changes in protein secondary structure, we could see that the mesolimbic, mesocortical and nigrostriatal dopaminergic pathways are particularly affected by vagus nerve stimulation. This is due to the co-occurrence of statistically significant changes in the content of non-ordered structure components, alpha helices, beta sheets, and the total area of Amide I. Macromolecular changes caused by peripheral vagus nerve stimulation may highlight a potential connection between the gastrointestinal system and the central nervous system in rat during the development of neurodegenerative disorders

Brain biopsy in the diagnosis of Creutzfeldt-Jakob disease with a history of prodromal psychiatric symptoms and catatonic behavior

Creutzfeldt-Jakob disease (CJD) is a neurodegenerative disorder belonging to the group of transmissible spongiform encephalopathies. The transition of physiological, soluble, neuroprotective prion protein PrPc into its insoluble, misfolded isoform PrPSc remains its central pathogenic event. The progressive accumulation of isoform PrPSc within the brain tissue results in spongiform degeneration and a plethora of clinical symptoms. Typically, CJD manifests as progressive dementia with myoclonus, visual or cerebellar dysfunction, pyramidal/extrapyramidal signs or akinetic mutism. However, a growing number of studies indicate that CJD may present with prodromal psychiatric manifestations including anhedonia, anxiety, irritability, depression, insomnia, psychosis and catatonic behavior. We present a case of CJD with a history of prodromal psychiatric symptoms and catatonic behavior diagnosed by brain biopsy

Głęboka stymulacja mózgu jako metoda leczenia depresji lekoopornej w przebiegu choroby afektywnej dwubiegunowej — przegląd badań neuroobrazowych i eksperymentalnych

  Bipolar disorder (BD) — psychiatric disorder characterized by at least one manic or hypomanic state and recurrent episodes of depression, is one of the main causes of disability among young adults. Depression — dominant in the course of BD is particularly prone to be treatment resistant. A new experimental treatment for refractory depression in the course of bipolar disorder is deep brain stimulation (DBS), associated with a single neurosurgical low – risk procedure, causes immediate antidepressant effect. Neuroimaging studies have shown sIMFB (supero-lateral branch of the medial forebrain bundle) as the most reactive for deep brain stimulation. Further studies on stimulating sIMFB carried out in the selected groups of treatment-resistant depressive patients with BD are needed.      Choroba afektywna dwubiegunowa (ChAD) jest przewlekłym zaburzeniem psychicznym będącym jedną z głównych przyczyn niepełnosprawności wśród młodych dorosłych. Depresja w przebiegu ChAD stanowi dominującą fazą choroby, a jednocześnie główny czynnik obniżający jakość życia pacjentów, odpowiedzialny za największą śmiertelność w tej grupie klinicznej. Epizody depresji są również szczególnie narażone na lekooporność. Nową eksperymentalną metodą leczenia depresji lekoopornej w przebiegu ChAD jest głęboka stymulacja mózgową (DBS) związana z jednorazowym zabiegiem neurochirurgicznym obarczonym niewielkim ryzykiem niepowodzenia. Powoduje ona długotrwały antydepresyjny efekt u większości zbadanych do tej pory pacjentów z ChAD. Wyniki badań neuroobrazowych wskazują obszar grzbietowo-bocznej gałęzi pęczka przyśrodkowego przodomózgowia (slMFB) jako najbardziej reaktywny na głęboką stymulację mózgową. Łączy on pozostałe miejsca stymulacji wykorzystywane do tej pory w terapii DBS depresji lekoopornej. Dalsze badania nad stymulacją sIMFB, przeprowadzane w wyselekcjonowanych grupach, mogą stać się podstawą wprowadzenia nowej metody leczenia depresji lekoopornej w przebiegu ChAD.

Angiocentric glioma from a perspective of A-B-C classification of epilepsy associated tumors

Angiocentric glioma (AG) is a newly-classified, very rare, WHO grade I central nervous system (CNS) lesion, occurring usually in children and young adults. Only 52 patients with AG have been reported so far, making it one of the rarest neuropathological entities. Hereby we present two new cases of AG in young subjects with detailed neuropathological investigations and a neuroradiological picture along with a brief summary of all already published literature reports of this tumor. Histopathological examination of the resected tissue from both cases revealed similar changes characteristic of AG. The tumors were composed of spindle-like, elongated cells, forming characteristic pseudorosettes around vessels and diffusively infiltrating surrounding tissue, trapping neurons between tumor cells. Noticeably, some neoplastic cells encrusting vessels extended far beyond the main tumor mass. Hypothetically, this may be responsible for the recurrence of the tumor even in the case of apparently total excision. In immunohistochemistry, AG cells were glial fibrillary acidic protein (GFAP) and vimentin positive, also exhibiting a strikingly significant epithelial membrane antigen (EMA) dot-like staining pattern. In one of the cases, electron microscopy revealed ependymal differentiation features such as microvilli and cilia. Taken together, all these data strongly confirm a dual astroglial-ependymal nature of the tumor. Follow up corroborates benign character of this neoplasm. Both AGs reported here were immunonegative for the product of the mutated IDH-1 gene what, according to our best knowledge, has never been reported so far. It may suggest that in their pathogenesis AGs differ from grade II astrocytomas, which in most cases harbor a mutation of IDH-1. Noteworthy, neuroimaging in our cases was relatively characteristic but not conclusive, therefore biopsy (at least) is mandatory. A newly proposed so called "A-B-C" classification of long-term epilepsy-associated tumors (LEATs) places AG in a category named ANET. The authors shortly review the A-B-C classification of LEATs