"febrile schizophrenia" in Russia and "lethal catatonia" in the west). The immediate initiation of intensive therapy can now save most of these patients. The use of antipsychotics in lethal catatonia is considered ineffective and very dangerous. Instead, psychiatrists recommend the use of benzodiazepines, symptomatic therapy, as well as dantrolene, bromocriptine, ketamine and amantadine for treatments of this condition. Causes The exact causes of oneiroid syndrome are unknown. However, it is pathologically connected to the following conditions: Endogenous diseases: schizophrenia (especially catatonic schizophrenia). Exogenous organic diseases: infectious (encephalitis), intoxication (by hallucinogens, for example), traumatic brain injury, epilepsy, delirium tremens. Most often, this pathology is noted in schizophrenia (oneiroid catatonia), but sometimes it is described with organic brain lesions and intoxications. There is no self-consciousness disorder in oneiroid syndrome with exogenous diseases. There are no catatonia phenomena, and the syndrome ends more rapidly. Oneiroid syndrome in exogenous organic diseases is evidence of a severe deterioration in the patient's response to the organic disease, and its transition to amential syndrome or mental fog is an even more unfavorable symptom. Exogenous organic oneiroid is different from schizophrenic oneiroid. In most cases, the described exogenous psychoses occupy an intermediate position between delirium and oneiroid, with a rapid and dynamic development of symptoms and an increase in psychotic symptoms occurring during the evening (as is typical for delirium). Clinical resolution of such psychoses after deep sleep also points to a case of delirium. All of this allows us to relate these diagnostic categories to have the variants of delirium ("fantastic delirium"). Hallucinogens (LSD, hashish, ketamine) and hormonal preparations (for example, corticosteroids) may cause exogenous oneiroid syndrome. Stages of the oneiroid syndrome Later in 1961 the Bulgarian psychiatrist S. T. Stoianov studied the dynamics and the course of the oneiroid syndrome in "periodic", or recurrent schizophrenia. In the ICD-9 was a diagnosis : recurrent schizophrenia without other specifications (also known as periodic schizophrenia or circular schizophrenia). It was deleted from the ICD-10. In the DSM-5 there is no such diagnosis, either. According to this research the syndrome has six stages in its course: initial general-somatic and vegetative disorder delusional mood affective-delusional depersonalisation and derealisation fantastic-delusional and affective depersonalisation and derealisation illusional depersonalisation and derealisation, and catatonic-oneiroid state in the culmination. Electroencephalography In most of the cases of the oneiroid syndrome, there were crude pathological changes in the electroencephalography (EEG). See also Clouding of consciousness Delirium References Further