1/14. hallucinations in Parkinson's disease: prevalence, phenomenology and risk factors.hallucinations, mainly of a visual nature, are considered to affect about one-quarter of patients with Parkinson's disease. They are commonly viewed as a side-effect of antiparkinsonian treatment, but other factors may be involved. The aim of this study was to determine the phenomenology, prevalence and risk factors of hallucinations in Parkinson's disease. Two-hundred and sixteen consecutive patients fulfilling clinical criteria for Parkinson's disease were studied. Demographic and clinical variables were recorded, including motor and cognitive status, depressive symptoms and sleep-wake disturbances. patients with and without hallucinations were compared using non-parametric tests, and logistic regression was applied to significant data. hallucinations had been present during the previous 3 months in 39.8% of the patients, and fell into three categories: minor forms, consisting of a sensation of a presence (person), a sideways passage (commonly of an animal) or illusions were present in 25.5% of the patients (an isolated occurrence in 14.3%), formed visual hallucinations were present in 22.2% (isolated in 9.3%) and auditory hallucinations were present in 9.7% (isolated in 2.3%). patients with minor hallucinations had a higher depression score than non-hallucinators but did not differ in other respects. Logistic regression analysis identified three factors independently predictive of formed visual hallucinations: severe cognitive disorders, daytime somnolence and a long duration of Parkinson's disease. These findings indicate that, when minor hallucinations are included, the total prevalence is much higher than previously reported. A simple side-effect of dopaminergic treatment is not sufficient to explain the occurrence of all visual hallucinations. The main risk factor in treated patients is cognitive impairment, although sleep-wake cycle disturbances, and possibly other factors related to the duration of the disease, act as cofactors.- - - - - - - - - - ranking = 1keywords = illusion (Clic here for more details about this article) |
2/14. Oneiroid syndrome: a concept of use for western psychiatry.Oneiroid syndrome (OS), or dream-like fantastic delusional derangement of consciousness, is characterized by a kaleidoscopic quality of psychopathological experiences, wherein reality, illusions and hallucinations are merged into one. It is typically accompanied by motor and, in particular, catatonic disturbances. This syndrome is an uncommon psychiatric state, which is hardly mentioned in standard psychiatric textbooks. OS is a neglected entity among DSM-oriented psychiatrists because it deals with a phenomenological approach in contrast to the European attitude, which deals with detailed clinical descriptions. Here, we propose detailed clinical descriptions with a number of consecutive stages of the OS development, illustrated by two vignettes with typical variants of oneiroid syndrome, in order to raise the awareness of psychiatrists who are not familiar with this state, and to try to open a window to the inner life of those patients suffering from this syndrome. These cases may also serve as illustration of certain principles which, when understood, may be found to lead in turn to a deeper knowledge of the psychopathology of other more commonplace conditions.- - - - - - - - - - ranking = 1keywords = illusion (Clic here for more details about this article) |
3/14. On the syndrome of the "spare limb": one case.We describe a case of a brain-damaged patient who had a peculiar bodily illusion which could not be labelled an hallucination but seemed somatognosically and phenomenologically similar to the phantom limb without amputation. The patient, who showed left hemiplegia, felt a third upper limb (without seeing it) which he himself defined as "spare." The spare limb was not deformed; it could be moved and controlled by the patient, and there was no sensation of pain. The patient did not show psychopathological or cognitive disorders. A possible interpretation of the phenomenon is as a "phantom movement" of the paralysed limb: the mental representation of the movement of the limb was dissociated from the bodily representation of his own limb and so was still present in his consciousness despite the paralysis.- - - - - - - - - - ranking = 1keywords = illusion (Clic here for more details about this article) |
4/14. Persisting visual hallucinations and illusions in previously drug-addicted patients.BACKGROUND: Tetrahydrocannabinol (cannabis) and lysergic acid diethylamide (LSD) are psychomimetic agents that induce impairment of sensory perception. illusions and hallucinations are mostly visual. Most frequently the visual phenomena occur in conjunction with drug abuse. patients AND methods: Three previously drug-addicted patients were examined for either persisting or spontaneously recurrent visual phenomena. Two patients complained of persisting visual illusions (vibrations, dyskinetopsia and impaired depth perception) during more than 12 months after an excessive use of cannabis. The third patient was a multiple drug abuser (LSD for 6 years) and complained of visual hallucinations and palinopsia following heavy ethanol intake, 20 years after stopping the use of any drug. RESULTS: Results from neuro-ophthalmic and neurological examinations were normal for the first two patients. The third patient presented abnormal visual fields with preserved visual acuity; electroencephalography was abnormal, suggesting an underlying toxic encephalopathy. CONCLUSIONS: Persistent visual illusions or hallucinations can occur during several months after an intake of cannabis. Flash-back phenomena are frequent amongst LSD abusers. They rarely occur at long times after the last intake (20 years in the present case); when they do so, precipitating factors are often present (ethanol, medication, anesthesia). Such phenomena reflect the cortical dysfunctions that can be induced by illegal substances.- - - - - - - - - - ranking = 6keywords = illusion (Clic here for more details about this article) |
5/14. Out-of-body experience and autoscopy of neurological origin.During an out-of-body experience (OBE), the experient seems to be awake and to see his body and the world from a location outside the physical body. A closely related experience is autoscopy (AS), which is characterized by the experience of seeing one's body in extrapersonal space. Yet, despite great public interest and many case studies, systematic neurological studies of OBE and AS are extremely rare and, to date, no testable neuroscientific theory exists. The present study describes phenomenological, neuropsychological and neuroimaging correlates of OBE and AS in six neurological patients. We provide neurological evidence that both experiences share important central mechanisms. We show that OBE and AS are frequently associated with pathological sensations of position, movement and perceived completeness of one's own body. These include vestibular sensations (such as floating, flying, elevation and rotation), visual body-part illusions (such as the illusory shortening, transformation or movement of an extremity) and the experience of seeing one's body only partially during an OBE or AS. We also find that the patient's body position prior to the experience influences OBE and AS. Finally, in five patients, brain damage or brain dysfunction is localized to the temporo-parietal junction (TPJ). These results suggest that the complex experiences of OBE and AS represent paroxysmal disorders of body perception and cognition (or body schema). The processes of body perception and cognition, and the unconscious creation of central representation(s) of one's own body based on proprioceptive, tactile, visual and vestibular information-as well as their integration with sensory information of extrapersonal space-is a prerequisite for rapid and effective action with our surroundings. Based on our findings, we speculate that ambiguous input from these different sensory systems is an important mechanism of OBE and AS, and thus the intriguing experience of seeing one's body in a position that does not coincide with its felt position. We suggest that OBE and AS are related to a failure to integrate proprioceptive, tactile and visual information with respect to one's own body (disintegration in personal space) and by a vestibular dysfunction leading to an additional disintegration between personal (vestibular) space and extrapersonal (visual) space. We argue that both disintegrations (personal; personal-extrapersonal) are necessary for the occurrence of OBE and AS, and that they are due to a paroxysmal cerebral dysfunction of the TPJ in a state of partially and briefly impaired consciousness.- - - - - - - - - - ranking = 1keywords = illusion (Clic here for more details about this article) |
6/14. Visual command hallucinations in a patient with pure alexia.Around 25% of patients with visual hallucinations secondary to eye disease report hallucinations of text. The hallucinated text conveys little if any meaning, typically consisting of individual letters, words, or nonsense letter strings (orthographic hallucinations). A patient is described with textual visual hallucinations of a very different linguistic content following bilateral occipito-temporal infarcts. The hallucinations consisted of grammatically correct, meaningful written sentences or phrases, often in the second person and with a threatening and command-like nature (syntacto-semantic visual hallucinations). A detailed phenomenological interview and visual psychophysical testing were undertaken. The patient showed a classical ventral occipito-temporal syndrome with achromatopsia, prosopagnosia, and associative visual agnosia. Of particular significance was the presence of pure alexia. illusions of colour induced by monochromatic gratings and a novel motion-direction illusion were also observed, both consistent with the residual capacities of the patient's spared visual cortex. The content of orthographic visual hallucinations matches the known specialisations of an area in the left posterior fusiform gyrus--the visual word form area (VWFA)--suggesting the two are related. The VWFA is unlikely to be responsible for the syntacto-semantic hallucinations described here as the patient had a pure alexic syndrome, a known consequence of VWFA lesions. Syntacto-semantic visual hallucinations may represent a separate category of textual hallucinations related to the cortical network implicated in the auditory hallucinations of schizophrenia.- - - - - - - - - - ranking = 1keywords = illusion (Clic here for more details about this article) |
7/14. Suppression of complex visual hallucinatory experiences by occipital transcranial magnetic stimulation: a case report.Abstract We report a patient with visual hallucinations and illusions along with an associated visual field defect after bilateral ischemic damage to his occipital visual cortex. These hallucinations were long-standing and of both simple and complex (well-formed) type. Application of low frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) to the occipital cortex led to a complete cessation of visual hallucinatory symptoms. The use of TMS to probe the neurophysiology, and possibly alleviate, visual hallucinatory experiences is discussed.- - - - - - - - - - ranking = 1keywords = illusion (Clic here for more details about this article) |
8/14. Organic mental disorders associated with bupropion in three patients.bupropion hydrochloride is a phenylaminoketone antidepressant whose clinical pharmacology is poorly understood. Part of bupropion's action may be attributed to inhibition of dopamine reuptake that may induce organic mental disorders in certain susceptible patients. We report three cases of organic mental disorders in patients receiving bupropion hydrochloride for treatment of the depressed phase of their bipolar-type mood instability. The organic mental disorders that occurred in these patients were characterized largely by visual disturbances--visual hallucinations and visual illusions--although one patient also experienced auditory hallucinations. The patients' use of concomitant medications and potential drug interactions are carefully evaluated and the literature on bupropion's ability to induce organic mental disorders is reviewed. We suggest a number of possible mediating mechanisms for these syndromes including dose-related dopaminergic augmentation, accumulation of toxic metabolites, predisposition to psychosis, and drug interactions.- - - - - - - - - - ranking = 1keywords = illusion (Clic here for more details about this article) |
9/14. Vivid dreams, hallucinations, psychosis and REM sleep in guillain-barre syndrome.We conducted a prospective controlled study of the clinical and biological determinants of the mental status abnormalities in 139 patients with guillain-barre syndrome (GBS) and 55 patients without GBS placed in the intensive care unit (ICU controls). There were mental status changes in 31% of GBS patients and in 16% of controls (odds ratio = 2.3; P = 0.04). In GBS patients, they included vivid dreams (19%), illusions (30%, including an illusory body tilt), hallucinations (60%, mainly visual) and delusions (70%, mostly paranoid). They appeared a median 9 days after disease onset (range 1-40 days, during the progression or the plateau of the disease), and lasted a median 8 days. Seven (16%) patients experienced the symptoms before their admission to the ICU. hallucinations were frequently hypnagogic, occurring as soon as the patients closed their eyes. Autonomic dysfunction, assisted ventilation and high CSF protein levels were significant risk factors for abnormal mental status in GBS patients. CSF hypocretin-1 (a hypothalamic neuropeptide deficient in narcolepsy) levels, measured in 20 patients, were lower in GBS patients with hallucinations (555 /- 132 pg/ml) than in those without (664 /- 71 pg/ml, P = 0.03). Since the mental status abnormalities had dream-like aspects, we examined their association with rapid eye movement sleep (REM sleep) using continuous sleep monitoring in 13 GBS patients with (n = 7) and without (n = 6) hallucinations and 6 tetraplegic ICU controls without hallucinations. Although sleep was short and fragmented in all groups, REM sleep latency was shorter in GBS patients with hallucinations (56 /- 115 min) than in GBS patients without hallucinations (153 /- 130 min) and in controls (207 /- 179 min, P < 0.05). In addition, sleep structure was highly abnormal in hallucinators, with sleep onset in REM sleep periods (83%), abnormal eye movements during non-REM sleep (57%), high percentages of REM sleep without atonia (92 /- 22%), REM sleep behaviour disorders and autonomic dysfunction (100%), reminiscent of a status dissociatus. The sleep abnormalities, that were almost absent in non-hallucinated GBS patients, were not exclusively related to ICU conditions, since they also appeared out of ICU, and were reversible, disappearing when the mental status abnormalities vanished while the patients were still in ICU. In conclusion, the mental status abnormalities experienced by GBS patients are different from the ICU delirium, are strongly associated with autonomic dysfunction, severe forms of the disease and possibly with a transitory hypocretin-1 transmission decrease. sleep studies suggest that mental status abnormalities are wakeful dreams caused by a sleep and dream-associated disorder (status dissociatus).- - - - - - - - - - ranking = 1keywords = illusion (Clic here for more details about this article) |
10/14. hyperglycemia with occipital seizures: images and visual evoked potentials.PURPOSE: hyperglycemia may rarely be seen with visual seizures. observation of both visual evoked potentials (VEPs) and magnetic resonance imaging (MRI) in visual status epilepticus (SE) has not been reported. We describe acute and follow-up VEP and MRI findings of a patient with hyperglycemia-related visual SE of occipital origin. methods: In a 59-year-old diabetic woman, complex visual hallucinations and illusions developed with < or =10 seizures per hour as an initial manifestation of nonketotic hyperglycemia. RESULTS: neurologic examination revealed ictal nystagmus to the right and continuous right hemianopsia. Ictal electroencephalography (EEG) and Tc-99m hexamethylpropylene amine oxime (HMPAO) single-photon emission computed tomography (SPECT) revealed an epileptogenic focus in the left occipital lobe. MRI with fluid-attenuated inversion recovery showed focal subcortical hypointensity and gyral hyperintensity. Follow-up MRI showed only minimal gyral hyperintensity at 6 months. The P100 amplitude of VEP was significantly higher at the right occipital area during SE, but slightly higher on the left after the patient had been seizure free for 6 months. CONCLUSIONS: Occipital seizures and hemianopsia can be caused by hyperglycemia and may be accompanied by special MRI and VEP findings.- - - - - - - - - - ranking = 1keywords = illusion (Clic here for more details about this article) |
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