Visual hallucinations in psychologically normal people: Charles Bonnet's syndrome

Teunisse, Robert J.; Zitman, Frans G.; Cruysberg, J.R.M.; Hoefnagels, W.H.L.; Verbeek, A.L.M.

doi:10.1016/s0140-6736(96)90869-7

Cited by 368 publications

(346 citation statements)

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“…The resulting strengthening of aberrant, internally focused memories might contribute to the dissociation of mental processes from changing social context and lead to delusions and hallucinations. Hallucinations are observed with sensory and social deprivation, even in healthy individuals (Hayashi et al, 1992;Teunisse et al, 1996), and strongly increase with seclusion in schizophrenic patients (Kennedy et al, 1994).…”

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confidence: 99%

Storage, recall, and novelty detection of sequences by the hippocampus: Elaborating on the SOCRATIC model to account for normal and aberrant effects of dopamine

2001

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ABSTRACT:In order to understand how the molecular or cellular defects that underlie a disease of the nervous system lead to the observable symptoms, it is necessary to develop a large-scale neural model. Such a model must specify how specific molecular processes contribute to neuronal function, how neurons contribute to network function, and how networks interact to produce behavior. This is a challenging undertaking, but some limited progress has been made in understanding the memory functions of the hippocampus with this degree of detail. There is increasing evidence that the hippocampus has a special role in the learning of sequences and the linkage of specific memories to context. In the first part of this paper, we review a model (the SOCRATIC model) that describes how the dentate and CA3 hippocampal regions could store and recall memory sequences in context. A major line of evidence for sequence recall is the "phase precession" of hippocampal place cells. In the second part of the paper, we review the evidence for theta-gamma phase coding. According to a framework that incorporates this form of coding, the phase precession is interpreted as cued recall of a discrete sequence of items from long-term memory. The third part of the paper deals with the issue of how the hippocampus could learn memory sequences. We show that if multiple items can be active within a theta cycle through the action of a short-term "buffer," NMDA-dependent plasticity can lead to the learning of sequences presented at realistic item separation intervals. The evidence for such a buffer function is reviewed. An important underlying issue is whether the hippocampal circuitry is configured differently for learning and recall. We argue that there are indeed separate states for learning and recall, but that both involve theta oscillations, albeit in possibly different forms. This raises the question of how neuromodulatory input might switch the hippocampus between learning and recall states and more generally how different neuromodulatory inputs reconfigure the hippocampus for different functions. In the fifth part of this paper we review our studies of dopamine and dopamine/NMDA interactions in the control of synaptic function. Our results show that dopamine dramatically reduces the direct cortical input to CA1 (the perforant path input), while having little effect on the input from CA3. In order to interpret the functional consequences of this pathway-specific modulation, it is necessary to understand the function of CA1 and the role of dopaminergic input from the ventral tegmental area (VTA). In the sixth part of this paper we consider several possibilities and address the issue of how dopamine hyperfunction or NMDA hypofunction, abnormalities that may underlie schizophrenia, might lead to the symptoms of the disease. Relevant to this issue is the demonstrated role of the hippocampus in novelty detection, a function that is likely to depend on sequence recall by the hippocampus. Novelty signals are generated when reality does not match ...

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confidence: 99%

Storage, recall, and novelty detection of sequences by the hippocampus: Elaborating on the SOCRATIC model to account for normal and aberrant effects of dopamine

2001

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“…As seen in literature review, CBS does not concurrently occur with cognitive deficits [15]. As evidence by the presence cognitive impairment and hallucinations among experimentally blindfolded individuals, it is extremely difficult to include cognitive impairment as an eliminating factor when considering CBS as a differential diagnosis in patients presenting with visual hallucinations because visual impairments can negatively impact cognition [14].…”

Section: Discussionmentioning

confidence: 99%

“…As evidence by the presence cognitive impairment and hallucinations among experimentally blindfolded individuals, it is extremely difficult to include cognitive impairment as an eliminating factor when considering CBS as a differential diagnosis in patients presenting with visual hallucinations because visual impairments can negatively impact cognition [14]. Teunisse et al [15] came up with diagnostic criteria for CBS based on a study conducted on 505 visually handicapped individuals. The following was resulted as criteria for diagnosing CBS: one complex visual hallucination within a 4 week period, a period between the first and the last hallucinations exceeding 4 weeks, full or partial retention of insight to the unreal nature of the hallucinations, absence of delusions and absence of hallucinations in other sensory modalities [15,16].…”

Section: Discussionmentioning

confidence: 99%

“…Teunisse et al [15] came up with diagnostic criteria for CBS based on a study conducted on 505 visually handicapped individuals. The following was resulted as criteria for diagnosing CBS: one complex visual hallucination within a 4 week period, a period between the first and the last hallucinations exceeding 4 weeks, full or partial retention of insight to the unreal nature of the hallucinations, absence of delusions and absence of hallucinations in other sensory modalities [15,16]. Based on the aforementioned, our patient met the criteria with a clear presentation of symptoms.…”

Section: Discussionmentioning

confidence: 99%

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Charles Bonnet Syndrome in an Elderly Patient Following Cataract Surgery

Akinyemi¹,

Dabul²,

Cabrera³

et al. 2017

J Psychiatry

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“…4 In fact, eye closure has been documented to both extinguish the hallucinations and on other occasions bring on the visual hallucinations. 5 Symptoms of CBS often occur in the context of sudden and unexpected reduction in visual function, 6 and may occur after a latent period of days to weeks after visual impairment.…”

Section: Commentmentioning

confidence: 99%