Charcot–Wilbrand syndrome
Charcot–Wilbrand syndrome | |
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Specialty | Neurology |
Charcot–Wilbrand syndrome (CWS) is dream loss following focal brain damage specifically characterised by visual agnosia and loss of ability to mentally recall or "revisualize" images.[1] The name of this condition dates back to the case study work of Jean-Martin Charcot and Hermann Wilbrand, and was first described by Otto Potzl as "mind blindness with disturbance of optic imagination".[2][3] MacDonald Critchley, former president of the World Federation of Neurology, more recently summarized CWS as "a patient loses the power to conjure up visual images or memories, and furthermore, ceases to dream during his sleeping hours".[4] This condition is quite rare and affects only a handful of brain damage patients. Further study could help illuminate the neurological pathway for dream formation.
Symptoms and signs
Traditional classification
Combing early studies, the traditional symptoms of CWS centered on visual irreminiscence, prosopagnosia, and topographic agnosia. However, due to significant differences in the observations of Charcot and Wilbrand's case work, this syndrome bridged the entire loss of dreaming, whether it be due to the isolated inability of the brain to produce images while asleep as Charcot had dictated, or the complete loss of dreaming all together as with Wilbrand. This has led to the terming of Charcot and Wilbrand variants, which corresponded to either the loss of dream imagery and visual irreminiscence or the complete ceasing of dream experience often coupled with agnosia.[2]
Modern classification
There is new focus on the type of injury and analysis of
Physiological causes
In patients with loss of visual imagery during sleep, instances of acute-onset brain damage such as
Similarly, in patients with complete loss or suppression of dreaming there is typically an association with focal, acute-onset cerebral lesions like hemorrhage, thrombosis, or trauma.[2] Early attempts to locate the lesion site responsible for the cessation of dreaming on a universal scale have led to the parietal lobe[7] with no bias to either side, and single lesions of either hemisphere commonplace. Recent case studies of dream loss have found evidence suggesting that damage to the parietal is not necessary for CWS.[6] Additionally, in some of the cases of parietal lobe lesions, the lesion continued into the occipitotemporal regions, further blurring the localization of global dream loss. In almost all cases, dreaming returned within 12 months, implying a possibility that the site of interest was only connected to the damaged regions, most likely through neural pathways, further complicating localization.[7]
Relation to REM sleep
REM sleep or
Detection methods
While scientific dream analysis has been avoided in the past given the difficulty in quantifying and qualifying the experience of patients, emerging technology has made it easier to chart brain activity and target physiological areas responsible for dream function.[10]
Polysomnography
A
fMRI
Dream journals
Dream journals are an effective tool for patients to quantify their dreaming experience.[10] By recording the frequency of dreams and the level of detail, dream journals can be combined with other physiological data to arrive at the best picture of dream synthesis. Additionally dream journal data can help to organize the bizarre features within the dream experience such as discontinuities (incomprehensible shifts of time or location), incongruities (mismatching plot elements), and uncertainties (confusion over discrete concepts) which are useful to the dreamer.[13]
Medical significance
Until recently CWS was considered extremely rare and it is now recognized slightly more often as an acute phase of focal brain damage.[2] While CWS patients do not experience any serious effects, dreaming is believed to provide some relatively important functions to the health of the human mind. It is hypothesized that a reverse learning mechanism occurs while dreaming that facilitate the unlearning of unfavorable pathways to the organism. Complete failure of such a system has been postulated to lead to a state of almost perpetual obsession coupled with hallucinatory associations.[14] In addition it has been postulated that dreams account for emotional preservation, with the emotions one feels during nightmares and joyful dreams solidifying and checking the successful ability to express them.[10] Lastly Freudian dream content analysis, although lacking in credibility in the modern scientific community, once held that dreams hold the key to understanding and emancipating the subconscious.[15]
Potential for research
Refining the dream pathway
Since CWS patients have limited to nonexistent symptoms other than dream loss, studying these cases can give great insight into the physiological basis of dreams.[16] The regions of damage and condition affecting them can be compared to the severity of the dream-loss to help create a map of importance when it comes to synthesizing and remembering dream images.[citation needed]
Post-traumatic stress disorder
The diagnosis criteria for
Depression
Major depression which is believed to be modified by
History
Jean-Martin Charcot
In 1883
Hermann Wilbrand
In 1887 Hermann Wilbrand was studying an elderly female subject with bilateral posterior cerebral artery thrombosis.[18] This subject displayed a complete inability to dream coupled with an inability to recognize familiar places, a condition known more recently as topographic agnosia.[6] Additionally a condition known as prosopagnosia, or the inability to recognize familiar faces was also noted in the patient. Wilbrand's contribution revolves around the complete inability to produce dreams with the presence of agnosias as possible side conditions.[citation needed]
See also
References
- ^ Nielsen J.:Agnosia, Apraxia, Aphasia: Their Value in Cerebral Localization, 2nd ed. New York, Hoeber,1946.
- ^ a b c d e f Chokroverty Seds. Sleep Disorders Medicine: Basic Science, Technical Considerations, and Clinical Aspects. 3rd ed. Philadelphia: Saunders/Elsevier; 2009.
- ^ Pötzl O.: Die Aphasielehre vom Standpunkt der klinischen Psychiatrie, I: Die optisch-agnostischen Storungen (die verschiedenen Formen der Seelenblindheit) [The Aphasia Doctrine from the Standpoint of Clinical Psychiatry, I: Optic-Agnosic Disorders (the Different Forms of Mind-Blindness)], Leipzig, Deuticke, 1928.
- ^ Critchley M.:The Parietal Lobes, London, Edward Arnold,1953.
- ^ a b Murri L., Arena R., Siciliano G., et al.: Dream recall in patients with focal cerebral lesions. Arch Neurol 1984; 41:183.
- ^ a b c d e Bischof, M., & Bassetti, C. L. (2004). Total dream loss: A distinct neuropsychological dysfunction after bilateral PCA stroke. Annals of Neurology, 56(4)
- ^ a b Solms M.: The Neuropsychology of Dreams: A Clinico-anatomical Study, Hillsdale, NJ, Erlbaum, 1997.
- ^ a b c d Brown, R. E., Basheer, R., McKenna, J. T., Strecker, R. E., & McCarley, R. W. (2012). CONTROL OF SLEEP AND WAKEFULNESS. Physiological Reviews, 92(3), 1087–1187. doi: 10.1152/physrev.00032.2011
- ^ Vetrivelan, Ramalingam, Fuller, Patrick M., Tong, Qingchun, & Lu, Jun. (2009). Medullary Circuitry Regulating Rapid Eye Movement Sleep and Motor Atonia. The Journal of Neuroscience, 29(29), 9361–9369. doi: 10.1523/jneurosci.0737-09.2009
- ^ a b c d Hobson, J. Allan. (2003). Dreaming: An Introduction to the Science of Sleep (January 16, 2003 ed.): OXFORD.
- ^ Iber C, Ancoli-Israel S, Chesson A, and Quan SF for the American Academy of Sleep Medicine. The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications, 1st ed.: Westchester, Illinois: American Academy of Sleep Medicine, 2007.
- ISBN 978-0-87893-286-3
- ^ Hobson, J. A., Hoffman, S. A., Helfand, R., & Kostner, D. (1987). Dream bizarreness and the activation-synthesis hypothesis. Human Neurobiology, 6(3), 157–164.
- ^ Crick, F., & Mitchison, G. (1983). THE FUNCTION OF DREAM SLEEP. Nature, 304(5922), 111–114. doi: 10.1038/304111a0
- ^ Freud, S. (1900) The Interpretation of Dreams. New York: Avon, 1980.
- ^ Bentes, C., Costa, J., Peralta, R., Pires, J., Sousa, P., & Paiva, T. (2011). Dream recall frequency and content in patients with temporal lobe epilepsy. Epilepsia, 52(11), 2022–2027. doi: 10.1111/j.1528-1167.2011.03290.x
- ^ Charcot J-M.: Un cas de suppression brusque et isolée de la vision mentale des signes et des objets, (formes et couleurs) [On a case of sudden isolated suppression of the mental vision of signs and objects (forms and colours)]. Progrès Médical 1883; 11:568.
- ^ Wilbrand H.: Ein Fall von Seelenblindheit und Hemianopsie mit Sectionsbefund [A case of mind-blindness and hemianopia with autopsy results]. Dtsch Z Nervenheilkd 1892; 2:361.