Remission of hemineglect and anosognosia during vestibular stimulation

Cappa, Stefano F.; Sterzi, Roberto; Vallar, Giuseppe; Bisiach, Edoardo

doi:10.1016/0028-3932(87)90115-1

Cited by 377 publications

(152 citation statements)

References 9 publications

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“…For example, caloric vestibular stimulation in patients with somatoparaphrenia (denial of ownership of the left arm seen in right parietal stroke) produces a dramatic, albeit temporary, recovery from denial; the patient suddenly starts acknowledging his/her arm. 10,18 Can caloric vestibular stimulation also affect phantoms?…”

Section: Caloric Vestibular Stimulationmentioning

confidence: 99%

Plasticity and functional recovery in neurology

Ramachandran¹

2005

Clinical Medicine

109

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-Experiments on patients with phantom limbs suggest that neural connections in the adult human brain are much more malleable than previously assumed. Three weeks after amputation of an arm, sensations from the ipsilateral face are referred to the phantom; this effect is caused by the sensory input from the face skin 'invading' and activating deafferented hand zones in the cortex and thalamus. Many phantom arms are 'paralysed' in a painful position. If a mirror is propped vertically in the sagittal plane and the patient looks at the reflection of his/her normal hand, this reflection appears superimposed on the 'felt' position of the phantom. Remarkably, if the real arm is moved, the phantom is felt to move as well and this sometimes relieves the painful cramps in the phantom. Mirror visual feedback (MVF) has shown promising results with chronic regional pain syndrome and hemiparesis following stroke. These results suggest two reasons for a paradigm shift in neurorehabilitation. First, there appears to be tremendous latent plasticity even in the adult brain. Second, the brain should be thought of, not as a hierarchy of organised autonomous modules, each of which delivers its output to the next level, but as a set of complex interacting networks that are in a state of dynamic equilibrium with the brain's environment. Both principles can be potentially exploited in a clinical context to facilitate recovery of function.

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Section: Caloric Vestibular Stimulationmentioning

confidence: 99%

Plasticity and functional recovery in neurology

Ramachandran¹

2005

Clinical Medicine

109

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“…For example a functional and anatomical relationship between spatial neglect subsequent to right hemispheric brain damage-leading to deWcits in spatial and bodily processing-and vestibular disturbances has previously been discussed (for an overview see Karnath and Dietrich 2006). This link is supported by the fact that caloric vestibular stimulation and galvanic vestibular stimulation (GVS) may temporarily decrease symptoms of spatial neglect such as rightwards bias in visuo-spatial tasks (Cappa et al 1987;Rode et al 1992;Bottini et al 2005) as well as symptoms of disturbed bodily awareness (Vallar 1998;Fink et al 2003). Vestibular dysfunctions have also been reported in neurological patients with disturbed own body perceptions due to damage in the temporo-parietal cortex (Devinsky et al 1989;Blanke et al 2004).…”

Section: Introductionmentioning

confidence: 98%

Influence of galvanic vestibular stimulation on egocentric and object-based mental transformations

2007

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The vestibular system analyses angular and linear accelerations of the head that are important information for perceiving the location of one's own body in space. Vestibular stimulation and in particular galvanic vestibular stimulation (GVS) that allow a systematic modiWcation of vestibular signals has so far mainly been used to investigate vestibular inXuence on sensori-motor integration in eye movements and postural control. Comparatively, only a few behavioural and imaging studies have investigated how cognition of space and body may depend on vestibular processing. This study was designed to diVerentiate the inXuence of left versus right anodal GVS compared to sham stimulation on object-based versus egocentric mental transformations. While GVS was applied, subjects made leftright judgments about pictures of a plant or a human body presented at diVerent orientations in the roll plane. All subjects reported illusory sensations of body self-motion and/ or visual Weld motion during GVS. Response times in the mental transformation task were increased during right but not left anodal GVS for the more diYcult stimuli and the larger angles of rotation. Post-hoc analyses suggested that the interfering eVect of right anodal GVS was only present in subjects who reported having imagined turning themselves to solve the mental transformation task (egocentric transformation) as compared to those subjects having imagined turning the picture in space (object-based mental transformation). We suggest that this eVect relies on shared functional and cortical mechanisms in the posterior parietal cortex associated with both right anodal GVS and mental imagery.

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“…The fact that unrealistic optimism and anosognosia have been independently associated with the same brain region suggests that the similarity between them is more than superficial. This possibility generates a key empirical prediction, deriving from the surprising finding that caloric vestibular stimulation temporarily abolishes anosognosia for hemiplegia (Cappa et al, 1987;Rode et al, 1992;Ramachandran, 1995). Signals from the vestibular nuclei also project via the thalamus to (predominately contralateral) cortical and subcortical structures (Miller & Ngo, 2007).…”

Section: Introductionmentioning

confidence: 99%

“…Notably, fMRI investigations have found that the cortical network activated during vestibular stimulation includes the pars opercularis region in the IFG (Lobel et al, 1998;Fasold et al, 2002). Remarkably, a number of studies have found that patients who previously have denied their left-sided hemisyndrome will transiently acknowledge it after left-ear irrigation with cold water (Cappa et al, 1987;Rode et al, 1992;Ramachandran, 1995).…”

Section: Introductionmentioning

confidence: 99%

Vestibular stimulation attenuates unrealistic optimism

McKay

Tamagni

Palla

et al. 2013

Cortex

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INTRODUCTION: Unrealistic optimism refers to the pervasive tendency of healthy individuals to underestimate their likelihood of future misfortune, including illness. The phenomenon shares a qualitative resemblance with anosognosia, a neurological disorder characterized by a deficient appreciation of manifest current illness or impairment. Unrealistic optimism and anosognosia have been independently associated with a region of right inferior frontal gyrus, the pars opercularis. Moreover, anosognosia is temporarily abolished by vestibular stimulation, particularly by irrigation of the left (but not right) ear with cold water, a procedure known to activate the right inferior frontal region. We therefore hypothesized that left caloric stimulation would attenuate unrealistic optimism in healthy participants. METHODS: Thirty-one healthy right-handed adults underwent cold-water caloric vestibular stimulation of both ears in succession. During each stimulation episode, and at baseline, participants estimated their own relative risk of contracting a series of illnesses in the future. RESULTS: Compared to baseline, average risk estimates were significantly higher during left-ear stimulation, whereas they remained unchanged during right-ear stimulation. Unrealistic optimism was thus reduced selectively during cold caloric stimulation of the left ear. CONCLUSIONS: Our results point to a unitary mechanism underlying both anosognosia and unrealistic optimism, and suggest that unrealistic optimism is a form of subclinical anosognosia for prospective symptoms. Results: Compared to baseline, average risk estimates were significantly higher during left-ear stimulation, whereas they remained unchanged during right-ear stimulation.Unrealistic optimism was thus reduced selectively during cold caloric stimulation of the left ear. Conclusions:Our results point to a unitary mechanism underlying both anosognosia and unrealistic optimism, and suggest that unrealistic optimism is a form of subclinical anosognosia for prospective symptoms.

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Remission of hemineglect and anosognosia during vestibular stimulation

Cited by 377 publications

References 9 publications

Plasticity and functional recovery in neurology

Plasticity and functional recovery in neurology

Influence of galvanic vestibular stimulation on egocentric and object-based mental transformations

Vestibular stimulation attenuates unrealistic optimism

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