Asomatognosia

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Asomatognosia
Specialty Neurology

Asomatognosia (also Somatoagnosia) is a neurological disorder characterized as loss of recognition or awareness of part of the body. [1] [2] The failure to acknowledge, for example, a limb, may be expressed verbally or as a pattern of neglect. The limb may also be attributed to another person, a delusion known as somatoparaphrenia. However, they can be shown their limb and this error is temporarily corrected. [3] [4] Some authors have focused on the prevalence of hemispatial neglect in such patients. [5]

Contents

Asomatognosia is the inability to feel, recognize, or be conscious of one's own specific body parts or bodily conditions (Whishaw, 2015). Generally, asomatognosia often arises from damage to the right parietal lobe (Whishaw, 2015). Evidence indicates that damage to the right hemisphere often results from a stroke or pre-existing hemispatial neglect, or inattention to the left visual field (Antoniello, 2016) (Keenan, 2004). Individuals who suffer from somatoparaphrenia, a specific form of asomatognosia, ignore or deny ownership of a body part contralateral to the brain lesion (Feinberg, 1990). Although this condition can affect one or both sides of the body, most patients exhibit the inability to recognize limbs/body parts (i.e., arm, leg, head, breast) on the left side of their body as their own (Keenan, 2004). While individuals with asomatognosia typically suffer large lesions across several temporoparietal sectors, those with somatoparaphrenia also suffer lesions in the right medial and orbitofrontal regions of the brain (Feinberg 2010).

History

In 20th century literature, asomatognosia was often distinguished from the closely related somatoparaphrenia. According to Gerstmann's (1942) definition, asomatognosia was described as the "imperception of the affected limbs or body half, in various degrees from simple forgetting to obstinate denial of their existence." Critchley (1953) [6] numbered various deficits of body image, including somatoparaphrenia and the rare loss of awareness of one body half corresponding to asomatognosia or hemidepersonalization. He stated that these (as well as other bodily) phenomena are not "sharply demarcated" and that it is not uncommon for one condition to merge into another. In Hécaen (1972) hemiasomatognosia and disownership were also distinguished but closely linked. Feinberg and colleagues (1990, 2010) forwarded a different definition, according to which verbal asomatognosia was defined as the denial of ownership, while somatoparaphrenia as a subtype of asomatognosia where patients also display delusional misidentification and complex confabulation. [7]

The term asomatognosia was coined from the Greek: a (without), soma (stem somat– body or bodily), and gnosis (knowledge), thus defined as the "lack of awareness [of ownership] of one's body parts". [8] The word Somatoagnosia (constructed from the same roots) is sometimes also used instead. [9] [10] [11]

Patient cases

In most commonly observed instances, individuals with this condition fail to recognize and sense their left arm after suffering lesions to the right hemisphere (Keenan, 2004). In one specific instance, a patient suffering from asomatognosia tried to throw her own left arm into a garbage can because she believed it was her husband's arm repeatedly falling on her and disrupting her sleep (Keenan, 2004). Even when patients are told that the body part belongs to them, many will deny the reality and remain firm in their belief that it is not a part of them. There is a case in which a patient with severe asomatognosia had the ability to use his right hand to trace his paralyzed left arm to his own left shoulder, but still failed to acknowledge that the left arm belonged to him (Keenan, 2004). Overall, there is an interesting phenomenon in which individuals will claim that the body part belongs to someone of the opposite gender within their family. For example, women with asomatognosia tend to claim that their left arm belongs to a man (i.e., their husband) while men claim their arm belongs to a woman, such as his daughter or wife. There also exist patients that treat the arm as a child or small animal. (Keenan, 2004)

In addition to instances of asomatognosia in which patients deny ownership of a specific part, this condition is also associated with the following: anosognosia (unawareness or denial of illness), anosodiaphoria (indifference to illness), autopagnosia (inability to localize and name body parts), and asymbolia for pain (absence of typical reactions to pain). Out of these varieties of asomatognosia, autopagnosia is the only one in which an individual struggles to recognize the right side of their body due to lesions in the left parietal cortex (Whishaw, 2015).

See also

Related Research Articles

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The parietal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus.

Anosognosia is a condition in which a person with a disability is cognitively unaware of having it due to an underlying physical condition. Anosognosia results from physiological damage to brain structures, typically to the parietal lobe or a diffuse lesion on the fronto-temporal-parietal area in the right hemisphere, and is thus a neuropsychiatric disorder. A deficit of self-awareness, the term was first coined by the neurologist Joseph Babinski in 1914, in order to describe the unawareness of hemiplegia.

<span class="mw-page-title-main">Hemispatial neglect</span> Asymmetrically-impaired spatial awareness due to a brain hemisphere being damaged

Hemispatial neglect is a neuropsychological condition in which, after damage to one hemisphere of the brain, a deficit in attention and awareness towards the side of space opposite brain damage is observed. It is defined by the inability of a person to process and perceive stimuli towards the contralesional side of the body or environment. Hemispatial neglect is very commonly contralateral to the damaged hemisphere, but instances of ipsilesional neglect have been reported.

<span class="mw-page-title-main">Angular gyrus</span> Gyrus of the parietal lobe of the brain

The angular gyrus is a region of the brain lying mainly in the posteroinferior region of the parietal lobe, occupying the posterior part of the inferior parietal lobule. It represents the Brodmann area 39.

<span class="mw-page-title-main">Visual extinction</span>

Visual extinction is a neurological disorder which occurs following damage to the parietal lobe of the brain. It is similar to, but distinct from, hemispatial neglect. Visual extinction has the characteristic symptom of difficulty to perceive contralesional stimuli when presented simultaneously with an ipsilesional stimulus, but the ability to correctly identify them when not presented simultaneously. Under simultaneous presentation, the contralesional stimulus is apparently ignored by the patient, or extinguished. This deficiency may lead to difficulty on behalf of the patient with processing the stimuli's 3D position.

<span class="mw-page-title-main">Homonymous hemianopsia</span> Visual field loss on the left or right side of the vertical midline

Hemianopsia, or hemianopia, is a visual field loss on the left or right side of the vertical midline. It can affect one eye but usually affects both eyes.

Focal neurologic signs also known as focal neurological deficits or focal CNS signs are impairments of nerve, spinal cord, or brain function that affects a specific region of the body, e.g. weakness in the left arm, the right leg, paresis, or plegia.

Autotopagnosia from the Greek a and gnosis, meaning "without knowledge", topos meaning "place", and auto meaning "oneself", autotopagnosia virtually translates to the "lack of knowledge about one's own space," and is clinically described as such.

Somatoparaphrenia is a type of monothematic delusion where one denies ownership of a limb or an entire side of one's body. Even if provided with undeniable proof that the limb belongs to and is attached to their own body, the patient produces elaborate confabulations about whose limb it really is or how the limb ended up on their body. In some cases, delusions become so elaborate that a limb may be treated and cared for as if it were a separate being.

<span class="mw-page-title-main">Quadrantanopia</span> Loss of vision in a quarter of the visual field

Quadrantanopia,quadrantanopsia, refers to an anopia affecting a quarter of the visual field.

<span class="mw-page-title-main">Middle cerebral artery syndrome</span> Medical condition

Middle cerebral artery syndrome is a condition whereby the blood supply from the middle cerebral artery (MCA) is restricted, leading to a reduction of the function of the portions of the brain supplied by that vessel: the lateral aspects of frontal, temporal and parietal lobes, the corona radiata, globus pallidus, caudate and putamen. The MCA is the most common site for the occurrence of ischemic stroke.

Anosodiaphoria is the inability to recognize the full importance of a neurological disability brought on by a brain lesion. It might be specifically associated with defective functioning of the frontal lobe of the right hemisphere.

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The sense of agency (SoA), or sense of control, is the subjective awareness of initiating, executing, and controlling one's own volitional actions in the world. It is the pre-reflective awareness or implicit sense that it is I who is executing bodily movement(s) or thinking thoughts. In non-pathological experience, the SoA is tightly integrated with one's "sense of ownership" (SoO), which is the pre-reflective awareness or implicit sense that one is the owner of an action, movement or thought. If someone else were to move your arm you would certainly have sensed that it were your arm that moved and thus a sense of ownership (SoO) for that movement. However, you would not have felt that you were the author of the movement; you would not have a sense of agency (SoA).

The neuroanatomy of memory encompasses a wide variety of anatomical structures in the brain.

<span class="mw-page-title-main">Allochiria</span> Medical condition

Allochiria is a neurological disorder in which the patient responds to stimuli presented to one side of their body as if the stimuli had been presented at the opposite side. It is associated with spatial transpositions, usually symmetrical, of stimuli from one side of the body to the opposite one. Thus a touch to the left side of the body will be reported as a touch to the right side, which is also known as somatosensory allochiria. If the auditory or visual senses are affected, sounds will be reported as being heard on the opposite side to that on which they occur and objects presented visually will be reported as having been presented on the opposite side. Often patients may express allochiria in their drawing while copying an image. Allochiria often co-occurs with unilateral neglect and, like hemispatial neglect, the disorder arises commonly from damage to the right parietal lobe.

Amorphosynthesis, also called a hemi-sensory deficit, is a neuropsychological condition in which a patient experiences unilateral inattention to sensory input. This phenomenon is frequently associated with damage to the right cerebral hemisphere resulting in severe sensory deficits that are observed on the contralesional (left) side of the body. A right-sided deficit is less commonly observed and the effects are reported to be temporary and minor. Evidence suggests that the right cerebral hemisphere has a dominant role in attention and awareness to somatic sensations through ipsilateral and contralateral stimulation. In contrast, the left cerebral hemisphere is activated only by contralateral stimuli. Thus, the left and right cerebral hemispheres exhibit redundant processing to the right-side of the body and a lesion to the left cerebral hemisphere can be compensated by the ipsiversive processes of the right cerebral hemisphere. For this reason, right-sided amorphosynthesis is less often observed and is generally associated with bilateral lesions.

Constructional apraxia is a neurological disorder in which people are unable to perform tasks or movements even though they understand the task, are willing to complete it, and have the physical ability to perform the movements. It is characterized by an inability or difficulty to build, assemble, or draw objects. Constructional apraxia may be caused by lesions in the parietal lobe following stroke or it may serve as an indicator for Alzheimer's disease.

<span class="mw-page-title-main">Olaf Blanke</span> Swiss and German physician, neurologist and neuroscientist

Olaf Blanke is a Swiss and German physician, neurologist and neuroscientist. He holds the Bertarelli Foundation Chair in Cognitive Neuroprosthetics at the École Polytechnique Fédérale de Lausanne (EPFL). He directs the Laboratory of Cognitive Neuroscience at the Brain Mind Institute of EPFL and is professor of Neurology at Geneva University Hospitals. Blanke is known for his research on the neurological bases of self-consciousness and out-of-body experiences.

Dyschiria, also known as dyschiric syndrome, is a neurological disorder where one-half of an individual's body or space cannot be recognized or respond to sensations. The term dyschiria is rarely used in modern scientific research and literature. Dyschiria has been often referred to as unilateral neglect, visuo-spatial neglect, or hemispatial neglect from the 20th century onwards. Psychologists formerly characterized dyschiric patients to be unable to discriminate or report external stimuli. This left the patients incapable of orienting sensory responses in their extrapersonal and personal space. Patients with dyschiria are unable to distinguish one side of their body in general, or specific segments of the body. There are three stages to dyschiria: achiria, allochiria, and synchiria, in which manifestations of dyschiria evolve in varying degrees.

References

  1. ↑ Arzy, S.; Overney, L. S.; Landis, T.; Blanke, O. (2006). "Neural Mechanisms of Embodiment". Archives of Neurology. 63 (7): 1022–5. doi: 10.1001/archneur.63.7.1022 . PMID   16831974.
  2. ↑ Vallar, G. & Ronchi, R. (2009). Somatoparaphrenia: a body delusion. A review of the neuropsychological literature. Experimental Brain Research, 192:3, 533–551
  3. ↑ Feinberg, T., Venneri, A., Simone, A.M., et al. (2010). The neuroanatomy of asomatognosia and somatoparaphrenia. Journal of Neurology, Neurosurgery & Psychiatry, 81, 276–281
  4. ↑ Bottini, Gabriella; Bisiach, Edoardo; Sterzi, Roberto; Vallar, Giuseppe (2002): "Feeling touches in someone else's hand." NeuroReport 13 (2), 249–252.
  5. ↑ A.J. Larner (12 November 2010). A Dictionary of Neurological Signs. Springer Science & Business Media. p. 43. ISBN   978-1-4419-7095-4.
  6. ↑ Critchley, Macdonald (1953). The Parietal Lobes. E. Arnold.
  7. ↑ Ronchi, Roberta; Park, Hyeong-Dong; Blanke, Olaf (1 January 2018), Vallar, Giuseppe; Coslett, H. Branch (eds.), "Chapter 15 - Bodily self-consciousness and its disorders", Handbook of Clinical Neurology, The Parietal Lobe, 151, Elsevier: 313–330, doi:10.1016/B978-0-444-63622-5.00015-2, ISBN   978-0-444-63622-5, PMID   29519466 , retrieved 29 January 2024
  8. ↑ Montross, Christine (6 February 2014). Falling into the Fire: A Psychiatrist's Encounters with the Mind in Crisis. Oneworld Publications. ISBN   978-1-78074-367-7.
  9. ↑ Puente, Antonio E.; Tonkonogy, Joseph M. (23 January 2009). Localization of Clinical Syndromes in Neuropsychology and Neuroscience. Springer Publishing Company. ISBN   978-0-8261-1968-1.
  10. ↑ Gillen, Glen (25 October 2010). Stroke Rehabilitation - E-Book: A Function-Based Approach. Elsevier Health Sciences. ISBN   978-0-323-06775-1.
  11. ↑ O'Sullivan, Susan B.; Schmitz, Thomas J.; Fulk, George (25 January 2019). Physical Rehabilitation. F.A. Davis. ISBN   978-0-8036-9464-4.
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