Stereognosis

Stereognosis (also known as haptic perception or tactile gnosis) is the ability to perceive and recognize the form of an object in the absence of visual and auditory information, by using tactile information to provide cues from texture, size, spatial properties, and temperature, etc.[1] In humans, this sense, along with tactile spatial acuity, vibration perception, texture discrimination and proprioception, is mediated by the posterior column-medial lemniscus pathway of the central nervous system. Stereognosis tests determine whether or not the parietal lobe of the brain is intact.[2] Typically, these tests involved having the patient identify common objects (e.g. keys, comb, safety pins) placed in their hand without any visual cues.[3] Stereognosis is a higher cerebral associative cortical function.[4]:71

Astereognosis is the failure to identify or recognize objects by palpation in the absence of visual or auditory information, even though tactile, proprioceptive, and thermal sensations may be unaffected.[5] It may be caused by disease of the sensory cortex or posterior columns.[6] People suffering from Alzheimer's disease show a reduction in stereognosis.[7] Astereognosis can be caused by damage to the posterior association areas of the parietal, temporal, or occipital lobes, or the postcentral gyrus of either hemisphere.[5] For other types of dementia, stereognosis does not appear to decline.

References

  1. ↑ Yekutiel, M., Jariwala, M., & Stretch, P. (1994). Sensory deficit in the hands of children with cerebral palsy: a new look at assessment and prevalence. Dev Med Child Neurol, 36:61-24.
  2. ↑ Silvestri: Saunders Comprehensive Review for the NCLEX-RN Exam
  3. ↑ Unsworth, C.A. (2007). Cognitive and Perceptual Dysfunction. In S.B. O'Sullivan & T.J. Schmitz (Eds.), Physical Rehabilitation, 5th ed. (pp. 1180-1181). Philadelphia: F.A. Davis Company.
  4. ↑ Blumenfield, Hal (2002). Neuroanatomy Through Clinical Cases. Sunderland, MA: Sinauer. ISBN 0-87893-060-4.
  5. 1 2 Mauguiere, F., Desmedt, J.E., & Courjon, J. (1983). Astereognosis and dissociated loss of frontal or parietal components of somatosensory evoked potentials in hemispheric lesions. Brain, 106:271-311.
  6. ↑ Bickley, Lynn; Szilagui, Peter (2007). Bates' Guide to Physical Examination and History Taking (9th ed.). Lippincott Williams & Wilkins. ISBN 0-7817-6718-0.
  7. ↑ F. J. Huff, J. T. Becker, S. H. Belle, R. D. Nebes, A. L. Holland, and F. Boller (1987). "Cognitive deficits and clinical diagnosis of Alzheimer's disease". Neurology 37 (1119): 1119–24. doi:10.1212/wnl.37.7.1119. PMID 3601078.


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