Disorders of perception


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Disorders of perception

  1. 1.  Individuals capable of receiving information on sensation. Data is then organized to make it meaningful and comprehensible. The organized entities are called percepts. This processing of the data to represent reality is called PERCEPTION.
  2. 2.  Sensory Distortion- Constant real perceptual object which is perceived in a distorted way Sensory Deception- new perception that may occur that may or may not be in response to external stimuli Disorders in the experience of time
  3. 3.  Changes in Intensity - Increased intensity of sensation- hyperesthesia seen in increasing sensations or lowering of physiological threshold. Seen in anxiety depressive disorder, Hangover from alcohol Migraine hypochondria cal personalities
  4. 4.  Increased sensitivity to noise – Hyperacusis Decreased sensitivity to noise – Hypoacusis Delirious Depression Attention deficit disorder
  5. 5.  Visual perception – affected by this are brought about by toxic drugs Xanthopsia- Coloring of Yellow Chloropsia - Coloring of green Erythropsia- Coloring of red Derealization- Everything looks unreal and strange Mania- looks perfect and beautiful
  6. 6. Change in percieved shape of an object Retinal disease Disorders of accommodation Temporal and Parietal Lobe Lesions Poisoning with Atropine and Hyoscine SCHIZOPHRENIA
  7. 7.  Micropsia – a visual disorder in which the patient sees objectso Smaller than they really areo Farther away than they really are Macropsia – opposite to micropsia
  8. 8.  Experience of retreat of subjects into the distance without any change in space - porropsia Edema of the retina Partial Paralysis of accomdation Diseases affecting the nerves controlling accommodation
  9. 9.  MACROPSIA : Scarring of retina with retractionand complete paralysis of accommodation. DYSMEGALOPSIA: Objects are perceived larger in one side and smaller in the other. Atropine, Hyoscine poisoning Chronic arachnoiditis METAMORPHOSIA: Irregular in shape.
  10. 10.  Psychopathological point of view Physical- Determined by physical events Personal- Personal judgement of passage of timeMania- Time passes quicklyDepression- Time passes slowlyAcute Schizophrenia- personal time goes in fits and startsAcute organic states (temporal disorientation) disorders of time is seen in milder form there may be over estimation of time.
  11. 11.  Illusions- Misinterpretation of a single stimuli arising from a single stimuli Stimuli from a perceived object are combined with a mental image to produce a false perception. Derived from set and lack of perceptual clarity Delirium Severe depression with delusions of guilt
  12. 12.  Complete Illusion – These depends on misreading words in newspapers or missing misprints because we read the word as if it were capable Affect Illusion- These arise in the context of particular mood state Paradolia – vivid illusions occur without the patient making any effort ; are the result of excessive fantasy thinking and a vivid visual imagery.
  13. 13.  False perception which is not a sensory distortion or misinterpretation but which occurs at the same time as real perception. Essential criteria for an operational definition1. Percept like experience in the absence of an external stimuli2. Percept like stimuli which has full force and impact of real perception3. Percept like experience which is unwilled, occurs spontaneously and cannot be readily controlled by percipient.
  14. 14.  Intense emotions Suggestion Disorders of sense organs Sensory deprivation Disorders of CNS Psychiatric disorders
  15. 15.  depressed patients with delusions of guilt; hallucination tends to be disjointed or short phases Occurrence of continuous persistent hallucinatory voices in severe depression should arouse the suspicion of schizophrenia or some intercurrent physical disease.
  16. 16.  Normal subjects can be made to hallucinate Hypnotic hallucinations do not produce objective effects similar to those produced by ordinary perceptions such as complimentary after images and so on
  17. 17.  Hallucinatory voices may be heard in ear disease Visual hallucination is seen in eye diseases but usually there is disorder of the CNS as well. Peripheral lesions of sense organs may play a part in hallucinations in organic states
  18. 18.  If all incoming stimuli are related to minimum in a normal subject they will begin to hallucinate after few hours Usually these are changing visual hallucinations and repetitive phrases BLACK PATCH DISEASE delirium following cataract extraction in the aged result of sensory deprivation and mild senile brain changes
  19. 19.  Lesions of diencephalons and cortex can produce hallucination that are not only visual but can be auditory.
  20. 20.  Hearing Vision Smell Taste Touch Pain and deep sensation Vestibular sensations The sense of presence
  21. 21.  Hearing (auditors) may be elementary or unformed. Elementary – noises, bells or undifferentiated whispers ; in organic states Partly organized- music Completely organized- hallucinatory voices- schizophrenia- persecutory in nature Severe depression also ‘voices’ can be heard but less well formed than schizophrenia
  22. 22. Imperative hallucination Voices sometimes act upon individuals and give instructions. may or may not act upon themAuditory hallucinations Adverse Neutral Helpful Incomprehensible nonsense Neologism
  23. 23.  Thought echo - hearing one’s own thoughts being spoken loud, voice may come from inside or outside the head.i. GEDANKENAUTWERDEN- thoughts are spoken at the same time or before they are occurring.ii. ECHO DE LA PENSES- thoughts are spoken just after they occurred. Running commentary hallucinations are usually abusive.
  24. 24.  Elementary- flashes of light Partly organized- patterns Completely organized- visions of people animals or objects.Scenic hallucinations- whole scenes are hallucinated like a cinema filmMore commonly seen in deliriumseen in psychiatric disorders associated with epilepsy.
  25. 25.  Patients with visual and auditory hallucinations co occur as a whole Temporal lobe epilepsy Late onset of schizophrenia (protracted)
  26. 26.  Visual Hallucinations are more common in organic states with clouding of consciousness than in the functional psychoses Small animals are often hallucinated in delirium Extremely rare in schizophrenia Occasionally without any psychopathology CHARLES BONNET SYNDROME Produced by drugs of abuse typically consist of diffuse distortions of existing visual world.
  27. 27. Seen in Schizophrenia Organic states like temporal lobe epilepsy Depression (uncommon)PADRE PIO PHENOMENON- religious people can smell around certain saints
  28. 28. Seen in Schizophrenia Organic statesDepressed patient often describes loss of taste.
  29. 29.  Formication- a feeling that animals are crawling over the body; not uncommon in organic states Cocaine bug – formication occurring with delusion of persecution in cocaine psychosis Sexual Hallucinations- seen in acute and chronic schizophrenia
  30. 30.  Classified into 3 types1. Superficial2. Kinesthetic3. Visceral
  31. 31.  Thermic – a cold wind blowing across the face Haptic- feeling a hand brushing against the skin Hygic- feeling fluid such as water running from the head into the stomach Paraesthetic- pins and needles. Mostly organic.
  32. 32.  affects muscles and joints Patient feels their limbs are being twisted pulled or moved Seen in schizophrenics Organic states such as alcohol intoxication and benzodiazepine withdrawal
  33. 33.  Visceral hallucinations (SIMS 2003). Twisting and tearing pains Very bizarre complaints- organs being ripped out and flesh ripped from his body Seen in chronic schizophrenia
  34. 34.  Organic states Schizophrenia Hysteria Normal people – feverently religious
  35. 35.  Type of mental image that although clear and vivid lack the substantiality of perceptions Full consciousness Located in subjective space Definite outlines, compete sound Constancy retained Relevant to emotions, needs and actions Depends on the observer for existenceHystericalAttention seeking personalities
  36. 36.  Functional hallucinations : a auditory stimulus causes the hallucination, but it is experienced as well as the hallucination. Chronic schizophrenia Reflex Hallucination : a stimulus in one sensory field produces a hallucination in one another. Morbid variety of synaesthesia.
  37. 37.  Extracampine hallucination : Hallucinations that is outside the limits of the sensory field.o Seen in healthy people as hypnagogic hallucinationo Schizophreniao Organic conditions- epilepsy
  38. 38.  Autoscopy (phantom mirror image) -The patient sees himself and knows that it is he. Not just visual hallucination , because even kinesthetic and somatic sensations are present Normal subjects- emotionally disturbed, tired and exhausted depressed Hysteria Schizophrenia
  39. 39.  Acute and sub acute delirious states Epilepsy Focal lesions in parieto occipital region Toxic infective states whose effect is greatest in basal regions of the brain Drug addiction Chronic alcoholismNEGATIVE AUTOSCOPYINTERNAL AUTOSCOPY
  40. 40.  Occur when the subject is falling asleep during drowsiness Are discontinuous Appears to force themselves on the subject Do not form part of an experience in which the subject participates unlike DREAM Commonest is auditory. His name being called May be geometrical designs , abstract shapes , faces , figures or scenes from nature EEG shows alpha rhythm
  41. 41.  Occurs when the subject is waking up Hallucinations persisting from sleep when the eyes are open More in narcolepsy.
  42. 42.  Occurs in any sensory modality and may occur in various neurological or psychiatric disorders  Depends oni. General condition of the brainii. Recent experiencesiii. Psychodynamic factorsiv. Effect of local lesion
  43. 43.  Stimulation of visual projection areas in the walls of the calacrine fissure causes perception of flashes of light as does stimulation or irritation of optic radiation. Lesions of optic tract and lateral geniculate bodies. Spontaneous V H – sensory defect Complex scene hallucination – stimulation of posterior part of temporal lobe.
  44. 44. Almost exclusively the result of lesion which produces sensory defectPHANTOM LIMB Most common organic somatic hallucination 95% of amputation after 6 yrs of age Pt feels he sees the limb from which in fact he is not receiving any sensations either because limb has been amputated or sensory pathway destroyed.
  45. 45.  Most phantom limbs are produced by peripheral and central disorders. Occasionally it develops from lesion of peripheral nerve or the medulla or spinal cord. Thalamoparietal lesions have phantom third arm or leg. Correspond to the previous image of the limb.
  46. 46.  Whistling , buzzing, drumming and even bells heard by patients with middle ear disease or internal disease Caused by epileptic foci and space occupying lesions in the temporal lobes
  47. 47.  Occurs most often in temporal lobe epilepsy ass with salivation and chewing and sniffing Stimulating the depths of the sylvian fissure around the transverse temporal gyri.OLFACTORY HALLUCINATIONS temporal lobe epilepsy.
  48. 48.  These are multisensory hallucinations but they do not include somatic sensations, which is to be expected because the somatic sensory area is separated from the temporal lobe by sylvian fissure.
  49. 49. 1) Confusional hallucinosis: i. consciousness is clouded ii. Visual hallucinosis are prominent iii. Auditory hall are mainly music , noises or odd words but connected sentences are already heard.2) Self reference hallucinosis: i. Pt hears people talking about him ii. Rough idea about what the voices are saying but unable to reproduce them
  50. 50. 3) Verbal Hallucinosis Pt hears clear voices which talk about him and he can reproduce their content accurately4) Fantastic hallucinosis i. Hallucinosis of all kinds seem to occur ii. Pt describes fantastic experiences based on auditory and visual hallucination iii. Sometimes the patient describes dream experiences as if they were real iv. These pts usually have mass hallucinations
  51. 51.  Hyperschemazia –  ORGANIC CAUSES percieved o Brown Sequard magnifications of body Syndrome parts o PVD, MS, thrombosis When part of the body of PICA feels larger than the  NON ORGANIC normal CAUSES o Hypochondriasis o Conversion disorder o Depersonalization
  52. 52.  Aschemazia- perception of body parts as absent Hyposchemazia – Body parts as diminished Paraschemazia – distorted of body image as a feeling that body parts are distorted or twisted from rest of the body. Hemisomatognosia- Unilateral lack of body image in which the person behaves as if one side of body is missing
  53. 53.  Anosgnosia- ‘denial of illness’ –Rt hemisphere strokes denied their knowledge early after stroke and refused to admit to any weakness in their left arm Somatoparaphrenia- delusional beliefs about the body, distorted, inanimate , severed, or in any other ways abnormal.
  54. 54. THE ENDFish PsychopharmacologyAndrew Sims- Symptoms in themindComprehensive text book ofPsychiatry- Kaplan andSaddock