Neuro clinics 31- The pupils -basic


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Neuro clinics 31- The pupils -basic

  1. 1. Neuro-Clinics 31 The pupils Dr Pratyush Chaudhuri Supported by Nirmal Clinics
  2. 3. Basics <ul><li>Pupils are controlled by constrictor fibres supplied by parasympathetic nerves. </li></ul><ul><li>Radial fibres controlled by sympathetic fibres </li></ul>
  3. 4. Basics <ul><li>Resting size depends on the amount of light falling on the eye and depends on the integrity of the parasymapthetic system. </li></ul><ul><li>Increased activity of the symapathetic system is reflected in the slight dilatation of the pupils. </li></ul>
  4. 5. <ul><li>Small pupils are asymptomatic because of ability to focus close. </li></ul><ul><li>Dilated pupils cause blurring of vision o close vision. </li></ul>
  5. 6. Parasympathetic pathway
  6. 8. Afferent pathway lesion <ul><li>Marcus Gunn Pupil </li></ul><ul><li>When the eye is stimulated with bright light – there will be sustained constriction of pupil </li></ul><ul><li>If the abnormal eye is stimulated there will be an ill-sustained constriction followed by dilatation. (Pupillary escape phenomenon) </li></ul><ul><li>Due to decrease in the number of fibers sub serving the light reflex. </li></ul>
  7. 9. <ul><li>Wernike’s pupillary reaction </li></ul><ul><li>A lesion of one side optic tract affects the direct reflex </li></ul><ul><li>but if properly shown properly to the unaffected half of the same eye – reflex may be elicited. </li></ul>
  8. 11. <ul><li>Lesions compressing or infiltrating the tectum of the midbrain (area of the sup collicular bodies) will interfere with the decussating fibers o the peri-aqueductal area </li></ul><ul><li>Results in fixed semi-dialted pupils with loss of upward gaze. </li></ul><ul><li>Parinaud syndrome </li></ul>
  9. 12. Argyll Robertson pupil <ul><li>Small irregular , fixed to light but reactive to accomodation </li></ul><ul><li>Due to lesion in the Edinger Westphal Nu </li></ul><ul><li>Causes – neurosyphilis, pinealomas, diabetes, wernicke’s encephalopathy, brainstem encephalitis and multiple sclerosis. </li></ul><ul><li>Cannot be dilated with atropine </li></ul>
  10. 13. Reverse Argyll Robertson pupil <ul><li>Rare </li></ul><ul><li>Asociated with epidemic encephalitis lathergica </li></ul><ul><li>Pupils react to light but not to accomodation. </li></ul>
  11. 16. Adie pupil or tonic pupil <ul><li>Possible viral cause </li></ul><ul><li>Associated with loss of sweating and knee jerks </li></ul><ul><li>Widely dilated circular pupil that may react very slowly to very bright light but more definite to accomodation. </li></ul>
  12. 18. Sympathetic pathways <ul><li>Starts in the hypothalamus </li></ul><ul><li>Considerable degree of cortical ipsilateral control </li></ul><ul><li>Three neurons </li></ul><ul><li>Hypothal to lateral grey in sp cord C8 -T1 – celio-spinal centre of Budge </li></ul><ul><li>From spinal cord to superior cervical ganglion via white rami of nerve root C8 – T1 </li></ul><ul><li>From superior cervical ganglion to the blood vessels and pupil </li></ul>
  13. 21. activity <ul><li>Innervate sup and inferior tarsus muscles of Muller and orbitalis (causes “upside down’’ ptosis) </li></ul><ul><li>Nasociliary vasomotor fibers --- ciliary ganglion---- blood vessels of the eye. </li></ul><ul><li>Pupillo-dilatation </li></ul>
  14. 22. Abnormalities of sympathetic pathway <ul><li>Horners syndrome </li></ul><ul><li>Miosis </li></ul><ul><li>Ptosis </li></ul><ul><li>Congested conjunctiva </li></ul><ul><li>Hyper or hypo hedrosis </li></ul><ul><li>Heterochromia in congenital horners </li></ul><ul><li>Apparent enopthalmos </li></ul>
  15. 23. Hemisphere level <ul><li>After thalamic bleed, hemispherectomy & massive infarction </li></ul><ul><li>Ipsilateral </li></ul>
  16. 24. Brain stem level <ul><li>Associated with spinothalamic tract so there will be pain and temperature loss on the opposite side. </li></ul><ul><li>Vascular lesions, MS, pontine gliomas and brain stem encephalitis </li></ul><ul><li>Associated with anhydrosis </li></ul>
  17. 25. Cervical cord level <ul><li>Associated with central cord lesions (loss of pain sensation in the arm, loss of arm reflexes and sometimes bilateral Horners) </li></ul><ul><li>Anhydrosis </li></ul><ul><li>Causes: syringomyelia, glioma, ependymoma and cervical trauma. </li></ul>
  18. 26. Root lesion at T1 <ul><li>Pancoast syndrome ( wasting of small muscles of the hand, severe nocturnal pain in shoulder and axilla & horners syndrome) due to metastasis to apical pleura. </li></ul><ul><li>Cervical rib </li></ul><ul><li>Avulsion of lower brachial pexus (klumpke’s paralysis) </li></ul><ul><li>Aneurysm of aortic arch. </li></ul>
  19. 28. Sympathetic chain <ul><li>No anhydrosis </li></ul><ul><li>Due to causes in the neck </li></ul><ul><li>Occlusion of carotid art, dissection of carotid art, migraine, malignancies, irradiation of neck </li></ul>
  20. 30. Pupillary abnormalities in the unconscious <ul><li>Normal </li></ul><ul><li>Unequal </li></ul><ul><li>Bilateral dilated </li></ul><ul><li>Bilateral pinpoint </li></ul>
  21. 31. Reaction Small (miotic) pupil Large (mydriatic) pupils Non-reactive to light A-R pupils Pontine hemorrhage Opiates Pilocarpine drops <ul><li>HA pupils </li></ul><ul><li>Post traumatic irridoplegia </li></ul><ul><li>Atropine </li></ul><ul><li>Overdosage of glutethemide, amphetamine, cocain or derivatives </li></ul><ul><li>Poisoning: belladona, dhatura </li></ul><ul><li>Brain death </li></ul>Reactive to light Old age Holmes Adie pupil Horners syndrome Anisocoria Iritis Anxiety Childhood Physiological anisocoria
  22. 32. That’s all folks