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Structures affected in PCA syndromes

Symptoms and signs of stroke depends on the areas of brain affected and the stuctures involved .The various structures involved in central and peripheral territory stroke is given below
Peripheral territory infarction
  • Homonymous hemianopia (often upper quadrantic): Calcarine cortex or optic radiation nearby.
  • Bilateral homonymous hemianopia, cortical blindness, awareness or denial of blindness; tactile naming, achromatopia (color blindness), failure to see to-and-fro movements, inability to perceive objects not centrally located, apraxia of ocular movements, inability to count or enumerate objects, tendency to run into things that the patient sees and tries to avoid-Bilateral occipital lobe with possibly the parietal lobe involved. 
  • Verbal dyslexia without agraphia, color anomia: Dominant calcarine lesion and posterior part of corpus callosum.
  • Memory defect: Hippocampal lesion bilaterally or on the dominant side only.
  • Topographic disorientation and prosopagnosia: Usually with lesions of nondominant, calcarine, and lingual gyrus.
  • Simultanagnosia, hemivisual neglect: Dominant visual cortex, contralateral hemisphere. 
  • Unformed visual hallucinations, peduncular hallucinosis, metamorphopsia, teleopsia, illusory visual pread, palinopsia, distortion of outlines, central photophobia: Calcarine cortex.
  • Complex hallucinations: Usually nondominant hemisphere.
Central territory infarction
  • Thalamic syndrome: sensory loss (all modalities), spontaneous pain and dysesthesias, choreoathetosis, intention tremor, spasms of hand, mild hemiparesis: Posteroventral nucleus of thalamus; involvement of the adjacent subthalamic body or its afferent tracts. 
  • Thalamoperforate syndrome: crossed cerebellar ataxia with ipsilateral third nerve palsy (Claude’s syndrome): Dentatothalamic tract and issuing third nerve
  • Weber’s syndrome: third nerve palsy and contralateral hemiplegia: Third nerve and cerebral peduncle.
  • Contralateral hemiplegia:  Cerebral peduncle
  • Paralysis or paresis of vertical eye movement, skew deviation, sluggish pupillary responses to light, slight miosis and ptosis (retraction nystagmus and “tucking” of the eyelids may be associated):Supranuclear fibers to third nerve,interstitial nucleus of Cajal, nucleus of Darkschewitsch, and posterior commissure.
  • Contralateral rhythmic, ataxic action tremor; rhythmic postural or “holding” tremor (rubral tremor): Dentatothalamic tract.