Assessing the Level of Consciousness
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Assessing the Level of Consciousness

Dr Gilberto Leung and Dr Gary Lau Subtitles in English for this video can be displayed by clicking on  (first button on the bottom right hand corner of the video). Our level of consciousness is governed by our cerebral cortex as well as the subcortical ascending reticular formation. Patients with normal consciousness have a high level…

Ischaemic Changes of Different Anatomical Regions or Vascular Territories
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Ischaemic Changes of Different Anatomical Regions or Vascular Territories

Bilateral watershed infarct The non-contrast CT brain shown is from a patient with bilateral watershed infarct. Here, chronic ischaemic changes can be seen along the external or cortical watershed zones  (Figures 1 and 2). These “borderzones” is where the terminal vasculature of the anterior cerebral artery and middle cerebral artery meet as well as where the middle…

Osmotic Demyelination Syndrome

Osmotic Demyelination Syndrome

This is a set of cranial MRIs from a patient with osmotic demyelination syndrome, formerly called central pontine myelinolysis. Osmotic demyelination syndrome occurs when wide fluxes in serum sodium levels are induced by too rapid correction of hyponatremia. Oligodendrocytes, which forms the myelin sheaths, are particularly vulnerable to osmotic changes. If the osmotic stress is…

Ocular Alignment and Extra-ocular Movement Examination
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Ocular Alignment and Extra-ocular Movement Examination

Subtitles in English for this video can be displayed by clicking on  (first button on the bottom right hand corner of the video). Stereopsis (three dimensional vision) is important in our every day lives. This ability is dependent on aligning both foveae on the same object with slightly dissimilar perspectives to give a perception of depth….