Neuroanatomy
Dr Raymond Chang
Subtitles in English for this video can be displayed by clicking on (first button on the bottom right hand corner of the video). The size of the pupillary aperture at any point in time is dependent on a balance between sympathetic tone, parasympathetic tone, the light reflex and the near reflex. The light reflex is an…
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…
Subtitles in English for this video can be displayed by clicking on (first button on the bottom right hand corner of the video). Inspection of the Lower Limbs After positioning the patient on the bed and ensuring adequate exposure, the lower limbs should be inspected as follow: The examiner should stand at the end of the bed and…
The gait is wide-based and the patient requires assistance from the physician for stabilization. The patient cannot turn within one or two steps but requires multiple steps. The physician then asks the patient to perform tandem-walking at the end of the video but the patient is unable to do so due to severe instability. The…
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…
Intention tremor can be elicited by the finger-nose test. In normal patients, the movements between the physician’s finger and patient’s nose should be smooth, but adjustment is allowed according to the patient’s upper limb power. This man has intention tremor and impaired finger-nose test on the right side, whilst the left side is normal. Discussion on intention…