Neuroanatomy
Dr Raymond Chang
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…
As one can appreciate in this video, this middle-aged man has right-sided intention tremor. The right index finger shows exaggerated tremor when approaching the target, i.e. his nose and physician’s finger. Please note that the examiner should place his finger at around one arm’s length from the patient. This is so that the patient could…
In this patient, there is a mild esotropia on neutral gaze as the left eye is slightly deviated medially. There is impaired left eye abduction resulting in diplopia when the patient is instructed to look towards the left. Discussion of the sign Abduction of the eye is controlled by the lateral rectus muscle, which is…
In this video, the patient exhibits a positive heel-shin test on the right side. Compared to the left (normal) side, the right lower limb is seen to be rather clumsy. The heel-shin test is a test to screen for ipsilateral cerebellar function. Once again, clear instructions are required for this test, and you could see…
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…
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…