Case Report: 57 yr old male executive with progressing dementia on MRI shows asymmetrical left anterior temporal/ hippocampal atrophy including parahippocampal gyrus with dilated temporal horn and subtle gliotic foci , possibly representing Semantic variant of primary progressive aphasia of FTLD Group in view of typical presentation.
Teaching points by Dr MGK Murthy, Dr David and Technologist Mr Ram Murti
1.Imaging evaluation of dementias can be grouped in to
(a) Global cortical atrophy (GCA) (score of 0-3(called knife blade variety) depending on the quantum of volume loss)( In senile and other varieties more important)
(b)Medial Temporal Lobe atrophy (MTA) -Visual rating score of 0-4 (depending on choroid fissure/temporal horn and height of hippocampal loss)(Alzheimers disease more important)
(c)Koedam Score for parietal lobe atrophy (score of 0-3)((Senile more important)
(d) Fazekas Score (periventricular hyperintesntieis) (score of 0-3 depending on number and confluencing pattern)(senile &FTLD more important)
(e)Strategic infarcts (some areas vital for cognition) (Thalami/ Watershed zones/ parieto -temporal and temporo-occipital/ angular gyrus)( In Multiinfarct dementia variety more important)
2.Semantic variant of primary progressive aphasia or simply referred to as semantic dementia is a language variant of Fronto Temporal Lobe Dementias (previous Picks disease) (FTLD accounts for 5-10%of dementias)
3.clinically it displays (a)confrontation naming (b) single word comprehensions are decreased along with (c) impaired object knowledge (d) surface dyslexia / dysgraphia (e) spared repetition and speech production including motor /grammar speech
4. Early on, loss of temporal lobe function leads to language dysfunction (with speech maintained called Empty fluent speech) and later frontal variety gets added .
5.Alzheimers can be differentiated by no loss of memory for lifes memorable events (episodic memory)