DEC 10, a brief saga: hemianopsia

Authors' Note: Loss of sight in half of an eye's visual field is a medically well-characterized and significant lesion known as hemianopsia, or occasionally hemianopia. An attack on the underlying lesion, often deep within the brain is in the province of neurosurgeons, and often a multidisciplinary team is needed. The bitemporal pattern discussed here, involving the lateral half of each eye's visual field, is less common than homonomous hemianopsia. For further reading on this topic, the Wikipedia article is suggested.

Authors' Note:  Lesions in the occipital, or posterior portion of the brain's cerebral hemispheres are notorious for producing visual disruption. Each side of this sensitive area of brain tissue is targeted at integrating one half of the patient's visual field (to left or right). So for example, a tumour in the right side of the occipital lobe interrupts the signals arriving from the nerve fibres in the right side of the retina in both eyes; the patient's ability to see objects in the well-defined semi-circular zone to his left is eliminated in a fashion that is homonomous, i.e. congruent - both eyes are affected similarly. The resulting pattern of contralateral loss of visual sensation (homonomous hemianopsia) may be mapped by a test known as perimetry (visual-field analysis).

You can check your knowledge of brain structure and function in health and disease by reviewing our entire collection of illustrated verses on this topic. To review 'BRAINCHECK' on the topic-oriented  blog "Edifying Nonsense", click HERE.

 

 For the purpose of this blog, a 'brief saga' is defined as a poem, usually narrative, but occasionally expository, that tell its story in at least 15 lines. Most commonly, the format involves three stanzas in limerick form, constituting a single submission to the online humor site 'Omnificent English Dictionary in Limerick Form'. On the OEDILF site, rigorous standards for content and format are involved in a collaborative editing process that may take several weeks to over a year. 

 There are now over 40 of these lengthier bits of doggerel featured at OEDILF in Giorgio's "Author's Showcase". The OEDILF number for each accepted multiverse poem is shown here on the slide with its first verse. We have been blog-publishing these poetic adventures here monthly since January 2020.

To access the next 'brief saga' on this blog (January 2023), proceed to... 'Squid in the Time of Covid'.  

To access the most recent previous 'brief saga' (November 2022), back up to 'Palindrome Workshop'.

To access all of our 'brief sagas' by the year of their creation, click on your selection below.

2020
2021
2022
2023.