Why Is It Difficult to Predict Language Impairment and Outcome in Patients with Aphasia after Stroke? Andreas Charidimou et al Chris Anzalone

Why I chose this topic What is a stroke What is aphasia Article summary Take home message Questions Presentation Overview

Personally interested in learning about lesions and enjoy reading research papers on them Implications of such studies (in treatment and understanding of aspects of brain function) I was immediately drawn to this paper for these reasons. Lesion Studies

Stroke (This paper focuses on brain lesions caused by stroke) Traumatic Brain Injury Genetic Defects (tumors, epilepsy, certain diseases) Surgical Procedures Common Causes of Brain Lesions?

cerebrovascular accident (CVA) Strokes are defined as a loss of brain function due to a disturbance in the blood supply to the brain Types of stroke: Ischemic (loss of blood flow) Hemorrhagic (bursting of vessel) What is a Stroke

Vascular Supply to The Brain Three main arteries Implications of a damaged or non- functioning artery

Broadly defined as the loss of ability to understand or express speech, caused by brain damage. Most well-known aphasias What is Aphasia?

There are many different names for different types of language impairments one can have. Some common ones include: Global Aphasia – impacts both speech production and speech comprehension Anomic Aphasia – problems recalling words or names of objects Broca’s Aphasia – language expression problems Wernicke’s Aphasia – language receptive problems Acute vs Progressive forms of aphasia: Types of Aphasia

Differences in prognosis (some fully recover, some do not) What does it depend on? In treatment specialists aim to help you communicate to the best of your ability. help restore as much of your speech and language as possible. find alternative ways of communicating. Treatments

Damage to “language areas” does not always produce expected deficits Why is the over-simplified story still taught to college level students Scientific community needs time to drift away from old schools of thought Types of Aphasia: Why so Many Misconceptions?

What was the authors’ primary objective in writing this article? Highlight the reasons why language impairments are not very predictable The Goal of this Paper

Pure aphasias are rare and present themselves differently JfYl6HXw&list=PLNk1_DijaIP5db0YYK91kvsKArppoEhHX JfYl6HXw&list=PLNk1_DijaIP5db0YYK91kvsKArppoEhHX There is more going on than we think. Why is Predicting Language Impairment Difficult?

Looking at the Brain Paul Broca’s actual patients’ brains Different physical lesions

atypical lesion-to-deficit correspondence The authors found many studies that highlighted this fact that often times the language deficits seen in aphasic patients does not align with the brain damage that they have. Other Factors Making it Difficult

Example of “Atypical” Lesion-Deficit Correlation Intact Wernicke’s Area Damage to left putamen Wernicke’s Area

Reliability of large population studies vs. small case studies About 20 sites in L hemisphere involved in language Damage to these sites = language impairments Large Population Studies

Difficult to localize a brain lesion based on behavior Lesions to any brain region or network that plays some role in language could produce aphasia in the individual. Accuracy of terms referring to specific aphasia types So What do We Know?

My thoughts: Over all I enjoyed it. The article was easy to understand The authors did a good job providing various specifics to make their point It was refreshing to read an article providing evidence as to why we DON’T know something, rather than trying to convince us why something is true. Your thoughts? Personal Thoughts About the Article?

There is a lot of room to grow and much to learn in our understanding of brain lesions as they relate to language. Likely there will be a positive correlation between our understanding of language in the brain and our understanding on the implications of specific brain lesions on language. Concluding Remarks

QUESTIONS?