Dyslexia is a learning difference often recognized during childhood, primarily affecting reading, writing, and spelling. While it is commonly associated with developmental stages, a significant question arises about whether individuals can develop dyslexia later in life. This article explores the nature of dyslexia and distinguishes between its developmental form and a condition that can indeed emerge in adulthood due to specific neurological events.
Understanding Dyslexia
Developmental dyslexia is a neurodevelopmental condition present from birth, characterized by difficulties with accurate and fluent word recognition, spelling, and decoding. These challenges typically stem from a deficit in the phonological component of language, affecting the ability to process sounds in words. Dyslexia is not a reflection of intelligence or effort; individuals with dyslexia often have average or above-average intellectual capabilities. The condition makes tasks like reading, spelling, and writing more challenging despite conventional teaching.
Acquired Dyslexia
While developmental dyslexia is present from childhood, acquired dyslexia (or alexia) can manifest later in life. This distinct condition refers to the loss of previously established reading ability due to brain damage. Unlike developmental dyslexia, a neurodevelopmental difference, acquired dyslexia is a new onset condition in someone who previously possessed typical reading skills. Acquired dyslexia results from a specific neurological event. Its symptoms may resemble those of developmental dyslexia, but the underlying cause differs.
Causes of Acquired Dyslexia
Acquired dyslexia occurs due to damage to specific brain regions involved in language and reading processing. Common causes include stroke, particularly affecting the left brain hemisphere where most language functions are located. Traumatic brain injury (TBI) is another cause, as head injuries can damage parts of the brain responsible for reading. Brain tumors can also lead to acquired dyslexia, especially those located in the left hemisphere, by damaging neural pathways critical for reading.
Neurodegenerative diseases, such as Alzheimer’s and primary progressive aphasia, can impair reading abilities. These conditions involve the gradual degeneration of nerve cells, affecting language and cognitive functions over time. Infections causing brain inflammation, like encephalitis or meningitis, can also result in brain cell damage and impaired blood flow, impacting the brain’s ability to process written language. Damage to areas like the occipitotemporal junction or the angular gyrus, involved in visual word form processing, can disrupt reading.
Recognizing and Managing Acquired Dyslexia
Recognizing acquired dyslexia in adults involves observing new difficulties with reading that were not present before. Symptoms can include trouble reading familiar words, misreading words, struggling to understand written text, and problems with spelling. Individuals might find silent reading easier than reading aloud, or have difficulty with specific types of words, such as irregularly spelled words. Diagnosis typically involves a neurological evaluation and neuropsychological testing to assess reading skills and identify affected brain regions.
Management strategies for acquired dyslexia often involve speech and language therapy tailored to the individual’s specific reading deficits. Therapists may use various approaches, such as sight word drills, functional reading tasks, and exercises to retrain reading pathways in the brain. Compensatory strategies, like using a “window” to focus on one word at a time, can help improve reading fluency. Assistive technologies, such as text-to-speech software, can also aid individuals in accessing written information. Recovery depends on the extent of brain damage, the person’s age, and the intensity of rehabilitation efforts.