Crossed aphasia. An update

Patient With Crossed Aphasia Undergoing Long-Term Speech Therapy: A Case Report

Crossed aphasia (CA) is a type of aphasia caused by cerebral hemispheric lesions on the same side of the dominant hand. The prevalence of CA is extremely rare. To the best of our knowledge, this is the first case report in Korea to conduct 6 years of long-term speech therapy in a case of a patient with CA. The patient was a 57-year-old right-handed man with aphasia caused by extensive acute infarction in the right middle cerebral artery territory. He presented with global aphasia, right-left disorientation, and agraphia. Language function recovered in the first 6 months and then plateaued.

Crossed Aphasia as a Manifestation of Glioblastoma

Language and speech function is commonly accepted to be a heavily lateralized function. Greater than 95% of right-handed individuals have left hemispheric dominance for language, and reports in the literature of crossed aphasia (language deficits in a right-handed individual from right-sided pathology) are scant. We report the case of a 52-year-old woman presenting with crossed aphasia from a right temporal glioblastoma. We then expand on a discussion of crossed aphasia in the setting of brain tumors.

Language lateralization of Chinese-English bilingual patients with temporal lobe epilepsy: a functional MRI study

Functional MRI was used to examine language lateralization of Chinese characters and English words associated with temporal lobe epilepsy (TLE) in Chinese-English bilinguals with left or right TLE. The results suggest that the neural basis of processing Chinese and English seems to be different, as normal controls demonstrated left hemispheric lateralization in reading English words but bi-hemispheric lateralization in reading Chinese characters. This difference in the neural bases of Chinese and English processing was found to affect the patterns in change-of-language processing associated with TLE. That is, whereas left-TLE patients were more likely than right-TLE patients to demonstrate a bi-hemispheric language involvement in reading English, both left- and right-TLE patients demonstrated primarily bilateral hemispheric involvement for reading Chinese characters.

Language dominance in neurologically normal and epilepsy subjects: a functional MRI study

Language dominance and factors that influence language lateralization were investigated in right-handed, neurologically normal subjects (n = 100) and right-handed epilepsy patients (n = 50) using functional MRI. Increases in blood oxygenation-dependent signal during a semantic language activation task relative to a non-linguistic, auditory discrimination task provided an index of language system lateralization. As expected, the majority of both groups showed left hemisphere dominance, although a continuum of activation asymmetry was evident, with nearly all subjects showing some degree of right hemisphere activation. Using a categorical dominance classification, 94% of the normal subjects were considered left hemisphere dominant and 6% had bilateral, roughly symmetric language representation. None of the normal subjects had rightward dominance. There was greater variability of language dominance in the epilepsy group, with 78% showing left hemisphere dominance, 16% showing a symmetric pattern and 6% showing right hemisphere dominance. Atypical language dominance in the epilepsy group was associated with an earlier age of brain injury and with weaker right hand dominance. Language lateralization in the normal group was weakly related to age, but was not significantly related to sex, education, task performance or familial left-handedness.