Transient crossed aphasia during focal right-hemisphere seizure

Brain, 2005

It is well recognized that the incidence of atypical language lateralization is increased in patients with focal epilepsy. The hypothesis that shifts in language dominance are particularly likely when epileptic lesions are located in close vicinity to the so-called language-eloquent areas rather than in more remote brain regions such as the hippocampus has been challenged by recent studies. This study was undertaken to assess the effect of lesions in different parts of the left hemisphere, lesions present during language acquisition, on language lateralization. We investigated 84 adult patients with drug-resistant focal epilepsy with structural lesions and 45 healthy control subjects with an established functional MRI language paradigm. Out of the 84 patients 43 had left hippocampal sclerosis, 13 a left frontal lobe lesion and 28 a left temporal-lateral lesion. All these lesions were likely to have been present during the first years of life during language acquisition. To assess the lateralization of cerebral language representation globally as well as regionally, we calculated lateralization indices derived from activations in four regions of interest (i.e. global, inferior frontal, temporo-parietal and remaining prefrontal). Patients with left hippocampal sclerosis showed less left lateralized language representations than all other groups of subjects (P < 0.005). This effect was independent of the factor of region, indicating that language lateralization was generally affected by a left hippocampal sclerosis. Patients with left frontal lobe or temporal-lateral lesions displayed the same left lateralization of language-related activations as the control subjects. Thus, the hippocampus seems to play an important role in the establishment of language dominance. Possible underlying mechanisms are discussed.

Brain and Language, 1998

Stroke is the most frequent serious neurological disorder in the world and the third leading cause of death in many countries. Among the diverse cognitive deficits caused by stroke, aphasia is the one of the most devastating. Among aphasia types, Wernicke's aphasia (as described by Wernicke) consists of the loss of comprehension, loss of ability to read and write, and distortion of oral speech. Hearing is intact. Within the Geschwind-Lichtheim model, the disorder is due to cortical lesions: Brodmann's areas 22 and 39 (namely, Wernicke's area). Diaschisis is a functional impairment at a site in the brain remote from the lesion causing it. Cerebellar diaschisis after cortical insult is detailed in the literature; however, cortical diaschisis after cerebellar insult remains a rarely reported occurrence. In the chronic stage of stroke, contralateral cerebellar blood flow and metabolism are depressed, which is known as crossed cerebellar diaschisis (CCD). We reported a Wernicke's aphasia caused by CCD following cerebellar hemorrhage. The patient was a 56 years old, right-handed male. He lived in Beijing and was a businessman. He was admitted by the department of Neurology, Beijing Tiantan Hospital on 10th Aug, 2007. His wife's major complaint was deterioration of his language skills for one month, and she recalled that the patient suffered from cerebellar hemorrhage two months ago and was given some treatment at hospital. When he went home after one month, she found that the patient had difficulty with word-finding. Specifically, when the patient needed words to express his needs, he could not accurately say the correct word but could express his needs with gestures. On the other hand, he had significant impairment in auditory comprehension and he could not perform sentence completion tasks. However, he could perform well in reading comprehension at the sentence level (sentence comprehension, reading instructions and reading the test). His performance in writing names of objects and pictures matching were poor, and could not write down some words during writing and dictation tasks. He was diagnosed as Wernicke's aphasia by using the Western Aphasia Battery. His aphasia severity gradation was level four. Why did cerebellar hemorrhage produce his aphasia? Using positron emission tomography (PET), we found decreased perfusion of the bilateral frontal and temporal lobes, consistent with regional loss of neural activity. As shown in Figure 1, the result of PET showed that bilateral frontal and temporal lobes, especially the right frontal and temporal lobes were in a state of glucose hypometabolism. We gave him language training twice a day, and we observed his language ability improved quickly. We proposed that the patient's aphasia resulted from both anterograde disconnection of the corticopontocerebellar tracts and retrograde deafferentation of dentatothalamocortical projections. This patient provides a case of CCD elicited by cerebellar hemorrhage.

Behavioural …, 2007

We described a 56-years-old man with a diagnosis of "non-fluent primary progressive aphasia" (NfPPA). An accurate neuropsychological, neurological and neuroimaging evaluation was performed in order to assess clinical and behavioural features of the patient. From a neuropsychological point of view, the patient showed a typical cognitive profile of subjects affected by NfPPA: a prominent language deficit, associated with impairments in several cognitive domains after three years from the onset of the symptomatology. The most intriguing feature is that SPECT revealed hypoperfusion in the right frontal cortex, albeit the patient is right-handed. This unexpected finding shows that NfPPA may arise not only from cortical abnormalities in the language-dominant left hemisphere but also from right hemisphere involvement in a right hander (crossed aphasia).

Journal of Neurology, Neurosurgery & Psychiatry, 1999

Objectives-Global aphasia without hemiparesis (GAWH) is an uncommon stroke syndrome involving receptive and expressive language impairment, without the hemiparesis typically manifested by patients with global aphasia after large left perisylvian lesions. A few cases of GAWH have been reported with conflicting conclusions regarding pathogenesis, lesion localisation, and recovery. The current study was conducted to attempt to clarify these issues. Methods-Ten cases of GAWH were prospectively studied with language profiles and lesion analysis; five patients had multiple lesions, four patients had a single lesion, and one had a subarachnoid haemorrhage. Eight patients met criteria for cardioembolic ischaemic stroke. Results-Cluster analysis based on acute language profiles disclosed three subtypes of patients with GAWH; these clusters persisted on follow up language assessment. Each cluster evolved into a different aphasia subtype: persistent GAWH, Wernicke's aphasia, or transcortical motor aphasia (TCM). Composite lesion analysis showed that persistent GAWH was related to lesioning of the left superior temporal gyrus. Patients with acute GAWH who evolved into TCM type aphasia had common lesioning of the left inferior frontal gyrus and adjacent subcortical white matter. Patients with acute GAWH who evolved into Wernicke's type aphasia were characterised by lesioning of the left precentral and postcentral gyri. Recovery of language was poor in all but one patient. Conclusions-Although patients with acute GAWH are similar on neurological examination, they are heterogeneous with respect to early aphasia profile, language recovery, and lesion profile. (J Neurol Neurosurg Psychiatry 1999;66:365-369)

Global aphasia is an acquired language disorder characterized by severe impairments in all modalities of language. The specific sites of injury commonly include Wernike′s and Broca′s areas and result from large strokes - particularly those involving the internal carotid or middle cerebral arteries. Rarely, deep subcortical lesions may cause global aphasia. We present three cases with global aphasia due to a more rare cause: left thalamic hemorrhage. Their common feature was the large size of the hemorrhage and its extension to the third ventricule. HMPAO-SPECT in one of the cases revealed ipsilateral subcortical, frontotemporal cortical and right frontal cortical hypoperfusion. Left thalamic hemorrhage should be considered in the differential diagnosis of global aphasia.

Epilepsia, 2009

Epilepsy & Behavior, 2003

Hemispheric language dominance, as determined by intracarotid short-acting barbiturate injections (Wada testing), was retrospectively evaluated in 44 right-handed patients with medically intractable left (n=26) or right (n=18) temporal lobe epilepsy (TLE). Atypical hemispheric language ...

Seizure-european Journal of Epilepsy, 2003

The 25-year-old right-handed woman suffering from temporal lobe epilepsy (TLE) was referred to our centre for presurgical evaluation. MRI showed a right-sided hippocampal sclerosis. During video-EEG-recorded seizures, abdominal aura was followed by oral automatisms, during which she was completely reactive to external stimuli, although she was unable to speak. Ictal EEG showed right temporal seizure pattern, without contralateral propagation. She had abnormal speech postictally. Speech-activated functional transcranial Doppler sonography revealed right-sided speech dominance. She has become seizure free after a right-sided amygdalo-hippocampectomy. In our patient, contradictory clinical ictal lateralising signs (automatisms with preserved responsiveness vs. ictal and postictal dysphasia) occurred during right-, speech-dominant-sided seizures. This is the first report when automatisms with preserved consciousness occurred during a seizure originating and involving the speech-dominant hemisphere.

Neurological Sciences, 2011

Atypical patterns of language activation in functional MRI (fMRI) are not unusual, particularly in patients with severe epilepsy. Still, the functional significance of these activations is under debate. We describe a case of a right-handed patient affected by drug-refractory right temporal lobe epilepsy in whom pre-surgical fMRI showed bilateral language activations, greater in the right hemisphere (RH). After surgery, a right subdural hematoma caused epileptic status and severe aphasia. This post-surgical complication of a crossed aphasia confirmed the prior fMRI findings of RH language thus stressing the value of pre-surgical fMRI evaluations, even when surgery is planned in the RH of a right-handed patient.

Annals of Neurosciences, 2012

Romanian Journal of Neurology

Previous data obtained especially from rTMS studies indicate that right hemisphere recruitment has a limiting effect on recovery of poststroke aphasia in right handed patients by inhibiting the activation of intact perilesional areas in left hemisphere and preventing them from regaining function. New researches bring new arguments to support the positive influence of right hemisphere on restoration of language and communication. In this paper we try to review the latest evidences regarding the contribution of the right hemisphere to post-stroke aphasia recovery.

Epilepsia, 2006

Early acquired lesions are considered to be a risk factor for atypical language lateralization in epilepsy, whereas developmental lesions are not. Hippocampal sclerosis (HS) can be understood as an early, acquired lesion, whereas developmental tumors (DT) are thought to originate in utero. We assessed whether language lateralization differs between these groups of temporal lobe epilepsy patients. Methods: We used 3-Tesla functional MRI (f MRI) to assess 41 patients (16 DT, 25 HS) and 50 controls, performing a nounverb-generation task. f MRI data were processed by using SPM2. A laterality index (LI) was calculated based on the number of activated voxels in left-and right-sided frontal lobe language areas. Atypical lateralization was considered if the index was ≤0.2. Results: Patients had a lower LI (0.42 ± 0.5) than controls (0.6 ± 0.3; p ≤ 0.05), but the LI was not different between DT (0.44 ± 0.5) and HS patients (0.43 ± 0.4; p = 0.9). The frequency of atypical lateralization was increased in patients (27%) compared with controls (8%) but was similar in both patient groups (DT, 31%; HS, 24%). HS patients had an earlier onset and longer duration of epilepsy and a higher frequency of significant antecedent events (p ≤ 0.05). Conclusions: Patients with TLE demonstrate a deviation toward atypical language lateralization. However, language lateralization was not different between patients with presumably acquired lesions compared with patients with developmental pathology. This suggests that the nature of the temporal lobe lesion does not influence overall language lateralization.

2016

Both the degree to which the left-hemisphere is specialized for language and the relative ability of the right-hemisphere to subserve language function are underspecified. The present study sought to identify whether the right-frontal fMRI activation seen in a number of case studies in patients with left-sided brain lesions exists as a group-level trend in patients with left-frontal tumors. It also sought to examine the possible compensatory nature of this activation. Thus, a retrospective analysis of 197 brain tumor patients who had undergone pre-surgical fMRI language mapping was conducted. Patients with left-frontal tumors were found to be more likely to show rightor co-dominant fMRI activation during language mapping tasks compared to patients who had tumors elsewhere in the brain. Further, patients with left-frontal tumors who were identified as rightor co-dominant for language were found to possess more intact language function as measured by the Boston

Epilepsia, 2017

Objective: To investigate the occurrence of ictal and postictal aphasia in different focal epilepsy syndromes. Methods: We retrospectively analyzed the video-electroencephalographic monitoring data of 1,118 patients with focal epilepsy for seizure-associated aphasia (SAA). Statistical analysis included chi-square analysis and Fisher's exact test. Results: We identified 102 of 1,118 patients (9.1%) in whom ictal or postictal aphasia (SAA) was part of their recorded seizures (n = 59 of 102; 57.8%) or who reported aphasia by history (n = 43; 42.2% only reported aphasia by history). Postictal aphasia was present in 18 patients (30.5%). Six of the 59 patients had both ictal and postictal aphasia (10.2%). SAA occurred either with left hemisphere seizure onset or with seizures spreading from the right to the left hemisphere. SAA was most common in patients with parieto-occipital epilepsy (10.9%; five of 46 patients), followed by patients with temporal (6.7%; 28 of 420 patients), focal (not further localized; 4.8%; 22 of 462 patients), and frontal epilepsy (2.1%; four of 190 patients; p = 0.04). SAA was more common in parieto-occipital epilepsy than in frontal epilepsy (p = 0.02). In contrast, there was no significant difference in SAA between temporal and parieto-occipital epilepsy (p = 0.36). Significance: SAA has a high lateralizing but limited localizing value, as it often reflects spread of epileptic activity into speech-harboring brain regions.