Abstract 1122‐000205: Bilateral ACA Stroke ‐ A Case Report of an Unusual Presentation

Introduction : Bilateral ACA strokes are rare, with one stroke registry reporting 2 cases out of 1490 strokes (1). These strokes are even less common in the absence of anatomic variants, such as an azygos ACA. Diagnosis may be difficult given the variability in clinical presentation. Methods : This is a case report. Results : A 51‐year‐old right handed man with no cerebrovascular risk factors on no antithrombotic medications presented two hours from last known well with complaints of generalized weakness, inability to speak or move, and feeling numb all‐over during intercourse. He reported rapid improvement in symptoms. Emergency room exam was notable for right leg weakness (3/5) and left leg plegia with intact sensation. Hoover’s sign was positive in the left leg and the patient was able to bear some weight while standing with a two‐person assist. A computed tomography angiogram (CTA) of his head and neck was preliminarily interpreted as normal. No azygos ACA or single internal carotid artery origin for the ACAs were present. His exam improved to an isolated left foot dorsiflexor and plantar flexor weakness. The decision was made not to use thrombolytics based on his symptoms and exam which were improving and not entirely consistent with acute stroke. Brain magnetic resonance imaging demonstrated bilateral parasagittal acute strokes. It was later noted the that non‐contrast head CT demonstrated bilateral hyperdense ACAs. Conclusions : This case demonstrates the difficulty in diagnosing bilateral ACA infarcts in a previously healthy adult in the setting of whole‐body numbness and positive Hoover’s sign. In retrospect, his transient inability to speak or move may have been transient akinetic mutism or callosal disconnection syndrome. Additionally, this case emphasizes the importance of evaluating for the hyperdense ACA sign (2) in patients complaining of bilateral leg weakness.

The Role of White Matter Disconnection in the Symptoms Relating to the Anarchic Hand Syndrome: A Single Case Study

The anarchic hand syndrome refers to an inability to control the movements of one’s own hand, which acts as if it has a will of its own. The symptoms may differ depending on whether the brain lesion is anterior, posterior, callosal or subcortical, but the relative classifications are not conclusive. This study investigates the role of white matter disconnections in a patient whose symptoms are inconsistent with the mapping of the lesion site. A repeated neuropsychological investigation was associated with a review of the literature on the topic to identify the frequency of various different symptoms relating to this syndrome. Furthermore, an analysis of the neuroimaging regarding structural connectivity allowed us to investigate the grey matter lesions and white matter disconnections. The results indicated that some of the patient’s symptoms were associated with structures that, although not directly damaged, were dysfunctional due to a disconnection in their networks. This suggests that the anarchic hand may be considered as a disconnection syndrome involving the integration of multiple antero-posterior, insular and interhemispheric networks. In order to comprehend this rare syndrome better, the clinical and neuroimaging data need to be integrated with the clinical reports available in the literature on this topic.

The Role of White Matter Disconnection in the Symptoms Relating to the Anarchic Hand Syndrome: A Single Case Study

The anarchic hand syndrome refers to an inability to control the movements of one’s own hand which acts as if it had a will of its own. The symptoms may differ depending on whether the brain lesion is anterior, posterior, callosal or subcortical, but the relative classifications are not conclusive. This study investigates the role of white matter disconnections in a patient whose symptoms are inconsistent with the mapping of the lesion site. A repeated neuropsychological investigation was associated with a review of the literature on the topic to identify the frequency of various different symptoms relating to this syndrome. Furthermore, an analysis of the neuroimaging regarding structural connectivity allowed us to investigate the grey matter lesions and white matter disconnections. The results indicated that some of the patient’s symptoms were associated with structures that, although not directly damaged, were dysfunctional due to a disconnection in their networks. This suggests that the anarchic hand may be considered as a disconnection syndrome involving the integration of multiple antero-posterior, insular and interhemispheric networks. In order to comprehend this rare syndrome better, the clinical and neuroimaging data need to be integrated with the clinical reports available in the literature on the topic.

Disrupted Subcortical-Cortical Connections in a Phonological but Not Semantic Task in Chinese Children With Dyslexia

Reading disability has been considered as a disconnection syndrome. Recently, an increasing number of studies have emphasized the role of subcortical regions in reading. However, the majority of research on reading disability has focused on the connections amongst brain regions within the classic cortical reading network. Here, we used graph theoretical analysis to investigate whether subcortical regions serve as hubs (regions highly connected with other brain regions) during reading both in Chinese children with reading disability (N = 15, age ranging from 11.03 to 13.08 years) and in age-matched typically developing children (N = 16, age ranging from 11.17 to 12.75 years) using a visual rhyming judgment task and a visual meaning judgment task. We found that the bilateral thalami were the unique hubs for typically developing children across both tasks. Additionally, subcortical regions (right putamen, left pallidum) were also unique hubs for typically developing children but only in the rhyming task. Among these subcortical hub regions, the left pallidum showed reduced connectivity with inferior frontal regions in the rhyming judgment but not semantic task in reading disabled compared with typically developing children. These results suggest that subcortical-cortical disconnection, which may be particularly relevant to the phonological and phonology-related learning process, may be associated with Chinese reading disability.