Thalamo-mesencephalic Branches of the Posterior Cerebral Artery: a 3D Rotational Angiography Study.

PURPOSE: The thalamo-mesencephalic (TM) branches of the posterior cerebral artery (PCA) supply critical structures. Previous descriptions of these vessels are inconsistent and almost exclusively rely on cadaver studies. We aimed to provide a neuroradiological description of TM vessels in vivo based on routine 3D rotational angiographies (3D-RA). METHODS: We analyzed 3D-RAs of 58 patients with pathologies remote from the PCA. PCA-origins were considered. Delineation, origin and number of branches of the collicular artery (CA), the accessory CA (ACA), the posterior thalamoperforating artery (PTA), the thalamogeniculate artery (TGA), and the posterior medial (PMCA) and lateral (PCLA) choroid arteries were assessed. The PTAs were categorized based on Percheron's suggested classification. RESULTS: A CA was identified in 84%, an ACA in 20%. The PTA was delineated in 100%. In 27%, PTA anatomy had features of several Percheron types (n = 7) or vessels emanating from a net like origin (n = 9). 26% had a type IIb PTA. A fetal type PCA origin with hypoplastic ipsilateral P1 was observed in 5 cases with type IIa (n = 2) or type IIb (n = 3) PTAs originating from contralateral P1. The TGA was identified in 85% of patients, with ≥ 2 branches in 67%. The PMCA was delineable in 41%, the PLCA in 100%. CONCLUSION: The prevalence of a proper "Artery of Percheron" type IIb PTA seems to be higher than previously reported. A fetal type P1-origin may be predictive of a type IIa/b PTA emanating from contralateral P1. 3D-RA may be useful for planning PCA interventions, as impairment of TM branches is a severe risk.

The MAKRO Screening - an assessment tool for discourse deficits in adults with dysexecutive symptoms following TBI.

INTRODUCTION: Discourse impairments are common sequelae following TBI. Even though handling discourse is thought to be a basic requirement for social participation and quality of life, few test procedures to assess discourse disorders have been developed so far. OBJECTIVE: The main aim of this prospective cohort study was to evaluate the use of the MAKRO Screening for detecting deficits in discourse production and reception in a group of participants with TBI in the post-acute and chronic phase and their relation to executive functions (EF) and severity of brain injury. METHOD: Twenty individuals with TBI and a control group of healthy speakers performed on the MAKRO and on tests of EF (Regensburger Verbal Fluency Test; Tower of London; WAIS-IV digit span index). Group performance was evaluated on the basis of a scoring system and qualitative discourse analysis with focus on main concepts and coherence. Further, MAKRO scores were correlated with measures of EF. OUTCOMES: Individuals with TBI demonstrated significantly poorer performance within all MAKRO subtests. Discourse analysis revealed fewer main concepts and more frequent use of thematically inappropriate utterances. Performance can be partly explained by severity of initial injury and executive disorders. MAKRO presents a reliable and functional measure for discourse impairments.

Nonverbal Semantics Test (NVST)-A Novel Diagnostic Tool to Assess Semantic Processing Deficits: Application to Persons with Aphasia after Cerebrovascular Accident.

Assessment of semantic processing capacities often relies on verbal tasks which are, however, sensitive to impairments at several language processing levels. Especially for persons with aphasia there is a strong need for a tool that measures semantic processing skills independent of verbal abilities. Furthermore, in order to assess a patient's potential for using alternative means of communication in cases of severe aphasia, semantic processing should be assessed in different nonverbal conditions. The Nonverbal Semantics Test (NVST) is a tool that captures semantic processing capacities through three tasks-Semantic Sorting, Drawing, and Pantomime. The main aim of the current study was to investigate the relationship between the NVST and measures of standard neurolinguistic assessment. Fifty-one persons with aphasia caused by left hemisphere brain damage were administered the NVST as well as the Aachen Aphasia Test (AAT). A principal component analysis (PCA) was conducted across all AAT and NVST subtests. The analysis resulted in a two-factor model that captured 69% of the variance of the original data, with all linguistic tasks loading high on one factor and the NVST subtests loading high on the other. These findings suggest that nonverbal tasks assessing semantic processing capacities should be administered alongside standard neurolinguistic aphasia tests.