ABSTRACT
Primary progressive aphasia (PPA) is an overarching term for a heterogeneous group of neurodegenerative diseases which affect language processing. Impaired picture naming has been linked to atrophy of the anterior temporal lobe in the semantic variant of PPA. Although atrophy of the anterior temporal lobe proposedly impairs picture naming by undermining access to semantic knowledge, picture naming also entails object recognition and lexical retrieval. Using multivariate analysis, we investigated whether cortical atrophy relates to different types of naming errors generated during picture naming in 43 PPA patients (13 semantic, 9 logopenic, 11 nonfluent, and 10 mixed variant). Omissions were associated with atrophy of the anterior temporal lobes. Semantic errors, for example, mistaking a rhinoceros for a hippopotamus, were associated with atrophy of the left mid and posterior fusiform cortex and the posterior middle and inferior temporal gyrus. Semantic errors and atrophy in these regions occurred in each PPA subtype, without major between-subtype differences. We propose that pathological changes to neural mechanisms associated with semantic errors occur across the PPA spectrum.
Subject(s)
Aphasia, Primary Progressive/diagnosis , Aphasia, Primary Progressive/psychology , Neuropsychological Tests , Temporal Lobe/pathology , Aged , Aphasia, Primary Progressive/etiology , Aphasia, Primary Progressive/pathology , Atrophy , Comprehension , Female , Humans , Language , Male , Middle Aged , Multivariate Analysis , SemanticsABSTRACT
BACKGROUND: Trigeminal neuralgia and central sensory disturbances are common in patients with multiple sclerosis. The anatomic correlation to lesions in the trigeminal nuclei in the brainstem is not well studied. OBJECTIVE: We studied the anatomical characteristics of demyelinating lesions of the trigeminal complex in the brainstem on MRI in patients with MS and Clinically Isolated syndrome (CIS). MATERIALS AND METHODS: 43 Patients with MS or CIS and MRI lesions in the trigeminal complex in the brainstem were selected from a large database of patients referred for MRI because of trigeminal symptoms. RESULTS AND CONCLUSION: A linear plaque involving the intrapontine fascicular part of the trigeminal nerve and lesions of the spinal trigeminal nucleus and tract seem to be distinctive MRI findings in patients with RRMS or CIS.