The acute behavioral syndrome of anterior thalamic infarction: A prospective study of 12 cases

Abstract

Using systematic investigations, including neurological and neuropsychological examinations and computed tomography and magnetic resonance imaging analyzed on anatomical maps, we prospectively studied 12 patients (age range, 63+/-19 years) with an isolated anterior thalamic infarct. They had acute, severe, perseverative behavior, which was apparent in thinking, speech, and all memory and executive tasks, combined with increased sensitivity to interference. They also showed superimposition of mental activities normally processed sequentially (e.g., giving biographical information while working on a calculation test), which we called palipsychism (from the Greek palin [again] and the Greek psyche [soul]). In addition, all 12 patients (8 with a left-sided infarct, 4 with a right-sided infarct) had word-finding difficulties, 7 of 12 with impaired naming, 8 of 12 with dysarthria, and 5 of 12 with hypophonia. Comprehension, repetition, written abilities, and reasoning were consistently preserved, but apathy was usual. All patients had anterograde memory impairment, with a delayed recall deficit, primarily verbal in left-sided infarcts and visuospatial in right-sided infarcts. Dysexecutive features such as difficulty in programming motor sequences were always present. Visual neglect or topographic disorientation was found in 3 patients. Magnetic resonance imaging emphasized involvement of the anterior group of thalamic nuclei, the mamillothalamic tract, and the anterior part of the internal medullary lamina, with structural sparing of the dorsomedial and ventrolateral nuclei. Sequential follow-up examinations showed spectacular improvement within a few months, with the only significant persisting abnormalities being memory dysfunction and apathy. The acute behavioral syndrome of anterior thalamic infarction is dominated by palipsychism, which corresponds to an overlap of sequential cognitive processes in two or more domains. Its association with severe perseverative behavior with increased sensitivity to interference, anterograde memory retrieval deficit, intrusions, naming difficulties with dysarthria and hypophonia, and apathy is suggestive of this type of infarct.

Lateral and anterior thalamic lesions impair independent memory systems

“…In human infarct cases with ILn damage and in Korsakoff's syndrome cases there is some evidence of deficits in response memory or related tasks (Mair et al , 2002Holdstock et al 1999;Exner et al 2001). There is also evidence that amnesia is specifically related to damage in the AT and its related pathways (von Cramon et al 1985;Ghika-Schmid and Bogousslavsky 2000;Harding et al 2000). Variability and uncertainty across strategically placed lesions is common both in human cases (Parkin et al 1994;Della Sala et al 1997;Van der Werf et al 2000, 2003Schmahmann 2003) and animal models of diencephalic amnesia.…”

Vascular Syndromes of the Thalamus

“…Memory is severely impaired, but language is relatively spared. In the series of Ghika-Schmid and Bogousslavsky, 27 dysarthria, hypophonia, anomia, and decreased verbal and nonverbal fluency were noted, but comprehension, writing, reading, and repetition were normal. The major clinical feature in all patients, however, was persistent deficits in new learning, as well as apathy.…”

Unraveling the contributions of the diencephalon to recognition memory: A review

“…Comparisons of when thalamic strokes do and do not induce amnesia have consistently found that damage to this tract is the best predictor of memory loss (Von Cramon et al 1985;Ghika-Schmid and Bogousslavsky 2000;Van der Werf et al 2000, 2003bCarrera et al 2004). One of these studies also linked recognition deficits to mammillothalamic tract damage ( Van der Werf et al 2003b).…”