Biomedical subjects

Marian Gomez Beldarrain

Publications and source records attributed to Marian Gomez Beldarrain.

4 recordsLinked to original sources

PubMed2005

Only spontaneous counterfactual thinking is impaired in patients with prefrontal cortex lesions.

Counterfactual thoughts (CFT) are mental simulations of what might have been if another behavior had been executed. They are pervasive in everyday life, help people learn from experience, modulate their emotional state, and contribute to decision-making and social functioning. To test the hypothesis that the prefrontal cortex (PFC) is involved in the generation, content, and use of CFT, we studied 18 patients with strictly prefrontal cortex lesions. Our results indicated that the PFC is crucial only for self-generated counterfactual reflections. We did not detect CFT generation differences based on lesion location within the PFC. CFT performance correlated positively with measures of attention, creativity, verbal skills, conscientiousness, and self-esteem and negatively with depression and dysexecutive symptoms. An impairment in counterfactual thinking may contribute to the lack of regret and insight often observed in patients with frontal lobe lesions.

Adult↗

PubMed2003

The ocular ischemic syndrome.

The ocular ischemic syndrome represents a serious blinding condition due to retinal ischemia secondary to hemodynamically significant carotid artery stenosis. However, this condition has received little attention in the neurological literature and is likely underdiagnosed. We here describe a patient with bilateral severe carotid stenosis and progressive visual loss due to ocular ischemia. The best management for this condition remains controversial and should be established by including these patients into randomized trials of carotid surgery.

Aged↗

PubMed2002

Tissue plasminogen activator administration does not result in clinically relevant neuropsychological dysfunction in patients with myocardial ischemia.

BACKGROUND: Recent evidence from animal models has demonstrated that tPA can be neurotoxic to the hippocampus and cerebellum. Since tPA is used in patients with myocardial infarction and has been approved for the treatment of acute ischemic stroke, we carried out a pilot study to investigate whether its administration could result in any clinically relevant neuropsychological dysfunction, with particular attention to those structures most involved in the animal model. PATIENT AND METHODS: Patients with acute myocardial infarction (AMI) who were subjected to thrombolysis with r-tPA and without evidence of prior or concomitant neurological-neuropsychological damage, were eligible. Controls consisted of patients with AMI not candidate for thrombolysis or patients with severe angina admitted to the intensive care unit. A detailed neurological and neuropsychological evaluation was performed, which included mood, visual and verbal memory, psychomotor speed processing and motor dexterity and visuomotor sequence learning. RESULTS: Ten patients and 13 controls were included. No significant differences between both groups were found, although all the subjects performed in the lower limits of the normal range on the Purdue pegboard test (motor dexterity) and digit-symbol test (psychomotor speed). There was no evidence of depression, as assessed by the Hamilton scale, that could have interfered with performance. Declarative memory (Rey auditory-verbal learning test) as well as visual memory (Rey-Osterrieth figure copy) and visuomotor sequence learning (serial reaction time task) were normal, without between-group differences. CONCLUSIONS: tPA administration at the usual doses did not result in detectable neuropsychological abnormalities in patients with myocardial ischemia.

Adult↗

PubMed2001

Prefrontal lesions impair the implicit and explicit learning of sequences on visuomotor tasks.

OBJECTIVE: (1) To verify whether the prefrontal cortex (PFC) is specifically involved in visuomotor sequence learning as opposed to other forms of motor learning and (2) to establish the role of executive functions in visuomotor sequence learning. BACKGROUND: Visuomotor skill learning depends on the integrity of the premotor and parietal cortex; the prefrontal cortex, however, is essential when the learning of a sequence is required. METHODS: We studied 25 patients with PFC lesions and 86 controls matched for age and educational level. Participants performed: (1) a Pursuit Tracking Task (PTT), composed of a random tracking task (perceptual learning) and a pattern tracking task (explicit motor sequence learning with learning indicated by the decrease in mean root square error across trial blocks), (2) a 12-item sequence version of a serial reaction time task (SRTT) with specific implicit motor sequence learning indicated by the rebound increase in response time when comparing the last sequence block with the next random block, and (3) a neuropsychological battery that assessed executive functions. RESULTS: PFC patients were impaired in sequence learning on the pattern tracking task of the PTT and on the SRTT as compared to controls, but performed normally on the PTT random tracking task. Learning on the PTT did not correlate with learning on the SRTT. PTT performance correlated with planning functions while SRTT performance correlated with working memory capacity. CONCLUSIONS: The PFC is specifically involved in explicit and implicit motor sequence learning. Different PFC regions may be selectively involved in such learning depending on the cognitive demands of the sequential task.

Adult↗