Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cerebral Decortication”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1997

An exploratory comparison of three methods of memory assessment with the intracarotid amobarbital procedure.

This paper has two objectives. The first is to compare three methods of amobarbital memory assessment in 172 adults prior to epilepsy surgery. The three methods are significantly different from one another and there was only a moderate degree of concordance between them; concordance depended upon the method, the side of surgery, and the side of speech. The second objective of the paper is to evaluate the relative abilities of the methods of differentiate, prior to surgery, patients who did and who did not suffer mild to moderate postoperative losses in verbal memory following surgery. To meet this objective a subsample of patients was selected based on the presence or absence of this type of memory loss. Significant differences in the ability of the amobarbital methods to identify the patients at risk for postoperative memory loss were observed, with the method assessing recall memory during drug presence having the best prediction rate.

Adult↗
PubMed1986

Performance of manual copying tasks after focal cortical lesions.

Patients with unilateral frontal or temporal excisions and normal control subjects were required (1) to copy single, difficult positions of the arm, fingers, or both, and (2) to copy the experimenter as three hand positions were presented one after the other at an increasing rate. All patient groups were impaired relative to the control group on both tasks, but on the second task patients with frontal lesions were also impaired relative to those with temporal lesions. Results suggested a role of the left-and right-frontal lobes in rapid execution of multiple manual responses.

Adolescent↗
PubMed1988

Language and memory functions after long recovery periods in left-hemispherectomized subjects.

Two subjects who had infantile brain damage and left hemispherectomies at the ages of 17 and 18 yr are assessed after 28 and 16 yr recovery periods. Deficits on the comprehension of passive-negative sentences disappeared when the subjects read rather than heard the sentences, and performances were normal on the Token and Reporter's Tests, and tests of verbal memory. These results suggest that if damage to the left hemisphere occurs early in life and there is a long recovery period, the right hemisphere can mediate verbal memory and the more subtle aspects of language. This provides support for the hypothesis that the two hemispheres are equipotential for language and verbal memory.

Adult↗
PubMed1986

Making reference: the cohesive use of pronouns in the narrative discourse of hemidecorticate adolescents.

The cohesive use of referential language in narrative production reveals communicative goals as well as specific aspects of language use. A formalism for analyzing pronominal cohesion was developed and applied to the narrative discourse of three hemidecorticate adolescents. The results revealed hemisphere-dependent differences in overall narrative skill as well as distinct individual discourse strategies. Neither left hemidecorticate planned narration in extended discourse units: One demonstrated a linear and highly explicit discourse style with redundant over-statement of referent nouns and the other produced narratives cluttered with pronouns of both correct and ambiguous reference, relying on nonpersonal pronouns at considerable cost to narrative specificity. The right hemidecorticate produced narratives that were more economical in form and richer in content: He was the only subject able to maintain simultaneous story lines with multiple pronouns and referential relationships cohesively embedded. All subjects expressed at least some story content, but only the right hemidecorticate narratives conveyed suggestion and implication as well as explicit statement.

Adolescent↗
PubMed1986

Classification and recall of pictures after unilateral frontal or temporal lobectomy.

Classification and recall of pictures of familiar objects were studied in 21 normal control subjects and 75 patients with unilateral cerebral excisions. The patients with frontal-lobe excisions were impaired at categorizing the pictures and at recalling the objects depicted. Left and right temporal-lobe groups performed the sorting task normally, but the left temporal-lobe groups were impaired at recalling picture names. The right temporal-lobe groups were unimpaired. A negative correlation between the number of items uncategorized and the number recalled was found in the right frontal-lobe group but not in the left, who were impaired also at recalling the items that they had classified correctly. It is concluded that impaired categorization played a major role in determining the recall deficits in the right frontal-lobe group but not in the left, whose impaired recall may also be due to defective retrieval. The poor recall of the left temporal-lobe groups is thought instead to depend on abnormally rapid forgetting.

Adolescent↗
PubMed1998

Selective spatial memory impairment after right unilateral temporal lobectomy.

Deficits in performance of both spatial and visual tasks are common following tissue loss in the right temporal lobe. Since spatial and visual attributes are frequently confounded in experimental tasks, we have studied patients following unilateral temporal lobectomy, in an attempt to determine which aspect mediates the observed deficits. Spatial and visual memory performance was compared in normal controls (n = 16), left temporal (LTL; n = 19) and right temporal (RTL; n = 19) lobectomy patients, by presentation of eight abstract designs in a spatial array for subsequent recall and recognition of the designs (visual memory) and recall of their spatial position (spatial memory). By varying the retention intervals for each group, all three groups were matched on both recall and recognition of the designs at sub-ceiling levels. In contrast, recall of the position of the designs (spatial memory), tested at equivalent delays to those of the visual memory tests, revealed a deficit in the RTL patients compared to both controls and LTL patients (p < 0.05). Magnetic resonance imaging (MRI) was used to quantify the extent of resection of the hippocampus and parahippocampal regions in the two patient groups and showed a significant correlation between hippocampal and parahippocampal removal and spatial memory in the RTL group only. These data support the notion of a disproportionately large involvement of the right hippocampus and adjacent regions in spatial memory.

Adult↗
PubMed1977

The role of early left-brain injury in determining lateralization of cerebral speech functions.

Preparatory to craniotomy for the relief of medically refractory focal epilepsy, the lateralization of cerebral speech functions was determined by the Wada intracarotid Amytal test in 134 patients with clinical and radiologic evidence of an early left-hemisphere lesion. Their results were compared with those for 262 patients (140 right-handed, 122 left-handed), who were tested in a similar way. One-third of the patients with early lesions were still right-handed, and 81% of these right-handers were left-hemisphere dominant for speech. In the non-right-handers, speech was represented in the left cerebral hemisphere in nearly a third of the group, in the right hemisphere in half the group, and bilaterally in the remainder. Bilateral speech representation was demonstrated in 15% of the non-right-handers without early left-brain injury and in 19% of those with evidence of such early injury, whereas it was extremely rare in the right-handed groups. In addition, nearly half the patients with bilateral speech representation exhibited a complete or partial dissociation between errors of naming and errors in the repetition of verbal sequences after Amytal injection into left or right hemispheres. This points to the possibility of a functionally asymmetric participation of the two hemispheres in the language processes of some normal left-handers. The results of the Amytal speech tests in this series of patients point to locus of lesion as one of the critical determinants in the lateralization of cerebral speech processes after early left-brain injury. It is argued that in such cases the continuing dominance of the left hemisphere for speech in largely contingent upon the integrity of the frontal and parietal speech zones.

Adolescent↗
PubMed1993

Transient enhancement of low-threshold calcium current in thalamic relay neurons after corticectomy.

1. The alterations of voltage-sensitive calcium currents produced in thalamic cells by injury were investigated under voltage clamp using patch-clamp recordings in the whole-cell configuration. 2. One day after unilateral cortical ablation in immature rats (postnatal day 7), low-threshold transient calcium (T) currents in acutely isolated thalamic relay neurons (RNs) were increased by 68% compared with contralateral controls (P < 0.001). Three days after the operation, T currents in injured neurons were at 44% of control levels (P < 0.001). On the other hand, high-threshold (L) calcium currents in RNs did not change over the same interval. 3. To investigate the mechanism for the increase of T current, both kinetics and voltage dependency of activation and inactivation were examined. At a test voltage of -40 mV, the activation time constant decreased from 4.1 to 3.2 ms (P < 0.05); however, this small change was insufficient to explain the large increase in T current. Time constants for both fast and slow inactivation did not change significantly, nor did voltage dependence of activation or inactivation of thalamic T currents. 4. Methyl-phenyl-succinimide (MPS, 1 mM), a compound known to block T currents, was used to examine possible alterations in the pharmacological properties of T channels after injury. MPS was more effective in reducing T currents in normal versus injured RNs (24 and 20% reductions, respectively; P < 0.05), suggesting that pharmacological properties of T channels in the injured RNs may be different from those of the normal RNs.(ABSTRACT TRUNCATED AT 250 WORDS)

Afferent Pathways↗
PubMed1984

Asymmetrical effects of unilateral cortical suction lesions: behavioral characterization.

Behavioral effects of unilateral frontocortical suction lesions in the right and left hemisphere were characterized by a computerized activity monitoring system. Lesions of the right frontal cortex produced postoperative hyperactivity consisting of increases in the total distance traveled, average distance per movement, and average speed of movement. Vertical, rotational, and stereotypic measures were not changed. Animals receiving left hemisphere lesions did not differ from sham-operated controls on any behavioral variable. The lateralized hyperactivity resulting from lesions of the right frontal cortex was confined to increased length and speed of horizontal movement and did not appear to represent a generalized increase in all components of spontaneous activity.

Animals↗