Biomedical subjects

Michael M Saling

Publications and source records attributed to Michael M Saling.

11 recordsLinked to original sources

PubMed2004

The amygdala and sexual drive: insights from temporal lobe epilepsy surgery.

The aim of this study was to explore the relationship between the amygdala and human sex drive. We compared amygdalar volume in groups of patients with or without sexual changes after temporal lobe resection and in age-matched neurologically normal subjects. Forty-five patients with intractable temporal lobe epilepsy who underwent surgical resection in the Comprehensive Epilepsy Program at the Austin and Repatriation Medical Centre completed a semistructured interview and questionnaire relating to sexual outcome after surgery. Volumetric analyses of both amygdalae were conducted on the patients' preoperative T(1)-weighted magnetic resonance imaging scans and those of 46 neurologically normal controls. Patients who reported a postoperative sexual increase had a significantly larger amygdalar volume contralateral to the site of their resective surgery than patients with a sexual decrease or no change than control subjects. There was a significant positive relationship between contralateral amygdalar volume and the maximum degree of sexual change. We have demonstrated a relationship between contralateral amygdalar volume and sexual outcome in patients undergoing temporal lobe resection. This finding provides evidence for an important role of the amygdala in regulating human sexual behavior. A larger contralateral amygdala may contribute to the expression of increased or improved sexuality after temporal lobe resection.

Adult↗

PubMed2004

A high-field functional MRI study of quadri-lingual subjects.

We assessed six multilingual subjects by functional MRI using a Noun Verb Generation task in four different languages. We hypothesised that the degree of proficiency in each language would be related to the extent of functional activity measured in a region of interest analysis. Proficiency in each language was quantified using two neuropsychological tests. All four languages activated overlapping brain areas, corresponding to the major language regions. The number of activated voxels correlated with proficiency, so that the activated volume increased for languages in which a subject had poorer proficiency. Activation did not appear to be dependent on the age at which the language was learnt.

Adult↗

PubMed2004

Paradoxical results in the cure of chronic illness: the "burden of normality" as exemplified following seizure surgery.

Little has been written about processes of recovery following life-changing medical interventions for chronic illness. This article reviews our research with chronic epilepsy patients undergoing neurosurgery for the relief of intractable partial seizures. This research has given rise to a new conceptualization of adjustment and outcome following effective treatment of chronic illness, representing the first, detailed characterization of this process from a psychological and psychosocial perspective. Crucial to outcome are patient and family expectations prior to treatment, and learning to discard roles associated with chronic illness after treatment. These and the posttreatment affective functioning of the patient temper the view of medical outcome, and can account for paradoxical clinical effects, such as worsening patient psychosocial functioning in the context of medical treatment success. Our results have clear implications for the clinical management of chronically ill patients and their families to optimize treatment outcome.

Adaptation, Psychological↗

PubMed2004

Subtle microscopic abnormalities in hippocampal sclerosis do not predict clinical features of temporal lobe epilepsy.

PURPOSE: Subtle microdysplastic features are found in some patients with hippocampal sclerosis (HS) and refractory temporal lobe epilepsy. The significance of these findings is unknown. We investigated their frequency, relation to the pattern of HS, and clinical associations. METHODS: One-hundred forty patients with histologically confirmed HS (mean age at operation, 35 years; 85 women) were analyzed. The presence of HS and subtle structural abnormalities (SSAs) in the mesial temporal lobe and in the lateral neocortical tissue was assessed in detail. Antecedents, seizure characteristics, two verbal memory tests, and outcome in HS patients with and without SSAs were determined. RESULTS: SSAs were found in 60 (43%) of the 140 HS patients, being mesial only in 32 of the 60 cases, and lateral only in nine cases; the remaining 19 cases had both mesial and lateral abnormalities. The frequency of SSA was not related to the pattern of HS or other tested variables. Prolonged febrile convulsions were present in 26 (44%) patients with SSAs, and in 26 (34%) patients (not significant) without SSAs. The outcome after surgery did not differ between patients with SSAs (incidence rate ratio for seizure recurrence, 0.9; 95% confidence interval, 0.5-1.6) compared with patients without SSAs (reference ratio, 1). CONCLUSIONS: Forty-three percent of HS patients have SSAs in their lobectomy specimens. The presence of SSAs does not predict clinical characteristics, such as presence of prolonged febrile convulsions, postsurgical outcome, or neuropsychological performance, nor does it correlate with the histologic pattern of HS.

Adult↗

PubMed2003

Increased risk of cognitive impairment 3 months after mild to moderate first-ever stroke: a Community-Based Prospective Study of Nonaphasic English-Speaking Survivors.

BACKGROUND AND PURPOSE: Results of hospital-based studies indicate a high risk of cognitive impairment 3 months after stroke. There are no comprehensive data on this issue from prospective community-based studies comparing first-ever stroke patients with stroke-free subjects. METHODS: We administered a comprehensive neuropsychological battery to 99 community-based nonaphasic survivors of first-ever stroke at 3 months and 99 age- and sex-matched (1:1) stroke-free individuals. Domain-specific cognitive deficits were identified by blinded neuropsychological consensus. METHODS: Stroke patients were more likely to suffer any cognitive impairment (relative risk [RR], 1.5; 95% CI, 1.1 to 2.1) attributable mainly to a greater risk of single-domain cognitive impairment (RR, 2.8; 95% CI, 1.5 to 5.3) but not multiple-domain cognitive impairment (RR, 1.2; 95% CI, 0.8 to 1.9). CONCLUSIONS: In this community-based study, a first-ever stroke of mild to moderate severity was associated with a significant risk of cognitive impairment at 3 months, even in the absence of clinical aphasia. This was due primarily to an increased risk of solitary deficits rather than generalized deficits.

Adult↗

PubMed2003

Sexual outcome after epilepsy surgery.

The aim of this study was to provide a description of patient-perceived sexual change after temporal lobe resection (TLR) and extratemporal resection (ETR). Fifty-eight TLR and sixteen ETR patients completed a semistructured interview and questionnaire assessing sexual change after epilepsy surgery. Five areas of sexual functioning were addressed: sexual drive, thoughts/fantasies, interest, masturbation, and activity. Each patient's perception of sexual changes relative to perceived levels of normal functioning was assessed. Characteristically, the onset of sexual change occurred in the first three postoperative months and persisted to the time of interview. A postoperative sexual change was significantly more likely to be reported by patients who had undergone TLR (64%) than ETR (25%). In the TLR group, sexual change was significantly more frequent following right-sided resections. Marked sexual change occurred more frequently in females than males. Postoperative sexual change is an important outcome feature after epilepsy surgery. The predisposition of TLR patients to postoperative change provides further evidence for a temporal lobe contribution to sexual function.

Adolescent↗

PubMed2003

Correlation between language organization and diffusion tensor abnormalities in refractory partial epilepsy.

PURPOSE: Atypical language organization is more frequently found in patients with refractory partial epilepsy than in healthy controls; however, the reasons for this are not well known. Here we assess the relation between language laterality index (LI) and white-matter tract changes. METHODS: Nine patients with refractory partial epilepsy were assessed with a 3-T GE scanner. Functional magnetic resonance imaging (fMRI) of language and diffusion tensor imaging (DTI) were acquired. For the fMRI, a noun-verb generation task was performed, all images were motion corrected, and activated pixels in classic language areas were counted. The DTI images were acquired in six standard directions with an initial non-diffusion-weighted scan. The "average anisotropy" was determined in a region of interest in the frontal lobe, temporal lobe, and parietal lobe white matter. An asymmetry index (AI) was calculated for language and DTI. Atypical language lateralization was diagnosed if the lateralization index (LI)-language was smaller than 0.4. RESULTS: Two of the nine patients had atypical language localization (LI-language, -0.6, and 0.3); both had left temporal DTI asymmetry (LI-DTI, -0.3 and -0.2). The remaining seven patients had typical language localization, and no marked DTI abnormalities. Asymmetry in temporal lobe DTI correlated with LI-language (r= 0.8; p = 0.006). CONCLUSIONS: Atypical language lateralization in patients with partial epilepsy may be associated with white-matter tract abnormalities.

Adolescent↗

PubMed2002

Verbal memory in left temporal lobe epilepsy: evidence for task-related localization.

We explored the hypothesis that components of verbal memory are subserved by separate temporal lobe structures in patients with temporal lobe structures in patients with temporal lobe epilepsy [correction]. Uptake of 18F-fluorodeoxyglucose (FDG) measured by positron emission tomography, hippocampal volume, and memory for arbitrarily and semantically related verbal paired associates were examined in 27 patients with left temporary lobe epilepsy. Scores from memory tests performed outside the scanner were regressed against normalized resting FDG uptake at each voxel. Significant regression was seen in the left perirhinal cortex (Talaraich coordinates x, y, z: -29, 10, -34; p < 0.05) for arbitrarily related word pairs. For semantically related paired associates, significant regression was present in the left inferior temporal gyrus (x, y, z: -48, -18, -24; p < 0.05). In subsequent analyses, mean FDG uptake within a spherical region of interest centered on the perirhinal peak predicted performance on both tasks. Mean FDG uptake in a region of interest centered on the inferior temporal peak made an additional, independent contribution to memory for semantically related pairs. Hippocampal volumes did not explain any additional variance in memory scores. Our findings indicate that heterogeneity in the left temporal lobe structures mediating verbal memory function, and support the view that the perirhinal cortex is an important mnemonic substrate.

Adolescent↗

PubMed2002

Direct and indirect measures of verbal relational memory following anterior temporal lobectomy.

Medial temporal lobe (MTL) structures are implicated in forming conjunctions between events in order to form enduring relational memories; these memories are not evident using direct measures with varieties of amnesic subjects. Extratemporal brain structures are thought to be responsible for preserved memories, which are sometimes detectable using indirect measures. The present study tests this theory of multiple memory systems by examining whether preserved learning can be demonstrated for relational material in MTL-disordered subjects using an indirect measure which minimises conscious mediation of performance. The subjects had undergone anterior temporal lobectomy for relief of temporal lobe epilepsy: left-sided (LATL) cases had a mild verbal amnesia and right-sided (RATL) cases had better verbal memory, forming a comparison group. A direct measure of verbal relational memory was provided by successive trials of cued recall in a specially-constructed paired associate learning task with arbitrarily paired words; pairs consisted of either concrete or abstract words. LATL subjects performed worse than RATL subjects, and particularly so with abstract words. Following direct testing, memory for the pairings was measured indirectly using a masked recognition priming technique. RATL subjects showed savings in RT, demonstrating that masked priming can reveal evidence of the formation of conjunctions. Critically, LATL subjects showed no evidence of preserved learning with priming. Thus when MTL structures are damaged, relational memory appears to be affected without exception, consistent with the tenets of multiple memory systems theory.

Adult↗

PubMed2002

Differential functional magnetic resonance imaging language activation in twins discordant for a left frontal tumor.

Eight-year-old twins, one with a left frontal tumor and aphasic seizures, the other neurologically normal, underwent serial assessment of expressive language with functional magnetic resonance imaging and neuropsychology. The affected twin showed a significant amount of right hemisphere activation coincident with behavioral deterioration in expressive language and late growth in the tumor. This pattern of language dysfunction and the left language dominance of her co-twin suggested that the affected twin was also left dominant for language, and the significance of her right activation is discussed. We postulate that the right hemisphere activation represents a stabilizing mechanism in the context of a developmental and progressive lesion in language cortex rather than language transfer per se.

Brain Neoplasms↗

PubMed2002

Paired associate performance in the early detection of DAT.

Subjects underwent longitudinal neuropsychological assessment in order to retrospectively determine which measures of cognitive function best predicted later development of dementia of the Alzheimer type (DAT). Three groups of subjects were studied: normal controls, patients with early DAT, and questionable dementia subjects (QD). All subjects were assessed using a battery of standard neuropsychological measures and two subtests from the Cambridge Neuropsychological Test Automated Battery (CANTAB), paired associate learning and delayed matching to sample. A structured interview was also used to elicit a profile of the subject's daily functioning. Subjects were assessed every 6 months for 2 years. At the 6 month assessment, almost half of the QD group exhibited significant deterioration in scores on the computerized paired associate learning subtest, while maintaining their scores on standard measures. At the conclusion of the study, all of this QD subgroup fulfilled the NINCDS-ADRDA criteria for probable DAT pertaining to significant cognitive and functional deterioration. Performance on the C

Aged↗