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Biomedical subjects

M M Saling

Publications and source records attributed to M M Saling.

At least 19 recordsLinked to original sources

Relationship between language lateralization and handedness in left-hemispheric partial epilepsy.

OBJECTIVE: To investigate the relationship between language lateralization and handedness in patients with epilepsy and a left-sided seizure focus and in healthy control subjects. METHODS: We recruited a consecutive series of 74 patients and 70 control subjects. Functional MRI, using a noun-verb generation task, was performed to establish the language laterality index (LI). Handedness was quantified using the Edinburgh Handedness Inventory. RESULTS: Patients showed a shift toward atypical language lateralization (0.43 +/- 0.47; controls 0.57 +/- 034; p < or = 0.05) and left-handedness (55 +/- 57; controls 74 +/- 39; p < or = 0.05). The LI and handedness were correlated in patients (r = 0.54; F = 25.9; p < 0.001) but not in control subjects (r = 0.1; F = 0.64; NS). A combination of left-handedness and atypical LI was more frequent in patients (12%) than control subjects (0%; p < or = 0.05). Crossed hemispheric specialization (e.g., right-handedness associated with atypical LI) was equally frequent in patients (20%) and control subjects (16%; NS). CONCLUSION: In epilepsy patients with a left-sided seizure focus, language lateralization is correlated to handedness. The increased frequency of left-handedness and associated atypical language lateralization is most likely related to the left-hemispheric seizure focus, influencing hemispheric specialization for both domains.

Adolescent↗

Language cortex activation in normal children.

OBJECTIVE: To describe a protocol for use in young children and adolescents for determining language representation. METHODS: We performed 130 fMRI studies in 48 children and 17 adults. Verb generation (VG) and orthographic lexical retrieval (OLR) were used. The localization and lateralization of activation was rated visually. Regional voxel counts measured asymmetry and extent of activation. RESULTS: Activation was predominantly left-lateralized (children 85%, adults 94%), and there was no difference in the localization of activation for either paradigm. Children's typical sites of activation included mesial (96%), inferior (94%) and middle frontal (92%) gyri, the inferior (85%) and superior (65%) temporal cortex, and the cerebellum (67%). Less frequently activated sites were insular (50%) and posterior parietal (48%) cortices. Quantitative asymmetry index scores and visual inspection of laterality were concordant. Greater quantitative asymmetry for VG than OLR occurred in children. Laterality was not related to age, sex, task proficiency, or handedness. Frontal region voxel counts lower in children than adults and left sided counts correlated with task proficiency. CONCLUSIONS: Language fMRI can be performed in young children using resources available to clinical centers. The similarity in frequency of left language lateralization between children and adults suggests that language representation establishes early in development. The reduced amount of frontal region of interest activation in task-specific regions in children may reflect different levels of ability. However, the left-right distribution of activation does not appear to depend on task performance or age. These normative data provide a basis for decisions about language laterality in pediatric patients.

Adolescent↗

Progressive dementia after first-ever stroke: a community-based follow-up study.

OBJECTIVES: To examine the risk and determinants of a progressive dementia syndrome and cognitive impairment not dementia (CIND) in community-based nonaphasic first-ever stroke cases 1 year after stroke, relative to a matched community-based stroke-free group. METHODS: Matched cohort design, with cognitive tests given on two occasions 9 months apart to 99 mild-to-moderate first-ever stroke patients and 99 age- and sex-matched people without stroke. At follow-up, progressive dementia or CIND were diagnosed, with judges blinded to stroke/nonstroke status. RESULTS: Progressive dementia was diagnosed in 12.5% of stroke patients and 15.4% of those without strokes (RR 1.1, 95% CI 0.5 to 2.2, p = 0.85). CIND was diagnosed in 37.5% of stroke patients and 17.6% of participants without strokes (RR 2.1, 95% CI 1.2 to 3.4, p = 0.003). In multivariable regression, age (p = 0.04) and baseline cognition (p < 0.001) were independently associated with dementia whereas stroke (p = 0.002), age (p = 0.05), baseline cognition (p = 0.001), and baseline mood (p = 0.03) were independently associated with CIND at follow-up. CONCLUSIONS: In this community-based nonaphasic sample, mild-to moderate first-ever stroke was not associated with the presence of progressive dementia 1 year later, but was clearly associated with a greater risk of cognitive impairment not dementia (CIND). Baseline mood impairment remained independently associated with CIND at 1 year after taking into account stroke, age, and baseline cognitive ability.

Aged↗

"Clockness" in the detection of dementia: a semantic-conceptual effect.

We studied aspects of clock cognition that might underlie the sensitivity of the CDT in screening for dementia of the Alzheimer type (DAT). Two groups, 15 patients with mild-moderate DAT and 15 controls, were assessed with the CDT and specially designed tests of clock-related cognition. Patients were impaired on the CDT, but they did not differ from controls in copying a clock face or selecting the correct representation of a given time. Patients were worse than controls at distinguishing between clock and nonclock objects, detecting anomalies in clocks, and in setting time irrespective of response format. These findings suggest that semantic-conceptual aspects of clock-related cognition are important in discriminating between patients with DAT and controls.

Aged↗

A neurocognitive account of frontal lobe involvement in orthographic lexical retrieval: an fMRI study.

The present study aimed to examine the relationship between activation induced by an orthographic lexical retrieval (OLR) task and performance across time on the standard clinical version of OLR, the Controlled Oral Word Association Test (COWAT). The number of significantly activated pixels in a frontal lobe region of interest (encompassing middle and inferior frontal gyri) were measured for the left and right cerebral hemispheres in 20 volunteers. A relationship between the pixel count and the total number of words retrieved during the COWAT was found for the left but not the right hemisphere. Further examination of the left-sided relationship showed that the number of pixels in the left middle frontal region of interest correlated significantly with the second, but not the first, 30-s COWAT epoch. By contrast, the first epoch, but not the second, correlated significantly with the pixel count within the left inferior frontal region of interest. These relationships suggest differential involvement of dorsolateral and ventrolateral prefrontal cortex in specific cognitive processes fundamental to the production of language. Interindividual variation in activation levels may reflect underlying differences in cognitive processing capacity. This study is the first attempt to examine the relationship between fMRI activation and standard verbal fluency performance.

Adult↗

The longitudinal course of adjustment after seizure surgery.

Surgical alleviation of chronic epilepsy can give rise to a process of adjustment as the chronically ill patient learns to become well. This process can manifest clinically as an array of symptoms which we have previously described as the 'burden of normality'. The aim of this study was to explore the longitudinal course of post-operative adjustment by mapping the incidence of symptoms of the burden of normality over a period of 2 years, and examining symptom occurrence relative to seizure outcome. A series of 90 anterior temporal lobectomy (ATL) patients was drawn from our Seizure Surgery Follow-up and Rehabilitation Program. All patients were prospectively assessed using the Austin CEP Interview, which covers symptoms of the burden of normality. In total, 66% of patients reported symptoms at some time within the first 2 years of surgery. Symptoms often emerged by the 3 month review, but were still seen frequently in the second year. At the 24 month review, patients who had been seizure free or experienced auras only within the previous 18 months were significantly more likely to report symptoms compared to patients who had experienced complex partial and/or generalized tonic-clonic seizures (P = 0.03). Surgical alleviation of seizures in chronic epilepsy brings with it the burden of normality. Recognition of this syndrome is essential in maximizing patient outcome.

Adult↗

Subjective complaints, verbal fluency, and working memory in mild multiple sclerosis.

Patients with mild multiple sclerosis (MS) regularly report subjective complaints characterized by generalized cognitive inefficiency. A feature of these complaints is reduced verbal fluency, for example, losing the thread of conversation. Mild MS patients and controls were compared on subjective complaints, verbal fluency, and working memory, and the possible role of working memory was investigated. As predicted, subjective difficulties and verbalfluency each correlated with working memory. Subjective difficulties and verbal fluency were also related. Within the control group, the subjective difficulties were associated only with depression. On the other hand, in the MS group, subjective difficulties were unrelated to affective state but were correlated with working memory. For the patients, partialing out depression and anxiety did not influence any of the correlations involving subjective difficulties, verbal fluency, or working memory. These findings support the proposal that working memory impairment underlies subjective complaints of mild MS patients and that verbal dysfluency is part and parcel of this phenomenon.

Adult↗

Interictal discourse production in temporal lobe epilepsy.

Discourse production was investigated in 16 patients with left-temporal-lobe epilepsy (LTLE) and 17 neurologically normal relatives. Narrative was elicited with the Joanette and Goulet (1989) eight frame "Cowboy" cartoon on three immediately consecutive occasions. Variables of interest were fluency (words/s), speaking time, and word count. While controls produced increasingly concise forms of the story over repetitions, the TLE group became more verbose. Fluency did not not differentiate the groups. These findings suggest that LTLE is associated with macrolinguistic disturbances. The role of capacity limitations and motivational factors in TLE discourse production is discussed.

Adolescent↗

Components of verbal learning and hippocampal damage assessed by T2 relaxometry.

We studied a group of 31 temporal lobe epilepsy patients (25 left, 6 right) with unilateral hippocampal sclerosis evident on magnetic resonance imaging. Single slice T2 relaxation times were acquired for the left and right hippocampi. Principal components analysis of preoperative memory data resulted in two factors that reflect a distinction between arbitrary and semantic forms of verbal recall. The former component correlated with left hippocampal T2 relaxation time, while the latter component did not. This study suggests that variation in left hippocampal integrity is more related to the acquisition of arbitrary associates than semantically structured material, and reinforces the possibility that the left temporal lobe is functionally heterogeneous with respect to memory.

Adolescent↗

Anterior temporal abnormality in temporal lobe epilepsy: a quantitative MRI and histopathologic study.

OBJECTIVE: To examine the nature and frequency of anterior temporal lobe (AT) abnormalities that occur in intractable temporal lobe epilepsy (TLE). METHODS: We reviewed the MR scans and clinical histories of 50 consecutive patients with intractable TLE. Histopathology was available in 42 surgically treated cases. RESULTS: MRI demonstrated loss of the gray-white matter differentiation and decreased T1- and increased T2-weighted signal in the ipsilateral AT in 58% of the 50 patients. This appearance was observed in 64% of the 36 patients with hippocampal sclerosis (HS) but was also seen in patients without HS. These changes were associated with temporal lobe atrophy, a higher hippocampal T2 relaxation time, and a history of febrile convulsions. Pathologic examination showed that the MRI appearances were not caused by dysplasia, degenerative abnormalities, or inflammatory change. Histologic quantitation showed increased glial cell nuclei counts in the intractable TLE cases compared with controls. There was no difference in glial cell numbers between cases with AT abnormality and those without this appearance. Presence or absence of changes was not predictive of preoperative neuropsychology, postoperative change in neuropsychology, or seizure outcome after surgery. CONCLUSIONS: These frequently seen ipsilateral changes are not caused by gliosis and may reflect a nonspecific increase in water content in the temporal lobe. This may be due to myelin abnormalities or some other as yet unidentified pathologic factor.

Adolescent↗

Outcome of temporal lobectomy: expectations and the prediction of perceived success.

PURPOSE: This study examined the independent contributions of medical and psychosocial factors to perceived surgical success. We aimed to develop a multidimensional model predictive of perceived surgical outcome. METHODS: Fifty anterior temporal lobectomy (ATL) patients were prospectively assessed, using a formally coded, semistructured clinical interview. This has been routinely administered pre- and post-operatively as part of a larger, nationwide study of Australian ATL patients. The interview covers a broad range of epileptological, psychiatric, neuropsychological and psychosocial issues. Variables from these domains were examined in relation to the patient's perception of surgical success at the 6-month post-operative review. RESULTS: Variables that correlated with success were analysed using principal components analysis and multiple regression. A predictive model of perceived surgical success emerged, which highlighted the multidimensionality of outcome. Independent effects were observed for both medical and psychosocial factors. These included the patients' pre-operative expectations of surgery, their post-operative seizure outcome, and affective state. The findings also highlighted the importance of discarding sick role behaviours associated with chronic epilepsy, after surgery. CONCLUSIONS: Traditional outcome measures (seizure frequency, post-operative affect) are significant in the patient's evaluation of surgical success. These traditional measures, however, do not account for the process of psychosocial adjustment surrounding seizure surgery. This process involves two major components: (1) positive anticipation of change prior to surgery, and (2) learning to discard roles associated with chronic epilepsy after surgery.

Adult↗

Reorganization of verbal memory and language: a case of dissociation.

Left-to-right reorganization of verbal memory following early left hemisphere damage has been reported in patients whose expressive language is governed by the right hemisphere. We present a case in which verbal memory performance was intact, despite severe left mesial temporal damage, and despite aphasia on left internal carotid sodium amytal ablation. The distribution and degree of left mesial temporal damage was assessed visually and quantitatively on MRI. These findings raise the possibility that verbal memory may shift to the language-nondominant hemisphere as a result of early left mesial temporal damage.

Brain Damage, Chronic↗

Patient readmission and support utilization following anterior temporal lobectomy.

The aim of this study was to examine factors precipitating patient readmission, following anterior temporal lobectomy (ATL) for refractory epilepsy. A second aim was to explore the use of hospital outpatient and community support services ('outpatient services') by this patient population. These aims served the more general goal of identifying patients most likely in need of services additional to those routinely provided by our Seizure Surgery Follow-up and Rehabilitation Programme. The medical records of 100 consecutive ATL patients were retrospectively examined for the incidence and diagnoses precipitating acute readmission, and the utilization of additional outpatient services. Twenty-one patients (21%) required readmission post-ATL, totalling 47 readmissions between them. Psychiatric diagnoses were the most prevalent (53%), including anxiety, depression and/or post-ictal psychosis. Epileptological diagnoses were the other main precipitant (28%). Additional outpatient services were predominantly utilized for ongoing psychological support. Of the 21 patients requiring readmission, 10(10%) also needed additional outpatient services. These patients were predominantly female or unemployed, in contrast to male or employed patients who tended to require readmission only. Seventeen patients (17%) were maintained within the community using additional outpatient services only. Characteristics of these patients included disrupted family dynamics, limited social networks, and/or a psychiatric history. These patients were also more frequently beyond the 24-month follow-up period of the programme. A profile of patients most in need of additional support services can be constructed to assist team planning of proactive management strategies for the rehabilitation phase of ATL.

Acute Disease↗

Familial partial epilepsy with variable foci: a new partial epilepsy syndrome with suggestion of linkage to chromosome 2.

Familial partial epilepsy with variable foci (FPEVF) joins the recently recognized group of inherited partial epilepsies. We describe an Australian family with 10 individuals with partial seizures over four generations. Detailed electroclinical studies were performed on all affected and 17 clinically unaffected family members. The striking finding was that the clinical features of the seizures and interictal electroencephalographic foci differed among family members and included frontal, temporal, occipital, and centroparietal seizures. Mean age of seizure onset was 13 years (range, 0.75-43 years). Two individuals without seizures had epileptiform abnormalities on electroencephalographic studies. Penetrance of seizures was 62%. A genome-wide search failed to demonstrate definitive linkage, but a suggestion of linkage was found on chromosome 2q with a LOD score of 2.74 at recombination fraction of zero with the marker D2S133. FPEVF differs from the other inherited partial epilepsies where partial seizures in different family members are clinically similar. The inherited nature of this new syndrome may be overlooked because of relatively low penetrance and because of the variability in age at onset and electroclinical features between affected family members.

Adult↗

Pattern and significance of cerebral microemboli during coronary artery bypass grafting.

BACKGROUND: Strokes that occur during coronary artery bypass grafting are often caused by embolism. Intraoperative transcranial Doppler monitoring can detect cerebral microemboli. The aims of this study were to identify the pattern of microembolic phenomena during various stages of coronary artery bypass grafting, to verify whether numbers of high-intensity transient signals correlated with early neuropsychologic deficits, and to identify, using magnetic resonance imaging scans, whether radiologic evidence of cerebral infarction correlated with microembolic numbers during the bypass period. METHODS: Forty-one consecutive patients undergoing coronary bypass grafting with transcranial Doppler monitoring were enrolled in this study. All had preoperative and postoperative magnetic resonance imaging brain scans. A subgroup of 32 patients were studied by comparing microembolic load and early neuropsychological outcomes. RESULTS: Transcranial Doppler monitoring confirmed that most microemboli occurred during cardiopulmonary bypass. A significant early neuropsychological deficit after coronary artery bypass grafting did correspond to the total microembolic load during bypass (p = 0.008). However, patients with cerebral infarction on magnetic resonance imaging had significantly more microembolic signal during the preincision phases and not during the bypass period. CONCLUSIONS: Microembolic load during bypass is associated with early neuropsychologic deficits. In contrast, patients who show evidence of strokes during coronary artery bypass grafting have a higher microembolic load during the preincision phase than those without cerebral infarction. Differing mechanisms may be responsible for these different outcomes.

Aged↗

Patient expectations of temporal lobe surgery.

PURPOSE: The purpose of this study was to examine expectations of postoperative quality of life expressed by patients undergoing anterior temporal lobectomy (ATL) for the control of intractable seizures. An important component of this study was an exploration of the relationship between preoperative expectations and perceived success of the operation. METHODS: Psychosocial functioning of 60 patients was assessed pre- and postoperatively, using a standardised, semistructured clinical interview. Preoperative assessment included a detailed examination of the patients' expectations of surgery, while postoperative assessment at 6 months examined the patients' perception of surgical success with respect to seizure outcome and postoperative psychosocial status. RESULTS: A range of expectations were expressed about postoperative outcome. These were classified into 11 posthoc categories. Patients who perceived the operation as a success tended to endorse 'practical' expectations (i.e., driving, employment, activities) preoperatively, rather than expectations of a psychologic or social nature (i.e., self-change, relationships). These patients experienced fewer postoperative seizures and psychosocial difficulties. In contrast, a perceived lack of success was associated with greater emphasis on psychosocial expectations preoperatively. These patients experienced a greater number of perceived postoperative psychosocial difficulties, and more postoperative seizures. CONCLUSIONS: Preoperative expectations of surgery formed an important baseline against which to assess postoperative outcome, and should constitute a routine part of assessment in studies of psychosocial outcome of ATL.

Adaptation, Psychological↗