Presurgical Assessment (presurgical + assessment)

Distribution by Scientific Domains


Selected Abstracts


Lateralising Value of Neuropsychological Protocols for Presurgical Assessment of Temporal Lobe Epilepsy

EPILEPSIA, Issue 3 2003
Nozomi Akanuma
Summary: ,Purpose: To estimate the value of neuropsychological measurements in determining the side of seizure onset for presurgical assessment in patients with temporal lobe epilepsy. The lateralising value of neuropsychological protocols was evaluated for all patients and in subpopulations depending on surgical outcome with regard to seizure control, speech dominance, neuropathology, and need for intracranial EEG recordings. Methods: A battery of neuropsychological procedures was carried out preoperatively in 125 patients who underwent left (n = 66) or right (n = 59) temporal lobectomies. Binary logistic regression analysis was performed to find sets of variables that allowed the best prediction of the side of seizure onset (assumed to be the operated-on side). Results: Combinations of noninvasive neuropsychological tests and Wada subscores showed the highest lateralising values: 80.8% for all patients, 79.4% in seizure-free patients, 86.0% in patients not rendered seizure free, 85.7% in left speech patients, 77.8% in non,left speech patients, 89.3% in patients with mesial temporal sclerosis (MTS), 78.1% in non-MTS patients, 80.3% in patients who underwent intracranial EEG recordings, and 77.3% in those who did not. Conclusions: The lateralising value (80-90%) of neuropsychological protocols appears similar to that of other tests widely accepted for lateralisation (ictal and interictal scalp EEG and neuroimaging). Attention should be paid to neuropsychological results, particularly from the Wada test, during presurgical assessment of temporal lobe epilepsy, as they can provide strong support for findings from other lateralising tests, particularly in patients with presumed MTS or in left-speech patients. [source]


Lateralizing and Localizing Values of Ictal Onset Recorded on the Scalp: Evidence from Simultaneous Recordings with Intracranial Foramen Ovale Electrodes

EPILEPSIA, Issue 11 2001
G. Alarcón
Summary: ,Purpose: The value of scalp recordings to localize and lateralize seizure onset in temporal lobe epilepsy has been assessed by comparing simultaneous scalp and intracranial foramen ovale (FO) recordings during presurgical assessment. The sensitivity of scalp recordings for detecting mesial temporal ictal onset has been compared with a "gold standard" provided by simultaneous deep intracranial FO recordings from the mesial aspect of the temporal lobe. As FO electrodes are introduced via anatomic holes, they provide a unique opportunity to record simultaneously from scalp and mesial temporal structures without disrupting the conducting properties of the brain coverings by burr holes and wounds, which can otherwise make simultaneous scalp and intracranial recordings unrepresentative of the habitual EEG. Methods: Simultaneous FO and scalp recordings from 314 seizures have been studied in 110 patients under telemetric presurgical assessment for temporal lobe epilepsy. Seizure onset was identified on scalp records while blind to recordings from FO electrodes and vice versa. Results: Bilateral onset (symmetric or asymmetric) was more commonly found in scalp than in FO recordings. The contrary was true for unilateral seizure onset. In seizures with bilateral asymmetric onset on the scalp, the topography of largest-amplitude scalp changes at onset does not have localizing or lateralizing value. However, 75,76% of seizures showing unilateral scalp onset with largest amplitude at T1/T2 or T3/T4 had mesial temporal onset. This proportion dropped to 42% among all seizures with a unilateral scalp onset at other locations. Of those seizures with unilateral onset on the scalp at T1/T2, 65.2% showed an ipsilateral mesial temporal onset, and 10.9% had scalp onset incorrectly lateralized with respect to the mesial temporal onset seen on FO recordings. In seizures with a unilateral onset on the scalp at electrodes other than T1/T2, the proportions of seizures with correctly and incorrectly lateralized mesial temporal onset were 37.5 and 4.2%, respectively. Thus the ratio between incorrectly and correctly lateralized mesial temporal onsets is largely similar for seizures with unilateral scalp onset at T1/T2 (16.7%) and for seizures with unilateral scalp onset at electrodes other than T1/T2 (11.2%). The onset of scalp changes before the onset of clinical manifestations is not associated with a lower proportion of seizures with bilateral onset on the scalp, or with a higher percentage of mesial temporal seizures or of mesial temporal seizures starting ipsilateral to the side of scalp onset. In contrast, the majority (78.4%) of mesial temporal seizures showed clinical manifestations starting after ictal onset on FO recordings. Conclusions: A bilateral scalp onset (symmetric or asymmetric) is compatible with a mesial temporal onset, and should not deter further surgical assessment. Although a unilateral scalp onset at T1/T2 or T3/T4 is associated with a higher probability of mesial temporal onset, a unilateral onset at other scalp electrodes does not exclude mesial temporal onset. A unilateral scalp onset at electrodes other than T1/T2 is less likely to be associated with mesial temporal onset, but its lateralizing value is similar to that of unilateral scalp onset at T1/T2. The presence of clinical manifestations preceding scalp onset does not reduce the localizing or lateralizing values of scalp recordings. [source]


Ultrasound for Accurate Measurement of Invasive Breast Cancer Tumor Size

THE BREAST JOURNAL, Issue 3 2006
Ashraf Shoma FRCS
Abstract: Accurate presurgical assessment of tumor size is important for choosing appropriate treatment, especially with the increasing use of neoadjuvant and minimally invasive therapy. Breast sonography is increasingly used by breast surgeons as a part of their basic clinical evaluation. We undertook this study to compare clinical evaluation, mammography, and breast sonography for evaluating breast tumor size. A prospective analysis of 124 consecutive patients with palpable breast cancer was performed. Tumor masses belonging to T1 and small T2 were selectively selected. All women had clinical, mammographic, and sonographic assessment of tumor size. Measurements were compared to the pathologic tumor size of the surgical specimen. Both mammographic and sonographic measurements tend to underestimate tumor size, while clinical assessment tends to overestimate it. Ultrasound was significantly more accurate in determining tumor size. The maximal tumor diameter measured was within 2 mm of the pathologic tumor size in 45.2% of cases measured by breast ultrasound, 28.2% of cases measured by mammography, and 14.5% of cases measured clinically. These data suggest that ultrasound is more accurate than clinical breast examination and mammography in assessing breast cancer size. Ultrasound assessment should be used by surgeons as an accurate adjunct to clinical examination in outpatient breast clinics. [source]


Ictal onset localization of epileptic seizures by magnetoencephalography

ACTA NEUROLOGICA SCANDINAVICA, Issue 4 2002
C. Tilz
Objective, The aim of this study was to localize the ictal onset zone of focal epileptic seizures by magnetoencephalography (MEG) and to compare the results with interictal MEG localizations, ictal and interictal electroencephalography (EEG) results and magnetic resonance imaging (MRI) in epilepsy surgery candidates. Material and methods , Data of 13 patients with partial seizures during MEG recording were analysed. Measurements were performed with a Magnes II dual unit system. Results, In six of 13 cases, the ictal onset zone could be localized by MEG, with all interictal MEG findings being confirmed by ictal MEG results. In four cases, the ictal MEG localization results were corresponding to the ictal EEG localization results. In two cases, EEG yielded no comparable information. Conclusion , Ictal onset localization is feasible with MEG. Both interical and ictal MEG contribute valuable information to the presurgical assessment of epilepsy patients. [source]


Prognostic factors in the surgical treatment of medically intractable epilepsy associated with mesial temporal sclerosis

ACTA NEUROLOGICA SCANDINAVICA, Issue 6 2001
M. J. Hennessy
Objectives, To assess the prognostic factors determining seizure remission after temporal lobectomy for intractable epilepsy associated with mesial temporal sclerosis (MTS) at pathology. Methods, The clinical and investigative features of 116 consecutive patients who had temporal lobe surgery for drug-resistant epilepsy and MTS at pathology were assessed using actuarial statistics and logistic regression analysis. Results, At a median follow-up of 63 months the probability of achieving at least a 1-year period of continuous seizure freedom was 67%. Factors contributing to a favourable outcome were interictal EEG localization to the operated lobe and the absence of secondarily generalized seizures. These were also selected in the multivariate analysis, although at lower statistical significance (P=0.08 and 0.09, respectively). Perinatal complications were associated with a significantly worse outcome but overall, complicated febrile convulsions and congruent neuropsychological deficits were not significantly predictive variables. Conclusions, The present findings may aid in the non-invasive presurgical assessment of patients with intractable TLE and clinical and neuroimaging evidence of MTS. [source]


Advanced imaging: Magnetic resonance imaging in implant dentistry

CLINICAL ORAL IMPLANTS RESEARCH, Issue 1 2003
A review
Abstract: For accurate and safe placement of dental implants, and planning of associated surgery, a full assessment of the surgical anatomy of the site is necessary. Thus, it is highly desirable to have tomographic, sectional information available, to permit the implant to be aligned correctly. In recent years, X-ray computed tomography (CT) has become accepted as the gold standard in assessment, but the exposure to ionising radiation can be substantial. Artefacts due to dental restorations can also be significant, and some doubts may exist over the accuracy of reformatted CT. Magnetic resonance imaging (MRI) entails no exposure to ionising radiation, and allows direct acquisition of tomographic information in any desired plane. Sequential studies may be safely performed, allowing us a valuable insight into bone graft behaviour. Other than in a small number of cases, MRI may be safely used for presurgical assessments. Artefacts are few and in most cases localised. The surgical confidence from the sectional information gained is a significant step forward in the safe placement of dental implants. [source]