Intra-Operative Direct Electrical Stimulations of the Central Nervous System: The Salpêtrière Experience With 60 Patients

Indications of surgical treatment for lesions in the central nervous system depend on the risk of a definitive neurological deficit, related to the benefit of resection. Detection of eloquent areas is then necessary because of major individual variability. Neuro-imaging functional techniques are in development and are beginning to be efficient for cortical sensorymotor mapping, but still lack sensitivity and specificity for language mapping, and remain unable to give real-time data during surgery and to perform sub-cortical mapping. The more precise and reliable method of functional mapping is represented by the intra-operative direct electrical stimulations (DES), which allow identification and preservation of essential pathways for motricity, sensibility and language, at each level of the central nervous system (cortico-subcortical). We report our experience of DES in the surgery of tumours and vascular malformations located in supra-tentorial brain eloquent areas, with a consecutive series of 60 patients operated on under general or local anaesthesia, from November 1996 until May 1999 in our department at La Salpêtrière Hospital. Presenting symptoms in the 60 subjects (39 males, 21 females, mean age: 45 years) were seizures in 37 cases with normal clinical examination, and mild neurological deficit in 29 cases. MRI showed 60 supra-tentorial brain lesions: 30 precentral, 12 postcentral, 14 perisylvian in the dominant hemisphere, 4 deep-seated. All subjects underwent surgical resection using DES, with supratentorial cortico-subcortical mapping under general anaesthesia for motor areas detection in 43 cases and under local anaesthesia for sensori-motor and/or language tasks in 17 cases. The final histological diagnosis was 44 gliomas (31 low-grade and 13 high-grade), 9 metastasis, 3 cavernomas, 4 arteriovenous malformations (AVM). Resection was total or subtotal in 52 cases (87%) and partial in 8 cases (13%). 29 patients had no post-operative deficit, while the other 31 patients were impaired post-operatively, with in all cases, except 3, a complete recovery delayed for 15 days to 3 months (overall morbidity: 5%). The median follow up was 14 months. Intra-operative direct electrical stimulations of the central nervous system constitute a reliable, precise and safe method, allowing the realization of a functional mapping useful for all operations of lesions located in eloquent areas. This technique allows a minimization of definitive post-operative neurological deficit, and concurrently an improvement in the quality of resection.     

A decade of spontaneous long-term course of psychogenic impairment in a community population sample

Background: Our epidemiological study demonstrates the spontaneous long-term course of predominantly psychosocially influenced (“psychogenic”) disorders (neurotic spectrum disorders, personality disorders, stress reactions and somatoform disorders) in a representative community sample of the normal adult population of Mannheim, an industrial and university town in Germany. The natural spontaneous course of these disorders in a population sample over a long period remains largely unknown. Method: Beginning in 1979 (n _t1 = 600) a random population sample was investigated three times over a mean period of approximately 11 years. The last follow-up study ended in 1994 (n _t3 = 301). The follow-up sample was representative of the t1 sample. Psychodynamically trained and clinically experienced interviewers used a semi-structured interview and standardized clinical and psychometric instruments. Psychogenic impairment was assessed using a standardized expert rating (Impairment Score, IS). Results: The mean sum-score of psychogenic impairment after 11 years exceeded the value at t1. The case rate (point prevalence, ICD diagnosis + clinical cut-off/IS) increased from 21.6% at t1 to 26.2% at t3 in the investigated follow-up sample. Intra-individual correlation of psychogenic impairment between t1 and t3 was high (r = 0.55). We found strong evidence for an unfavorable long-term course of psychogenic impairment and only a weak tendency (23.1%) for spontaneous remission of clinically relevant psychogenic impairment. Within a regression model clinical variables, childhood development conditions and personality traits at t1 predicted psychogenic impairment at t3. Conclusion: All clinical variables conclusively indicate an unfavorable spontaneous long-term course of psychogenic impairment. Together with the well-known high prevalence of psychogenic disorders in the normal population, this underlines the need for early therapeutic and preventive intervention. Accepted: 20 August 1999     

Neurological soft signs in schizophrenia: Assessment and correlates

A German version of the Neurological Evaluation Scale (NES) was administered to 143 schizophrenic patients, 45 of them being severly chronic and disabled. Seventy-eight alcohol-dependent inpatients and 57 healthy volunteers were tested as control groups. Neurological soft signs (NSS) were rated with convincing agreement. Schizophrenic patients are more impaired on all scales than healthy controls. The chronic, severly disabled schizophrenic patients are more impaired compared with the main group of schizophrenic patients and both control groups. A significant patients and alcohol-dependent patients was only found for the subscale Motor Coordination. Compared with healthy controls the alcohol-dependent patients show a higher NES total score. The NES total score was related to the relative width of the third ventricle. Total score and subscales were correlated consistently with the level of cognitive functioning as measured by the Raven Standard Progressive Matrices and various neuropsychological tests presumably sensitive to dysfunctions of the prefrontal cortex. The NSS were related to positive as well as to negative symptoms, the correlations with negative symptoms being confined to items of Cognitive Disorganization. This close association of psychomotor and cognitive dysfunctions may be seen as related to the frequently discussed dysfunctions of the prefrontal cortex or the neurointegrative deficit postulated by Meehl.     

Dynamic assessment of pelvic floor function in women using the intravaginal device test

The aim of the study was to assess pelvic floor function and dysfunction using intravaginal devices (IVD test). One hundred and eighty-five patients were evaluated, 65 (35.1%) in the control group without genital prolapse and 120 (64.9%) in the study group, with prolapse. Anatomic changes were evaluated on a scale described by Halban, and functional classification based on palpation of the muscles of the pelvic floor during contraction. Additionally, weighted vaginal devices were used to assess pelvic floor function. Statistic analysis was performed with the Spearman-Pearson correlation coefficient, the ² test and the response/ operator characteristic curve. There was an acceptable correlation between the IVD test and the functional classification of 0.75. Using this classification, the IVD test showed 86.58% sensitivity, 75.72% specificity, and had a positive predictive value 73.95% and a negative predictive value of 87.64%. Significant differences between pelvic floor muscle activity in those patients with and without genital prolapse were observed (X²=58.28, P=<0.005). It was concluded that pelvic floor assessment can be done through the evaluation of active muscle strength or pelvic floor integrity using the functional classification and the IVD test.EDITORIAL COMMENT: In 1988, Peattie and Plevnick introduced the use of weighted vaginal cones to exercise the pelvic floor muscles and treat stress urinary incontinence [1]. Contreras-Ortiz and Nuñez build on this earlier work, using a similar technique to assess pelvic floor muscle function and integrity. Specifically, pelvic floor function is assessed by a combination of digital palpation of the pubococcygeus muscle at rest and during contraction; pelvic floor integrity is assessed by the patient's ability to retain a weighted cone vaginally for 1 minute. Scoring of these two parameters can then be objectively followed for therapeutic response to treatment for urinary incontinence or pelvic relaxation. Many of us forget to palpate the pubococcygeus muscle at rest and during an elicited contraction during baseline or follow-up examination. As this study indicates, simple assessment of pelvic floor function and integrity is possible, and should be used both clinically and in research.     

The functional restoration approach for chronic spinal disability

The functional restoration approach to treating chronic spinal disability consists of a medically directed, interdisciplinary team approach to physical reconditioning and a cognitive-behavioral crisis intervention procedure for dealing with related psychosocial problems. One- and two-year follow-up studies have demonstrated the clinical efficacy of this approach. The present article describes this approach and summarizes the research documenting its success in treating patients with chronic spinal disability. This article also highlights the pitfalls in misunderstanding and misrepresenting the components of the functional restoration approach when evaluating treatment efficacy.     

In vivo CT measurement of blood-brain transfer constant of iopamidol in human brain tumors

Summary We have developed an in vivo method of measuring the blood-brain transfer constant (K) of iopamidol and the cerebral plasma volume (V_p) in brain tumors using a clinical X-ray CT scanner. In patient studies, Isovue 300 (iopamidol) was injected at a dosage of 1 ml/kg patient body weight. Serial CT scans of the tumor site and arterial blood samples from a radial artery were taken up to 48 min after injection. The leakage of iopamidol into the brain through the blood-brain barrier was modelled as an exchange process between two compartments, the intravascular plasma space and the tissue interstitial space. Using this model and the concentration measurements in blood plasma and tissue, quantitative estimates of K and V_p in brain tumors were obtained. In addition, distribution of the estimated values of K and V_p in tumors were displayed as false colour functional images overlaid on the conventional CT scan.In a study of twelve patients with anaplastic astrocytoma (n = 3), glioblastoma multiforme (n = 4) or metastases (n = 5) the mean K and VP values in tumor were found to be 0.0273 ± 0.0060 ml/min/g and 0.068 ± 0.11 ml/g respectively. These values were significantly higher than those in grey or white matter in the contralateral normal hemisphere (p < 0.05). The functional images showed variations in K and V_p within the tumor which were difficult to perceive in the original contrast enhanced CT scans.     

Rats bred for ethanol sensitivity: Impairment of swimming by ethanol and pentobarbital

Rats selectively bred for disparate degrees of ethanol-induced depression of spontaneous locomotor activity (most affected = MA; least affected = LA) were trained on a swim task. Undrugged rats of the MA line swam significantly faster than rats of the LA line. Ethanol, 0.0–2.25 g/kg i.p., produced dose-dependent increases in swim time in rats of the 13th generation (F13). Averaged over trials, these increases were greater in LA than in MA rats and greater in males than in females, but there was no sex difference in peak impairment. Increases in swim time were uncorrelated with predrug performance. These findings were confirmed in younger F17 rats receiving 1.75 g EtOH/kg i.p. Although the lines differed in ethanol-induced impairment, F17 males of the two lines were not differentially impaired by pentobarbital (12.5–22.5 mg/kg, i.p.). The existence of task-dependent line differences in ethanol sensitivity emphasizes the nonunitary nature of ethanol-induced behavioral depression.     

A neuropsychological investigation of dementia in motor neurone disease (MND)

Different clinical criteria for diagnosing dementia were compared in a sample of 69 patients with motor neurone disease (MND). Participants’ performances on a computerised battery of neuropsychological tests were evaluated to assess the usefulness of these tests in predicting dementia in MND. The results indicated that when diagnostic criteria for frontotemporal (FTD) were used as part of a questionnaire method of diagnosing dementia the incidence of dementia in MND was considerably greater than traditional estimates suggest. Through a series of logistic and multiple regressions the results demonstrated that neuropsychological test performance related well to diagnostic classifications of dementia. MND patients with a clinical diagnosis of dementia were likely to demonstrate impaired new learning; poor working memory and planning; slowness in information processing and rigidity in thinking. These features, which are typical of cases of FTD, suggest that the dementia of MND is usefully characterised as a form of FTD. The finding that neuropsychological impairment correlated with behavioural features of dysexecutive impairment in daily living, indicates that the management focus in MND must be broadened to include cognitive/behavioural issues.     

Cortical activation during retrieval of arithmetical facts and actual calculation: a functional magnetic resonance imaging study

By using functional magnetic resonance imaging (fMRI), the neural substrates involved in mental recitation of the single-digit multiplication table and serial subtraction were studied. The former depends mostly on well-learned arithmetical facts, while the latter requires arithmetic processing. Activation during each task was compared with that in a number counting control. During the recitation of single-digit multiplication, the activated regions included the area lying along the left intraparietal sulcus, the premotor and supplementary motor areas, and the posterior portion of the left inferior frontal gyrus. The areas activated during serial subtraction included these areas as well as the bilateral prefrontal and right parietal areas. From the results obtained during retrieval of the multiplication table in this study and previous studies, it was concluded that semantic memory of the multiplication table is stored in the area lying along the intraparietal sulcus and that the frontal areas play an executive role in utilizing the semantic memory of arithmetical facts. It was assumed that the arithmetical facts requiring actual calculation are also stored in the same region. The additional activation during serial subtraction compared with the activation during retrieval of the multiplication table is probably due to the processes of actual calculation. These processes include proper alignment of digits, which may have caused the right parietal activation, and maintaining digits needed for the mental serial subtractions, which may have caused the bilateral prefrontal activation.     

Effect on electroencephalogram of chewing flavored gum

The objective of the present study was to evaluate the effect on the electroencephalogram (EEG) of a chewing gum with and without our prepared new flavor. Electroencephalograms were obtained after the following three tests: chewing pure gumbase with sucrose (standard gumbase), chewing flavored standard gum and the inhalation of flavored aromatic oil. As the control, we used the pre-stimulus control EEG record without a stimulus. We examined the relationship between the pre-stimulus control record and the post-stimulus record using the changes of power in four bands. Chewing the standard gumbase led to an increase in the alpha wave and a decrease in the beta wave. Chewing the flavored standard gum and inhaling the flavored aromatic oil each increased the alpha and beta waves. In addition, chewing the flavored standard gum led to a change in the ratio of theta wave in the frontal area. The difference in the theta, alpha and beta bands in chewing gum with and without the added flavor suggested that the flavor as well as chewing could induce concentration with a harmonious high arousal state in brain function.