EEG monitoring during carotid surgery: who should do the monitoring?

Recently, a new hematopoietic growth factor, stem cell factor, the ligand for the c-kit-proto-oncogene, has been cloned. The gene for this factor or for its receptor are deleted in two well known series of mice mutants which display pleiotropic stem cell defects. Therefore, this factor supposedly plays an important role in stem cell biology. This paper reviews some of the elegant genetic work which led to the discovery of the factor and of its receptor, the biological effects that this factor exerts in the hematopoietic system in normal individuals and in patients with Diamond-Blackfan anemia and speculates on some of its potential clinical applications.     

On the uses of intracranial pressure monitoring

Intracranial pressure monitoring with an intra-ventricular catheter, an external transducer and a continuous chart recorder was undertaken in 15 patients with acute brain damage and in six patients suspected of suffering from long-standing raised intracranial pressure. In the acute cases, monitoring was useful in the diagnosis of raised intracranial pressure and in the assessing of the efficacy of its treatment. In the chronic cases, the clinical suspicion of raised pressure was confirmed or refuted without doubt. Complications were minimal, and the method was judged to be of considerable value in selected cases.     

Chronic pancreatitis and neoplasia: correlation or coincidence

Renal biopsy specimens from patients with membranous nephropathy (MN) were studied using immunohistochemical labelling to clarify the aetiological significance of Helicobacter pylori antigen in this disease. Sixteen specimens were examined, from 7 male and 9 female MN patients. Renal specimens from patients with diabetic nephropathy and IgA nephropathy, and from autopsied patients without renal diseases were obtained as controls. Immunohistochemical labelling was performed using one polyclonal antibody and three monoclonal antibodies against H. pylori. Specimens from 11 of the MN patients revealed granular deposits along the glomerular capillary walls, which reacted positively with polyclonal antibody after trypsin pretreatment. None of the control specimens revealed positive labelling. The MN specimens showed no positive reaction with the primary antibody, which had been treated for immunoabsorption testing using sonicated H. pylori. We also determined H. pylori status in these MN patients histologically and/or serologically. Of the 11 patients whose glomeruli were positive for anti-H. pylori antibody, 7 were suitable for analysis, and all were regarded as positive for H. pylori infection. These results suggest that the presence of a specific antigen in the glomeruli of patients with MN and H. pylori infection may be involved in the pathogenesis of MN.     

Automatic EEG analysis during long-term monitoring in the ICU

To assist in the reviewing of prolonged EEGs, we have developed an automatic EEG analysis method that can be used to compress the prolonged EEG into two pages. The proposed approach of Automatic Analysis of Segmented-EEG (AAS-EEG) consists of 4 basic steps: (1) segmentation; (2) feature extraction; (3) classification; and (4) presentation. The idea is to break down the EEG into stationary segments and extract features that can be used to classify the segments into groups of like patterns. The final step involves the presentation of the processed data in a compressed form. This is done by providing the EEGer with a representative sample from each group of EEG patterns and a compressed time profile of the complete EEG. To verify the above approach, 41 6 h EEG records were assessed for normality via the AAS-EEG and conventional EEG approaches. The difference between the overall assessment via compressed and conventional EEG was within one abnormality level 100% of the time, and within one-half level for 73.6% of the records. We demonstrated the feasibility and reliability of automatically segmenting and clustering the EEG, thus allowing the reduction of a 6 h tracing to a few representative segments and their time sequence. This should facilitate review of long recordings during monitoring in the ICU.     

Continuous intracranial pressure monitoring: review of techniques and presentation of method

Continuous monitoring of intracranial pressure has proved to be of value in guiding the treatment of patients with diffuse cerebral trauma or edema. The evolution of monitoring devices is reviewed from simple lumbar puncture through intraventricular, subdural, epidural and external monitoring with progressively more sophisticated equipment. The device reported in detail connects the subarachnoid space to an on-line data reducer that calculates the percentage time the intracranial pressure is in 16 pressure ranges of 5 mmHg each and portrays it on a histogram. The pressure at that moment, the total range of the intracranial pressure, the level of pressure the patient has had for the largest percented of time, and pressure waves, if present, can all be determined by this process.     

Evaluation of an automatic seizure detection method for the newborn EEG

In another publication, we described a set of methods for automatic detection of EEG seizures in the newborn. We describe here the evaluation of these methods using a completely new set of data, which were not used in developing the method. This testing data set consisted of recording from 54 patients, lasting an average of 4.4 h. Recordings had 8-16 channels and were obtained, in approximately equal numbers, from 3 institutions in Canada, the USA and Australia. Recording conditions varied from short recordings fully attended by a technologist to overnight recordings largely unattended. The average seizure detection rate was 69% (77%, 53%, 84% in the 3 institutions). False detections occurred at the average rate of 2.3/h (4.1, 1.0, 2.7 in the 3 institutions), with fluctuations that reflected largely the technical quality and level of supervision of the recordings. The results are similar to those obtained in the commonly used method of epilepsy monitoring in adults and allow us to envisage clinical application.     

Selective shunting with EEG monitoring is safer than routine shunting for carotid endarterectomy

The muscular and skeletal systems of the long neck were morphologically examined in order to clarify their modification and their functional significance in the giraffe (Giraffa camelopardalis). The longissimus, the thoracic and cervical, spinalis and semispinalis, the cranial and caudal head oblique, and the multifidus muscles, and the nuchal ligament were observed at their origin and insertion. The atlas, axis, and the third cervical vertebra were measured and examined. The modified spinous processes provided the large attachment surface for the strong nuchal ligament and for the muscles of the axis and other cervical vertebrae, while the muscle tendons had their origin in the ventrocaudally-enlarged transverse process. It is concluded that the modified muscles with their expanded belly and tendon have the functions of occupying the interspace among long vertebrae, and also of supporting the head and neck by means of their wide attachment to the altered vertebral processes.     

Xanthurenic acid inhibits the activity of an experimental epileptogenic focus in the rat hippocampus

Comparative analysis of application effectiveness of endolymphatic and conventional ways of preparations introduction at the time of preoperative schedule and the patients treatment with a wide spread destructive lung tuberculosis was conducted an original schemes of endolymphatic therapy application before and early after the operation are adduced. Endolymphatic application of preparations permitted to reduce the postoperative pleural empyema with bronchial fistula occurrence by 20.1%, without bronchial fistula-by 4.8%, the specific process exacerbation-by 8%, operative wound suppuration-by 10.5%, to reduce the general mortality by 18.8%.     

Ureterosciatic hernia: an anatomical radiographic correlation

A case of ureterosciatic hernia is presented with 3-dimensional computerized tomography reconstruction of the pelvis. The anatomical defect is defined. A total of 13 previously reported cases and the options for surgical repair are reviewed.     

Propofol sedation during awake craniotomy for seizures: electrocorticographic and epileptogenic effects

This prospective study evaluated the effects of propofol sedation on the incidence of intraoperative seizures and the adequacy of electrocorticographic (ECoG) recordings during awake craniotomy performed for the management of refractory epilepsy. Thirty patients scheduled for temporal or frontal lobectomy for epilepsy under bupivacaine scalp block were randomized to receive patient-controlled propofol sedation (PCS) combined with a basal infusion of propofol (n = 15) or neurolept analgesia using an initial bolus dose of fentanyl (0.7 microg/kg) and droperidol (0.04 mg/kg) followed by a fentanyl infusion (n = 15). Propofol administration was suspended 15 min before ECoG recording in the PCS group. The occurrence of inappropriate intraoperative seizures was noted and, based on blind review, the adequacy of ECoG recordings was compared. A higher incidence of intraoperative seizures was noted among the neurolept patients (6 vs 0, P = 0.008). Intraoperatively, ECoG recordings were adequate to proceed with resection in both groups. Evidence of low spike activity on ECoG did not correlate with the type of sedation administered. Higher frequency background ECoG activity was noted among patients who received propofol, but this did not interfere with ECoG interpretation. The use of propofol sedation does not appear to interfere with ECoG during epilepsy surgery, provided administration is suspended at least 15 min before recording.     

Attention problems in epilepsy: possible significance of the epileptogenic focus

Investigation of the relation between epilepsy and cognition presents serious methodologic problems because several factors may contribute to impair neuropsychological performances in epileptic persons. Benign epilepsy of childhood with rolandic paroxysmal discharges (EPR) may be a very useful model of investigation in relation to opportunity to examine subjects without brain damage, therapy, and negative environmental influences. Thus, neuropsychological dysfunction in patients with EPR may support the hypothesis that epilepsy itself plays a specific role in the genesis of cognitive disturbances. We assessed the impact of the laterality of the epileptogenic focus on cognition of children with EPR. All subjects performed a figure cancellation task, a test used to evaluate mainly attention mechanisms and abilities in processing visuospatial information. Results showed that children with right-sided (or bilateral) focus scored worse, whereas children with left-sided focus performed as well as the control subjects. Our data agree with those of studies suggesting that focal discharges may be related to poor cognitive performance. Evidence of a concordance between neurophysiologic and neuropsychologic findings may have great practical and theoretical implications in management of epileptic patients.     

Ambulatory monitoring of A/EEG in the preoperative assessment of partial epilepsy

INTRODUCTION: Electroencephalography, together with new neuroimaging techniques is still the main diagnostic tool for pre-operative assessment of epilepsy. The electrical episodes, both ictal and intercritical, are random paroxystic phenomena with regard to presentation, so the conventional EEG is sometimes of limited value. Therefore, in recent years, long duration EEG monitoring techniques have been favoured, with or without simultaneous recording of clinical behaviour, permitting recording for an indefinite period. Amongst these techniques, monitoring using cassette recording (A/EEG) if of specific interest since it permits the study of outpatients. OBJECTIVE: The main aim of surgical treatment of epilepsy is to abolish or reduce the number of crises. Therefore it is essential to localize the epileptogenic area as precisely as possible. The A/EEG has made a major contribution to the procedure of pre-operative assessment because of the considerable information it gives regarding the recording and character of the crises. MATERIAL AND METHODS: During the past three years, preoperative assessment has been carried out in our hospital on 44 patients with drug-resistant partial epilepsy. A total of 103 long duration cassette recordings (A/EEG) were done. Of these, 58 were done with surface electrodes and individualized set-up depending on the EEG findings, 8 with semi-invasive (sphenoid) electrodes, and 37 recordings used implanted sub-dural electrode strips. RESULTS: Combined study of the results obtained with these techniques permitted localization of the lesive-epileptogenic complex in 42 of these patients. We present the results obtained and conclude that A/EEG monitoring is useful in the pre-operative assessment of epilepsy.     

Chronic disease management: an outpatient approach

The current climate of managed care has sparked efforts to reduce costs in patient care. In many cases, this has resulted in more efficient methods of patient management: chronic disease management in an outpatient setting appears to be one such success story. For critical care nurses interested in working beyond the boundaries of a traditional ICU, chronic disease management clinics represent an alternative environment in which they may apply their skills. Nancy Brass-Mynderse, RN, MSN, CCRN, a clinical nurse specialist (CNS) with 18 years of experience in critical care, was instrumental in development of the Scripps Health Chronic Disease Clinic at Green Hospital of Scripps Clinic, San Diego, Calif. Brass-Mynderse currently supervises the operation of the clinic, along with Omana Kaliangara, RN, MSN, CFNP, a nurse practitioner. Brass-Mynderse received her bachelor's degree from the University of Arizona, Tucson, Ariz, and her master's degree from San Diego State University. She recently obtained her family nurse practitioner certificate from California State University, Dominguez Hills, Calif. Kaliangara received her bachelor's degree from San Jose State University, San Jose, Calif, and her nurse practitioner certificate from the University of California, San Francisco, Calif. After working in family medicine and a diabetic clinic, Kaliangara developed an interest in the management of chronic diseases. In an interview with CRITICAL CARE NURSE in September, Brass-Mynderse and Kaliangara took time to discuss the development and operation of the clinic, and to recount some of their success stories.     

A new approach for early assessment of the epileptogenic potential of quinolones

The epileptogenic potential of pefloxacin and norfloxacin, two quinolone antibiotics, was investigated in vivo in three different animal species by measuring drug concentrations in cerebrospinal fluid (CSF), which is part of the biophase, at the onset of convulsions. Interestingly, the pefloxacin-to-norfloxacin concentration ratios in CSF were virtually constant across the species (7.0, 6.6, and 6.0 in mice, rats, and rabbits, respectively), suggesting that this approach could be used to predict the relative epileptogenic potential of quinolones in humans.     

Externally and internally controlled attention in infants: an EEG study

This work was designed to investigate EEG indices of Internally and Externally Controlled Attention in infancy. EEG was recorded in 15 infants aged 7-8 months under three experimental conditions: (1) visual attention to a new stimulation (Externally Controlled Attention or baseline condition); (2) attention guided by internal cognitive schemata during 'anticipatory' phase of the peek-a-boo game (Internally Controlled Attention); and (3) 'reappearance' phase of the peek-a-boo game when the experimenter talked and smiled to an infant (reappearance). The relative power (RP) in 4-5 single-Hz theta sub-band increased under both phases of the peek-a-boo game. The reactive changes of 4-5 single-Hz RP at prefrontal and frontal leads under the Internally Controlled Attention condition positively correlated with the total time during which an infant was able to maintain ICA. The RP in 5-6 single-Hz theta sub-band significantly increased only under the Internally Controlled Attention condition and did not correlate with the total time of this type of attention. The results support the concept of 'Diffuse Theta-Response System' that is active during expectancy and effortfully focused attention. In contrast to theta, the RP in 6-7, 7-8, and 8-9 single-Hz bands decreased during both phases of the game. The decrease was maximal at precentral leads and most probably reflected blockage of the sensorimotor (mu) rhythm due to higher motility and muscular tension in the game situation. It is concluded that EEG is an adequate vehicle for investigation of brain mechanisms of attention and voluntary control in infants.     

The EEG in intensive care units for diagnosis, monitoring and prognosis (author's transl)

The clinical electroencephalography of the sixth and seventh decade of this century saw its task in the coordination of EEG-findings and nosological entities. The method seemed to be limited to the discovery of positive correlations of EEG-patterns and diagnoses. The psychopharmacological induced psychodynamics of psychoses, the EEG-dynamics of epileptic patients--enforced by anticonvulsant drugs--and the modern intensive medicine teach us nowaday to leave static EEG-reflection and instead turn to a more pathophysiological way of thinking. Clinical EEG deals only with an actual sample of a continuum, a functional diagram of age, brain metabolism, vigilance and a possibly convulsive capacity. The comparison of samples enables us to have a better insight into the gradient of steppness of EEG-pattern changes. It is to be correlated with clinical and biochemical parameters. Further comparison of samples allows criterions concerning the extent of cerebral lesion, its course, termination, with or without neurological deficiency. In a series of cases of acute neurological, neuropsychiatric and internal diseases the above mentioned necessity of a more pathophysiological EEG-interpretation is being demonstrated.