Low-voltage Pattern Research Articles

Cerebrospinal fluid drainage in posthaemorrhagic ventricular dilatation leads to improvement in amplitude‐integrated electroencephalographic activity

Progressive posthaemorrhagic ventricular dilatation (PHVD) may induce abnormal amplitude-integrated electroencephalographic (aEEG) activity prior to clinical deterioration or significant cerebral ultrasound changes. These abnormalities might be ameliorated with cerebrospinal fluid (CSF) drainage. The aims of this study were to investigate the occurrence of aEEG-abnormalities with progressive PHVD in relation to clinical and cerebral ultrasound changes and to evaluate whether CSF drainage results in aEEG improvement. aEEG and cerebral ultrasound scans were performed in 12 infants with PHVD, before and after CSF drainage, until normalization of aEEG occurred. aEEG was abnormal with progressive PHVD in all patients. Concurrently, 60% of the patients were clinically stable without deterioration in ultrasonographic cerebral abnormalities. Post drainage, continuous pattern was restored in all but one patient, whereas the frequency of discontinuous pattern decreased in nine patients and burst-suppression pattern decreased in all but one patient. Low-voltage pattern was only observed in one patient who suffered severe grade IV IVH and died one week after EVD placement. Sleep-wake cycling matured in 75%. These findings demonstrate the impact of CSF drainage on compromised aEEG-activity associated with PHVD. aEEG changes indicative of impaired cerebral function were apparent before clinical deterioration or major ultrasound changes. These changes were reversible with CSF drainage. aEEG should therefore be used in addition to clinical observation and ultrasound when monitoring PHVD.

Risikostratifizierung und Therapie kardialer Amyloidosen

Cardiac amyloidoses are a heterogeneous group of cardiomyopathies that are resistant to treatment and are associated with a poor outcome. Standard heart failure treatment is usually not well tolerated and the underlying disease remains unaffected. The clinical picture is uncharacteristic. Cardiac amyloidosis is often associated with dysfunction of additional organs. Early cardiac amyloid involvement usually reveals left ventricular hypertrophy, impairment of longitudinal shortening and diastolic ventricular function. Without adequate therapy (bi-)ventricular hypertrophy will progress to severe systolic ventricular function decrease. The combination of low voltage pattern, left ventricular hypertrophy and granular sparkling is characteristic for advanced cardiac amyloid involvement. Cardiac magnetic resonance imaging and scintigraphy yield further information on the pattern and severity of cardiac involvement. In unclear cases (left ventricular) endomyocardial biopsy is necessary. Detection of early cardiac involvement and proper identification of patients at high risk for sudden cardiac death due to rapid progressive amyloidosis is still incompletely defined. Referral to specialized centers is strongly recommended.

Rapid Progression of Left Ventricular Wall Thickness Predicts Mortality in Cardiac Light-chain Amyloidosis

Cardiac amyloidosis (CA) is the most problematic cause of heart failure because medical treatment strategies are not well tolerated. Due to its high mortality, identification of patients at high risk is crucial for treatment strategies such as heart transplantation prior to chemotherapy for amyloid disease. Left ventricular wall thickness (LVT) progression was retrospectively compared with electrocardiographic and echocardiographic parameters for risk prediction in 39 patients with histologically proven cardiac amyloidosis. Seventeen deaths occurred, equivalent to 1- and 3-year survival rates of 62.1% and 55.0%, respectively. LVT progression in deceased patients was 2.02 +/- 0.85 mm/month compared with 0.19 +/- 0.03 mm/month in survivors (p < 0.001). Autologous stem-cell transplantation (n = 22, or 54%) reduced LVT progression as compared with not receiving stem cells (0.21 +/- 0.04 mm/month vs 1.45 +/- 0.57 mm/month, p < 0.005). LVT progression correlated with maximal LVT and absolute LVT increase. Progression of LVT was more rapid in patients with impaired LV ejection fraction (LVEF) than preserved LVEF (2.16 +/- 1.04 mm/month vs 0.30 +/- 0.13 mm/month, p < 0.001). LVT closely correlated with survival, whereas initial, maximum or absolute increase in LVT did not. Further predictors of survival were LVEF, autologous stem-cell transplantation and low voltage, but not diastolic dysfunction. Multivariate analysis identified LVT progression as the strongest independent parameter for survival. LVT progression is a powerful risk predictor in light-chain CA, superior to parameters such as LVEF, LVT or a low-voltage pattern. Improved survival by high-dose chemotherapy and stem-cell transplantation is paralleled by a reduction in LVT progression. Repetitive echocardiographic assessment appears indicated in CA patients to identify candidates for heart transplantation in amyloidosis.

Background patterns and sleep‐wake cycles on amplitude‐integrated electroencephalography in preterms younger than 30 weeks gestational age with peri‐/intraventricular haemorrhage

The objective of this prospective study was to evaluate the influence of peri-/intraventricular haemorrhage (PIVH) grades I-IV on amplitude-integrated electroencephalographic (aEEG) activity in preterm infants<30 weeks gestational age (GA). The aEEG tracings of the first 2 weeks of life of 56 preterm infants younger than 30 weeks GA (2 groups: group A=23-26 weeks GA, group B=27-29 weeks GA) born during a 4-year period with PIVH grades I-IV were assessed for the relative duration of four background aEEG activity patterns (continuous pattern, discontinuous high-voltage pattern, discontinuous low-voltage pattern and nearly isoelectric pattern), the presence of seizure activity and the appearance of sleep-wake cycles and compared to the tracings of 75 neurologically healthy preterms without PIVH. Analysis of aEEG background activity showed a decrease of continuous activity whereas discontinuous activity increased in both groups with larger haemorrhages (grades III and IV) and when compared to controls. Suspected seizure activity was more common with increasing degree of bleeding in group A (50% with PIVH I or II, 75% with PIVH III or IV) and when compared to controls and was the same with increasing degree of bleeding in group B (47% with PIVH I or II, 45% with PIVH III or IV). Sleep-wake cycles were less common with larger haemorrhages in both groups (group A: 41% with PIVH I or II, 25% with PIVH III or IV; group B: 52% with PIVH I or II, 9% with PIVH III or IV) and when compared to controls. The aEEG characteristics of severe PIVH consist in a combination of a more discontinuous background pattern, a lack of sleep-wake cycles and a higher likelihood of seizure activity when compared to age-matched controls.

Prophylactic implantation of cardioverter-defibrillator in patients with severe cardiac amyloidosis and high risk for sudden cardiac death

Cardiac light-chain amyloidosis carries a high risk for death predominantly from progressive cardiomyopathy or sudden death (SCD). Independent risk factors for SCD are syncope and complex nonsustained ventricular arrhythmias. The purpose of this study was to test whether prophylactic placement of an implantable cardioverter-defibrillator (ICD) reduces SCD in patients with cardiac amyloidosis. Nineteen patients with histologically proven cardiac amyloidosis and a history of syncope and/or ventricular extra beats (Lown grade IVa or higher) received an ICD. During a mean follow-up of 811 +/- 151 days, two patients with sustained ventricular tachyarrhythmias were successfully treated by the ICD. Two patients underwent heart transplantation, and seven patients died due to electromechanical dissociation (n = 6) or glioblastoma (n = 1). Nonsurvivors more often showed progression of left ventricular wall thickness, low-voltage pattern, ventricular arrhythmias (Lown grade IVa or higher), and higher N-terminal pro-brain natriuretic peptide levels than did survivors. Bradycardias requiring ventricular pacing (VVI 40/min <1%, DDD 60/min 6% +/- 1%) occurred only rarely. Patients with cardiac amyloidosis predominantly die as a result of electromechanical dissociation and other diagnoses not amenable to ICD therapy. Selected patients with cardiac amyloidosis may benefit from ICD placement. Better predictors of arrhythmia-associated SCD and randomized trials are required to elucidate the impact of ICD placement in high-risk patients with cardiac amyloidosis.

Cardiac amyloidosis diagnosed incidentally by bone scintigraphy

Case history. An 84-year-old man with systemic hypertension had papillary carcinoma of the thyroid and lymph node metastases that were treated with thyroidectomy. He also had atrial fibrillation with a slow ventricular response (minimum heart rate on 24-hour Holter monitoring of 42 beats/min) and left bundle branch block. The patient had a good exercise tolerance (600 yd on flat ground), with no cardiac symptoms. The results of his examination were otherwise unremarkable. Transthoracic echocardiogram showed a normal left ventricular size but a dilated left atrium, with mild mitral, aortic, and tricuspid regurgitation. Technetium 99m sestamibi myocardial perfusion scintigraphy after 1 month of echocardiography (Figure 1) showed no evidence of ischemia but an ejection fraction of 28% (Figure 2), suggesting the possibility of primary or secondary muscle disorder. A VVIR pacemaker was inserted, and thyroxine administration was started. While receiving thyroxine, the patient had residual papillary thyroid carcinoma and pulmonary metastases developed. Twelve months after thyroidectomy, fluid overload and pulmonary congestion developed, and he started taking furosemide, with resolution of symptoms to New York Heart Association class II. Eighteen months after thyroidectomy, lower back pain developed, and a Tc-99m methylene diphosphonate bone scan showed no bone metastases, but there was unusually high and homogeneous myocardial uptake of Tc-99mMDP, suggesting an infiltrative disease, possibly amyloidosis (Figure 3). Repeat echocardiography showed features suggestive of cardiac amyloidosis (Figure 4), with increased septal thickness (2.8 cm) relative to the posterior wall (1.9 cm), reduced left ventricular systolic function, a dilated left atrium (5.0 cm) with no evidence of organic mitral valve disease, and a biventricular restrictive filling pattern. The electrocardiogram at that time showed a low-voltage pattern. The patient’s condition deteriorated, and he died 2 months later at home. Postmortem examination was not performed. Discussion. This case illustrates presumed cardiac amyloidosis diagnosed incidentally by bone scan. Bone scintigraphy does not show appreciable uptake of tracer in the normal heart. Myocardial uptake of the Tc-99m– labeled bone-seeking agents was shown in the 1980s to be suggestive of cardiac amyloidosis. However, endomyocardial biopsy remains the standard for the diagnosis of myocardial amyloidosis. In a prospective study of endomyocardial biopsy–proven amyloidosis, only 1 of 5 patients had intense uptake. The authors concluded that uptake of the bone agent (pyrophosphate in their study) by the myocardium makes the diagnosis of amyloidosis highly likely but is not sufficiently sensitive to warrant routine screening of patients. In a separate study of patients with 5 different types of amyloidosis with bone scans, echocardiography was shown to be more sensitive than bone scintigraphy in the diagnosis of cardiac amyloidosis. Further uptake of bone agent in the myocardium has also been described in a patient with chronic renal failure undergoing hemodialysis and severe hyperparathyroidism. This was associated with other features of hyperparathyroidism on bone scan such as lytic bone lesion as a result of a brown tumor and diffuse extraskeletal uptake in the lungs, kidneys, and femoral arteries. This was reported to partially regress after 4 years of parathyroidectomy. Isolated uptake of bone agent in the heart would have high specificity for suspecting amyloidosis, but bone scintigraphy is not the most sensitive method for detecting cardiac amyloidosis. This would depend on the affinity of calcium for the bone agent between different types on amyloid fibrils. From the Royal Brompton Hospital, National Heart and Lung Institute, Imperial College London, and Royal Marsden Hospital, London, England. Reprint requests: Kshama Wechalekar, MBBS, DRM, DNB, Department of Nuclear Medicine, Royal Brompton Hospital, Sydney Street, London SW3 6NP, England; K.Wechalekar@rbht.nhs.uk. J Nucl Cardiol 2007;14:750-3. 1071-3581/$32.00 Copyright © 2007 by the American Society of Nuclear Cardiology. doi:10.1016/j.nuclcard.2007.07.002

Non‐invasive predictors of survival in cardiac amyloidosis

Patients with cardiac amyloidosis (CA) have increased mortality. Clinical, electrocardiographic, and echocardiographic parameters were assessed for risk-stratification of CA. CA was confirmed by endomyocardial biopsy in 59 patients (54.8+/-1.2 years) with light-chain (n = 43) or transthyretin amyloidosis (n = 16). Six patients without CA served as controls (NCA). Clinical symptoms, electrocardiographic, and echocardiographic parameters were analyzed for prognostic significance. Of the patients with light-chain amyloidosis, 14 died and 2 underwent heart transplantation. 1-/3-year survival was 68%/63%. Survival depended on left ventricular function (LV-EF), LV mass, radius/wall thickness, septum thickness, low voltage pattern (LVP), conduction delay, NYHA class, and stem cell transplantation. A multivariate model only contained LV-EF and LVP; the beneficial effect of stem cell transplantation was cancelled out as this treatment was withheld in patients with highest cardiac risk. Survival was most limited if both risk factors occurred. Cardiac involvement in transthyretin amyloidosis showed better survival (2 deaths, 1-/3-year survival 91%/83%). Analysis of prognostic risk factor utility in all amyloid patients (light-chain and transthyretin) again revealed LVP and LV-EF, and aetiology of amyloidosis as independent survival parameters. Prognosis of CA is poor, but aetiology of amyloid, LVP, and LV-EF allows identification of patients at highest risk of death, who may require individual treatment approaches (heart transplantation prior to causative therapy).

Intra- and Extrauterine Maturation of Amplitude-Integrated Electroencephalographic Activity in Preterm Infants Younger than 30 Weeks of Gestation

Objective: To prospectively investigate the longitudinal changes of amplitude-integrated electroencephalographic (aEEG) activity in preterm infants <30 weeks gestational age (GA). Methods: Infants (GA <30 weeks) without evidence of neurological abnormalities had weekly aEEG recordings performed. The relative duration of the three aEEG patterns (discontinuous low voltage, discontinuous high voltage and continuous) was determined and the influence of GA and postnatal age (PNA) on the occurrence of each pattern was assessed. Results: Ninety-eight infants (median GA 26 weeks; range 23–29 weeks) were studied. With higher GA (OR 1.68, 95% CI 1.33–2.13) and PNA (OR 1.91, 95% CI 1.53–2.38), the likelihood for the occurrence of continuous activity increased. The discontinuous low-voltage pattern was less likely to occur with increasing GA (OR 0.68, 95% CI 0.55–0.83) and PNA (OR 0.70, 95% CI 0.61–0.81). Conclusion: Maturation of aEEG activity in preterm infants is influenced by both GA and PNA.

Auto power and coherence analysis of delta-theta band EEG during the waking-sleeping transition period

To evaluate the spatio-temporal variation of delta and theta band EEGs during the waking-sleeping transition period, auto power and coherence analyses of scalp EEGs were carried out on 12 male subjects. The 7 auto power and 21 coherence values obtained from the 7 areas were studied every 20 s from 5 min before stage 1 onset to 24 min after stage 1 onset. The consecutive samples of spectra were computed for two frequency bands (delta: 2.5–3.5 Hz; theta: 4.0–7.5 Hz). Auto power started to increase after stage 1 onset and terminated 8.4 min after stage 2 onset. Topograms of each band power changed with progression towards deep sleep from the flat or relatively low voltage pattern without any focus to the frontopolar-parietal pattern or the fronto-parietal dominant pattern. Principal component analysis of the coherence values revealed generalized and localized components in each band. The generalized component was distributed across scalp areas, while the localized component was distributed in frontopolar-frontal areas. The generalized component decreased to the plateau level of non-rapid eye movement (NREM) sleep 5.4 min after stage 2 onset. The localized component started to increase after stage 1 onset and reached the plateau level of NREM sleep 2.4 min after stage 2 onset. These results indicate that the delta-theta band EEG structures of the waking-sleeping transition period may not be uniform across the scalp areas and the hypnagogic period may start after stage I onset and continue for 8.4 min after stage 2 onset.

Predictive value of early continuous amplitude integrated EEG recordings on outcome after severe birth asphyxia in full term infants.

The background pattern in single channel amplitude integrated EEG recordings (aEEG) was recorded in 47 infants within the first six hours after birth to see if this could predict outcome after birth asphyxia. The aEEG background pattern during the first six hours of life was continuous and of normal voltage in 26 infants. All these infants survived; 25 were healthy, one had delayed psychomotor development. A continuous but extremely low voltage pattern was present in two infants, both of whom survived with severe handicap. Five infants had flat (mainly isoelectric) tracings during the first six hours of life; four died in the neonatal period, and one survived with severe neurological handicap. Burst-suppression pattern was identified in 14 infants, of whom five died, six survived with severe handicap, and three were healthy at follow up. The type of background pattern recorded within the first six postnatal hours in the aEEG tracings predicted outcome correctly in 43 of 47 (91.5%) infants. Use of aEEG monitoring can predict outcome, with a high degree of accuracy, after birth asphyxia, within the first six hours after birth. The predictive value of a suppression-burst pattern was, however, somewhat lower than the other background patterns. The aEEG seems to be a feasible technique for identifying infants at high risk of subsequent brain damage who might benefit from interventionist treatment after asphyxia.

Reversal of low voltage and infarction pattern on the surface electrocardiogram after renal hemodialysis for pulmonary edema

A case is presented in which markedly low surface electrocardiographic (ECG) voltage and an infarction pattern are rapidly reversed with renal hemodialysis for pulmonary edema. A patient presenting with QRS voltages below 0.1 mV in all the limb and augmented limb leads and a waveform pattern suggestive of an anterior and inferior myocardial infarction experienced a dramatic increase in voltage and a reversal of the infarction pattern after dialysis. A hypothesis is proposed in which alterations in chest wall impedance and in electrolytes are involved in the ECG changes resulting from dialysis. This case illustrates one source of diagnostic error, and that dialysis may result in large, rapid changes in the ECG. Diagnostic errors may be avoided by obtaining serial ECGs in patients undergoing dialysis.

The heart in Portuguese amyloidosis

A systematic investigation was performed in patients with familial amyloidotic polyneuropathy, Portuguese type (AFp) to assess the pattern and incidence of cardiac involvement. Of 327 patients investigated, ECG abnormalities were present in 285 (87.2%). Low voltage and QS pattern in V1, V2, V3 were found in 51.3% and 35.7% patients respectively. Conduction disturbances were present in 211 (64.5%). Sinus node disease, 1st degree and Wenckebach interventricular blocks were frequent. Complete atrioventricular block was observed in only 2 patients (0.6%). Left anterior hemi-block was present in 30.8%, left bundle branch block in 3.9%, left posterior hemi-block in 2.4% and right bundle branch block in 2.1%. Holter monitoring showed a much higher incidence of conduction disturbances, most of these occurring at night. The mean values of septum and posterior wall thickness and mass evaluated by echocardiography in 72 patients were normal. The systolic and diastolic global and regional functions, determined in 12 patients, analysing the echo by a digitization computer technique, were normal. In 7% a trivial pericardial effusion was observed. In 16 patients with ECG changes and normal echocardiograms the technetium 99m pyrophosphate scanning was negative. We conclude that the ECG is the most precise, sensitive and clinically useful method for detecting cardiac amyloidosis in patients with AFp. In spite of the rarity of congestive and restrictive patterns, the incidence and severity of conduction disturbances does not allow us to consider heart disease in AFp as a benign entity.

Differences in Aphasic Symptoms, Findings of Electroencephalography and Cranial Computed Tomography between Cerebral Infarction and Cerebral Hemorrhage

Eighty-six stroke patients which was comprised of 63 cases of cerebral infarction and 23 cases of cerebral hemorrhage with speech disturbance and sign of dominant hemispheric lesion in chronic stage were investigated using the Standard Language Test for Aphasia, EEG including photic stimulation and cranial computed tomography (CCT). The purpose of this study was to demonstrate the differences between cerebral infarction and cerebral hemorrhage as seen in aphasic symptoms, EEG and CCT findings and also investigate the possible causes of those differences. In cerebral infarction, aphasic symptoms were variable in each case according to its type and severity. Although in cerebral hemorrhage, mild aphasia such as amnestic aphasia and mild Broca's aphasia were more commonly observed. In the cases of cerebral infarction, EEG findings were also variable and tended to show mild to moderate abnormality and low voltage in nature. Many of the cerebral hemorrhagics indicated severely abnormal EEG which consisted of high voltage slow wave and defective photic driving on both sides. In cerebral infarction, CCT revealed that distribution of low density area was again variable and was located mainly in the cortex. Although in the cases of cerearal hemorrhage, the low density area had a tendency to be confined to the basal ganglia and /or to the internal capsule. Some cases of cerebral infarction with wide spread low density area including more than three cerebral lobes showed normal to slightly abnormal EEG. In contrast with this, severely abnormal EEGs were rather common among the cases of cerebral hemorrhage with low density area which tended to be strictly confined to the basal ganglia and / or the internal capsule. From these results, the common site of the lesion was considered to be a major factor in the difference between cerebral infarction and cerebral hemorrhage as seen in aphasic symptoms, EEG and CCT findings. Namely, many cases of cerebral infarction have lesions in the cerebral cortex which produce aphasic symptoms of various kinds and affected voltage generator which is manifested by a low voltage pattern of EEG. In the cases of cerebral hemorrhage, common lesions were found in the deep structure involving the thalamocortical projection, which bring deafferentiation effect on EEG which is characterized by a high voltage slow wave.

Electroencephalographic Findings in Children With Moyamoya Disease

The EEG findings in 25 children with moyamoya disease were studied. Characteristic findings such as posterior slow, centrotemporal slow (CT slow), "rebuildup" after the end of hyperventilation, and sleep spindle depression were observed. Posterior slow activity was mainly observed in the EEGs examined within a short period (mean, 10 months) after onset, CI slow activity after a longer period (mean,, 28 months), and a diffuse low-voltage pattern after these periods (mean, 56 months). Buildup after the end of hyperventilation, which we refer to as "rebuildup," was discovered in more than half of the cases.

周期性四肢麻痺の一例

A case of idiopathic periodic paralysis was studied by using various clinical and laboratory examinations, and the, conclusion of our studies are as follows:(1) Leucocyte count increased during the spontaneous attack, however it showed normal value when the attack was abated.(2) Cerebrospinal pressure was elevated during the attack was going on and it returned to normal thereafter.(3) Seru m potassium did not show any remarkable entrance into the erythrocyte when the attack was provoked by the glucose infusion containing insulin.(4) ECG showed typical hypokalemic pattern during th e provoked paralysis, that is prolongation of P-R interval, depression of the RS-T segment and the appearance of U wave and so on.(5) EMG showed normal pattern before the provocation, but it showed diminution of frequency of NMU, low amplitude NMU voltage and polyphasic pattern at the onset of the provocation and then it finally showed electrical silence even by the voluntary contraction and then the patient became fainted. But five hours after the provocation his EMG began to show low amplitude NMU voltage by administration of Solita T3 and KCL tablets.24 hours later, his EMG showed recovery of the amplitude of NMU, the interference wave by the strong contraction, and polyphasic pattern became obvious and his fatigability was restored almost completely.48 hours later EMG showed nearly normal pattern.

Note on the Statistical Theory of Mass Spectra

First Page

Der Wert von Familienuntersuchungen f�r die Beurteilung des Niederspannungs-EEG nach geschlossenem Sch�delhirntrauma

Using 101 cases with cerebral concussions or contusions, whose first EEG had been taken within the first four weeks after the accident, the problem was examined, how frequently the trauma gives rise to a transitory voltage depression. A certain depression could be seen in most cases. The EEG of ten persons could not be distinguished from the „low voltage type“, which had been characterized in an earlier paper as a fairly distinct and in many cases dominantly inherited EEG variant. A short time after the trauma, transitory low voltage patterns seem to be especially frequent. They may be, but must not be combined with other — general or focal — abnormalities. The importance of genetic examinations (twin and family data) for the differential diagnosis of these cases is stressed. In this connection, some examples for the use of twin data in EEG diagnosis are given.