MR-guided transcranial brain HIFU in small animal models

Recent studies have demonstrated the feasibility of transcranial high-intensity focused ultrasound (HIFU) therapy in the brain using adaptive focusing techniques. However, the complexity of the procedures imposes provision of accurate targeting, monitoring and control of this emerging therapeutic modality in order to ensure the safety of the treatment and avoid potential damaging effects of ultrasound on healthy tissues. For these purposes, a complete workflow and setup for HIFU treatment under magnetic resonance (MR) guidance is proposed and implemented in rats. For the first time, tissue displacements induced by the acoustic radiation force are detected in vivo in brain tissues and measured quantitatively using motion-sensitive MR sequences. Such a valuable target control prior to treatment assesses the quality of the focusing pattern in situ and enables us to estimate the acoustic intensity at focus. This MR-acoustic radiation force imaging is then correlated with conventional MR-thermometry sequences which are used to follow the temperature changes during the HIFU therapeutic session. Last, pre- and post-treatment magnetic resonance elastography (MRE) datasets are acquired and evaluated as a new potential way to non-invasively control the stiffness changes due to the presence of thermal necrosis. As a proof of concept, MR-guided HIFU is performed in vitro in turkey breast samples and in vivo in transcranial rat brain experiments. The experiments are conducted using a dedicated MR-compatible HIFU setup in a high-field MRI scanner (7 T). Results obtained on rats confirmed that both the MR localization of the US focal point and the pre- and post-HIFU measurement of the tissue stiffness, together with temperature control during HIFU are feasible and valuable techniques for efficient monitoring of HIFU in the brain. Brain elasticity appears to be more sensitive to the presence of oedema than to tissue necrosis.

Catatonia: a syndrome appears, disappears, and is rediscovered

Catatonia is the psychiatric syndrome of disturbed motor functions amid disturbances in mood and thought first described in 1874. It was quickly found in 10% to 38% of psychiatric populations. After it was tied to schizophrenia as a type in the psychiatric classification, its recognition became increasingly limited and by the 1980s questions were asked as to where the catatonics had gone. The decline is largely owing to the change in venue for psychiatric practice from asylum to office, the rejection of physical examination, and the dependence on item rating scales for diagnosis. In the 1970s, broad surveys again showed that catatonia was as common as before among patients with mania and depression, and as a toxic response to neuroleptic drugs. The latter recognition, that the neuroleptic malignant syndrome is the same syndrome as malignant catatonia, and is effectively treated as such, sparked a renewed interest. Clinicians developed rating scales to identify the catatonia syndrome and applied the immediate relief afforded by a barbiturate or a benzodiazepine as a diagnostic test, the lorazepam test. Effective treatments were described as high doses of benzodiazepines and electroconvulsive therapy (ECT). Surveys using catatonia rating scales showed catatonia to have many faces. Catatonia is presently limited to a type of schizophrenia in the psychiatric classification. Its recognition as a disorder of its own, such as delirium and dementia, should now be recognized. This experience reinforced the utility of the medical model for diagnosis. An application for melancholia is described.

Perioperative Mortality Risk Score using Pre- and Post-operative Risk Factors in Older Patients

We developed a risk score for 30-day postoperative mortality: the Perioperative Mortality risk score. We used a derivation cohort from a previous study of surgical patients aged 70 years or more at three large metropolitan teaching hospitals, using the significant risk factors for 30-day mortality from multivariate analysis. We summed the risk score for each of six factors creating an overall Perioperative Mortality score. We included 1012 patients and the 30-day mortality was 6%.

The three preoperative factors and risk scores were (“three A's”): 1) age, years: 70 to 79=1, 80 to 89=3, 90+=6; 2) ASA physical status: ASA I or II=0, ASA III=3, ASA IV=6, ASA V=15; and 3) preoperative albumin <30 g/l=2.5.

The three postoperative factors and risk scores were (“three I's”) 1) unplanned intensive care unit admission =4.0; 2) systemic inflammation =3; and 3) acute renal impairment=2.5. Scores and mortality were: <5=1%, 5 to 9.5=7% and ≥10=26%.

We also used a preliminary validation cohort of 256 patients from a regional hospital. The area under the receiver operating characteristic curve (C-statistic) for the derivation cohort was 0.80 (95% CI 0.74 to 0.86) similar to the validation C-statistic: 0.79 (95% CI 0.70 to 0.88), P=0.88. The Hosmer-Lemeshow test (P=0.35) indicated good calibration in the validation cohort. The Perioperative Mortality score is straightforward and may assist progressive risk assessment and management during the perioperative period. Risk associated with surgical complexity and urgency could be added to this baseline patient factor Perioperative Mortality score.

Non-invasive transcranial ultrasound therapy based on a 3D CT scan: protocol validation and in vitro results

A non-invasive protocol for transcranial brain tissue ablation with ultrasound is studied and validated in vitro. The skull induces strong aberrations both in phase and in amplitude, resulting in a severe degradation of the beam shape. Adaptive corrections of the distortions induced by the skull bone are performed using a previous 3D computational tomography scan acquisition (CT) of the skull bone structure. These CT scan data are used as entry parameters in a FDTD (finite differences time domain) simulation of the full wave propagation equation. A numerical computation is used to deduce the impulse response relating the targeted location and the ultrasound therapeutic array, thus providing a virtual time-reversal mirror. This impulse response is then time-reversed and transmitted experimentally by a therapeutic array positioned exactly in the same referential frame as the one used during CT scan acquisitions. In vitro experiments are conducted on monkey and human skull specimens using an array of 300 transmit elements working at a central frequency of 1 MHz. These experiments show a precise refocusing of the ultrasonic beam at the targeted location with a positioning error lower than 0.7 mm. The complete validation of this transcranial adaptive focusing procedure paves the way to in vivo animal and human transcranial HIFU investigations.

László Meduna's pilot studies with camphor inductions of seizures: the first 11 patients

In his autobiography, László Meduna described the first session of convulsive therapy using intramuscular camphor as occurring on January 23, 1934 at Royal National Hungarian Institute of Psychiatric and Neurology at Budapest-Lipótmezo in Hungary. Unearthed records of the patients treated at this institution reveal that Meduna's dose-finding experiments began on January 2, 1934. The symptomatology and history of illness, diagnosis, socio-demographic data, the seizure characteristics, and immediate and long term outcomes of the first 11 patients are described. These first trials elicited seizures in less than half the injections. Seizures of various durations (including missed seizures) and double (tardive) seizures were recorded. Mutism, refusal to eat requiring tube feeding, and other signs of catatonia dominated the psychopathology of 7 of the first 11 patients. Two improved sufficiently to be discharged from the hospital and third patient became fit for occupational therapy. These records exhibit the meticulous systematic nature of the first human trials with induced seizures and the fortuitous nature of the first human trials with induced seizures and the fortuitous nature in patient selection of catatonic patients--an illness that is most responsive to induced seizures.

Is baseline medication resistance associated with potential for relapse after successful remission of a depressive episode with ECT? Data from the Consortium for Research on Electroconvulsive Therapy (CORE)

OBJECTIVE

To test whether pre-electroconvulsive therapy (ECT) medication resistance is associated with post-ECT relapse rates.

METHOD

In a post hoc analysis of data from a large multicenter trial of post-ECT relapse prevention strategies (conducted from May 1997 to July 2004), we assessed whether response to antidepressant medications prior to ECT for a unipolar nonpsychotic depressive episode (DSM-IV) was associated with differential relapse rates after remission with ECT. Baseline (i.e., pre-ECT) medication use was assessed with the Antidepressant Treatment History Form. Following remission with ECT that was stable for 1 week, patients were randomly assigned to receive 6 months of treatment with either combination lithium carbonate/nortriptyline or continuation ECT. Relapse was assessed with the 24-item Hamilton Rating Scale for Depression. There were 146 patients followed in the first week after remission (termed the interim week in this study), and 73 in the randomized phase of the study. For the purposes of this trial, medication resistance is defined as not having responded to at least 1 adequate trial of an antidepressant medication before ECT.

RESULTS

In the first week after acute remission, 9.8% of patients not having at least 1 antidepressant medication trial met relapse criteria, while 31.4% of medication-resistant patients met relapse criteria, a difference that was statistically significant (p = .026). In the randomized phase of the study, 34.6% of non-medication-resistant patients relapsed, while 50.0% of medication-resistant patients relapsed, a difference that was not significant (p = .434).

CONCLUSION

We conclude that nonpsychotic patients who had at least 1 adequate antidepressant medication trial before ECT may be especially prone to early relapse after successful acute remission with ECT.

Formation of a boundary-free dust cluster in a low-pressure gas-discharge plasma

An attraction between negatively charged micron-sized plastic particles was observed in the bulk of a low-pressure gas-discharge plasma under microgravity conditions. This attraction had led to the formation of a boundary-free dust cluster, containing one big central particle with a radius of about 6 microm and about 30 1 microm-sized particles situated on a sphere with a radius of 190 microm and with the big particle in the center. The stability of this boundary-free dust cluster was possible due to its confinement by the plasma flux on the central dust particle.

A meta-analysis of cardiac electrophysiology computational models

Computational models of cardiac electrophysiology are exemplar demonstrations of the integration of multiple data sets into a consistent biophysical framework. These models encapsulate physiological understanding to provide quantitative predictions of function. The combination or extension of existing models within a common framework allows integrative phenomena in larger systems to be investigated. This methodology is now routinely applied, as demonstrated by the increasing number of studies which use or extend previously developed models. In this study, we present a meta-analysis of this model re-use for two leading models of cardiac electrophysiology in the form of parameter inheritance trees, a sensitivity analysis and a comparison of the functional significance of the sodium potassium pump for defining restitution curves. These results indicate that even though the models aim to represent the same physiological system, both the sources of parameter values and the function of equivalent components are significantly different.

Multiscale modelling of drug-induced effects on cardiac electrophysiological activity

Many drugs fail in the clinical trials and therefore do not reach the market due to adverse effects on cardiac electrical function. This represents a growing concern for both regulatory and pharmaceutical agencies as it translates into important socio-economic costs. Drugs affecting cardiac activity come from diverse pharmacological groups and their interaction with cardiac electrophysiology can result in increased risk of potentially life threatening arrhythmias, such as Torsade de Pointes. The mechanisms of drug interaction with the heart are very complex and the effects span from the ion channel to the whole organ level. This makes their investigation using solely experimental in vitro and in vivo techniques very difficult. Computational modelling of cardiac electrophysiological behaviour has provided insight into the mechanisms of cardiac arrhythmogenesis, with high spatio-temporal resolution, from the ion channel to the whole organ level. It therefore represents a powerful tool in investigating mechanisms of drug-induced changes in cardiac behaviour and in their pro-arrhythmic potential. This article presents a comprehensive review of the recent advances in detailed models of drug action on cardiac electrophysiological activity.

Károly Schaffer and his school: the birth of biological psychiatry in Hungary, 1890-1940

In the first third of the twentieth century, neuropathology seemed to offer the key to unlock the causes of psychiatric illness. Among the top centers devoted to the microscopic anatomy of the brain was that of Károly Schaffer in Budapest. Schaffer, a pioneer in the histopathology of Tay-Sachs-Schaffer disease, was also a charismatic teacher, bringing forth a school of investigators in psychopathology. Among them was László Meduna, who originated convulsive therapy. Despite the importance of the Schaffer school, it is almost unknown outside of Hungary, largely the result of the introduction of neurophysiological, neurochemical and molecular genetic methods that distracted attention away from histopathological contributions in psychiatry after the Second World War. The microscopic study of the brain and its diseases seemed increasingly less important. The present biographical account of Károly Schaffer and his school seeks to bring this important story in the early history of biological psychiatry to a wider audience and explain why it has since been forgotten.

Transcostal high-intensity-focused ultrasound: ex vivo adaptive focusing feasibility study

Ex vivo experiments have been conducted through excised pork rib with bone, cartilage, muscle and skin. The aberrating effect of the ribcage has been experimentally evaluated. Adaptive ultrasonic focusing through ribs has been studied at low power. Without any correction, the pressure fields in the focal plane were both affected by inhomogeneous attenuation and phase distortion and three main effects were observed: a mean 2 mm shift of the main lobe, a mean 1.25 mm spreading of the half width of the main lobe and up to 20 dB increase of the secondary lobe level. Thanks to time-reversal focusing, a 5 dB decrease in the secondary lobes was obtained and the ratio between the energy deposited at the target location and the total amount of energy emitted by the therapeutic array was six times higher than that without correction. Time-reversal minimizes the heating of the ribs by automatically sonicating between the ribs, as demonstrated by temperature measurements using thermocouples placed at different locations on the ribcage. It is also discussed how this aberration correction process could be achieved non-invasively for clinical application.

Rhombencephalosynapsis: prenatal imaging and autopsy findings

OBJECTIVES

Rhombencephalosynapsis is a rare, but increasingly recognized, brain malformation characterized by congenital fusion of the cerebellar hemispheres and absence of the vermis. Rhombencephalosynapsis is associated with significant developmental delay, seizures and involuntary head movements. We report four cases, with correlation of prenatal and postnatal imaging and autopsy findings.

METHODS

Over a 2-year period, four cases of rhombencephalosynapsis were diagnosed in the perinatal period, three in one center and one in another center. The clinical cases were reviewed, and correlation was made between the prenatal and postnatal imaging and autopsy findings where available.

RESULTS

All cases presented initially with ventriculomegaly on prenatal ultrasound examination. Subsequent magnetic resonance imaging (MRI) established the diagnosis in two cases and postnatal MRI established the diagnosis in a further two cases. Autopsy was available and confirmed the diagnosis in two cases. In one case the pregnancy was terminated, two infants died in the neonatal period and one died in infancy.

CONCLUSIONS

The cases in this perinatal series of rhombencephalosynapsis showed a very poor prognosis. The presence of ventriculomegaly on prenatal ultrasound imaging should alert the physician to consider rhombencephalosynapsis in the differential diagnosis. MRI appears to be the imaging modality of choice in establishing the diagnosis.

Short-term efficacy of physical therapy compared to splint therapy in treatment of arthrogenous TMD

A prospective randomized study was carried out to evaluate the efficacy of physical therapy in addition to splint therapy on treatment outcome in patients with temporomandibular disorders (TMD) with respect to objective and subjective parameters. Twenty-six patients suffering from an arthrogenic TMD and exhibiting a painfully restricted jaw opening were randomized in two groups. Thirteen patients were treated solely with Michigan splint (group I), 13 patients received supplementary physical therapy (group II). Before treatment a clinical examination and electronic recording of jaw movements were performed and subjective pain level was evaluated by visual analogue scales. After 3 months of therapy maintenance of improvement was evaluated. Within treatment groups comparison of data before and after treatment was analysed using Wilcoxon test. Groups were compared by Mann-Withney-U test. A P-value < 0.05 was considered significant. Compared with the baseline, in both groups mandibular movement capacity increased significantly after treatment, whereas subjective pain decreased significantly (P < 0.05). Active jaw opening increased from 28.6 +/- 5.8 to 35.9 +/- 4.8 mm in group I and from 30.1 +/- 5.4 to 40.8 +/- 4.1 mm in group II. After therapy the difference of active jaw opening between groups was significant (P < 0.05). Physical therapy also gave a supplementary improvement of protrusive mandibular movement capacity during electronic registration and subjective pain level. For none of these parameters this difference between groups was significant. Physical therapy seems to have a positive effect on treatment outcome of patients with TMD.

The efficacy of acute electroconvulsive therapy in atypical depression

OBJECTIVE

This study examined the characteristics and outcomes of patients with major depressive disorder (MDD), with or without atypical features, who were treated with acute bilateral electroconvulsive therapy (ECT).

METHOD

Analyses were conducted with 489 patients who met DSM-IV criteria for MDD. Subjects were identified as typical or atypical on the basis of the Structured Clinical Interview for DSM-IV obtained at baseline prior to ECT. Depression symptom severity was measured by the 24-item Hamilton Rating Scale for Depression (HAM-D(24)) and the 30-item Inventory of Depressive Symptomatology-Self-Report (IDS-SR(30)). Remission was defined as at least a 60% decrease from baseline in HAM-D(24) score and a total score of 10 or below on the last 2 consecutive HAM-D(24) ratings. The randomized controlled trial was performed from 1997 to 2004.

RESULTS

The typical (N = 453) and atypical (N = 36) groups differed in several sociodemographic and clinical variables including gender (p = .0071), age (p = .0005), treatment resistance (p = .0014), and age at first illness onset (p < .0001) and onset of current episode (p = .0008). Following an acute course of bilateral ECT, a considerable portion of both the typical (67.1%) and the atypical (80.6%) groups reached remission. The atypical group was 2.6 (95% CI = 1.1 to 6.2) times more likely to remit than the typical group after adjustment for age, psychosis, gender, clinical site, and depression severity based on the HAM-D(24).

CONCLUSION

Acute ECT is an efficacious treatment for depressed patients with typical or atypical symptom features.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00000375.