Validation of a non-motor fluctuations questionnaire in Parkinson's disease.

INTRODUCTION: Non-motor fluctuations (NMF) in Parkinson's disease (PD) remain poorly recognized but have a high impact on patients' quality of life. The lack of assessment tools limits our understanding of NMF, compromising appropriate management. Our objective was to validate a hetero-questionnaire for NMF in PD patients at different stages of the disease: without treatment, without motor fluctuations, with motor fluctuations. METHODS: We included patients in 15 centers in France. Our questionnaire, NMF-Park, resulted from previous studies, allowing us to identify the more pertinent NMF for evaluation. Patients reported the presence (yes or no) of 22 selected NMF, and their link with dopaminergic medications. The assessment was repeated at one and two years to study the progression of NMF. We performed a metrological validation of our questionnaire. RESULTS: We included 255 patients (42 without treatment, 88 without motor fluctuations and 125 with motor fluctuations). After metrological validation, three dimensions of NMF were found: dysautonomic; cognitive; psychiatric. The sensory/pain dimension described in the literature was not statistically confirmed by our study. DISCUSSION: Our questionnaire was validated according to clinimetric standards, for different stages of PD. It was clinically coherent with three homogeneous dimensions. It highlighted a link between fatigue, visual accommodation disorder, and cognitive fluctuations; and the integration of sensory/pain fluctuations as part of dysautonomic fluctuations. It focused exclusively on NMF, which is interesting considering the described differences between non-motor and motor fluctuations. CONCLUSION: Our study validated a hetero-questionnaire of diagnosis for NMF for different stages of PD.

Cancer-related fatigue and its determinants in a cohort of women with breast cancer: the DAMA Cohort.

Cancer-related fatigue (CRF) is one of the most prolonged discomforts suffered by people who have had cancer. Seventy-eight to ninety-six percent of cancer patients experience fatigue, especially while undergoing treatment. CRF is related to insomnia, anxiety, depression, and also varies depending on age. However, little is known about the factors contributing to CRF and better understanding of determinants of CRF makes it easier to identify early patients at risk and in designing intervention planning. The aim of this study was to assess the influence of precipitating factors (diagnosis of breast cancer and other clinical aspects) and perpetuating factors (social network, quality of life, mental disorders) on the presence of chronic fatigue in women from our cultural context, by social class each other determinants. METHODS: It was carried out a mixed cohort study (prospective and retrospective) using a convenience sample of women diagnosed with breast cancer. The information sources were data from the Brief Fatigue Inventory questionnaire and hospital medical records. The dependent variable was fatigue and the independent variables were age, social class, time since diagnoses, cohabitation, comorbidity, relapse, body mass index, mental health (anxiety and depression), social network, social support, and quality of life. RESULTS: Seventy-two percent of the women in the DAMA cohort reported moderate to severe fatigue. Risk of suffering from severe fatigue was greatest among individuals with low social class, those aged under 50 years, those with chronic disorders who had relapsed, and those with symptoms of anxiety and depression. In our study, CRF did not appear to be related to the stage of the cancer at diagnosis, or to the time since diagnosis. CONCLUSIONS: CRF is an element that the professionals responsible for the control and monitoring of women should take into account as another element to be taken into consideration.

Detection of incident breast and colorectal cancer cases from an administrative healthcare database in Catalonia, Spain.

OBJECTIVE: To validate the Catalan minimum basic data set (MBDS) of hospital discharges as an information source for detecting incident breast (BC) and colorectal cancer (CRC), against the Hospital del Mar Cancer Registry (RTHMar) in Barcelona (Spain) as the gold standard. METHODS: Using ASEDAT software (Analysis, Selection and Extraction of Tumour Data), we identified Catalan public hospital discharge abstracts in patients with a first-time diagnosis of BC and CRC in the years 2005, 2008, and 2011, aggregated by unique patient identifiers and sorted by date. Once merged with the RTHMar database and anonymized, tumour-specific algorithms were validated to extract data on incident cases, tumour stage, surgical treatment, and date of incidence. RESULTS: MBDS had a respective sensitivity and positive predictive value (PPV) of 78.0% (564/723) and 90.5% (564/623) for BC case detection; and 83.9% (387/461) and 94.9% (387/408) for CRC case detection. The staging algorithms overestimated the proportion of local-stage cases and underestimated the regional-stage cases in both cancers. When loco-regional stage and surgery were combined, sensitivity and PPV reached 98.3% and 99.8%, respectively, for BC and 96.4% and 98.4% for CRC. The differences between dates of incidence between RTHMar and MBDS were greater for BC cases without initial surgery, whereas they were generally smaller and homogeneous for CRC cases. CONCLUSIONS: The MBDS is a valid and efficient instrument to improve the completeness of a hospital-based cancer registry (HBCR), particularly in BC and CRC, which require hospitalization and are predominantly surgical.

Anxiety and depression in women with breast cancer: Social and clinical determinants and influence of the social network and social support (DAMA cohort).

BACKGROUND: Anxiety and depression are the most prevalent mental health pathologies among women with breast cancer. Social, clinical and contextual variables may influence emotional stress among women with breast cancer. The aim of this work is to study anxiety and depression in a cohort of women diagnosed with breast cancer between 2003 and 2013 in Barcelona. We evaluate social and clinical determinants. METHODS: We performed a mixed cohort study (prospective and retrospective) using a convenience sample of women diagnosed with breast cancer. The information sources were the Hospital Anxiety and Depression questionnaire and hospital medical records. Dependent variables were anxiety and depression; independent variables were social class, age, employment status, tumour stage at diagnosis, time since diagnosis, social network and social support. We performed a descriptive analysis, a bivariate analysis, and a multivariate logistic regression analysis. RESULTS: A total of 1086 (48.6%) women had some degree of anxiety-related problem. As for depression. In the case of depression, 225 (15%) women had some degree of depression-related problem. Low emotional support and social isolation were clear risk factors for having more anxiety and depression. Low social class was also a risk factor, and age also played a role. DISCUSSION: Our results show that women long period of cancer survival have high prevalences of anxiety than depression, and this prevalence of anxiety is higher than the general population. In addition, we found inequalities between social classes and the isolation and social support are worse too in low social class.

Historical reflections on neurosyphilis based on the 1826 treatise on general paralysis in demented patients by Louis Florentin Calmeil (1798-1895).

General paralysis is a neurological symptom of tertiary syphilis that was first identified in asylums as paralytic madness. The enlightened discussion of 60 clinicopathological cases provided by Louis Florentin Calmeil in his 1826 treatise greatly improved our knowledge of general paralysis. However, Calmeil was unable to relate this symptom to syphilis, although the latter was quite widespread at that time. Following a detailed reanalysis of Calmeil's observations with special attention to his clinical and demographic data, we conclude that this eminent clinician was unable to define the cause of general paralysis because his early 19th century mind was still under the influence of traditional knowledge and moral prejudices. For Calmeil, general paralysis belonged entirely to the realm of psychiatry.

Direct observation and imaging of a spin-wave soliton with p-like symmetry.

Spin waves, the collective excitations of spins, can emerge as nonlinear solitons at the nanoscale when excited by an electrical current from a nanocontact. These solitons are expected to have essentially cylindrical symmetry (that is, s-like), but no direct experimental observation exists to confirm this picture. Using a high-sensitivity time-resolved magnetic X-ray microscopy with 50 ps temporal resolution and 35 nm spatial resolution, we are able to create a real-space spin-wave movie and observe the emergence of a localized soliton with a nodal line, that is, with p-like symmetry. Micromagnetic simulations explain the measurements and reveal that the symmetry of the soliton can be controlled by magnetic fields. Our results broaden the understanding of spin-wave dynamics at the nanoscale, with implications for the design of magnetic nanodevices.

Direct Observation of a Localized Magnetic Soliton in a Spin-Transfer Nanocontact.

We report the direct observation of a localized magnetic soliton in a spin-transfer nanocontact using scanning transmission x-ray microscopy. Experiments are conducted on a lithographically defined 150 nm diameter nanocontact to an ultrathin ferromagnetic multilayer with perpendicular magnetic anisotropy. Element-resolved x-ray magnetic circular dichroism images show an abrupt onset of a magnetic soliton excitation localized beneath the nanocontact at a threshold current. However, the amplitude of the excitation ≃25° at the contact center is far less than that predicted (⪅180°), showing that the spin dynamics is not described by existing models.

Singlet-to-triplet interconversion using hyperfine as well as ferromagnetic fringe fields.

Until recently the important role that spin-physics ('spintronics') plays in organic light-emitting devices and photovoltaic cells was not sufficiently recognized. This attitude has begun to change. We review our recent work that shows that spatially rapidly varying local magnetic fields that may be present in the organic layer dramatically affect electronic transport properties and electroluminescence efficiency. Competition between spin-dynamics due to these spatially varying fields and an applied, spatially homogeneous magnetic field leads to large magnetoresistance, even at room temperature where the thermodynamic influences of the resulting nuclear and electronic Zeeman splittings are negligible. Spatially rapidly varying local magnetic fields are naturally present in many organic materials in the form of nuclear hyperfine fields, but we will also review a second method of controlling the electrical conductivity/electroluminescence, using the spatially varying magnetic fringe fields of a magnetically unsaturated ferromagnet. Fringe-field magnetoresistance has a magnitude of several per cent and is hysteretic and anisotropic. This new method of control is sensitive to even remanent magnetic states, leading to different conductivity/electroluminescence values in the absence of an applied field. We briefly review a model based on fringe-field-induced polaron-pair spin-dynamics that successfully describes several key features of the experimental fringe-field magnetoresistance and magnetoelectroluminescence.

¿Puede un mensaje de teléfono móvil incrementar la participación en programas de cribado poblacional de cáncer de mama? / Can a mobile phone short message increase participation in breast cancer screening programmes?

Objetivo. Evaluar el impacto del mensaje de teléfono móvil sobre la participación de las mujeres en un programa de detección precoz de cáncer de mama. Métodos. Se seleccionaron las 703 mujeres de un área básica de salud de Barcelona, invitadas a participar en un programa de detección precoz de cáncer de mama entre el 25 de enero de 2011 y el 22 de marzo de 2011 y con número de teléfono móvil registrado. Aleatoriamente se asignaron a grupo control (n = 470), que siguió el circuito habitual de citación, y grupo de intervención (n = 233), el cual recibió además un mensaje de texto recordatorio, tras la primera carta de invitación. Se compararon las tasas de participación entre ambos grupos según la edad, el nivel educativo y el comportamiento en ronda anterior, el número de llamadas de recitación según la participación, la edad y el nivel educativo y las diferencias en los porcentajes de exclusiones. Resultados. Globalmente el grupo de intervención presentó mayor participación (78,1 vs. 72,3%), tendencia que obtuvo significación estadística en las mujeres de 55-59 años (p = 0,036) y con nivel educativo medio (p = 0,014). El grupo de intervención presentó una media de llamadas de recitación significativamente menor (0,41 vs. 0,65), patrón observado en todas las categorías de las variables independientes y significativo en las franjas de edad más jóvenes, niveles educativos bajo y medio y mujeres previamente participantes (0,09 vs. 0,19, p = 0,012). Conclusiones. La incorporación del mensaje de teléfono móvil en un programa de detección precoz de cáncer de mama puede suponer un aumento de las tasas de participación y una mejora en la gestión del mismo (AU)

Objective. To evaluate the impact of a mobile phone short message on women's uptake in a breast cancer screening programme. Methods. A total of 703 women from a Basic Health Area of Barcelona, and with a mobile phone number registered, were invited to participate in a breast cancer screening programme between 25 January 2011 and 22 March 2011. The control group (n = 470) followed the usual appointment track, and the intervention group (n = 233) received, after the first letter of invitation, a mobile phone short message reminder. The differences between the two groups were analysed, comparing the uptake rates according to age, educational level, and participation in previous round, as well as the number of re-invitation calls to non-attenders according to uptake, age and level of education;and the percentages of exclusions of both groups. Results. The intervention group had a greater uptake than the control group (78.1% vs. 72.3%), with a significant trend observed in the 55-59 years age group (P = .036) and the low secondary educational level (P = .014).The intervention group mean of re-invitation calls of non-attenders lower than the control group (.41 vs. .65, P < .05), a pattern observed in all the categories of the independent variables, and among younger age groups, lower and middle educational levels, and previously participating women (.09 vs. .19, P = .012). Conclusions. The inclusion of a mobile phone short message in a breast cancer screening programme may increase uptake rates and lead to a management improvement (AU)

Desarrollo y validación de un algoritmo para identificar recidivas de cáncer a partir de bases de datos hospitalarias / Development and validation of an algorithm to identify cancer recurrences from hospital data bases

Objetivos. Los registros de tumores hospitalarios y las bases de datos hospitalarias son una fuente de información valiosa y eficiente para la investigación de recidivas de cáncer. El objetivo de este estudio fue desarrollar y validar algoritmos para identificar recidivas de cáncer de mama. Métodos. Estudio observacional retrospectivo de casos de cáncer de mama del registro de tumores de un centro hospitalario universitario de tercer nivel diagnosticados entre 2003 y 2009. A partir del cruce de bases de datos hospitalarias y la construcción de definiciones operativas se obtuvieron diferentes algoritmos de probable recidiva de cáncer con su correspondiente sensibilidad, especificidad, valor predictivo positivo y valor predictivo negativo. Resultados. Se identificaron 1.523 pacientes diagnosticados de cáncer entre 2003 y 2009. La solicitud de gammagrafía ósea tras 6 meses desde el primer tratamiento oncológico obtuvo la mayor sensibilidad (53,8%) y valor predictivo negativo (93,8%), y la realización de una prueba de anatomía patológica tras 6 meses desde el diagnóstico obtuvo la mayor especificidad (93,8%) y valor predictivo negativo (92,6%). La combinación de definiciones aumentó la especificidad y el valor predictivo positivo pero disminuyó la sensibilidad. Conclusiones. Se elaboraron diferentes algoritmos diagnósticos cuyas definiciones pueden ser útiles según los intereses y recursos del investigador. Un mayor valor predictivo positivo podría interesar para una estimación rápida del número de casos, y un mayor valor predictivo negativo para dar una estimación más exacta si se dispone de mayores recursos. Estos algoritmos se configuran como una herramienta versátil y adaptable a otros tumores y a las necesidades del investigador (AU)

Objectives. Hospital cancer registries and hospital databases are valuable and efficient sources of information for research into cancer recurrences. The aim of this study was to develop and validate algorithms for the detection of breast cancer recurrence. Methods. A retrospective observational study was conducted on breast cancer cases from the cancer registry of a third level university hospital diagnosed between 2003 and 2009. Different probable cancer recurrence algorithms were obtained by linking the hospital databases and the construction of several operational definitions, with their corresponding sensitivity, specificity, positive predictive value and negative predictive value. Results. A total of 1,523 patients were diagnosed of breast cancer between 2003 and 2009. A request for bone gammagraphy after 6 months from the first oncological treatment showed the highest sensitivity (53.8%) and negative predictive value (93.8%), and a pathology test after 6 months after the diagnosis showed the highest specificity (93.8%) and negative predictive value (92.6%). The combination of different definitions increased the specificity and the positive predictive value, but decreased the sensitivity. Conclusions. Several diagnostic algorithms were obtained, and the different definitions could be useful depending on the interest and resources of the researcher. A higher positive predictive value could be interesting for a quick estimation of the number of cases, and a higher negative predictive value for a more exact estimation if more resources are available. It is a versatile and adaptable tool for other types of tumors, as well as for the needs of the researcher (AU)

[Development and validation of an algorithm to identify cancer recurrences from hospital data bases]. / Desarrollo y validación de un algoritmo para identificar recidivas de cáncer a partir de bases de datos hospitalarias.

OBJECTIVES: Hospital cancer registries and hospital databases are valuable and efficient sources of information for research into cancer recurrences. The aim of this study was to develop and validate algorithms for the detection of breast cancer recurrence. METHODS: A retrospective observational study was conducted on breast cancer cases from the cancer registry of a third level university hospital diagnosed between 2003 and 2009. Different probable cancer recurrence algorithms were obtained by linking the hospital databases and the construction of several operational definitions, with their corresponding sensitivity, specificity, positive predictive value and negative predictive value. RESULTS: A total of 1,523 patients were diagnosed of breast cancer between 2003 and 2009. A request for bone gammagraphy after 6 months from the first oncological treatment showed the highest sensitivity (53.8%) and negative predictive value (93.8%), and a pathology test after 6 months after the diagnosis showed the highest specificity (93.8%) and negative predictive value (92.6%). The combination of different definitions increased the specificity and the positive predictive value, but decreased the sensitivity. CONCLUSIONS: Several diagnostic algorithms were obtained, and the different definitions could be useful depending on the interest and resources of the researcher. A higher positive predictive value could be interesting for a quick estimation of the number of cases, and a higher negative predictive value for a more exact estimation if more resources are available. It is a versatile and adaptable tool for other types of tumors, as well as for the needs of the researcher.

[Can a mobile phone short message increase participation in breast cancer screening programmes?]. / ¿Puede un mensaje de teléfono móvil incrementar la participación en programas de cribado poblacional de cáncer de mama?

OBJECTIVE: To evaluate the impact of a mobile phone short message on women's uptake in a breast cancer screening programme. METHODS: A total of 703 women from a Basic Health Area of Barcelona, and with a mobile phone number registered, were invited to participate in a breast cancer screening programme between 25 January 2011 and 22 March 2011. The control group (n=470) followed the usual appointment track, and the intervention group (n=233) received, after the first letter of invitation, a mobile phone short message reminder. The differences between the two groups were analysed, comparing the uptake rates according to age, educational level, and participation in previous round, as well as the number of re-invitation calls to non-attenders according to uptake, age and level of education;and the percentages of exclusions of both groups. RESULTS: The intervention group had a greater uptake than the control group (78.1% vs. 72.3%), with a significant trend observed in the 55-59 years age group (P=.036) and the low secondary educational level (P=.014).The intervention group mean of re-invitation calls of non-attenders lower than the control group (.41 vs. .65, P<.05), a pattern observed in all the categories of the independent variables, and among younger age groups, lower and middle educational levels, and previously participating women (.09 vs. .19, P=.012). CONCLUSIONS: The inclusion of a mobile phone short message in a breast cancer screening programme may increase uptake rates and lead to a management improvement.

Spin wave excitation patterns generated by spin torque oscillators.

Spin torque nano-oscillators (STNO) are nanoscale devices that can convert a direct current into short wavelength spin wave excitations in a ferromagnetic layer. We show that arrays of STNO can be used to create directional spin wave radiation similarly to electromagnetic antennas. Combining STNO excitations with planar spin waves also creates interference patterns. We show that these interference patterns are static and have information on the wavelength and phase of the spin waves emitted from the STNO. We describe a means of actively controlling spin wave radiation patterns with the direct current flowing through STNO, which is useful in on-chip communication and information processing and could be a promising technique for studying short wavelength spin waves in different materials.

Can the Gail model increase the predictive value of a positive mammogram in a European population screening setting? Results from a Spanish cohort.

AIMS OF THE STUDY: The Gail Model (GM) is the most well-known model to assess the individual risk of breast cancer (BC). Although its discriminatory accuracy is low in the clinical context, its usefulness in the screening setting is not well known. The aim of this study is to assess the utility of the GM in a European screening program. METHODS: Retrospective cohort study of 2200 reassessed women with information on the GM available in a BC screening program in Barcelona, Spain. The 5 year-risk of BC applying the GM right after the screening mammogram was compared first with the actual woman's risk of BC in the same screening round and second with the BC risk during the next 5 years. RESULTS: The curves of BC Gail risk overlapped for women with and without BC, both in the same screening episode as well as 5 years afterward. Overall sensitivity and specificity in the same screening episode were 22.3 and 86.5%, respectively, and 46.2 and 72.1% 5 years afterward. ROC curves were barely over the diagonal and the concordance statistics were 0.59 and 0.61, respectively. CONCLUSION: The GM has very low accuracy among women with a positive mammogram result, predicting BC both in the concomitant episode and 5 years later. Our results do not encourage the use of the GM in the screening context to aid the referral decision or the type of procedures after a positive mammogram or to identify women at high risk among those with a false-positive outcome.

Onset of a propagating self-sustained spin reversal front in a magnetic system.

The energy released in a magnetic material by reversing spins as they relax toward equilibrium can lead to a dynamical instability that ignites self-sustained rapid relaxation along a deflagration front that propagates at a constant subsonic speed. Using a trigger heat pulse and transverse and longitudinal magnetic fields, we investigate and control the crossover between thermally driven magnetic relaxation and magnetic deflagration in single crystals of Mn(12)-acetate.

Inter- and intraradiologist variability in the BI-RADS assessment and breast density categories for screening mammograms.

OBJECTIVE: The aim of this study was to evaluate reader variability in screening mammograms according to the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) assessment and breast density categories. METHODS: A stratified random sample of 100 mammograms was selected from a population-based breast cancer screening programme in Barcelona, Spain: 13 histopathologically confirmed breast cancers and 51 with true-negative and 36 with false-positive results. 21 expert radiologists from radiological units of breast cancer screening programmes in Catalonia, Spain, reviewed the mammography images twice within a 6-month interval. The readers described each mammography using BI-RADS assessment and breast density categories. Inter- and intraradiologist agreement was assessed using percentage of concordance and the kappa (κ) statistic. RESULTS: Fair interobserver agreement was observed for the BI-RADS assessment [κ=0.37, 95% confidence interval (CI) 0.36-0.38]. When the categories were collapsed in terms of whether additional evaluation was required (Categories III, 0, IV, V) or not (I and II), moderate agreement was found (κ=0.53, 95% CI 0.52-0.54). Intra-observer agreement for BI-RADS assessment was moderate using all categories (κ=0.53, 95% CI 0.50-0.55) and substantial on recall (κ=0.66, 95% CI 0.63-0.70). Regarding breast density, inter- and intraradiologist agreement was substantial (κ=0.73, 95% CI 0.72-0.74 and κ=0.69, 95% CI 0.68-0.70, respectively). CONCLUSION: We observed a substantial intra-observer agreement in the BI-RADS assessment but only moderate interobserver agreement. Both inter- and intra-observer agreement in mammographic interpretation of breast density was substantial. Advances in knowledge Educational efforts should be made to decrease radiologists' variability in BI-RADS assessment interpretation in population-based breast screening programmes.

[Acute axonal polyneuropathy and Gougerot-Sjögren syndrome]. / Polyneuropathie axonale aiguë et syndrome de Gougerot-Sjögren.

INTRODUCTION: Gougerot-Sjögren syndrome (GSS) is an autoimmune disease characterized by a lymphocytic infiltration and destruction of saliva and lachrymal glands. About 20% of patients develop a neurological involvement. CASE REPORT: A 29-year-old woman was admitted with a dysautonomic and sensorial neuropathy. Clinical manifestations (dry syndrome and positive Schirmer's test), blood (anti-SSA and anti-SSB antibodies) and histological (chronic sialadenitis) tests linked this neuropathy to a primary GSS. The characteristics of this case were acute onset (within a few days), severe clinical presentation (continued confinement to bed and malnutrition) and non-responsiveness to all treatments (intravenous immunoglobulins, corticosteroids, plasmapheresis, rituximab). CONCLUSION: This case illustrates various clinical signs and inconstant responsiveness to treatment of neuropathy associated with primary GSS.

[Surgical treatment of prolapse using laparoscopic promontofixation: technical principles and results]. / Traitement chirurgical du prolapsus par promontofixation par laparotomie: principes techniques et résultats.

UNLABELLED: Abdominal sacrofixation is the gold standard for the treatment of the prolapse. There are many ways to do it: technical, meshes, dissection, fixation of the mesh, associated procedures. Laparotomy is the classical procedure for sacrofixation. The basis of sacrofixation is to dissect the weak vesicovaginal and rectovaginal fascias and to replace with meshes spread out on the entire dissected surface. PROCEDURE: Suprapubic abdominal incision, dissection of the anterior vertebral ligament on the right of the promontory, dissection of the vesicovaginal and rectovaginal spaces; meshes are fixed anteriorly on the vagina, posteriorly on the levator ani and uterosacral ligaments. The peritoneum on the meshes is carefully closed to avoid later ileus. RESULTS: Redux is globally 10% (74-98%); the redux occur in the two years. Meshes exposure, spondilodiscitis, ileus are uncommon. In comparison with the vaginal procedures, there is less redux, less dyspareunia. But the drawbacks are postoperative pains, scars, eventration, low dissection difficult and some contraindications to the abdominal sacrofixation: respiratory insufficiency, morbid obesity, multi-operated abdomen, ascitis, aortoiliac aneurysms.

Propagation of magnetic avalanches in Mn12Ac at high field sweep rates.

Time-resolved measurements of the magnetization reversal in single crystals of Mn12Ac in pulsed magnetic fields, at magnetic field sweep rates from 1.5 kT/s up to 7 kT/s, suggest a new process that cannot be scaled onto a deflagrationlike propagation driven by heat diffusion. The sweep rate dependence of the propagation velocity, increasing from a few 100 m/s up to the speed of sound in Mn12Ac, indicates the existence of two new regimes at the highest sweep rates, with a transition around 4 kT/s that can be understood as a magnetic deflagration-to-detonation transition.