Shift Current with Gaussian Basis Sets and General Prescription for Maximally Symmetric Summations in the Irreducible Brillouin Zone.

The bulk photovoltaic effect is an experimentally verified phenomenon by which a direct charge current is induced within a non-centrosymmetric material by light illumination. Calculations of its intrinsic contribution, the shift current, are nowadays amenable from first-principles employing plane-wave bases. In this work, we present a general method for evaluating the shift conductivity in the framework of localized Gaussian basis sets that can be employed in both the length and velocity gauges, carrying the idiosyncrasies of the quantum-chemistry approach. The (possibly magnetic) symmetry of the system is exploited in order to fold the reciprocal space summations to the representation domain, allowing us to reduce computation time and unveiling the complete symmetry properties of the conductivity tensor under general light polarization.

Nonequilibrium Magneto-Conductance as a Manifestation of Spin Filtering in Chiral Nanojunctions.

It is generally accepted that spin-dependent electron transmission may appear in chiral systems, even without magnetic components, as long as significant spin-orbit coupling is present in some of its elements. However, how this chirality-induced spin selectivity (CISS) manifests in experiments, where the system is taken out of equilibrium, is still debated. Aided by group theoretical considerations and nonequilibrium DFT-based quantum transport calculations, here we show that when spatial symmetries that forbid a finite spin polarization in equilibrium are broken, a net spin accumulation appears at finite bias in an arbitrary two-terminal nanojunction. Furthermore, when a suitably magnetized detector is introduced into the system, the net spin accumulation, in turn, translates into a finite magneto-conductance. The symmetry prerequisites are mostly analogous to those for the spin polarization at any bias with the vectorial nature given by the direction of magnetization, hence establishing an interconnection between these quantities.

A Group-Theoretic Approach to the Origin of Chirality-Induced Spin-Selectivity in Nonmagnetic Molecular Junctions.

Spin-orbit coupling gives rise to a range of spin-charge interconversion phenomena in nonmagnetic systems where certain spatial symmetries are reduced or absent. Chirality-induced spin-selectivity (CISS), a term that generically refers to a spin-dependent electron transfer in nonmagnetic chiral systems, is one such case, appearing in a variety of seemingly unrelated situations ranging from inorganic materials to molecular devices. In particular, the origin of CISS in molecular junctions is a matter of an intense current debate. Here, we derive a set of geometrical conditions for this effect to appear, hinting at the fundamental role of symmetries beyond otherwise relevant quantitative issues. Our approach, which draws on the use of point-group symmetries within the scattering formalism for transport, shows that electrode symmetries are as important as those of the molecule when it comes to the emergence of a spin-polarization and, by extension, to the possible appearance of CISS. It turns out that standalone metallic nanocontacts can exhibit spin-polarization when relative rotations which reduce the symmetry are introduced. As a corollary, molecular junctions with achiral molecules can also exhibit spin-polarization along the direction of transport, provided that the whole junction is chiral in a specific way. This formalism also allows the prediction of qualitative changes of the spin-polarization upon substitution of a chiral molecule in the junction with its enantiomeric partner. Quantum transport calculations based on density functional theory corroborate all of our predictions and provide further quantitative insight within the single-particle framework.

[Effectiveness, adherence and usability of a teleneurorehabilitation programme to ensure continuity of care for patients with acquired brain injury during the COVID-19 pandemic]. / Efectividad, adhesión y usabilidad de un programa de teleneurorrehabilitación para garantizar la continuidad de cuidados en pacientes con daño cerebral adquirido durante la pandemia originada por la COVID-19.

INTRODUCTION: The health pandemic brought about by SARS-CoV-2 (COVID-19) has limited access to neurorehabilitation programmes for many patients who have suffered stroke, traumatic brain injury or acquired brain damage due to some other cause. As telerehabilitation allows for the provision of care in situations of social distancing, it may mitigate the negative effects of confinement. The aim of this study was to determine the efficacy, adherence and usability of a teleneurorehabilitation intervention for patients with acquired brain injury. PATIENTS AND METHODS: All patients included in a face-to-face neurorehabilitation programme at the time of the declaration of the state of alarm in Spain due to COVID-19 and who agreed to participate in the study were included in a teleneurorehabilitation programme. The effectiveness of the programme, understood as an improvement in independence, was quantified with the Barthel index. Adherence to the programme and usability of the tool were explored through questionnaires. RESULTS: Altogether, 46 patients, accounting for 70.6% of the total, participated in the study. Participants significantly improved their independence and showed an improvement in the Barthel index between the start (77.3 ± 28.6) and the end of the programme (82.3 ± 26). Adherence to the intervention was very high (8.1 ± 2.2 out of 10) and the online sessions were the most highly rated content. The tool used showed a high usability (50.1 ± 9.9 out of 60) and could be used without assistance by more than half the participants. CONCLUSION: The teleneurorehabilitation intervention was found to be effective in improving patients' independence, and promoted a high degree of adherence and usability.

TITLE: Efectividad, adhesión y usabilidad de un programa de teleneurorrehabilitación para garantizar la continuidad de cuidados en pacientes con daño cerebral adquirido durante la pandemia originada por la COVID-19.Introducción. La pandemia sanitaria originada por el SARS-CoV-2 (COVID-19) ha limitado el acceso a programas de neurorrehabilitación de muchos pacientes que han sufrido ictus, traumatismos craneoencefálicos o un daño cerebral adquirido por otra causa. Dado que la telerrehabilitación permite la provisión de cuidados en situaciones de distanciamiento social, podría atenuar los efectos negativos del confinamiento. El objetivo de este estudio fue determinar la eficacia, la adhesión y la usabilidad de una intervención de teleneurorrehabilitación dirigida a pacientes con daño cerebral adquirido. Pacientes y métodos. Todos los pacientes incluidos en un programa de neurorrehabilitación presencial en el momento de la declaración del estado de alarma en España con motivo de la COVID-19 y que aceptaron participar en el estudio fueron incluidos en un programa de teleneurorrehabilitación. La eficacia del programa, entendida como una mejora en la independencia, se cuantificó con el índice de Barthel. La adhesión al programa y la usabilidad de la herramienta se investigaron mediante cuestionarios. Resultados. Un total de 146 pacientes, el 70,6% del total, participó en el estudio. Los participantes mejoraron significativamente su independencia y mostraron una mejoría en el índice de Barthel entre el inicio (77,3 ± 28,6) y el fin del programa (82,3 ± 26). La intervención tuvo una gran adhesión (8,1 ± 2,2 sobre 10) y las sesiones en línea fueron el contenido mejor valorado. La herramienta utilizada mostró una elevada usabilidad (50,1 ± 9,9 sobre 60) y pudo ser utilizada sin ayuda por más de la mitad de los participantes. Conclusión. La intervención de teleneurorrehabilitación resultó ser eficaz para mejorar la independencia de los pacientes, y promovió una elevada adhesión y usabilidad.

Efectividad, adhesión y usabilidad de un programa de teleneurorrehabilitación para garantizar la continuidad de cuidados en pacientes con daño cerebral adquirido durante la pandemia originada por la COVID-19 / Effectiveness, adherence and usability of a teleneurorehabilitation programme to ensure continuity of care for patients with acquired brain injury during the COVID-19 pandemic

Introducción: La pandemia sanitaria originada por el SARS-CoV-2 (COVID-19) ha limitado el acceso a programas de neurorrehabilitación de muchos pacientes que han sufrido ictus, traumatismos craneoencefálicos o un daño cerebral adquirido por otra causa. Dado que la telerrehabilitación permite la provisión de cuidados en situaciones de distanciamiento social, podría atenuar los efectos negativos del confinamiento. El objetivo de este estudio fue determinar la eficacia, la adhesión y la usabilidad de una intervención de teleneurorrehabilitación dirigida a pacientes con daño cerebral adquirido. Pacientes y métodos: Todos los pacientes incluidos en un programa de neurorrehabilitación presencial en el momento de la declaración del estado de alarma en España con motivo de la COVID-19 y que aceptaron participar en el estudio fueron incluidos en un programa de teleneurorrehabilitación. La eficacia del programa, entendida como una mejora en la independencia, se cuantificó con el índice de Barthel. La adhesión al programa y la usabilidad de la herramienta se investigaron mediante cuestionarios. Resultados: Un total de 146 pacientes, el 70,6% del total, participó en el estudio. Los participantes mejoraron significativamente su independencia y mostraron una mejoría en el índice de Barthel entre el inicio (77,3 ± 28,6) y el fin del programa (82,3 ± 26). La intervención tuvo una gran adhesión (8,1 ± 2,2 sobre 10) y las sesiones en línea fueron el contenido mejor valorado. La herramienta utilizada mostró una elevada usabilidad (50,1 ± 9,9 sobre 60) y pudo ser utilizada sin ayuda por más de la mitad de los participantes. Conclusión: La intervención de teleneurorrehabilitación resultó ser eficaz para mejorar la independencia de los pacientes, y promovió una elevada adhesión y usabilidad.(AU)

Introduction: The health pandemic brought about by SARS-CoV-2 (COVID-19) has limited access to neurorehabilitation programmes for many patients who have suffered stroke, traumatic brain injury or acquired brain damage due to some other cause. As telerehabilitation allows for the provision of care in situations of social distancing, it may mitigate the negative effects of confinement. The aim of this study was to determine the efficacy, adherence and usability of a teleneurorehabilitation intervention for patients with acquired brain injury. Patients and methods: All patients included in a face-to-face neurorehabilitation programme at the time of the declaration of the state of alarm in Spain due to COVID-19 and who agreed to participate in the study were included in a teleneurorehabilitation programme. The effectiveness of the programme, understood as an improvement in independence, was quantified with the Barthel index. Adherence to the programme and usability of the tool were explored through questionnaires. Results: Altogether, 46 patients, accounting for 70.6% of the total, participated in the study. Participants significantly improved their independence and showed an improvement in the Barthel index between the start (77.3 ± 28.6) and the end of the programme (82.3 ± 26). Adherence to the intervention was very high (8.1 ± 2.2 out of 10) and the online sessions were the most highly rated content. The tool used showed a high usability (50.1 ± 9.9 out of 60) and could be used without assistance by more than half the participants. Conclusion: The teleneurorehabilitation intervention was found to be effective in improving patients’ independence, and promoted a high degree of adherence and usability.(AU)

[Clinical utility of the 64-card version of the Wisconsin Card Sorting Test in patients with traumatic brain injury]. / Utilidad clinica de la versión de 64 cartas del test de clasificación de cartas de Wisconsin en pacientes que han sufrido un traumatismo craneoencefálico.

AIMS: To analyze the validity of the single deck 64-card Wisconsin Card Sorting Test (WCST-64) compared to the standard version (WCST-128), and to study the sensibility of both versions to identify changes over time in patients with traumatic brain injury (TBI). PATIENTS AND METHODS: The WCST was administered twice across a 6-month period to a sample of 50 patients with TBI. Pearson correlation coefficients were calculated to examine bivariate associations between WCST-128 scores and the corresponding WCST-64 scores at inclusion and at follow-up. Agreement in classification of impairment (z = -1) or normal performance was calculated for the two tests (kappa). Significant change over time was also analyzed for both versions of the test (paired-samples t test). RESULTS: The results revealed positive and significant correlations between both measures as well as a significant agreement in the classification of patients as having deficits or not. Moreover, the WCST-128 and the WCST-64 showed similar ability to identify changes over time. CONCLUSIONS: Our findings showed strong associations between scores derived from the two test and support the comparability of both versions when analyzing cross-sectional or longitudinal data. The findings support the use of the WCST-64 in evaluations of executive deficits of patients with moderate and severe TBI.

[When do patients with traumatic brain injury lose verbal information? Implications for cognitive rehabilitation]. / Cuándo pierden la información verbal los pacientes con daño cerebral postraumático? Implicaciones para la rehabilitación cognitiva.

AIM: Longitudinal study of verbal learning and memory processes after traumatic brain injury (TBI). PATIENTS AND METHODS: Twenty-six patients who had sustained a moderate-severe TBI were assessed with a Spanish version of the California Verbal Learning Test at the time of admission and 6-months after inclusion in a multidisciplinary rehabilitation program that comprised rehabilitation strategies for memory impairments. Global memory indexes were determined, including retroactive interference, proactive interference and recall indexes controlled for level of verbal acquisition. Memory change over time was correlated to demographic and clinical relevant variables, including the level of patients' self-awareness. RESULTS: More than 75% of our patients presented learning, immediate memory and delayed memory deficits at baseline, with an important effect of retroactive interference (69%). At 6-month follow-up, 34.6% showed learning difficulties, 46.2% immediate memory deficits, and 53% delayed memory problems, with 34.6% of the patients showing retroactive interference. Chronicity, level of self-awareness and premorbid intelligence correlated to the degree of memory change over time. CONCLUSIONS: Prominent verbal memory problems developed, not only during the first months after TBI but also over time are mostly due to impaired consolidation related to an intense retroactive interference. These data should be considered when developing memory rehabilitation strategies.

¿Cuándo pierden la información verbal los pacientes con daño cerebral postraumático? Implicaciones para la rehabilitación cognitiva / When do patients with traumatic brain injury lose verbal information? Implications for cognitive rehabilitation

Estudio longitudinal sobre los procesos de aprendizaje y memoria verbal tras un traumatismo craneoencefálico(TCE). Pacientes y métodos. Se evaluaron 26 pacientes que habían sufrido un TCE con el test de aprendizaje verbal complutense de forma subaguda (1-5 meses después del TCE) y tras seis meses de rehabilitación multidisciplinar. Se determinaronlos coeficientes globales de la escala, incluyendo interferencia retro y proactiva y los índices de evocación controlados según el grado de aprendizaje previo. Se determinaron los índices de cambio a lo largo del proceso de seguimiento (puntuaciónglobal final de cada variable menos puntuación inicial) y se correlacionaron (Spearman) con las variables demográficas y clínicas con reconocido valor pronóstico, incluyendo el grado de conciencia de enfermedad. Resultados. Más de las tres cuartas partes de nuestros pacientes presentaban alteraciones de aprendizaje, de memoria inmediata y de memoria tardía,con un importante efecto de interferencia retroactiva en 18 (69%) pacientes. A los seis meses, un 34,6% presentaba alteraciones de aprendizaje, un 46,2% de memoria inmediata, un 53% de memoria tardía, y el efecto interferencial se mantenía en un 34,6%. La cronicidad, el grado de conciencia de los déficit y la capacidad intelectual premórbida correlacionaron con los índices de cambio. Conclusiones. La mayoría de los problemas de evocación que aparecen tanto de forma subaguda como crónica tras un TCE se debe a problemas de consolidación en relación con un potente efecto de interferencia retroactiva. Estos datos deben considerarse a la hora de diseñar estrategias de intervención terapéutica, dado su beneficio

Longitudinal study of verbal learning and memory processes after traumatic brain injury (TBI). Patients and methods. Twenty-six patients who had sustained a moderate-severe TBI were assessed with a Spanish version of the California Verbal Learning Test at the time of admission and 6-months after inclusion in a multidisciplinary rehabilitation program thatcomprised rehabilitation strategies for memory impairments. Global memory indexes were determined, including retroactive interference, proactive interference and recall indexes controlled for level of verbal acquisition. Memory change over timewas correlated to demographic and clinical relevant variables, including the level of patients’ self-awareness. Results. More than 75% of our patients presented learning, immediate memory and delayed memory deficits at baseline, with an importanteffect of retroactive interference (69%). At 6-month follow-up, 34.6% showed learning difficulties, 46.2% immediate memory deficits, and 53% delayed memory problems, with 34.6% of the patients showing retroactive interference. Chronicity, level ofself-awareness and premorbid intelligence correlated to the degree of memory change over time. Conclusions. Prominent verbal memory problems developed, not only during the first months after TBI but also over time are mostly due to impaired consolidation related to an intense retroactive interference. These data should be considered when developing memory rehabilitation strategies

‘Escalada de la conciencia’: un instrumento para mejorar la conciencia de enfermedad en pacientes con daño cerebral adquirido / The "awareness climbing". an educational board game for improving self-awareness following acquired brain injury

Objetivo. Determinar la eficacia de una herramienta lúdico-terapéutica (‘escalada de la conciencia’) como método para rehabilitar la conciencia de enfermedad en sujetos con daño cerebral adquirido (DCA). Pacientes y métodos. La ‘escalada de la conciencia’ es una herramienta lúdica que facilita la adquisición de conocimientos necesarios para la adecuada percepción de las deficiencias y pone en práctica estrategias de afrontamiento y compensación de las diferentes limitaciones funcionales generadas tras un DCA. Se incluyó a 17 pacientes con DCA (traumatismo craneoencefálico, 10; ictus, 5; otros, 2). El grado de conciencia de los déficit y de sus implicaciones funcionales se valoró mediante la Self-Awareness of Deficit Interview (SADI) antes y después de un programa de intervención que incluía esta herramienta. La entrevista SADI mide tres aspectos de la conciencia: autoconciencia de los déficit, conciencia de las consecuencias funcionales y capacidad de establecer metas realistas. Resultados. Inicialmente, cinco pacientes presentaban problemas de autopercepción de sus déficit; cuatro, problemas de autopercepción de su discapacidad, y nueve tenían dificultades para establecer metas realistas de futuro. A lo largo del proceso de seguimiento, la percepción de los déficit mejoró en diez pacientes, y la percepción de las dificultades generadas por tales déficit, en seis. El cambio más significativo fue que, tras las sesiones de entrenamiento, el 70% de los sujetos (n = 11) aprendió a establecer metas realistas en función de los problemas generados por su patología. Conclusión. Los resultados obtenidos en la entrevista SADI convierten la ‘escalada de la conciencia’ en un instrumento válido y útil en el proceso rehabilitador de la conciencia de enfermedad en pacientes con DCA

Aim. To establish the effectiveness of an educational board game for improving self-awareness following acquired brain injury. Patients and methods. The ‘awareness climbing’ is a board game format intervention for improving awareness of patients with acquired brain injury (ABI) and for facilitating the use of anticipatory and compensatory strategies. 17 patients with ABI (traumatic brain injury, 10; stroke, 5; others, 2) were included in a self-awareness rehabilitation program using the ‘awareness climbing’. Self-awareness was assessed with the Self-Awareness of Deficit Interview (SADI) before and after game intervention. According to the SADI self-awareness consists of three-interdependent levels: intellectual awareness (impairments), emergent awareness (disability) and anticipatory awareness, which involve the client predicting when impairments will affect his or her performance. Results. Initially five patients showed impaired intellectual awareness, four patients had difficulties on emergent awareness and nine patients showed deficits on anticipatory awareness. Intellectual awareness improved in 10 patients, while six patients experienced improvements in emergent awareness over the intervention period. The most striking change was an improvement in 70% of the sample (n = 11) in anticipatory awareness after game sessions. Conclusion. According to SADI scores we suggest that the ‘awareness climbing’ may be a useful tool for improving self-awareness after acquired brain injury

[The 'awareness climbing': an educational board game for improving self-awareness following acquired brain injury]. / 'Escalada de la conciencia': un instrumento para mejorar la conciencia de enfermedad en pacientes con dano cerebral adquirido.

AIM: To establish the effectiveness of an educational board game for improving self-awareness following acquired brain injury. PATIENTS AND METHODS: The 'awareness climbing' is a board game format intervention for improving awareness of patients with acquired brain injury (ABI) and for facilitating the use of anticipatory and compensatory strategies. 17 patients with ABI (traumatic brain injury, 10; stroke, 5; others, 2) were included in a self-awareness rehabilitation program using the 'awareness climbing'. Self-awareness was assessed with the Self-Awareness of Deficit Interview (SADI) before and after game intervention. According to the SADI self-awareness consists of three-interdependent levels: intellectual awareness (impairments), emergent awareness (disability) and anticipatory awareness, which involve the client predicting when impairments will affect his or her performance. RESULTS: Initially five patients showed impaired intellectual awareness, four patients had difficulties on emergent awareness and nine patients showed deficits on anticipatory awareness. Intellectual awareness improved in 10 patients, while six patients experienced improvements in emergent awareness over the intervention period. The most striking change was an improvement in 70% of the sample (n = 11) in anticipatory awareness after game sessions. CONCLUSION: According to SADI scores we suggest that the 'awareness climbing' may be a useful tool for improving self-awareness after acquired brain injury.

Brain tumor and pregnancy.

OBJECTIVE: To establish the indications for surgical intervention, at the appropriate gestational duration, for brain tumors in pregnant women, and to evaluate any association pregnancy hormones may have with the rate of growth or development of complications of brain tumors. METHODS: We observed seven women with brain tumors associated with pregnancy in a series of 126,413 pregnancies from 1983 to 1995. One woman presented with symptoms of intracranial hypertension, and neurologic signs were the first symptoms in two other women. One woman presented with a sudden hemorrhagic lesion, and three had focal seizures. All were evaluated with computed tomography, magnetic resonance imaging, or both. RESULTS: Six of the seven women had surgery; the seventh was treated with radiotherapy because the neuroradiologic studies suggested a quickly growing brainstem glioma. Diagnoses were confirmed on histology in six women: two with meningiomas, two with ependymomas, and two with low-grade astrocytomas (one of these had multiple astrocytomas). Estrogen and progesterone receptors were studied in two cases (one meningioma and one astrocytoma) and were present in both. CONCLUSION: Management of brain tumors should be tailored to the individual patient. There may be a relation between pregnancy hormones and the rate of brain tumor growth mediated through specific intracellular receptors.

24-year preoperative evolution of a temporal astrocytoma.

We report the case of a patient suffering since 5 months of age from complex focal seizures that could not be controlled with medication and who developed severe psychomotor retardation. When she was 25 years old she was operated on for a left temporal lobe type II astrocytoma which had been detected but misinterpreted on CT scans performed at 12 and 18 years of age. After surgical and radiotherapy treatment the patient was seizure-free for 9 months, but then epilepsy reappeared and the patient died 19 months after surgery. Postsurgical malignant transformation is suspected but not histologically confirmed.

Primary cranial vault lymphoma mimicking meningioma.

Primary lymphomas of the cranial vault are rare; only six patients have been described in the literature. We report a 75-year-old woman who was admitted to our hospital after a focal seizure. CT showed a homogeneous mass which, on contrast enhancement, was similar to a meningioma. The tumour was excised and found to be a centroblastic, centrocytic non-Hodgkin's lymphoma. Treatment was completed with radiotherapy and chemotherapy.

Serpentine aneurysm: regrowth after a superficial temporal artery-middle cerebral artery bypass and internal carotid artery ligation: case report.

Giant serpentine aneurysms (GSAs) are infrequent. We present a 37-year-old patient with a giant serpentine aneurysm of the left middle cerebral artery that was treated with a superficial temporal artery to middle cerebral artery bypass and ligature of the left internal carotid artery. After 2 years, the patient presented new symptoms of neurological deterioration and the computed tomographic scan and arteriography showed regrowth of the aneurysm, which was excised. Enlargement of a giant serpentine aneurysm once it has been treated with ipsilateral carotid ligation and/or bypass anastomosis is rare, and only two cases have been described previously.

Spinal epidural hemangiomas.

Two patients with epidural cavernous hemangiomas located at the lumbar and cervical spine are reported. The first case presented clinically as progressive paraparesis, and the second began with sudden tetraparesis after a strong physical exercise. Myelography and MRI were the diagnostic tools. Surgical decompression improved the signs and symptoms in both cases. Spinal epidural cavernous hemangiomas are rare lesions that are usually regarded as vascular hamartomas. Symptom onset may be insidious or acute and the prognosis after timely surgery is better when compared with that of intrathecal cavernous hemangiomas. The histology and treatment of these processes are discussed.

Primary intracranial arachnoidal cysts. A study of 67 childhood cases.

Sixty-seven cases (41 males and 26 females) of arachnoidal cysts in children under 11 years are reported. About 53% of cases were diagnosed before 1 year of life. Thirty-one (42.2%) were supratentorial (interhemispheric 9, temporal fossa 10, convexity 5, sylvian fissure 3, supra- and/or retrosellar 4); 31 (46.2%) infratentorial (supra- and/or retrocerebellar 22, foramen of Magendie 3, quadrigeminal cistern 5, pontocerebellar 1); 5 (7.5%) supra- and infratentorial. Macrocephaly was the presenting symptom in 48 cases (71.5%). Associated features were frequent: cranial asymmetry in 24; aqueductal stenosis in 10; agenesis of corpus callosum in 8; deficient cerebellar lobullation in 4; Chiari I malformation in 2; neurofibromatosis type 1 with dysgenetic zones of the brain in 1; arteriovenous malformation in 1. Diagnosis was made at autopsy in six cases in the days before computed tomography and magnetic resonance: three patients had a cyst in the supra- and retrocerebellar midline; two had a cyst in the quadrigeminal cistern and the sixth was a rare case with the cyst passing from the posterior fossa to the left lateral ventricle through a hole in the basal surface of the brain. Small and some middle-sized cysts were not treated. Big and some middle-sized cysts were usually treated by cysto- and/or ventriculoperitoneal shunts. Arachnoidal cysts of the quadrigeminal cistern usually present with aqueductal stenosis and have to be treated with ventriculoperitoneal shunt. Craniotomy and fenestration of the cysts were performed in some cases with good results. The average mental level of these children is usually moderately low.

[Antibiotic therapy of infected cerebrospinal fluid in hydrocephalus treated by a shunt]. / Antibioticoterapia del LCR infectado en hidrocefalias tratadas con shunt.

Nine hydrocephalic shunted children with infected cerebrospinal fluid (CSF) were treated. Ages ranged from 0 to 10 years. Diagnosis was made through clinical symptoms, CSF examination, echographic and computed tomography (CT). The microorganism which was seen more frequently, was S. epidermidis. This germ was more often found in young children. Treatment of these patients consisted of a systematic change of the shunt which was externally diverted, implantation of a CSF Ommaya reservoir in the lateral ventricle, and intraventricular and systemic administration of antibiotic, were made. Using this protocol CSF sterilization was obtained in all cases, after 5 to 12 days of treatment. CSF shunt infected with S. epidermidis can be effectively cleaned with daily intra-shunt vancomycin, and shunt infected with gram-negative are also cleaned with daily intra-shunt gentamycin.

An increment in unilateral carotid blood flow produces cerebral aneurysms in rats.

To study the effect of haemodynamic stress on cerebral aneurysm development, three groups of adult Wistar rats were used: 1) One group with ligation of the right common carotid artery; 2) One with an end-to-side common carotid artery anastomosis and 3) Another group that was sham-operated. Blood flow through the left common carotid artery was measured with an electromagnetic flow transducer (0.85 mm in diameter) in anesthetized animals. Before the experimental intervention, the mean carotid blood flow was 2.8 +/- 0.14 ml/min. Following carotid ligation the blood flow in the patent carotid artery increased 25 +/- 5% after 7 +/- 0.3 days and 37 +/- 18% after 149 +/- 23 days; whereas following carotid anastomosis, carotid blood flow increased 102 +/- 16% after 9.6 +/- 2 days and 103 +/- 35% after 169 +/- 15 days. The sham operation did not significantly affect carotid blood flow. Control values for mean arterial pressure (102 +/- 3 mmHg) and blood gases (PaO2 = 106 +/- 3.4 mmHg, PaCO2 = 38 +/- 1.2 mmHg and pH = 7.32 +/- 0.02) were similar in the three groups of rats and did not change significantly over time after the experimental procedure. Necropsy was carried out 149 +/- 15 days after the experimental intervention. No cerebral aneurysms were found in the rats with carotid ligation or which had been sham-operated, however, three of the eight rats (p less than 0.05) with carotid anastomosis presented single aneurysms in the anterior cerebral-anterior communicating arterial complex.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral arteriovenous malformations. Comparative results of surgical vs conservative treatment in 112 cases.

A group of 112 patients affected by cerebral arteriovenous malformations is reviewed. Sixty-six per cent of the cases presented with subarachnoid hemorrhage. Epilepsy was the main clinical feature in 20% of the cases. In 45 cases an intracerebral or intraventricular hematoma was diagnosed by CT-scan, angiography or was found during surgery. Seventy cases (62.5%) were operated upon and 42 cases were treated conservatively. In 57 operated cases, total excision of the AVM was confirmed by postoperative angiography. In this group there was no rebleeding during the follow-up period. Other 13 cases were submitted to partial excision of the AVM or clipping of the feeding vessels. In this latter group, 2 patients had later subarachnoidal rebleeding. Operative mortality was 11% in this series. Mortality caused by the AVM in the non-operated group was 20%. Comparing the morbidity in both groups, the operated group had a much better clinical evolution than the non-operated one. Regarding the final clinically results, an abnormal state of consciousness before surgery, a large size of the AVM and the presence of intracerebral hematoma appear to have a bad prognosis significance.