Selective Endothelial Hyperactivation of Oncogenic KRAS Induces Brain Arteriovenous Malformations in Mice.

OBJECTIVE: Brain arteriovenous malformations (bAVMs) are a leading cause of hemorrhagic stroke and neurological deficits in children and young adults, however, no pharmacological intervention is available to treat these patients. Although more than 95% of bAVMs are sporadic without family history, the pathogenesis of sporadic bAVMs is largely unknown, which may account for the lack of therapeutic options. KRAS mutations are frequently observed in cancer, and a recent unprecedented finding of these mutations in human sporadic bAVMs offers a new direction in the bAVM research. Using a novel adeno-associated virus targeting brain endothelium (AAV-BR1), the current study tested if endothelial KRASG12V mutation induces sporadic bAVMs in mice. METHODS: Five-week-old mice were systemically injected with either AAV-BR1-GFP or -KRASG12V . At 8 weeks after the AAV injection, bAVM formation and characteristics were addressed by histological and molecular analyses. The effect of MEK/ERK inhibition on KRASG12V -induced bAVMs was determined by treatment of trametinib, a US Food and Drug Administration (FDA)-approved MEK/ERK inhibitor. RESULTS: The viral-mediated KRASG12V overexpression induced bAVMs, which were composed of a tangled nidus mirroring the distinctive morphology of human bAVMs. The bAVMs were accompanied by focal angiogenesis, intracerebral hemorrhages, altered vascular constituents, neuroinflammation, and impaired sensory/cognitive/motor functions. Finally, we confirmed that bAVM growth was inhibited by trametinib treatment. INTERPRETATION: Our innovative approach using AAV-BR1 confirms that KRAS mutations promote bAVM development via the MEK/ERK pathway, and provides a novel preclinical mouse model of bAVMs which will be useful to develop a therapeutic strategy for patients with bAVM. ANN NEUROL 2021;89:926-941.

Long-term health-related quality of life in 262 patients with brain arteriovenous malformation.

OBJECTIVE: To discover the health-related quality of life (HRQOL) of patients with treated arteriovenous malformation (AVM), we used the self-applicable HRQOL instrument, the 15D, and analyzed the scores in both in the whole study population and specified cohorts. METHODS: The 15D questionnaires were mailed to adult patients with AVM alive in 2016 (n = 432) in our database. Patients with completely eradicated AVM (n = 262) were included in a subsequent analysis. The results were compared with those of the general population standardized for age and sex. Subgroup analyses were conducted for epilepsy, number of bleeding episodes, location of the lesion, modified Rankin Scale score, and Spetzler-Ponce classification (SPC) using independent-samples t test or analysis of covariance. Tobit regression was used to explain the variance in the 15D score. RESULTS: Patients had impaired HRQOL compared to the reference population (p < 0.0001). Deep location, multiple bleeding episodes, and refractory epilepsy were associated with impaired HRQOL. Patients in SPC A and B had similar posttreatment 15D scores, whereas those in class C had an impaired HRQOL. Significant explanatory variables in the regression model were age, sex, number of bleeding episodes, refractory epilepsy, and SPC. CONCLUSIONS: With careful patient selection, patients in SPC B can reach as favorable HRQOL as those in SPC A provided the operation is successful. Multiple bleeding episodes should be prevented with effective treatment aiming at complete AVM obliteration. The postoperative treatment of patients with AVM should focus on preventing depressive symptoms, anxiety, and epileptic seizures. We encourage other research groups to use HRQOL instruments to fully understand the consequences of neurologic and neurosurgical diseases on patients' HRQOL.

You or me? Disentangling perspectival, perceptual, and integrative mechanisms in heterotopagnosia.

Heterotopagnosia-without-Autotopagnosia (HwA) is characterized by the incapacity to point to body parts on others, but not on one's own body. This has been classically interpreted as related to a self-other distinction, with impaired visual representations of other bodies seen in third person perspective (3PP), besides spared own body somatosensory representations in 1PP. However, HwA could be impacted by a deficit in the integration of visual and somatosensory information in space, that are spatially congruent in the case of one's own body, but not for others' body. Here, we test this hypothesis in a rare neurological patient with HwA, H+, as well as in a control patient with a comparable neuropsychological profile, but without HwA, and in age-matched healthy controls, in two experiments. First, we assessed body part recognition in a new task where somatosensory information from the participant's body and visual information from the target body shown in virtual reality was never aligned in space. Results show that, differently from the flawless performance in controls, H+ committed errors for not only the body of others in 3PP, but for all conditions where the information related to the real and the target body was not spatially congruent. Then, we tested whether the integration between these multisensory bodily cues in space, as during visuo-tactile stimulation in the full-body illusion, improves the patient's performance. Data show that after the stimulation prompting visuo-tactile integration, but not in control conditions, the patient's abilities to process body parts improved up to normal level, thus confirming and extending the first findings. Altogether, these results support a new interpretation of HwA as linked to the matching between somatosensory inputs from one's body and visual information from a body seen at a distance, and encourage the application of multisensory stimulation and virtual reality for the treatment of body-related disorders.

Development of a Psychiatric Disorder Linked to Cerebellar Lesions.

Cerebellar dysfunction plays a critical role in neurodevelopmental disorders with long-term behavioral and neuropsychiatric symptoms. A 43-year-old woman with a cerebellum arteriovenous malformation and history of behavioral dysregulation since childhood is described. After the rupture of the cerebellar malformation in adulthood, her behavior morphed into specific psychiatric symptoms and cognitive deficits occurred. The neuropsychological assessment evidenced impaired performance in attention, visuospatial, memory, and language domains. Moreover, psychiatric assessment indicated a borderline personality disorder. Brain MRI examination detected macroscopic abnormalities in the cerebellar posterior lobules VI, VIIa (Crus I), and IX, and in the posterior area of the vermis, regions usually involved in cognitive and emotional processing. The described patient suffered from cognitive and behavioral symptoms that are part of the cerebellar cognitive affective syndrome. This case supports the hypothesis of a cerebellar role in personality disorders emphasizing the importance of also examining the cerebellum in the presence of behavioral disturbances in children and adults.

Quality of life and disability 12 months after surgery vs. conservative management for unruptured brain arteriovenous malformations: Scottish population-based and Australian hospital-based studies.

BACKGROUND: Few data are available on disability and quality of life (QOL) after surgery versus conservative management for unruptured brain arteriovenous malformations (uAVMs). OBJECTIVE: The aim of this study was to test the hypothesis that QOL and disability are worse after surgery ± preoperative embolisation for uAVM compared with conservative management. METHODS: We included consecutive patients diagnosed with uAVM from a prospective population-based study in Scotland (1999-2003; 2006-2010) and a prospective hospital-based series in Australia (2011-2015). We assessed outcomes on the modified Rankin Scale (mRS) and the Short Form (SF)-36 at ~ 12 months after surgery or conservative treatment and compared these groups using continuous ordinal regression in the two cohorts separately. RESULTS: Surgery was performed for 29% of all uAVM cases diagnosed in Scotland and 84% of all uAVM referred in Australia. There was no statistically significant difference between surgery and conservative management at 12 months among 79 patients in Scotland (mean SF-36 Physical Component Score (PCS) 39 [SD 14] vs. 39 [SD 13]; mean SF-36 Mental Component Score (MCS) 38 [SD 14] vs. 39 [SD 14]; mRS > 1, 24 vs. 9%), nor among 37 patients in Australia (PCS 51 [SD 10] vs. 49 [SD 6]; MCS 48 [SD 12] vs. 49 [SD 10]; mRS > 1, 19 vs. 30%). In the Australian series, there was no statistically significant change in the MCS and PCS between baseline before surgery or conservative management and 12 months. CONCLUSIONS: We did not find a statistically significant difference between surgery ± preoperative embolisation and conservative management in disability or QOL at 12 months.

Evaluation of Qualitative Outcomes after Surgical Intervention on Patients Affected by Arteriovenous Malformations.

BACKGROUND: Arteriovenous malformations are abnormal tangles of blood vessels that cause irregular connections between arteries and veins. Rupture of arteriovenous malformations represents a frequent complication associated with a neurological impairment and physical disability. METHODS: We investigated the relationship among coping dimensions and overall quality of life (QoL), and health status after surgical intervention in 20 patients affected by arteriovenous malformations. Each patient was administered a battery of self-report questionnaires (Short Form 12 Health Survey Questionnaire, Brief COPE Inventory, Beck Depression Inventory, and Hamilton Rating Scale for Anxiety). RESULTS: We found that surgical treatment of arteriovenous malformations affected subjective well-being and emotional aspects. Coping ability influenced the QoL and the presence of anxiety and depressive symptoms. We found a significant correlation between depression and humor (r = -.47, P = .03) and between QoL and self-distraction (r = -.48, P = .03) and humor (r = .44, P = .05). In particular, humor was a significant predictor of mental health and physical health. CONCLUSIONS: The presence of anxiety and depression was the cause of deterioration of QoL, even if psychological resources used to deal with the disease significantly modified the subjective perception of well-being. The evaluation of the impact of cerebrovascular disease on QoL should be a basis for planning and evaluating therapeutic and psychological rehabilitative interventions.

Toward a comprehensive assessment of functional outcomes in pediatric patients with brain arteriovenous malformations: the Pediatric Quality of Life Inventory.

OBJECTIVE Brain arteriovenous malformations (bAVMs) are rare in pediatric patients but represent the most common cause of hemorrhagic stroke in this population. Pediatric patients demonstrate superior outcomes in comparison with adult patients with similar lesions and presentations. Most studies of clinical outcomes of pediatric bAVMs use the modified Rankin Scale (mRS), despite a lack of validation in pediatric patients. METHODS The authors interviewed the parents of 26 pediatric patients who underwent multimodality bAVM treatment and administered the Pediatric Quality of Life Inventory (PedsQL)-a well-validated tool for pediatric outcomes that quantifies performance in a physical, emotional, social, and school domains. They also reviewed clinical information from the patients' medical charts. Statistical analysis was performed using a log-transformed t-test, the Mann-Whitney exact test, the Kruskal-Wallis test, and Spearman correlation. In addition, the literature was reviewed for prior reports of clinical outcome of pediatric cases of bAVM. RESULTS The average PedsQL health-related quality of life score was 71 ± 24, with an average age at diagnosis of 12.5 years and an average follow-up period of 6.8 years. Seventeen patients (65%) presented with hemorrhage and 4 (15%) with seizures. PedsQL scores correlated strongly and at a statistically significant level (p < 0.001) with mRS, Pediatric Overall Performance Category (POPC), Pediatric Cerebral Performance Category (PCPC), and Glasgow Outcome Scale scores. Multivariate modeling validated special education, corrective devices, and cure status as significant predictors of PedsQL scores. Statistically significant risk factors for undergoing placement of a ventriculoperitoneal shunt included lower Glasgow Coma Scale motor scores on admission (p = 0.042), cerebellar location (p = 0.046), and nidus volume (p = 0.017). Neither treatment modality nor location statistically affected clinical outcomes at follow-up. CONCLUSIONS There have been few studies of long-term clinical outcomes of bAVM in pediatric patients, and previously published studies have used conventional metrics that have been validated in the adult population, such as the mRS. Although these metrics can serve as reasonable surrogates, an accurate understanding of overall health-related quality of life is contingent on utilizing validated toolsets, such as the PedsQL.

Factors affecting surgery decision-making in patients with a chronic neurovascular condition.

AIMS AND OBJECTIVES: To explore the factors that affect patient decision-making for an elective surgery. BACKGROUND: Cerebral cavernous malformations are lesions found in the brain and spinal cord comprised of abnormal blood vessels, which bleed sporadically causing serious neurological deficits. Course of treatment for cerebral cavernous malformation is often ultimately left up to the patient, and can include symptom management or surgery. Decision-making for surgery in life-threatening conditions has been well documented in the literature. Less extensive research has focused on elective surgeries, where patients have a choice. There has been no research on the factors that affect decision-making for cavernous malformation patients. DESIGN: Correlational self-report survey. METHODS: In part of a larger online study, participants were asked to rate the importance of six factors on their decision-making about surgery for cavernous malformation. RESULTS: Factors that were rated most important for individuals' decision-making included doctor's opinion regarding surgery, presence of disabling symptoms, fear of symptoms getting worse or developing new symptoms, and availability of an expert surgeon. Results indicated that these were rated as more important than having social support during recovery or having the means to pay for surgery. Additionally, having social support during recovery was rated as significantly more important than having the means to pay for surgery. CONCLUSIONS: Factors that affect decision-making for patients diagnosed with cavernous malformation were similar to those found with other medical conditions requiring elective surgery. This study will assist healthcare workers in understanding the decision-making process of individuals who may choose an elective surgery for potentially disabling conditions with uncertain outcomes. RELEVANCE TO CLINICAL PRACTICE: Understanding the complex factors that affect decision-making in cavernous malformation will assist healthcare professionals to better communicate and support patients in their elective surgery decision-making.

Adolescents with vascular frontal lesion: A neuropsychological follow up case study.

The objective of this research was to identify clinically significant changes in cognitive functions in three adolescents who underwent surgery for resection of a focal vascular lesion in the frontal lobe. Cognitive functions, executive function, behavior regulation, emotion regulation, and social abilities were assessed prior to surgery, six and 24 months post-discharge. Significant clinical changes were observed during all the assessments. Cognitive changes after surgery are not homogeneous. Most of the significant clinical changes were improvements. Especially the significant clinical changes presented in EF domains were only improvements; these results suggest that EF were affected by the vascular lesion and benefitted by the surgery. After resection of a vascular lesion between 15 and 16 years of age the affected executive functions can continue the maturation process. Our results highlight the importance that assessments must include emotional aspects, even if deficits in these domains are not presented in the acute phase. Rehabilitation methods should promote the development of skills that help patients and their families to manage the emotional and behavioral changes that emerge once they are discharged from the hospital.

Julius Caesar's Epilepsy: Was It Caused by A Brain Arteriovenous Malformation?

Julius Caesar (100-44 BC) was one of the most charismatic political figures in history. Best remembered for his military achievements, he was also a writer, historian, and statesman. Through his constitutional reforms, he played an important role in the events that led to the end of the Roman Republic and the birth of the Roman Empire. Historical sources reveal that Julius Caesar suffered from headaches, seizures, and personality changes. In this essay, we highlight the life of Julius Caesar, with emphasis on the potential origin of his sickness. Although a definitive diagnosis obviously cannot be made, as new published studies showed a possible cerebrovascular etiology, a new hypothetical diagnosis is presented.

Neuropsychological outcomes of stereotactic radiotherapy for cerebral arteriovenous malformations.

To our knowledge, this is the first study to investigate cognitive outcome in patients with large or surgically inaccessible cerebral arteriovenous malformations (AVMs), who were treated with hypo-fractionated stereotactic radiotherapy (HSRT). A sample of 10 patients with AVMs was assessed up to 3.5 years post-HSRT. All patients were treated with HSRT to a total dose of 55 Gy in 11 fractions over a treatment period of 2.5 weeks. Neuropsychological assessments were given prior to radiotherapy and then at three time points following radiotherapy: 6 weeks, 6 months and 2.5-3.5 years post-treatment. The cognitive domains of attention, processing speed, learning, memory, semantic processing, naming, verbal fluency, visuospatial and executive function were assessed. Findings revealed that prior to radiotherapy the patient group was impaired in five of the nine cognitive domains. Post-treatment performances remained stable in the majority of domains; however, there was some fluctuation in semantic processing and memory performances. At 6 weeks post-treatment, a mild decrement was found in semantic processing ability; however, restoration to baseline levels was observed from 6 months onwards. At 2.5-3.5 years post-treatment, improvement was seen in the cohort's ability to remember new information when performances were compared with earlier time points. This study demonstrated improvements in memory several years after HSRT treatment. Further, this form of treatment was not associated with long-term, harmful cognitive side effects for these 10 patients encouraging further study of this treatment method. Further evaluation of the entire cohort is required to assess efficacy in terms of AVM obliteration and other potential side effects.

Factors predicting language lateralization in patients with perisylvian vascular malformations. Clinical article.

OBJECT: The authors conducted a study to determine the factors associated with right-sided language dominance in patients with cerebrovascular malformations. METHODS: Twenty-two patients with either arteriovenous malformations (AVMs [15 cases]) or cavernous malformations (7 cases) underwent functional MR (fMR) imaging studies of language function; a 3.0-T head-only unit was used. Lateralization indices were calculated separately for Broca and Wernicke areas. Lesion size, Spetzler-Martin grade, and the distance between the lesion and anatomically defined language cortex were calculated for each patient. RESULTS: Right-sided language dominance occurred in 5 patients, all of whom had AVMs within 10 mm of canonical language areas. Three patients had right-sided language dominance in the Wernicke area alone whereas 2 had right-sided language dominance in both Broca and Wernicke areas. Wada testing and intraoperative electrocortical stimulation were performed as clinically indicated to corroborate fMR imaging findings. CONCLUSIONS: The primary factor associated with right-sided language dominance was the AVM being within 10 mm of anatomically defined language areas. The lesion size and the Spetzler-Martin grade were not significant factors. Anomalous fMR imaging laterality was typically confined to the language area proximate to the lesion, with the distal language area remaining in the left hemisphere dominant. This study emphasizes the need to map each case individually in patients with left perisylvian AVMs. Assumptions about eloquent cortex based on anatomical landmarks (a key component of Spetzler-Martin grading) may have to be reconsidered.

[Neuropsychological signs in patients with arteriovenous malformations, cavernomas and hematomas of cerebellum].

Neuropsychological assessment was performed in 13 patients with arteriovenous malformations and 12 with cavernomas and hematomas of cerebellum before and after surgery. In all patients we identified syndromes that were similar to the damage of different areas of neocortex (predominately frontal lobe). Apraxia and disturbance of verbal memory were the most frequent signs. Half of patients after AVM embolization and all patients after direct surgery developed deterioration of verbal memory. Some patients after manipulations on right cerebellar hemisphere had micrography and perseverations. There were no severe mental disorders neither before nor after surgery. That was controversial to other similar studies. The most severe cognitive disorders were found after surgery on superior cerebellar artery and its branches.

Understanding the neuropsychologic outcome of pediatric AVM within a neurodevelopmental framework.

OBJECTIVE: This case series describes the long-term neuropsychologic functioning of 5 children with repaired arteriovenous malformations (AVMs). Results are presented within the context of a neurodevelopmental model to facilitate conceptualization and generate appropriate rehabilitation strategies for children with AVMs. BACKGROUND: The current case series expands upon previous research examining the long-term psychosocial functioning of these children with AVMs in which it was found that overall emotional functioning appeared adequate, although there were suggestions of defensiveness and areas of worry. In addition, global adaptive functioning was below average for most children with parental concerns about their child's socialization. METHOD: Five children with repaired AVMs in the cerebellum and frontal, temporal, and parietal lobes participated in a neuropsychologic evaluation assessing intellectual, language, memory, motor, visual-perceptual and visual-motor, and executive functions. RESULTS: These children demonstrated both localized and remote findings. More specifically, mild to moderate weaknesses in executive functions were suggested regardless of AVM location. CONCLUSIONS: The finding that children exhibited executive function difficulties regardless of AVM location is in keeping with the understanding of multiple cortical and subcortical pathways to and from the frontal lobes. In addition, it is possible that the processes of diaschisis and plasticity may play a role in the functional outcome of AVMs.

Patient concerns posthaemorrhagic stroke: a study of the Internet narratives of patients with ruptured arteriovenous malformation.

AIMS: To identify and describe the experiences and concerns of a sample of young haemorrhagic stroke patients who experienced a ruptured arteriovenous malformation and determine whether there are gender differences. BACKGROUND: Patients with arteriovenous malformation haemorrhage tend to be young adults, but little is known about their experiences and concerns. Some research suggest that there is a need to take gender into account when investigating their experiences and concerns. DESIGN: A content analysis of a sample of narratives posted by survivors of an arteriovenous malformation haemorrhage on an Internet site, to determine the extent to which writers discuss similar concerns and experiences. METHODS: The sample consists of 83 narratives. The author and a research assistant carefully considered the content of each narrative, created categories based upon this reading and then coded men and women's narratives separately, according to the topic discussed. RESULTS: Five main categories of topics were identified: 'symptoms', 'doctors and hospitals', 'rehabilitation and recovery', 'disabilities' and 'miscellaneous reflections'. The latter category contained the sub-categories 'arteriovenous malformation website', 'thanks', 'life now' and 'feelings'. Narratives varied greatly regarding how much each topic was addressed, but there were few gender differences. Overall, most attention was paid to discussing doctors and hospitals and most writers also paid significant attention to the importance of being able to share experiences with other survivors. CONCLUSIONS: For these narrators, the experience of being evaluated and treated for arteriovenous malformation haemorrhage is traumatic, leaves a lasting impact and men and women share similar concerns and experiences. Narrators show a need to talk about their experiences, especially with others who may share similar experiences. RELEVANCE TO CLINICAL PRACTICE: Knowing the concerns and perspectives of a sample of arteriovenous malformation patients may help nurses anticipate the concerns of their own haemorrhagic stroke patients and help improve patients' psychosocial well-being.

A case of evolving post-ictal language disturbance secondary to a left temporal arteriovenous malformation: jargon aphasia or formal thought disorder?

INTRODUCTION: Wernicke's dysphasia and formal thought disorder are regarded as distinct diagnostic entities although both are linked to pathology in the left superior temporal gyrus (STG). We describe a patient with focal pathology in the left STG, giving rise acutely to a fluent dysphasia, which gradually evolved into formal thought disorder. METHOD: Clinical, neuropsychological, neuropsychiatric, and neuroradiological assessment. RESULTS: A right-handed patient, AJ, presented acutely with a fluent dysphasia. His speech output gradually evolved from undifferentiated jargon, through neologistic jargon, to an intelligible but bizarre form of discourse. Comprehension was relatively well preserved. Radiology revealed an arteriovenous malformation in the left middle, and inferior temporal gyri, with reduced perfusion of the left STG. Six months later his overt dysphasia had recovered, but his speech retained some of its previous characteristics, in particular a tendency to a loose association of ideas which now suggested a disorder of thought. CONCLUSIONS: AJ's case illustrates that comprehension may be unexpectedly preserved in jargon aphasia, and that an overtly linguistic impairment can gradually evolve to an apparent disorder of thought. Indistinguishable formal thought disorders can result from "structural" and "functional" pathology in the dominant temporal lobe.

Domain-specific deficits in schizophrenia.

INTRODUCTION: Object recognition deficits are well documented in certain neurological disorders (e.g., Alzheimer's disease, herpes simplex encephalitis). Although agnosic problems have been documented in some patients with schizophrenia (Gabrovska et al., 2003), no study has investigated whether such deficits differentially affect specific categories of information (as they sometimes do in neurological cases). METHOD: In Part I of this study, we compared object recognition in 55 patients with chronic schizophrenia and 22 age- and NART IQ-matched healthy controls. In Part II, we present a detailed case study of one patient with schizophrenia (DH) who displays a severe category specific semantic knowledge for living things. RESULTS: Of the patients with schizophrenia, 75% had object recognition below the 5th percentile, and in 11% of cases, a highly specific classical category dissociation emerged (5 cases with nonliving deficit and 1 with living deficit); and two other patients showed strong dissociation for living things. These findings provide convincing evidence of a classical double dissociation across the two categories. In Part II, the in-depth case study of one schizophrenic patient (DH), documented a profound agnosia for living things. While DH displayed intact low level perceptual and spatial ability and could copy drawings, he was severely impaired at naming, picture-name matching, semantic fluency, and could not describe or draw items from memory. CONCLUSIONS: The presence of impaired object recognition in most schizophrenic patients, along with highly selective category specific deficits in a minority, is discussed with reference to similar findings in neurological patients.

Integration of functional brain information into stereotactic irradiation treatment planning using magnetoencephalography and magnetic resonance axonography.

PURPOSE: To minimize the risk of neurologic deficit after stereotactic irradiation, functional brain information was integrated into treatment planning. METHODS AND MATERIALS: Twenty-one magnetoencephalography and six magnetic resonance axonographic images were made in 20 patients to evaluate the sensorimotor cortex (n = 15 patients, including the corticospinal tract in 6), visual cortex (n = 4), and Wernicke's area (n = 2). One radiation oncologist was asked to formulate a treatment plan first without the functional images and then to modify the plan after seeing them. The pre- and postmodification values were compared for the volume of the functional area receiving > or =15 Gy and the volume of the planning target volume receiving > or =80% of the prescribed dose. RESULTS: Of the 21 plans, 15 (71%) were modified after seeing the functional images. After modification, the volume receiving > or =15 Gy was significantly reduced compared with the values before modification in those 15 sets of plans (p = 0.03). No statistically significant difference was found in the volume of the planning target volume receiving > or =80% of the prescribed dose (p = 0.99). During follow-up, radiation-induced necrosis at the corticospinal tract caused a minor motor deficit in 1 patient for whom magnetic resonance axonography was not available in the treatment planning. No radiation-induced functional deficit was observed in the other patients. CONCLUSION: Integration of magnetoencephalography and magnetic resonance axonography in treatment planning has the potential to reduce the risk of radiation-induced functional dysfunction without deterioration of the dose distribution in the target volume.

Improvement in cognitive function after right temporal arteriovenous malformation excision.

A patient is presented in whom right temporal AVM excision led to improved cognitive function. Neuropsychological assessment showed a significant postoperative improvement in Performance IQ (p = < 0.05), Full Scale IQ (p = < 0.05), and clinically in visual memory (p = < 0.10). Reversal of vascular steal may lead to increases in cognitive function. We recommend that patients undergoing AVM excision have a complete neuropsychological evaluation.

Prospective study of neuropsychological and psychosocial outcome following surgical excision of intracerebral arteriovenous malformations.

In this prospective study the neuropsychological and psychosocial function of 64 patients undergoing surgical resection of cerebral arteriovenous malformations was examined prior to surgery (T1), one month post-surgery (T2) and one year post-surgery (T3). A mild but widespread cognitive decline was observed pre-operatively. There was a trend toward decreased neuropsychological function at T2. All neuropsychological tests showed a trend toward improvement at T3 compared with both pre-operative (generally not statistically significant) and early post-operative values (generally significant). Patients were assessed for change between testing times. At T2 patients were more likely to have deteriorated than improved, whereas at T3 the group which had altered from baseline were more likely to have improved than deteriorated. Deterioration in some verbal/language tasks was more common for left sided AVMs. Outcome did not differ significantly for patients presenting with haemorrhage. Psychosocial function was unchanged at late follow-up for the majority of patients.