Postsurgical morbidity and mortality favorably informs deep brain stimulation for new indications including schizophrenia and schizoaffective disorder.

Background: Deep brain stimulation (DBS) shows promise for new indications like treatment-refractory schizophrenia in early clinical trials. In the first DBS clinical trial for treatment refractory schizophrenia, despite promising results in treating psychosis, one of the eight subjects experienced both a symptomatic hemorrhage and an infection requiring device removal. Now, ethical concerns about higher surgical risk in schizophrenia/schizoaffective disorder (SZ/SAD) are impacting clinical trial progress. However, insufficient cases preclude conclusions regarding DBS risk in SZ/SAD. Therefore, we directly compare adverse surgical outcomes for all surgical procedures between SZ/SAD and Parkinson's disease (PD) cases to infer relative surgical risk relevant to gauging DBS risks in subjects with SZ/SAD. Design: In the primary analysis, we used browser-based statistical analysis software, TriNetX Live (trinetx.com TriNetX LLC, Cambridge, MA), for Measures of Association using the Z-test. Postsurgical morbidity and mortality after matching for ethnicity, over 39 risk factors, and 19 CPT 1003143 coded surgical procedures from over 35,000 electronic medical records, over 19 years, from 48 United States health care organizations (HCOs) through the TriNetX Research Network™. TriNetXis a global, federated, web-based health research network providing access and statistical analysis of aggregate counts of deidentified EMR data. Diagnoses were based on ICD-10 codes. In the final analysis, logistic regression was used to determine relative frequencies of outcomes among 21 diagnostic groups/cohorts being treated with or considered for DBS and 3 control cohorts. Results: Postsurgical mortality was 1.01-4.11% lower in SZ/SAD compared to the matched PD cohort at 1 month and 1 year after any surgery, while morbidity was 1.91-2.73% higher and associated with postsurgical noncompliance with medical treatment. Hemorrhages and infections were not increased. Across the 21 cohorts compared, PD and SZ/SAD were among eight cohorts with fewer surgeries, nine cohorts with higher postsurgical morbidity, and fifteen cohorts within the control-group range for 1-month postsurgical mortality. Conclusions: Given that the subjects with SZ or SAD, along with most other diagnostic groups examined, had lower postsurgical mortality than PD subjects, it is reasonable to apply existing ethical and clinical guidelines to identify appropriate surgical candidates for inclusion of these patient populations in DBS clinical trials.

Striatal and Thalamic Auditory Response During Deep Brain Stimulation for Essential Tremor: Implications for Psychosis.

INTRODUCTION: The P50, a positive auditory-evoked potential occurring 50 msec after an auditory click, has been characterized extensively with electroencephalography (EEG) to detect aberrant auditory electrophysiology in disorders like schizophrenia (SZ) where 61-74% have an auditory gating deficit. The P50 response occurs in primary auditory cortex and several thalamocortical regions. In rodents, the gated P50 response has been identified in the reticular thalamic nucleus (RT)-a deep brain structure traversed during deep brain stimulation (DBS) targeting of the ventral intermediate nucleus (VIM) of the thalamus to treat essential tremor (ET) allowing for interspecies comparison. The goal was to utilize the unique opportunity provided by DBS surgery for ET to map the P50 response in multiple deep brain structures in order to determine the utility of intraoperative P50 detection for facilitating DBS targeting of auditory responsive subterritories. MATERIALS AND METHODS: We developed a method to assess P50 response intraoperatively with local field potentials (LFP) using microelectrode recording during routine clinical electrophysiologic mapping for awake DBS surgery in seven ET patients. Recording sites were mapped into a common stereotactic space. RESULTS: Forty significant P50 responses of 155 recordings mapped to the ventral thalamus, RT and CN head/body interface at similar rates of 22.7-26.7%. P50 response exhibited anatomic specificity based on distinct positions of centroids of positive and negative responses within brain regions and the fact that P50 response was not identified in the recordings from either the internal capsule or the dorsal thalamus. CONCLUSIONS: Detection of P50 response intraoperatively may guide DBS targeting RT and subterritories within CN head/body interface-DBS targets with the potential to treat psychosis and shown to modulate schizophrenia-like aberrancies in mouse models.

Review of serum prolactin levels as an antipsychotic-response biomarker.

Antipsychotics acting as antagonists at dopamine D2 receptors concentrated in the striatum are the cornerstone of effective treatment of psychosis. Substantial progress in treating persons with schizophrenia could be achieved by the identification of biomarkers which reliably determine the lowest efficacious dose of antipsychotics. Prolactin levels have been considered a promising treatment-response biomarker due to dopamine's regulation of serum prolactin levels through D2 receptors in the hypothalamic-pituitary pathway. Prolactin secretion in response antipsychotic administration is associated with the antipsychotics affinity for D2 receptors. This review assesses the available literature on the use of serum prolactin levels as an antipsychotic-response biomarker. Articles were identified through PubMed as well as the reference lists of full text articles available online. Relevant publications were summarized briefly to define the limitations and utility of serum prolactin levels as a tool for improving antipsychotic dosing. Serum prolactin levels in combination with prolactin-inducing potencies for each antipsychotic may help identify the lowest effective dose of antipsychotic medications. , In addition to the fact that prolactin secretion is dependent on serum antipsychotic levels and not brain levels, recent findings show that prolactin release is independent of the ß-arrestin-2 pathway and GSK3ß regulation, one branch of the pathway that has been implicated in antipsychotic efficacy. Therefore, serum prolactin is an indirect biomarker for treatment response. Further investigations are warranted to characterize prolactin-antipsychotic dose-response curves and systematically test the utility of measuring prolactin levels in patients to identify a person's lowest efficacious dose.

Approaches to neuromodulation for schizophrenia.

Based on the success of deep brain stimulation (DBS) for treating movement disorders, there is growing interest in using DBS to treat schizophrenia (SZ). We review the unmet needs of patients with SZ and the scientific rationale behind the DBS targets proposed in the literature in order to guide future development of DBS to treat this vulnerable patient population. SZ remains a devastating disorder despite treatment. Relapse, untreated psychosis, intolerable side effects and the lack of effective treatment for negative and cognitive symptoms contribute to poor outcome. Novel therapeutic interventions are needed to treat SZ and DBS is emerging as a potential intervention. Convergent genetic, pharmacological and neuroimaging evidence implicating neuropathology associated with psychosis is consistent with SZ being a circuit disorder amenable to striatal modulation with DBS. Many of the DBS targets proposed in the literature may modulate striatal dysregulation. Additional targets are considered for treating tardive dyskinesia and negative and cognitive symptoms. A need is identified for the concurrent development of neurophysiological biomarkers relevant to SZ pathology in order to inform DBS targeting. Finally, we discuss the current clinical trials of DBS for SZ, and their ethical considerations. We conclude that patients with severe symptoms despite treatment must have the capacity to consent for a DBS clinical trial in which risks can be estimated, but benefit is not known. In addition, psychiatric populations should have access to the potential benefits of neurosurgical advances.

Remotely Programmed Deep Brain Stimulation of the Bilateral Subthalamic Nucleus for the Treatment of Primary Parkinson Disease: A Randomized Controlled Trial Investigating the Safety and Efficacy of a Novel Deep Brain Stimulation System.

BACKGROUND: Deep brain stimulation (DBS) is the most commonly performed surgery for the debilitating symptoms of Parkinson disease (PD). However, DBS systems remain largely unaffordable to patients in developing countries, warranting the development of a safe, economically viable, and functionally comparable alternative. OBJECTIVE: To investigate the efficacy and safety of wirelessly programmed DBS of bilateral subthalamic nucleus (STN) in patients with primary PD. METHODS: Sixty-four patients with primary PD were randomly divided into test and control groups (1:1), where DBS was initiated at either 1 month or 3 months, respectively, after surgery. Safety and efficacy of the treatment were compared between on- and off-medication states 3 months after surgery. Outcome measures included analysis of Unified Parkinson's Disease Rating Scale (UPDRS) scores, duration of "on" periods, and daily equivalent doses of levodopa. All patients were followed up both 6 and 12 months after surgery. RESULTS: Three months after surgery, significant decrease in the UPDRS motor scores were observed for the test group in the off-medication state (25.08 ± 1.00) versus the control group (4.20 ± 1.99). CONCLUSIONS: Bilateral wireless programming STN-DBS is safe and effective for patients with primary PD in whom medical management has failed to restore motor function.

Correlated expression analysis of genes implicated in schizophrenia: identification of putative disease-related pathways.

Schizophrenia (SCZ) is a severe psychiatric disorder affecting 0.7% of the population.[1] When inadequately treated, subjects with SCZ experience symptoms that render them dysfunctional and unable to discern aspects of reality. Despite the fact that the majority of subjects with SCZ are sporadic cases and do not have a known family history of SCZ, a family history is one of the largest risk factors for developing SCZ.[2-4] A large genome-wide association study (GWAS) recently pinpointed 108 significant loci within the human genome that contribute to SCZ pathogenesis.[5] While some loci include genes that have been previously implicated in SCZ, the majority, due to the unbiased nature of the genetic investigation, include genes with unknown relevance to SCZ. This investigation is based on the premise that: 1) at least one of the genes at the 108 loci contribute to SCZ etiology; 2) some of the genes contributing to SCZ etiology are in a common pathway; and 3) some genes in a common pathway will have correlated gene expression. Gene expression data available in the gene expression omnibus (GEO) was used to identify correlated expression among the 369 genes (853 isoforms) found at the 108 loci associated with SCZ. Expression data came from bone marrow CD34+ selected cells isolated from 66 individuals (GSE4619). First, correlation among genes related to the DRD2 pathway was analyzed to test the hypothesis that some SCZ genes are in a common pathway and have correlated expression. Then, two pathways were generated based on correlated expression of genes at the 108 loci. One pathway consisted of the largest number of genes with correlated expression (56) and included four genes from the DRD2 pathway and seven of the 33 genes that were previously implicated in SCZ. The second pathway, a novel pathway of 12 genes, was constructed by excluding both the 33 genes that were previously implicated in SCZ and other genes that exhibited significantly correlated expression with these 33 genes. Correlated expression analysis among SCZ-associated genes at the 108 loci provides evidence implicating those genes with correlated expression in SCZ pathogenesis. In addition, these analyses will facilitate pathway identification creating starting points for targeted experiments to verify or refute the hypothetical pathways generated here. Ultimately identifying the genes and pathways at the 108 loci involved in SCZ genesis will inform novel pharmaceutical development for treatment and prevention of SCZ.

Elevated DISC1 transcript levels in PBMCs during acute psychosis in patients with schizophrenia.

BACKGROUND: Severe mental disorders like schizophrenia are a leading cause of disability in people in the prime years of their lives (aged 15 to 44 years). Relapse is a primary contributor to schizophrenia disease burden and is frequently attributed to medication noncompliance and inadequate doses. Currently, a patient's neuroleptic dose is titrated to clinical response within recommended dose ranges. Use of unbiased biomarkers of effective neuroleptic treatment-response would greatly facilitate the identification of a person's lowest effective dose to minimize unsafe side effects and improve compliance. Biomarkers may allow precisely tailored adjustments of neuroleptic dose to reduce relapse due to variable disease course. METHODS AND FINDINGS: Biomarkers of active psychosis were sought among persons with schizophrenia hospitalized with acute psychosis. The transcriptional response of peripheral blood mononuclear cells (PBMCs) to treatment of psychosis was measured using RNA expression profiling in 12-paired samples from patients with schizophrenia. The paired samples were collected early after treatment initiation and again just before patients were released from the hospital. Patients showed significant improvement in positive symptoms of psychosis assessed at each sample collection using a brief psychiatric rating scale (BPRS) (P<0.05). Preliminary evidence is presented indicating that decreased transcript levels of isoforms of disrupted in schizophrenia 1 (DISC1) measured in PBMCs were associated with treatment in 91% of samples (P=0.037). CONCLUSION: Further studies are warranted to identify neuroleptic-response biomarkers and to replicate this initial finding of association of DISC1 transcript levels with treatment of psychosis.

A 2-base pair deletion polymorphism in the partial duplication of the alpha7 nicotinic acetylcholine gene (CHRFAM7A) on chromosome 15q14 is associated with schizophrenia.

Multiple genetic linkage studies support the hypothesis that the 15q13-14 chromosomal region contributes to the etiology of schizophrenia. Among the putative candidate genes in this area are the alpha7 nicotinic acetylcholine receptor gene (CHRNA7) and its partial duplication, CHRFAM7A. A large chromosomal segment including the CHRFAM7A gene locus, but not the CHRNA7 locus, is deleted in some individuals. The CHRFAM7A gene contains a polymorphism consisting of a 2 base pair (2 bp) deletion at position 497-498 bp of exon 6. We employed PCR-based methods to quantify the copy number of CHRFAM7A and the presence of the 2 bp polymorphism in a large, multi-ethnic population. The 2 bp polymorphism was associated with schizophrenia in African Americans (genotype p=0.005, allele p=0.015), and in Caucasians (genotype p=0.015, allele p=0.009). We conclude that the presence of the 2 bp polymorphism at the CHRFAM7A locus may have a functional significance in schizophrenia.

Cerebral cavernous malformations: somatic mutations in vascular endothelial cells.

OBJECTIVE: Germline mutations in 3 genes have been found in familial cases of cerebral cavernous malformations (CCMs). We previously discovered somatic and germline truncating mutations in the KRIT1 gene, supporting the "2-hit" mechanism of CCM lesion formation in a single lesion. The purpose of this study was to screen for somatic, nonheritable mutations in 3 more lesions from different patients and identify the cell type(s) in which somatic mutations occur. METHODS: Somatic mutations were sought in DNA from 3 surgically excised, fresh-frozen CCM lesions by cloning and screening polymerase chain reaction products generated from KRIT1 or PDCD10 coding regions. Laser capture microdissection was used on isolated endothelial and nonendothelial cells to determine whether somatic mutations were found in endothelial cells. RESULTS: CCM lesions harbor somatic and germline KRIT1 mutations on different chromosomes and are therefore biallelic. Both mutations are predicted to truncate the protein. The KRIT1 somatic mutations (novel c.1800delG mutation and previously identified 34 nucleotide deletion) in CCMs from 2 different patients were found only in the vascular endothelial cells lining caverns. No obvious somatic mutations were identified in the 2 other lesions; however, the results were inconclusive, possibly owing to the technical limitations or the fact that these specimens had a small proportion of vascular endothelial cells lining pristine caverns. CONCLUSION: The "2-hit" mechanism occurs in vascular endothelial cells lining CCM caverns from 2 patients with somatic and Hispanic-American KRIT1 germline mutations. Methods for somatic mutation detection should focus on vascular endothelial cells lining pristine caverns.

Familial cerebral cavernous malformations: Rio de Janeiro study and review of the recommendations for management.

OBJECTIVE: Multiple cerebral cavernous malformation (CCM) is the hallmark of familial presentation of cavernous malformation in the brain. We describe an ongoing Familial Cerebral Cavernous Malformation Project in the Rio de Janeiro state showing genetic profile and the pattern of emergent neuroimaging findings of this particular population besides a review of the updated recommendations for management of familial CCM versus patients harboring sporadic lesions. METHOD: Four families of our cohort of 9 families were genetically mapped showing mutational profile linked to CCM1. The neuroimaging paradigm was shifted from T2*gradient-echo (GRE) sequence to susceptibility weighting MR phase imaging (SWI). RESULTS: Only two index cases were subjected to surgery. There was no surgical intervention in any of the kindreds of our entire cohort of 9 families of our Neurovascular Program within seven years of follow-up. The genetic sequencing for mutational profile in four of these families has demonstrated only CCM1 gene affected. Our management of the familial CCM is according to the review of the literature recommendations. CONCLUSIONS: The Project of Familial Cerebral Cavernous Malformations of Rio de Janeiro detected mutations of the gene CCM1 in the first four families studied. Familial cavernous malformation are to be settled apart from the more common sporadic lesion. A set of recommendations was searched for in the literature in order to deal with these specific patients and kindreds.

Familial cerebral cavernous malformations: Rio de Janeiro study and review of the recommendations for management / Malformação cavernosa cerebral familiar: um estudo no Rio de Janeiro e revisão das recomendações para tratamento

OBJECTIVE: Multiple cerebral cavernous malformation (CCM) is the hallmark of familial presentation of cavernous malformation in the brain. We describe an ongoing Familial Cerebral Cavernous Malformation Project in the Rio de Janeiro state showing genetic profile and the pattern of emergent neuroimaging findings of this particular population besides a review of the updated recommendations for management of familial CCM versus patients harboring sporadic lesions. METHOD: Four families of our cohort of 9 families were genetically mapped showing mutational profile linked to CCM1. The neuroimaging paradigm was shifted from T2*gradient-echo (GRE) sequence to susceptibility weighting MR phase imaging (SWI). RESULTS: Only two index cases were subjected to surgery. There was no surgical intervention in any of the kindreds of our entire cohort of 9 families of our Neurovascular Program within seven years of follow-up. The genetic sequencing for mutacional profile in four of these families has demonstrated only CCM1 gene affected. Our management of the familial CCM is according to the review of the literature recommendations. CONCLUSIONS: The Project of Familial Cerebral Cavernous Malformations of Rio de Janeiro detected mutations of the gene CCM1 in the first four families studied. Familial cavernous malformation are to be settled apart from the more common sporadic lesion. A set of recommendations was searched for in the literature in order to deal with these specific patients and kindreds.

OBJETIVOS: A apresentação de malformação cavernosa cerebral (CCM) através de múltiplas lesões cerebrais é a marca da forma familiar da doença. Os autores descrevem o Projeto Malformação Cavernosa Cerebral Familiar, em andamento no Rio de Janeiro, demonstrando o perfil genético e o padrão atual de achados neurorradiológicos dessa população específica e uma revisão das recomendações atuais para o manuseio e tratamento dos portadores dessa forma da doença versus os pacientes com malformação cavernosa cerebral esporádica. MÉTODO: Quatro familias de nossa coorte de 9 familias foram completamente mapeadas geneticamente e demonstraram padrão mutacional sempre ligado ao gene CCM1. O paradigma de neurimagens dessa população foi mudado para a seqüência de susceptibility weighting MR phase imaging (SWI) em substituição à seqüência T2*gradient-echo (GRE). RESULTADOS: Apenas 2 casos indices foram submetidos à ressecção cirúrgica. Não houve intervenção cirúrgica em nenhum outro parente de toda a coorte de 9 familias no período de sete anos de acompanhamento. O sequenciamento genético em busca do perfil mutacional foi completado em 4 familias demonstrando o acometimento do gene CCM1 em todas. O manuseio e tratamento de nossa população de malformação cavernosa cerebral familiar está de acordo com a revisão feita sobre recomendações da literatura. CONCLUSÃO: O Projeto Malformação Cavernosa Cerebral Familiar detectou mutações do gene CCM1 nas primeiras quatro famílias estudadas. Os portadores dessa forma de malformação cavernosa cerebral da doença devem ser considerados à parte na rotina de avaliação e tratamento em relação à forma esporádica da doença. As recomendações foram buscadas na literature para nortear o manuseio dessa população específica.

Spinal root arteriovenous malformations and same-segment cord cavernous malformation in familial cerebral cavernous malformation. Case report.

Spinal vascular malformations are uncommon lesions, and controversy persists regarding optimal investigation, classification, and treatment strategies. The authors report on a patient with a spinal root arteriovenous malformation (AVM) associated with a parenchymal cavernous malformation (CM) in the same spinal cord segment and describe a complete familial and molecular investigation. This 35-year-old woman presented with symptoms of progressive clinical spastic paraparesis. Magnetic resonance imaging results were suggestive of a spinal cord cavernoma associated with cerebral CMs. Her family history included 2 sisters treated for epilepsy. At surgery an intraspinal root AVM was found at the same level of the cord CM, and both lesions were completely removed. Cerebral gradient echo MR imaging disclosed multiple cavernomas in her relatives, which prompted the molecular diagnosis. On sequence analysis, a novel mutation on the cerebral CM1 (CCM1) gene (c796insA) was found. The authors report on a unique case of familial cerebral CM in which a spinal root AVM was situated next to a cord CM, and discuss the concomitant occurrence of altered nervous system angiogenesis and vasculogenesis.

Different spectra of genomic deletions within the CCM genes between Italian and American CCM patient cohorts.

Cerebral cavernous malformations (CCMs) are vascular abnormalities of the brain that can result in hemorrhagic stroke and seizures. Familial forms of CCM are inherited in an autosomal-dominant fashion, and three CCM genes have been identified. We recently determined that large genomic deletions in the CCM2 gene represent 22% of mutations in a large CCM cohort from the USA. In particular, a 77.6 kb deletion spanning CCM2 exons 2-10 displays an identical recombination event in eight CCM probands/families and appears to be common in the US population. In the current study, we report the identification of six additional probands/families from the USA with this same large deletion. Haplotype analysis strongly suggests that this common deletion derives from an ancestral founder. We also examined an Italian CCM cohort consisting of 24 probands/families who tested negative for mutations in the CCM1, CCM2, and CCM3 genes by DNA sequence analysis. Surprisingly, the common CCM2 deletion spanning exons 2-10 is not present in this population. Further analysis of the Italian cohort by multiplex ligation-dependent probe analysis identified a total of ten deletions and one duplication. The overall spectrum of genomic rearrangements in the Italian cohort is thus quite different than that seen in a US cohort. These results suggest that there are elements within all three of the CCM genes that predispose them to large deletion/duplication events but that the common deletion spanning CCM2 exons 2-10 appears to be specific to the US population due to a founder effect.

An adult case of leukoencephalopathy with intracranial calcifications and cysts.

We describe a 44-year-old woman with progressive headache, ataxia, and seizures in association with multifocal cerebral and cerebellar leukoencephalopathy, intracranial calcifications, and cysts. The cause of death was intracerebellar hemorrhage while taking warfarin. Pathologic features on biopsy included angiomatous-like blood vessels, intense gliosis, and Rosenthal fiber formation in the white matter. Genetic analyses did not identify any significant mutations in two candidate genes.

Spectrum of genotype and clinical manifestations in cerebral cavernous malformations.

OBJECTIVE: Cerebral cavernous malformations (CCMs) are focal dysmorphic blood vessel anomalies predisposing individuals to hemorrhagic stroke and epilepsy. CCMs are sporadic or inherited as autosomal dominant disease with three known genes. The hypothesis that genetic heterogeneity would account for the remarkable variability in CCM manifestations was tested. METHODS: CCM cases were prospectively enrolled. Germline CCM1 gene mutations were sought in 89 CCM samples. Associations with clinical manifestations and lesion characteristics were made among 41 symptomatic familial cases, including one cohort of 26 cases with CCM1 mutations and a second cohort of 15 cases without identifiable CCM1 mutations. The 15 cases were screened for CCM2 and CCM3 mutations. RESULTS: CCM1 mutations were found in 34 out of 50 subjects with familial disease and in none of 39 sporadic CCM cases. CCM2 and CCM3 mutations were found in three out of 10 families screened without CCM1 mutations. Clinical manifestations in 22 Hispanic-American cases with identical CCM1 mutations were highly variable. Fewer CCM1 patients experienced hemorrhage than others with familial disease (P = 0.0139 for all cases and P = 0.0442 for symptomatic cases). Adjusting for sex and age improved the logistic regression model, suggesting decreased numbers of patients with hemorrhage in CCM1 familial disease (P = 0.003 for all cases and P = 0.014 for symptomatic cases). Hemorrhage differences were not related to size or number of lesions. CONCLUSION: Factors in addition to CCM1 germline mutation contribute to CCM clinical manifestations. However, this evidence suggests that familial cases with CCM1 mutations may have less severe clinical manifestations than other familial cases.

Biallelic somatic and germ line CCM1 truncating mutations in a cerebral cavernous malformation lesion.

BACKGROUND AND PURPOSE: Cerebral cavernous malformations (CCMs) are focal dysmorphic blood vessel anomalies that predispose patients to hemorrhagic stroke and epilepsy. CCMs are sporadic or inherited and 3 genes (CCM1, CCM2, and CCM3) have been identified. However, the role of somatic mutation in CCM genesis has been disputed. The hypothesis that somatic mutations contribute to CCM lesion genesis is tested. METHODS: Mutations were identified by analysis of polymerase chain reaction (PCR) products spanning the 16 CCM1 coding exons with denaturing high-pressure liquid chromatography (DHPLC), cloning, and sequencing. Somatic mutation was verified 3 ways in lesion DNA and RNA samples. The somatic and germ line mutations were shown to be biallelic using allele specific reverse-transcribed PCR amplification and sequence analyses. RESULTS: A somatic 34-nucleotide deletion in CCM1 is identified in a CCM lesion along with a germ line CCM1 mutation (Q455X). The somatic mutation is not present in DNA or RNA isolated from the patient's blood. These 2 genetic hits are biallelic. CONCLUSIONS: Identification of biallelic CCM1 somatic and germ line truncating mutations strongly support the "two-hit" mechanism in this CCM lesion.

Variations in structural protein expression and endothelial cell proliferation in relation to clinical manifestations of cerebral cavernous malformations.

OBJECTIVE: Cerebral cavernous malformations (CCMs) are associated with hemorrhagic proliferation of endothelial-lined vascular caverns, resulting in hemorrhagic stroke, epilepsy, and other neurological manifestations. We hypothesize that structural protein expression and endothelial cell proliferation markers within CCM lesions are different in the setting of various clinical manifestations. METHODS: The percentage of immunohistochemically stained caverns positive for collagen IV, fibronectin, laminin, alpha-smooth muscle actin, myosin, and smoothelin and the percentage of dividing endothelial cells within caverns were determined in 36 excised CCM surgical specimens. These were compared in CCMs with different multiplicity, location, and size in patients of different age, sex, seizure status, and hemorrhage status. RESULTS: Comparisons of seven lesion features and clinical manifestations with the fraction of caverns containing the structural proteins studied and endothelial cell proliferation demonstrated no significant differences. A possible exception was the difference (P < 0.05) in the fraction (mean +/- standard deviation) of positively stained caverns for collagen IV between adult (0.63 +/- 0.39) and pediatric patients (0.87 +/- 0.21) as well as fewer caverns with laminin expression in older patients. These trends did not sustain significance with Bonferroni's correction for multiple comparisons. CONCLUSION: The fraction of caverns containing the particular structural proteins studied and endothelial cell proliferation within caverns are not correlated with particular lesion features and clinical manifestations that were investigated in CCMs. The possible fewer fractions of caverns containing collagen IV and laminin in adult lesions compared with pediatric lesions may have implications for lesion regression and quiescence with age.

Multiple spinal cavernous malformations with atypical phenotype after prior irradiation: case report.

OBJECTIVE AND IMPORTANCE: This is the first reported case of histologically proven multiple spinal cavernous malformations (CMs) associated with previous irradiation. There are only two cases reported in the literature of solitary spinal CM after irradiation. In addition, the lesions in our patient had an atypical magnetic resonance imaging appearance mimicking intraspinal drop metastasis. CLINICAL PRESENTATION: A 33-year-old man had an incidental finding of multiple enhancing intraspinal lesions as revealed by magnetic resonance imaging during staging tests for hepatocellular carcinoma. He had a history of Wilms' tumor at a young age with irradiation to the abdomen and pelvis. His family history included a paternal cousin with multiple cerebral CMs. The diagnosis of spinal drop metastasis was made, and further intervention was undertaken for confirmation. INTERVENTION: The patient underwent a lumbar laminectomy with durotomy and excision of two of the lesions. Macroscopic analysis revealed mulberry-like appearance with nerve root involvement, and pathological analysis confirmed the diagnosis of CM. Genetic testing of the patient and his affected cousin was negative for the CCM1 gene. CONCLUSION: The occurrence of multiple spinal lesions in the context of known neoplasia indicates a diagnosis of metastasis. Spinal CMs were not suspected preoperatively because of the atypical appearance revealed by magnetic resonance imaging scans, with uniform contrast enhancement and absence of hemosiderin rim. This case report is discussed relative to previous literature regarding radiation-induced CMs and other known causes of the disease.