Interneuron deficits in patients with the Miller-Dieker syndrome

Lissencephaly is characterized by a thickened cortex and loss of gyri, resulting in the brain having a smooth surface. Patients with lissencephaly frequently exhibit epilepsy and mental retardation, conditions often associated with a defect in inhibitory neurons. While lissencephaly has traditionally been considered a disorder of radial migration, recent data indicate interneurons migrate non-radially, while projection neurons migrate radially. To determine if an interneuron defect, and therefore a non-radial migration defect, exists in patients with lissencephaly, we studied the calretinin-expressing interneuron subpopulation in the brains from two fetuses and two children with lissencephaly and a deletion involving 17p13 deletion (Miller-Dieker syndrome) along with age-matched controls. Our data indicate fetuses with the Miller-Dieker syndrome have a significant (tenfold) reduction in the number of calretinin-expressing interneurons present, whereas minimal reductions in the number of calretinin-expressing interneurons are present in children with this disorder. These data parallel those seen in the Lis1^+/– mouse model of human lissencephaly, and are consistent with a non-radial cell migration defect in humans. Thus, when considering the pathogenesis of human lissencephaly and the clinical manifestations in these patients, defects in both non-radial cell migration (inhibitory interneurons) and radial migration (excitatory projection neurons) must be considered.     

Ⅱ型神经纤维瘤病随访50年一例报告

目的提高对Ⅱ型神经纤维瘤病的病因、临床表现、诊断和治疗的认识。方法结合文献，复习收治并随访50年的1例Ⅱ型神经纤维瘤病患者的临床资料和影像学资料，总结其疾病的临床演变过程和治疗经过。结果女性患者，53岁，无家族遗传史。临床表现为先后发病的双侧前庭神经许旺细胞瘤，符合Ⅱ型神经纤维瘤病的诊断。34岁时发现右侧前庭神经许旺细胞瘤，行开颅肿瘤切除术，后因肿瘤复发而行γ-刀立体定向放射治疗；42岁时诊断为左侧前庭神经许旺细胞瘤，行γ-刀立体定向放射治疗。影像学随访至今双侧前庭神经许旺细胞瘤无复发。同时存在右侧三叉神经许旺细胞瘤、多发脑膜瘤、脊膜瘤，以及周围神经的神经纤维瘤，神经系统受累广泛。近20年来多次施行手术及γ-刀立体定向放射治疗。病理诊断为前庭神经和三叉神经许旺细胞瘤、过渡型脑膜瘤、纤维型脑膜瘤、神经纤维瘤等。现患者能够生活完全自理，右侧面部感觉减退，右侧耳聋，右侧周围性面神经麻痹，左侧肢体肌力4级。结论Ⅱ型神经纤维瘤病为常染色体显性遗传性疾病，预后差，早期诊断和治疗对保留患者听力、延长生命和提高生活质量至关重要。     

Richards-Rundle syndrome,cochleovestibular dysfunction and neurofibromatosis in a family

Summary The Richards-Rundle syndrome (RRS) is characterized by hearing loss, mental deterioration, ataxia, primary hypogonadism and autosomal recessive transmission. In a sibship of six members we found two sisters with RRS together with baldness, impaired GH and PRL secretion after stimulation and different degrees of impaired insulin secretion. Cochleovestibular investigation of the sibship revealed in each subject more or less severe forms of bulbo-pontine cochleovestibular dysfunction. Three members of the same sibship had cutaneous signs of abortive forms of neurofibromatosis: the son of one of these subjects had a severe form of fully developed neurofibromatosis. Whether there is a pathogenetic linkage between the hereditary multisystemic degeneration (RRS), the dysembryopathy (neurofibromatosis) and the cochleovestibular dysfunction in this family is still not clear.

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Zusammenfassung Das Richards-Rundel-Syndrome (RRS) ist durch Gehörstörung, psychischen Abbau, Ataxie und primären Hypogonadismus charakterisiert und wird autosomal rezessiv vererbt. Unter sechs Geschwistern fanden wir zwei Schwestern mit dem RRS und zusätzlich Kahlheit, verminderter GH und PRL Sekretion nach Stimulierung sowie in unterschiedlichem Ausmaß auch eine verminderte Insulinsekretion. Eine Untersuchung des cochleovestibulären Apparates bei allen Geschwistern zeigte bei jedem mehr oder weniger ausgeprägte, bulbopontin lokalisierte cochleovestibuläre Funktionstörungen. Drei Mitglieder der gleichen Geschwisterschaft hatten Hautsymptome einer abortiven Neurofibromatose und der Sohn eines der Geschwister hatte eine schwere Form dieser Krankheit. Es bleibt allerdings noch offen, ob ein pathogenetischer Zusammenhang zwischen der erblichen multisystemischen Degeneration des RRS, der Dysembriopathie Neurofibromatose und der cochleovestibulären Funktionsstörung in der hier beschriebenen Familie besteht.

     

Spinal neurofibromatosis in a family with classical neurofibromatosis type 1 and a novel NF1 gene mutation

Familial spinal neurofibromatosis (FSNF) is a rare form of neurofibromatosis type 1 (NF1) characterized by multiple, histologically proven neurofibromas of the spinal roots leaving no intact segments and associated neurofibromas of major peripheral nerves. It is sometimes associated with other NF1 stigmata. Most patients have NF1 gene mutations. We describe a patient who fulfilled the diagnostic criteria for spinal neurofibromatosis and belonged to a family in which other affected members exhibited classical NF1 stigmata. A novel missense (c.7109 T > A; p.Val2370Asp) mutation in exon 39 of the NF1 gene was present in the affected family members. The family displayed extreme phenotypic variability in the spectrum of NF1. To our knowledge, this is the first patient with spinal neurofibromatosis in the context of classical NF1 with an NF1 gene mutation. The term FSNF is inaccurate as this condition simply reflects the typical autosomal dominant pattern of NF1 inheritance with phenotypoc variability and does not encompass patients with sporadic disease or those in the context of a classical NF1 phenotype as reported in the present family. The term could be replaced by “spinal neurofibromatosis”.     

Glioblastoma in adults with neurofibromatosis type I: A report of two cases

Neurofibromatosis type I (NF1) is a familial tumor syndrome with an autosomal‐dominant inheritance. NF1‐associated tumors often include neurofibromas, malignant peripheral nerve sheath tumors and pilocytic astrocytomas of the optic nerve. The presentation of NF1 patients with glioblastoma is a rare occurrence, with only a handful of cases reported in the literature. We report two cases of glioblastomas occurring in adults with NF1 and briefly review the relevant literature.     

Multiple pilocytic astrocytomas of the cerebellum in a 17-year-old patient with neurofibromatosis type I

Objective Approximately 10% of patients with neurofibromatosis I (NFI) patients will have central nervous system (CNS) tumors. The most common of these are hypothalamic–optic gliomas, followed by brainstem and cerebellar pilocytic astrocytomas. While isolated pilocytic astrocytomas in NFI are well described, the appearance of multiple pilocytic astrocytomas in an individual patient is less common. The most frequent combination in NFI patients with more than one pilocytic astrocytoma is optic tract/hypothalamic and brainstem. Other combinations are exceedingly rare; multiple pilocytic astrocytomas have only been reported once in the cerebral hemispheres in a patient with NFI. This report presents the first documented case, to our knowledge, of multiple pilocytic astrocytomas in the cerebellum of a patient with NF1. Methods Case report. Conclusion The finding of multiple cerebellar pilocytic astrocytomas in a patient with NF1 is important because it expands the spectrum of presentations for patients with NF1 and also highlights specific diagnostic and therapeutic challenges faced by the treating physicians. The genetic and molecular basis of NF1 is reviewed. Strategies of diagnosis and treatment outlined here are relevant to both patients with NF1 and all patients with multiple posterior fossa tumors.     

Functional MRI of visual-spatial processing in neurofibromatosis, type I

Visual-spatial impairment and neuroanatomical abnormalities are considered hallmark features of neurofibromatosis, type I (NF-I). Numerous studies have demonstrated visual-spatial deficits in children with NF-I, but few relations between these deficits and neuroanatomical abnormalities have been identified. We compared the functional neuroanatomy of cerebral regions involved in the spatial transformation of alphanumeric stimuli in individuals with NF-I and healthy control participants using functional magnetic resonance imaging (fMRI). Given the prevalence of visual pathway abnormalities and visual-spatial deficits in NF-I, we hypothesized that less neuronal hemodynamic activity would be found in occipital and parietal cortices in this group compared with controls. However, NF-I participants relied to a greater degree than controls on posterior cortex (including occipital, parietal, and middle temporal cortices) relative to lateral and inferior frontal regions during visual-spatial analysis. This pattern was significantly related to their behavioral performance on the fMRI task, which in turn was also positively correlated with reading scores. These findings support evidence of frontal cortical anomalies in NF-I and may provide a pathophysiological basis for cognitive deficits in NF-I.     

Cerebral vasculopathy in a Chinese family with neurofibromatosis type I mutation

Neurofibromatosis type I (NF1) is a hereditary, autosomal dominant, neurocutaneous syndrome that is attributed to NF1 gene mutation. NF1 has been associated with scoliosis, macrocephaly, pseudoarthrosis, short stature, mental retardation, and malignancies. NF1-associated vasculopathy is an uncommon and easily-overlooked presentation. Examination of a Chinese family affected by NF1 combined with cerebral vessel stenosis and/or abnormality suggested a possible relationship between NF1 and vessel stenosis. To determine which NF1 gene mutation is associated with vascular lesions, particularly cerebral vessel stenosis, we examined one rare family with combined cerebral vessel lesions or maldevelopment. Vascular lesions were detected using transcranial Doppler sonography and digital subtraction angiography in family members. Next, denaturing high-performance liquid chromatography and sequencing were used to screen for NF1 gene mutations. The results revealed a nonsense mutation, c.541C>T, in the NF1 gene. This mutation truncated the NF1 protein by 2659 aminoacid residues at the C-terminus and co-segregated with all of the patients, but was not present in unaffected individuals in the family. Exceptionally, three novel mutations were identified in unaffected family members, but these did not affect the product of the NF1 gene. Thus the nonsense mutation, c.541C>T, located in the NF1 gene could constitute one genetic factor for cerebral vessel lesions.     

Infantile spasms in patients with neurofibromatosis type 1

The authors report two patients with neurofibromatosis type 1 who were affected by infantile spasms. The infantile spasms were severe and unresponsive to anticonvulsant treatment. The authors maintain that infantile spasms may belong to the clinical features of neurofibromatosis type 1.     

Malignant intracerebral giant nerve sheath tumor in a 14-month-old girl with neurofibromatosis type 1: a case report

Introduction  Malignant intracerebral nerve sheath tumor (MINST) is extremely rare and the origin is still unclear. The authors present the clinical, radiological, and pathological features of a malignant intracerebral giant nerve sheath tumor. Case report  A giant tumor in the right frontotemporoparietal lobes causing a midline shift was detected in a 14-month-old girl who presented with developmental delay, vomiting, and lethargy. The physical examination was consistent with neurofibromatosis type 1 (NF-1). Subtotal resection was performed and the histopathological examination revealed the diagnosis of MINST. Discussion  There are only six cases of malignant intracerebral nerve sheath tumor in the literature. The presented case is the youngest and the occurrence of MINST in a 14-month-old girl may support the hypothesis of multipotent mesenchymal stem cell origin; however, the tumors which arise from multipotent mesenchymal stem cells may be seen in later stages of life. Another important feature of the presented case is the occurrence of MINST in NF-1. Conclusion  MINSTs are extremely rare tumors with unknown origin. The location, the degree, and the size of the tumor and the general condition of the patient are prognostic factors in MINSTs, like in other malignant tumors.     

Laryngeal plexiform schwannoma as first symptom in a patient with neurofibromatosis type 2

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterized by bilateral vestibular schwannomas. The initial symptoms of NF2 are usually hearing loss and tinnitus caused by vestibular schwannomas. Although other intracranial, spinal, or skin tumors also occur in NF2, laryngeal lesions are very rare. We report a rare case of NF2 with laryngeal plexiform schwannoma as first symptom. A 38-year-old man presented with a smooth-surfaced submucosal supraglottic mass. Two round masses in the left chest wall and left supraclavicular fossa were noted incidentally during investigation of the laryngeal mass. Magnetic resonance imaging (MRI) findings for these masses were identical to those of the laryngeal mass. No typical symptoms related to NF2 were identified. Histologically, the laryngeal tumor represented plexiform schwannoma. We thus considered that the two round masses in the left chest wall and left supraclavicular fossa might also represent plexiform schwannomas. NF2 was suspected, as a high incidence of multiple plexiform schwannomas has been suggested for patients with NF2. MRI of brain lesions demonstrated bilateral vestibular schwannomas and multiple meningiomas. Finally, NF2 with laryngeal plexiform schwannoma was diagnosed. Recognizing that multiple plexiform schwannomas could be associated with NF2 is important.     

Transformation of intracranial anaplastic astrocytoma associated with neurofibromatosis type I into gliosarcoma: Case report

Gliosarcoma is an uncommon malignant brain tumor composed of distinct sarcomatous and malignant glial cell elements. These tumors are defined as a variant of glioblastoma, and it can be developed by progression of the malignant glial cell tumors or primary tumors. We report a rare case with gliosarcomatous recurrence of anaplastic astrocytoma with neurofibromatosis type 1 (NF-1) followed by chemoradiation therapy. A 26-year-old male patient was presented with headache. Five years before admission, he had been diagnosed with NF-1. Magnetic resonance imaging (MRI) showed a well-demarcated, enhanced lesion in the right frontal lobe and multiple enhanced lesions in the scalp, lower cervical, thoracic, and upper lumbar regions. He underwent an osteoplastic craniotomy with total tumor resection. Histopathology of the tumor showed findings corresponding with anaplastic astrocytoma. He was followed by radiotherapy and chemotherapy postoperatively. A month later, his spinal lesion was also resected and confirmed pathologically as plexiform neurofibroma. The subsequent follow-up period of 27 months was uneventful until he developed a generalized tonic-clonic seizure. MRI showed tumor recurrence in the original site of the tumor. Re-exploration was carried out. Pathological examination displayed a biphasic pattern of the glial and sarcomatous components suggesting gliosarcoma.     

Gliomatosis cerebri with neurofibromatosis: an autopsy-proven case

Gliomatosis cerebri is a glial neoplastic process that is diffusely distributed through neural structures, whose anatomical configuration remains intact. Among the more than 19,000 cases hospitalized in Istanbul University Istanbul School of Medicine Department of Neurosurgery throughout the past 45 years, only 2 cases were diagnosed as gliomatosis cerebri, 1 by stereotactic ante-mortem diagnosis and the other after autopsy. In this paper, the autopsy-proven case of this rare disease with coexistent neurofibromatosis – the sixth case reported in the literature – is presented. Received: 15 July 1998     

Social functioning in adults with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a common single-gene disorder characterised by a diverse range of cutaneous, neurological and neoplastic manifestations. It is well recognised that children with NF1 have poor peer interactions and are at risk for deficits in social skills. Few studies, however, have examined social functioning in adults with NF1. We aimed to determine whether adults with NF1 are at greater risk for impairment in social skills and to identify potential risk factors for social skills deficits. We evaluated social skills in 62 adults with NF1 and 39 controls using self-report and observer-report measures of social behaviour. We demonstrate that adults with NF1 exhibit significantly less prosocial behaviour than controls. This deficit was associated with social processing abilities and was more evident in males. The frequency of antisocial behaviour was comparable between the two groups, however was significantly associated with behavioural regulation in the NF1 group. These findings suggest that poor social skills in individuals with NF1 are due to deficits in prosocial behaviour, rather than an increase in antisocial behaviour. This will aid the design of interventions aimed at improving social skills in individuals with NF1.     

Visuospatial processing in children with neurofibromatosis type 1

Neuroimaging studies investigating the neural network of visuospatial processing have revealed a right hemisphere network of activation including inferior parietal lobe, dorsolateral prefrontal cortex, and extrastriate regions. Impaired visuospatial processing, indicated by the Judgment of Line Orientation (JLO), is commonly seen in individuals with neurofibromatosis type 1 (NF-1). Nevertheless, few studies have examined the neural activity associated with visuospatial processing in NF-1, in particular, during a JLO task. This study used functional neuroimaging to explore differences in volume of activation in predefined regions of interest between 13 individuals with NF-1 and 13 controls while performing an analogue JLO task. We hypothesized that participants with NF-1 would show anomalous right hemisphere activation and therefore would recruit regions within the left hemisphere to complete the task. Multivariate analyses of variance were used to test for differences between groups in frontal, temporal, parietal, and occipital regions. Results indicate that, as predicted, controls utilized various right hemisphere regions to complete the task, while the NF-1 group tended to recruit left hemisphere regions. These results suggest that the NF-1 group has an inefficient right hemisphere network. An additional unexpected finding was that the NF-1 group showed decreased volume of activation in primary visual cortex (BA 17). Future studies are needed to examine whether the decrease in primary visual cortex is related to a deficit in basic visual processing; findings could ultimately lead to a greater understanding of the nature of deficits in NF-1 and have implications for remediation.     

Hippocampal sclerosis and associated focal cortical dysplasia-related epilepsy in neurofibromatosis type I

Neurofibromatosis type I (NF1) is a relatively common disorder associated with a range of neurologic sequelae. Refractory epilepsy occurs in 4–13% of NF1 patients. Hippocampal sclerosis and focal cortical dysplasia, both well-defined epilepsy-related entities, have been described in a subset of cases. To our knowledge, there has been only one other series describing coexistent focal cortical dysplasia and hippocampal sclerosis in the setting of NF1. We report two such patients who presented with intractable seizures requiring epilepsy surgery. Histologically, the hippocampal sclerosis specimen met criteria for the International League Against Epilepsy (ILAE) hippocampal sclerosis subtypes Ia and II respectively. The associated focal cortical dysplasia observed within the resected temporal lobe were both consistent with ILAE focal cortical dysplasia type IIIa (e.g. associated with a secondary lesion). Post-operatively, both patients had recurrence of habitual seizures, with one case continuing to have intractable seizures following two subsequent temporal lobectomies. Although hippocampal sclerosis association with focal cortical dysplasia is well document in epilepsy, it has been rarely described in the setting of neurofibromatosis type I. Although prior surgical series have shown good epilepsy surgery outcomes within neurofibromatosis type I, these two cases did not.     

Spontaneous regression of optic pathways gliomas in three patients with neurofibromatosis type I and critical review of the literature

Case reports The authors report their experience about three children (two girls, one boy; average age 1.6 years) with a spontaneous regression of optic gliomas. All of them had a previous diagnosis of neurofibromatosis type 1 (NF 1). None of them underwent surgery or biopsy nor received chemotherapy or radiotherapy. The complete regression was documented by MRI scans performed during a mean follow-up of 6.3 years.Literature review Moreover, the authors analyze the features of the 16 cases previously reported in English literature of spontaneously regressed optic gliomas with an overview of the different therapeutic strategies. The knowledge that this kind of tumor, particularly in young patients, may regress is important in the decision of the best therapeutic approach.     

Fatal glioblastoma multiforme in a patient with neurofibromatosis type I: the dilemma of systematic medical follow-up

Introduction Neurofibromatosis type I (NF1) is one of the most prevalent genetic diseases of the nervous system. Although the majority of NF1 patients are only mildly affected, the risk of developing malignancies is significantly increased in this population. Case report Here, we present a 9-year-old girl with clinical stigmata of NF1 and a rapidly evolving glioblastoma multiforme. Molecular genetic analysis uncovered a novel missense mutation in Exon 32 of the NF1 gene [c.6032C>A(p.Ala2011Glu)]. Discussion The girl’s death 3 days after diagnosis of the brain tumor exemplifies that NF1 still is a life-threatening disease despite its generally benign course in most patients. However, it remains questionable if a fatal course as reported here can be prevented by routine MRI screening.