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Biomedical subjects

Knut Brockmann

Publications and source records attributed to Knut Brockmann.

At least 19 recordsLinked to original sources

Treatment of epilepsy in Rett syndrome.

INTRODUCTION: Epilepsy is very frequent in Rett syndrome (RTT) patients and often difficult to treat. Because most cases of RTT are caused by mutations in the MECP2 gene it is reasonable to assume that convulsions are based on common pathogenetic mechanisms and thus should have a similar response to antiepileptic drugs. PURPOSE: To find the optimal treatment for epilepsy in RTT. METHODS: We performed a retrospective study on 110 female patients with confirmed MECP2 mutations. RESULTS: The median age was 10 years, 58% had a history of epilepsy and 55% received antiepileptic drugs (AEDs). Only sulthiame, carbamazepine and valproate were administered in an adequate frequency to allow statistical analysis. The best anticonvulsive results were seen in the RTT group that was treated with carbamazepine. Sulthiame was slightly less effective while valproate was significantly less effective. The rate of side effects was equivalent in all groups. In conclusion, carbamazepine should be recommended as first choice AED in RTT. If carbamazepine is not effective or not well tolerated sulthiame ought to be taken as second choice AED.

Adolescent↗

Quantitative proton MRS of cerebral metabolites in laminin alpha2 chain deficiency.

Congenital muscular dystrophy (CMD) due to merosin (laminin alpha2 chain) deficiency is an autosomal recessively inherited disorder characterized by severe muscular weakness and hypotonia from birth on. Brain involvement is the rule and characterized by variable T2 hyperintensities of white matter which appears swollen on cranial MRI. The pathophysiology of these white matter changes is not clear. In five patients with laminin alpha2 deficient CMD we performed short-echo time localized proton MRS with determination of absolute metabolite concentrations in grey and white matter. In affected white matter, a consistent pattern of metabolites was detected comprising reduced concentrations of N-acetylaspartate and N-acetylaspartylglutamate, creatine, and phosphocreatine, and to a milder degree of choline-containing compounds. In contrast, concentrations of myo-inositol were in the normal range. Spectra of cortical and subcortical grey matter were normal. The observed metabolite profile is consistent with white matter edema, that is reduced cellular density, and relative astrocytosis. This interpretation is in line with the hypothesis that laminin alpha2 deficiency results in leakage of fluids across the blood-brain barrier and a histopathological report of astrocytic proliferation in CMD.

Adolescent↗

Cerebral metabolic and structural alterations in hereditary spastic paraplegia with thin corpus callosum assessed by MRS and DTI.

INTRODUCTION: Hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) is a complicated form of autosomal-recessive hereditary spastic paraplegia. Characteristic clinical features comprise progressive spastic gait, cognitive impairment, and ataxia. Diagnostic MRI findings include thinning of the corpus callosum and non-progressive white matter (WM) alterations. METHODS: To study the extent of axonal involvement, we performed localized proton magnetic resonance spectroscopy (MRS) of the cerebral WM and cortical grey matter (GM) in a patient with HSP-TCC at 20 and 25 years of age. The second investigation included diffusion tensor imaging (DTI). RESULTS: While MRS of the GM was normal, affected WM was characterized by major metabolic alterations such as reduced concentrations of N-acetylaspartate and N-acetylaspartyl-glutamate, creatine and phosphocreatine, and choline-containing compounds as well as elevated levels of myo-inositol. These abnormalities showed progression over a period of 5 years. DTI revealed increased mean diffusivity as well as reduced fractional anisotropy in periventricular WM. The metabolic and structural findings are consistent with progressive neuroaxonal loss in the WM accompanied by astrocytic proliferation-histopathological changes known to occur in HSP-TCC. CONCLUSION: Our results are in agreement with the hypothesis that the primary pathological process in HSP-TCC affects the axon, possibly due to impaired axonal trafficking.

Adult↗

Spastic paraplegia with thin corpus callosum: description of 20 new families, refinement of the SPG11 locus, candidate gene analysis and evidence of genetic heterogeneity.

We studied 20 Mediterranean families (40 patients) with autosomal recessive hereditary spastic paraplegia and thin corpus callosum (ARHSP-TCC, MIM 604360) to characterize their clinical and genetic features. In six families (17 patients) of Algerian Italian, Moroccan, and Portuguese ancestry, we found data consistent with linkage to the SPG11 locus on chromosome 15q13-15, whereas, in four families (nine patients of Italian, French, and Portuguese ancestry) linkage to the SPG11 locus could firmly be excluded, reinforcing the notion that ARHSP-TCC is genetically heterogeneous. Patients from linked and unlinked families could not be distinguished on the basis of clinical features alone. In SPG11-linked kindred, haplotype reconstruction allowed significant refinement to 6 cM, of the minimal chromosomal interval, but analysis of two genes (MAP1A and SEMA6D) in this region did not identify causative mutations. Our findings suggest that ARHSP-TCC is the most frequent form of ARHSP in Mediterranean countries and that it is particularly frequent in Italy.

Adolescent↗

Pediatric multiple sclerosis: detection of clinically silent lesions by multimodal evoked potentials.

Pediatric patients with multiple sclerosis (MS) frequently do not meet MRI criteria for diagnosis because of lack of evidence of dissemination in space. We assessed the diagnostic utility of multimodal evoked potentials (EP). In 46% of 85 childhood patients with MS, spatial dissemination was detected by EP before the second clinical attack. EP may constitute an important tool for earlier diagnosis of pediatric MS.

Adolescent↗

Magnetic resonance imaging and proton magnetic resonance spectroscopy of megalencephaly and dilated Virchow-Robin spaces.

Megalencephaly with dilated Virchow-Robin spaces has been suggested to represent a new clinical entity. This report describes two males and a female who have been monitored from pregnancy. The patients manifest a relatively normal psychomotor development with some minor neurologic symptoms such as mild muscle hypotonia and clumsy motor performance. Biochemical and electrophysiologic tests were normal. In the white matter of the brain, a prominent dilatation of the Virchow-Robin spaces with some adjacent signal alterations could be demonstrated by magnetic resonance imaging. Magnetic resonance spectroscopy revealed normal metabolite concentrations in the cortical and deep gray matter and normal-appearing white matter. Affected white matter was characterized by mildly reduced to normal levels of myo-inositol and a decrease of all other metabolites including total N-acetyl moieties, choline-containing compounds, and total creatine. These data indicate that the dilatation of Virchow-Robin spaces reflects an underlying brain pathology causing neuroaxonal damage. Possible differential diagnoses are discussed.

Aspartic Acid↗

X-linked paroxysmal dyskinesia and severe global retardation caused by defective MCT8 gene.

We previously reported two unrelated boys aged 3 and 8 years with mutations in the thyroid hormone transporter gene MCT8 resulting in severe global retardation and an uncommon pattern of thyroid hormone abnormalities. We now further describe an unusual neurological phenotype associated with these mutations, namely paroxysmal kinesigenic dyskinesias (PKD), provoked by certain stimuli including changing of their clothes or diapers. It is not clear how the MCT8 defect causes PKDs. PKDs have been previously noted in patients with thyroid abnormalities. This novel X-linked condition widens the spectrum of secondary PKDs.

Child↗

Malignant ectomesenchymoma of the cerebrum. Case report and discussion of therapeutic options.

UNLABELLED: Malignant ectomesenchymoma is a rare tumour that contains both ectodermal and mesenchymal elements. Only three patients with a manifestation in the cerebrum and clinicopathological data have been reported until now. We present a patient with an intracerebral ectomesenchymoma, review the literature and discuss currently available therapeutic options. In a 10-year-old girl, a left suprasellar temporo-parieto-occipitally localised tumour was diagnosed. The tumour was completely excised macroscopically in two surgical sessions. For the mesenchymal part of the tumour she subsequently underwent multidrug chemotherapy followed by radiation therapy. Considering the neuroectodermal element of the tumour, radiotherapy was applied to the craniospinal axis with a local boost. Therapy was tolerated well without any severe side effects. Six years from diagnosis, the patient is alive without a tumour relapse. CONCLUSION: Due to the sparcity of reported cases with malignant ectomesenchymoma, the role of adjuvant therapy is unclear. Multimodal therapy may be able to improve outcome.

Brain Neoplasms↗

Identification of ten novel mutations in patients with eIF2B-related disorders.

Autosomal recessive inherited mutations in each of the five eukaryotic initiation factor 2B (eIF2B) subunits are known to cause white matter abnormalities with a wide continuum of clinical signs and severity leading to the concept of eIF2B-related disorders. The clinical spectrum extends from fatal infantile forms to adult forms with slow or absent neurological deterioration. In this study 15 well-characterised patients with the classical form of leukoencephalopathy with vanishing white matter (VWM) or with phenotypic variants like ovarioleukodystrophy were investigated for mutations in the genes EIF2B1, EIF2B2, EIF2B3, EIF2B4, and EIF2B5 encoding eIF2B. We identified one novel nonsense mutation (EIF2B4, c.625C>T, p.Arg209X), one novel frameshift mutation (EIF2B5, c.453_454del, p.Tyr152fsX12), eight novel missense muations (EIF2B1, c.547G>T, p.Val183Phe; EIF2B2, c. 586C>T, p.Pro196Ser; EIF2B4, c.806T>G, p.Leu269Arg; EIF2B5, c.203T>C, p.Leu68Ser; EIF2B5, c.220G>A, p.Ala74Thr; EIF2B5, c.805C>G, p.Arg269Gly; EIF2B5, c.929G>T, p.Cys310Phe; EIF2B5, c.1003T>C, p.Cys335Arg), and eight previously described alterations.

Adolescent↗

Moyamoya syndrome associated with hemolytic anemia due to Hb Alesha.

Moyamoya angiopathy is a well-known complication of sickle cell disease but has rarely been observed in other hemoglobinopathies. The authors describe a previously unreported association of hemolytic anemia due to a rare unstable hemoglobinopathy with abnormal oxygen affinity (Hb Alesha) and moyamoya syndrome in a 10-year-old girl. At age 4 she had recurrent migraine-with-aura-like symptoms. Cranial MRI, Doppler, and EEG examinations were not conclusive. Deterioration of her neurologic symptoms prompted a renewed EEG examination at 10 years of age, which revealed a re-buildup phenomenon. MRI and MR angiography now showed moyamoya angiopathy with stenotic and occlusive lesions of both internal carotid and middle cerebral arteries. Conventional angiography confirmed these findings. Reperfusion with three extra-intracranial bypasses terminated the transient ischemic attacks. The authors suggest that chronic hypoxemia may be the cause of occlusive moyamoya angiopathy in Hb Alesha and possibly other unstable hemoglobinopathies with altered oxygen affinity.

Anemia, Hemolytic↗

Visually self-induced seizures sensitive to round objects.

PURPOSE: To describe a previously unreported type of self-induced pattern-sensitive seizures in a child. METHODS: Evaluation of clinical and EEG features. RESULTS: An 18-month-old boy was initially seen with series of short focal tonic seizures self-induced by gazing intermittently at round objects. Self-induction of these seizures had an obvious relieving effect on the child. Covering the round object foiled further seizures but resulted in a tantrum. Later in the course, an increasing variety of patterns proved to be capable of inducing seizures, which occurred with increasing frequency and severity, including secondarily generalized tonic-clonic seizures. Interictal EEG revealed multifocal sharp-and-slow-waves. Ictal EEG showed no abnormalities during short focal seizures and rapidly generalizing epileptic discharges during a secondarily generalized seizure. No photosensitivity was noted. Motor and mental development of the boy stagnated over a period of 2 years. Behavioral therapy as well as medical treatment, consisting of various combinations of antiepileptic drugs (AEDs) together with a selective serotonin-reuptake inhibitor, were of merely transient benefit. Only combined pharmacotherapy, including valproate, sulthiame, and clobazam, resulted in seizure control at age 3 years 9 months. CONCLUSIONS: Visual capture of geometric patterns other than stripes or gratings may trigger focal seizures with secondary generalization. Synchronization of cortical neurons responsible for pattern recognition may account for epileptogenesis in this child.

Age Factors↗

Actin-related myopathy without any missense mutation in the ACTA1 gene.

Actinopathies are defined by missense mutations in the ACTA1 gene coding for sarcomeric actin, of which some 70 families have, so far, been identified. Often, but not always, muscle fibers carry large patches of actin filaments. Many such patients also have nemaline myopathy, qualifying actinopathies as a subgroup of nemaline myopathies. This article concerns a then newborn, now 2 1/2-year-old boy, the first and single child of nonconsanguineous parents, who was born floppy, requiring immediate postnatal assisted ventilation. A quadriceps muscle biopsy revealed large patches of thin myofilaments reacting at light and electron microscopic levels with antibodies against actin but only a few sarcoplasmic rods and no intranuclear rods. DNA analysis of the patient's and both parents' blood did not reveal any missense mutation in the ACTA1 gene. Thus, this congenital myopathy can be caused by a new type of ACTA1 gene mutation, a new non-ACTA1 gene mutation, or no mutation at all, designating it as an actin-related myopathy, perhaps a new type of congenital myopathy and a new member of protein aggregate myopathies marked by aggregation of proteins within muscle fibers, among them desminopathies, alpha-beta crystallinopathies, other desmin-related myopathies (also termed myofibrillar myopathies), actinopathies and, now, actin-related myopathies.

Actins↗

A novel syndrome combining thyroid and neurological abnormalities is associated with mutations in a monocarboxylate transporter gene.

Thyroid hormones are iodothyronines that control growth and development, as well as brain function and metabolism. Although thyroid hormone deficiency can be caused by defects of hormone synthesis and action, it has not been linked to a defect in cellular hormone transport. In fact, the physiological role of the several classes of membrane transporters remains unknown. We now report, for the first time, mutations in the monocarboxylate transporter 8 (MCT8) gene, located on the X chromosome, that encodes a 613-amino acid protein with 12 predicted transmembrane domains. The propositi of two unrelated families are males with abnormal relative concentrations of three circulating iodothyronines, as well as neurological abnormalities, including global developmental delay, central hypotonia, spastic quadriplegia, dystonic movements, rotary nystagmus, and impaired gaze and hearing. Heterozygous females had a milder thyroid phenotype and no neurological defects. These findings establish the physiological importance of MCT8 as a thyroid hormone transporter.

Base Sequence↗

Cerebral proton magnetic resonance spectroscopy in infantile Alexander disease.

Alexander disease (AD) is a rare genetic disorder of the central nervous system due to a dysfunction of astrocytes. The most common infantile form presents as a progressive leukodystrophy with macrocephalus. Recently, heterozygous de novo mutations in the gene encoding glial fibrillary acidic protein (GFAP) have been demonstrated to be associated with AD. We used localized proton magnetic resonance spectroscopy (MRS) to assess metabolic abnormalities in grey and white matter, basal ganglia, and cerebellum of 4 patients with infantile AD and GFAP mutations. Strongly elevated concentrations of myo-inositol in conjunction with normal or increased choline-containing compounds in all regions investigated point to astrocytosis and demyelination. Neuroaxonal degeneration, as reflected by a reduction of N-acetylaspartate, was most pronounced in cerebral and cerebellar white matter. The accumulation of lactate in affected white matter is in line with infiltrating macrophages. Metabolic alterations demonstrated by in vivo proton MRS are in excellent agreement with known neuropathological features of AD.

Alexander Disease↗

Cerebral proton magnetic resonance spectroscopy of a patient with giant axonal neuropathy.

Magnetic resonance imaging of a girl with giant axonal neuropathy revealed a progressive white matter disease. In close agreement with histopathological features reported previously, localized proton magnetic resonance spectroscopy at 9 and 12 years of age indicated a specific damage or loss of axons (reduced N-acetylaspartate and N-acetylaspartylglutamate) accompanied by acute demyelination (elevated choline-containing compounds, myo-inositol, and lactate) in white matter as well as a generalized proliferation of glial cells (elevated choline-containing compounds and myo-inositol) in both gray and white matter.

Axons↗

Progressive muscle weakness after high-dose steroids in two children with CIDP.

Corticosteroids and intravenous immunoglobulins belong to the first line of treatment in chronic inflammatory demyelinating polyneuropathy. In patients with a progressive course, plasma exchange and immunomodulatory drugs are added to the regimen. To reduce the side effects of long-term oral prednisolone, high-dose pulsatile intravenous methylprednisolone treatment has been advocated. We report two children with chronic inflammatory demyelinating polyneuropathy who, after high-dose intravenous pulsatile methylprednisolone, experienced a significant clinical deterioration with profound loss of muscle strength. Both patients improved after changing treatment to immunoglobulins in one and cyclosporine combined with immunoglobulins and oral prednisolone in the other.

Child↗