1/22. Fluctuation of computed tomographic findings in white matter in Alexander's disease. A Japanese boy developed febrile seizures and gait disturbance at 2 years of age and dysarthria a year later. He had generalized tonic-clonic seizures once or twice a year from the age of 4 years. Brain computed tomography (CT) showed symmetric low-density areas in the white matter of the frontal lobes. However, abnormal CT findings fluctuated occasionally, with no apparent change in clinical manifestations. Clinical evaluation at 9 years of age revealed hyper-reflexia, psychomotor retardation, megalencephaly, and slurred nasal speech. magnetic resonance imaging showed white matter abnormalities, predominantly in the frontal lobes. He was a heterozygote of the Arg239Cys mutation of the glial fibrillary acidic protein gene and was diagnosed with Alexander's disease. Fluctuation of CT findings in white matter may reflect blood-brain barrier dysfunction in Alexander's disease. ( info) |
2/22. Infantile Alexander's disease: serial neuroradiologic findings. Serial neuroimaging studies in Alexander's disease were obtained on an African-American girl who died at 4zx years of age. She presented with macrocephaly, psychomotor retardation, spasticity, a seizure disorder, and hydrocephalus. A thorough metabolic evaluation of defined leukodystrophies, including Krabbe's disease, adrenoleukodystrophy, metachromatic leukodystrophy, Canavan's disease, and leigh disease, was negative. A diagnosis of Alexander's disease was made based on the clinical features and ruling out all other possible causes. It was confirmed by pathologic findings of numerous subpial, subependymal, and perivascular Rosenthal fibers throughout the entire cerebrum. Interestingly, autopsy also identified the stenotic sylvian aqueduct owing to Rosenthal fiber accumulation, explaining the origin of hydrocephalus. The evolution of magnetic resonance imaging findings appears to be unique in this disease. ( info) |
| alexander disease (AD) is a rare disorder of cerebral white matter due to a dysfunction of astrocytes. The most common infantile form presents as a megalencephalic leukodystrophy. Recently, heterozygous de novo mutations in the glial fibrillary acidic protein gene (GFAP) have been demonstrated to be associated with AD. We report heterozygous mutations in GFAP in 5 patients, including a pair of monozygotic twins, with clinical and neuroradiological features of infantile AD. Novel mutations were detected affecting nucleotides 304 T --> C (L97 P) and 730 G --> C (R239 P) in two other patients. None of the parents of our patients carried the mutations stressing dominant de novo mutations as the cause of AD. The presence of an identical mutation 250 G --> A (R79 H) in both monozygotic twins with infantile AD points to the origin of these GFAP mutations in germ cells or very early postzygotic stages. ( info) |
4/22. MR imaging and 1H-MR spectroscopy in a case of juvenile alexander disease. The serial MR image and MR spectroscopy in the brain were examined in a young male diagnosed as having juvenile alexander disease. He had megalencephaly, psychomotor retardation, seizures, and increasing elevation of increasing alpha-B crystallin and heat shock protein 27 in the cerebrospinal fluid. Serial MR images demonstrated increased demyelination of the bilateral frontal region to left occipital region over several years. The myo-inositol/creatine ratio was significantly increased in both the demyelinated white matter and normal area in the MR spectroscopy. These results suggested that demyelination very slowly progressed from the frontal to occipital region and that glial degeneration may occur even in the unaffected white matter of patients with juvenile alexander disease. ( info) |
5/22. Identification of GFAP gene mutation in hereditary adult-onset Alexander's disease. Alexander's disease, a leukodystrophy characterized by Rosenthal fibers (RFs) in the brain, is categorized into three subtypes: infantile, juvenile, and adult. Although most are sporadic, occasional familial Alexander's disease cases have been reported for each subtype. Hereditary adult-onset Alexander's disease shows progressive spastic paresis, bulbar or pseudobulbar palsy, palatal myoclonus symptomatologically, and prominent atrophy of the medulla oblongata and upper spinal cord on magnetic resonance imaging. Recent identification of GFAP gene mutations in the sporadic infantile- and juvenile-onset Alexander's disease prompted us to examine the GFAP gene in two Japanese hereditary adult-onset Alexander's disease brothers with autopsy in one case. Both had spastic paresis without palatal myoclonus, and magnetic resonance imaging showed marked atrophy of the medulla oblongata and cervicothoracic cord. The autopsy showed severely involved shrunken pyramids, but scarce Rosenthal fibers (RFs). Moderate numbers of Rosenthal fibers (RFs) were observed in the stratum subcallosum and hippocampal fimbria. In both cases, we found a novel missense mutation of a G-to-T transition at nucleotide 841 in the GFAP gene that results in the substitution of arginine for leucine at amino acid residue 276 (R276L). This is the first report of identification of the causative mutation of the GFAP gene for neuropathologically proven hereditary adult-onset Alexander's disease, suggesting a common molecular mechanism underlies the three Alexander's disease subtypes. ( info) |
6/22. Alexander's disease in a neurologically normal child: a case report. We report the clinical and MRI findings of symmetric hyperintensity involving the deep and subcortical white matter of the frontal lobes in a neurologically normal child with macrocephaly. In this patient, a serum test for mutations in glial fibrillary acidic protein, used to diagnose Alexander's disease (AD), was positive. This case indicates an extraordinarily mild or early form of juvenile-onset AD. ( info) |
7/22. Atypical focal MRI lesions in a case of juvenile Alexander's disease. We present a juvenile case of Alexander's disease with atypical focal magnetic resonance imaging-detected lesions and elevated levels of lactate in cerebrospinal fluid. The diagnosis was based on the neuropathological finding of a diffuse accumulation of Rosenthal fibers within the brain and the spinal cord. The diagnosis was confirmed by detection of a mutation in exon 1 at nucleotide position 249 of glial fibrillary acidic protein cDNA, a finding previously reported in cases of infantile Alexander's disease. ( info) |
8/22. The clinicopathological spectrum of Rosenthal fibre encephalopathy and Alexander's disease: a case report and review of the literature. Alexander's disease is a leucodystrophy that usually presents in early childhood, but can infrequently arise in adults. It is characterised pathologically by megalencephaly, demyelination, and the presence of numerous Rosenthal fibres. Most cases have been shown to be due to mutations in the gene encoding glial fibrillary acidic protein. In rare instances, numerous Rosenthal fibres have been found at autopsy in patients who have suffered protracted debilitating systemic illnesses, some with associated brain stem signs, and in very rare instances in patients with no apparent neurological abnormality. The term "Rosenthal fibre encephalopathy" is used to distinguish these cases from those of Alexander's disease. We report the first case of Rosenthal fibre encephalopathy in a young man with AIDS, and review the literature. ( info) |
9/22. A novel GFAP mutation and disseminated white matter lesions: adult alexander disease? The recent discovery of heterozygous de novo mutations in the glial fibrillary acidic protein (GFAP) gene as the cause of infantile and juvenile alexander disease has shed new light on the long-standing debate whether the adult subtype has the same etiology as infantile and juvenile alexander disease. A 40-year-old man presented with subacute left hemiplegia and ataxia. Cranial MRI revealed disseminated patchy white matter changes involving the corpus callosum, basal ganglia and brainstem. CSF investigation demonstrated elevated total protein but was otherwise normal. mutation analysis of the GFAP gene was performed in the patient, his mother and healthy brother. A novel heterozygous mutation in exon 4, 681G-->C, predicting an amino acid substitution E223Q in the rod region of GFAP was detected in the patient and his mother but not in his healthy brother or 150 control chromosomes. We conclude that the patient is actually afflicted with alexander disease. mutation analysis of GFAP should be considered in patients with remitting neurological deficits, disseminated white matter lesions and absence of inflammatory CSF changes. ( info) |
| Heterozygous point mutations in the coding region of the human glial fibrillary acidic protein (GFAP) gene have been reported in patients with various forms of alexander disease (AD). We report a case of genetically confirmed adult-onset AD with palatal myoclonus, pyramidal tract signs, cerebellar signs, and marked atrophy of the medulla oblongata and spinal cord, autonomic dysfunction and heterozygous R416W GFAP mutation. Interestingly, this R416W mutation has also been reported in both infantile and juvenile forms of alexander disease. The fact that a R416W mutation causes various types of AD suggests that clinical severities of AD are due not only to the different sites and nature of mutations in GFAP, but also to other modifying factor(s). ( info) |