[Brain abscess due to Fusobacterium necrophorum in a patient with convulsion and no signs of meningitis]

Here, we report brain abscess due to Fusobacterium necrophorum (F. necrophorum) in a 78-year-old healthy man. He developed convulsion and did not have any signs of meningitis. Although the brain magnetic resonance imaging findings of the left occipital lobe were typical of a brain abscess, his cerebrospinal fluid examination revealed only slight pleocytosis and mild increase in protein levels. Thus, it was difficult to rule out the possibility of metastatic brain tumor; the patient's condition was provisionally diagnosed as symptomatic epilepsy secondary to brain abscess. His convulsion disappeared soon after administration of antiepileptic, antibacterial, and steroid agents. A craniotomy was performed to evacuate the abscess, and F. necrophorum was identified by culturing the abscess contents. After the operation, he was treated with appropriate antibacterial agents, which resulted in resolution of the brain abscess. Although Fusobacterium species are gram-negative anaerobic bacilli commensal of the human oropharynx, we need to recognize that Fusobacterium species can be a primary pathogen causing brain abscesses and may leave residual neurological sequelae without early appropriate treatment.

Multiplex families with multiple system atrophy

BACKGROUND

Multiple system atrophy (MSA) has been considered a sporadic disease, without patterns of inheritance.

OBJECTIVE

To describe the clinical features of 4 multiplex families with MSA, including clinical genetic aspects.

DESIGN

Clinical and genetic study.

SETTING

Four departments of neurology in Japan. Patients Eight patients in 4 families with parkinsonism, cerebellar ataxia, and autonomic failure with age at onset ranging from 58 to 72 years. Two siblings in each family were affected with these conditions.

MAIN OUTCOME MEASURES

Clinical evaluation was performed according to criteria by Gilman et al. Trinucleotide repeat expansion in the responsible genes for the spinocerebellar ataxia (SCA) series and for dentatorubral-pallidoluysian atrophy (DRPLA) was evaluated by polymerase chain reaction. Direct sequence analysis of coding regions in the alpha-synuclein gene was performed.

RESULTS

Consanguineous marriage was observed in 1 of 4 families. Among 8 patients, 1 had definite MSA, 5 had probable MSA, and 2 had possible MSA. The most frequent phenotype was MSA with predominant parkinsonism, observed in 5 patients. Six patients showed pontine atrophy with cross sign or slitlike signal change at the posterolateral putaminal margin or both on brain magnetic resonance imaging. Possibilities of hereditary ataxias, including SCA1 (ataxin 1, ATXN1), SCA2 (ATXN2), Machado-Joseph disease/SCA3 (ATXN1), SCA6 (ATXN1), SCA7 (ATXN7), SCA12 (protein phosphatase 2, regulatory subunit B, beta isoform; PP2R2B), SCA17 (TATA box binding protein, TBP) and DRPLA (atrophin 1; ATN1), were excluded, and no mutations in the alpha-synuclein gene were found.

CONCLUSIONS

Findings in these multiplex families suggest the presence of familial MSA with autosomal recessive inheritance and a genetic predisposition to MSA. Molecular genetic approaches focusing on familial MSA are expected to provide clues to the pathogenesis of MSA.

Polyglutamine disease: Recent advances in the neuropathology of dentatorubral-pallidoluysian atrophy

Polyglutamine diseases are hereditary neurodegenerative disorders that are caused by the expansion of a CAG repeat in the causative genes. They comprise at least nine disorders, including DRPLA, HD, and Machado-Joseph disease. Initially, the discovery of neuronal intranuclear inclusions (NIIs) in human brains and in a murine model of HD provided a plausible hypothesis that the expression of expanded polyglutamine stretches leads to NII formation, resulting in neuronal cell death in selective brain regions characteristic to each disease. Recent studies, however, suggest that nuclear dysfunction, especially transcriptional abnormalities caused by the diffuse intranuclear accumulation of mutant proteins, plays a pivotal role in the development and progression of clinical symptoms. Polyglutamine diseases have a similarity with neuronal storage disease, and this pathological process might become a target for the establishment of an effective therapy for these diseases.

Periaxin mutation in Japanese patients with Charcot-Marie-Tooth disease

Periaxin (PRX) plays an important role in the myelination of the peripheral nerve and consequently in the pathogenesis of Charcot-Marie-Tooth disease (CMT). To date, nine nonsense or frameshift PRX mutations have been reported in eight families with CMT. The patients with PRX mutations appeared to show characteristic clinical features with early onset but slow or no progression, a common result of mutations that lead to missing a C-terminal acidic domain. Here, we report a Japanese CMT patient with these characteristic clinical features, who was a compound heterozygote for PRX R1070X and L132FsX153 mutations. We previously reported that three Japanese isolated families also had the homozygous R1070X mutation. To examine the potential founder effect of the R1070X mutation in the Japanese population, we performed haplotype analysis and found that each R1070X allele lay on a different haplotype background in these four families. Therefore, the high frequency of the R1070X mutation among the Japanese population is not likely the consequence of a founder effect, but probably a result of a mutation hot spot.

Interference of CREB-dependent transcriptional activation by expanded polyglutamine stretches--augmentation of transcriptional activation as a potential therapeutic strategy for polyglutamine diseases

On the basis of the hypothesis that the interaction of mutant proteins with expanded polyglutamine stretches with transcriptional co-activator, TAFII130, leads to transcriptional dysregulation, the transcriptional activation of c-Fos and its suppression by expanded polyglutamine stretches was investigated. The phosphorylation of cAMP-responsive element binding protein (CREB) and induction of c-Fos in response to cAMP were strongly suppressed in Neuro2a cells expressing expanded polyglutamine. The suppression of CREB-dependent transcriptional activation was reversibly rescued by increasing the concentration of cAMP. Expanded polyglutamine-induced cytotoxicity was also substantially suppressed by augmenting CREB-dependent transcriptional activation with a high concentration of cAMP. FR901228, a histone deacetylase inhibitor, was also demonstrated as rescuing the expanded polyglutamine-induced suppression of CREB phosphorylation and c-Fos expression. Furthermore, nuclear fragmentation was significantly suppressed by FR901228. The co-expression of dominant-negative CREB vectors considerably abrogated the suppressive effect of cAMP and FR901228 on the expanded polyglutamine-induced nuclear fragmentation, suggesting that these compounds suppress polyglutamine-induced cytotoxicity, largely, via the enhancement of CREB-dependent transcriptional activation. These findings suggest that the interference of CREB-dependent transcriptional activation by expanded polyglutamine stretches is involved in the pathogenetic mechanisms underlying neurodegeneration, and that the augmentation of CREB-dependent transcriptional activation is a potential strategy in treating polyglutamine diseases.

Cerebral lipoma and the underlying cortex of the temporal lobe: pathological features associated with the malformation

Intracranial lipomas are believed to be congenital malformations rather than true neoplasms, resulting from the abnormal differentiation of the meninx primitiva, the undifferentiated mesenchyme. We report here the surgical pathological features of a lipoma that was located on the cerebral surface of an abnormally formed fissure, and the underlying cortex of the middle temporal gyrus of a 20-year-old woman. The mass was composed of typical adipose tissue in which a large number of blood vessels were present. Thick connective tissue associated with the arachnoid membrane covered the cortical surface. The cortex exhibited a polymicrogyric configuration in which the cortical ribbon was abnormally undulated and excessively folded. Reelin-immunolabeled Cajal-Retzius-cell-like cells were observed frequently in the fused molecular layer. The cortical lamination underlying the molecular layer was poorly defined. Along the border between the connective tissue and cortical surface, there was a narrow zone in which the mesenchymal and neuronal tissues were intermingled, and where immunohistochemical and ultrastructural investigations disclosed disruption of the basal lamina, prominent astrocytosis, and abundant axonal and synaptic profiles. These findings suggest that focal disturbances in cerebral cortical development occur in association with the development of lipomas.

[A pedigree of Charcot-Marie-Tooth disease type 4F (Periaxin mutation)]

We report a 51-year-old man genetically diagnosed as Charcot-Marie-Tooth disease type 4F. The patient was the first child of healthy, consanguineous parents. He had two sisters and one of them showed similar but milder symptoms. He had gait disturbance since childhood. Then he noticed muscle weakness of his hands at the age of early forties, and more difficulties in gait at the age of late forties. On examination at age 51, he showed absence of all deep tendon reflexes, weakness of the hand and distal leg muscles, pes cavus and decreased sensitivity to touch and vibration in the lower extremities. Electrophysiological studies of the median nerve showed delayed motor nerve conduction velocity and undetectable sensory nerve action potentials. The histology of his sural nerve revealed moderate loss of large myelinated fibers and the diameters of residual fibers shifted to small shown as size-frequency histogram. Many fibers are thinly myelinated and some of the Schwann cells looked as wrapping around the myelinate fibers with their processes. On gene analyses, we identified an Arg 1070 Stop homozygous mutation in the Periaxin, known to be a causative gene for CMT type 4F. Based on these observations, we emphasized that broad genetic analyses are necessary for diagnosis of CMT disease, including so far unidentified mutations among the Japanese populations.

Periaxin mutation causes early-onset but slow-progressive Charcot-Marie-Tooth disease

Periaxin (PRX) plays a significant role in the myelination of the peripheral nerve. To date, seven non-sense or frameshift PRX mutations have been reported in six pedigrees with Dejerine-Sottas neuropathy or severe Charcot-Marie-Tooth neuropathy (CMT). We detected a PRX mutation in three patients in the screening of 66 Japanese demyelinating CMT patients who were negative for the gene mutation causing dominant or X-linked demyelinating CMT. Three unrelated patients were homozygous for a novel R1070X mutation and presented early-onset but slowly progressive distal motor and sensory neuropathies. Mutations lacking the carboxyl-terminal acidic domain may show loss-of-function effects and cause severe demyelinating CMT.

SCA17 homozygote showing Huntington's disease-like phenotype

We report a homozygous case of spinocerebellar ataxia type 17 with 48 glutamines. The age of the patient at disease onset was not lower than those of heterozygotes with the same CAG-repeat sizes, but the clinical manifestations were rapidly progressive dementia and chorea. Neuronal loss was relatively restricted and most prominent in the Purkinje cell layer and striatum; however, intranuclear neuronal polyglutamine accumulation was widespread, with a high frequency in the cerebral cortex and striatum.