Effects of gait rehabilitation with a footpad-type locomotion interface in patients with chronic post-stroke hemiparesis: a pilot study

Objective:

We developed a footpad-type locomotion interface called the GaitMaster. The purpose of this pilot study was to examine the effects of gait rehabilitation using the GaitMaster in chronic stroke patients.

Design:

Randomized cross-over design.

Setting:

An outpatient department.

Subjects:

Twelve patients with chronic post-stroke hemiparesis.

Intervention:

In group A, patients underwent an ‘intervention phase’ followed by a ‘non-intervention phase’, whereas in group B, patients underwent the non-intervention phase first, followed by the intervention phase. In the four- or six-week intervention phase, participants underwent twelve 20-minute sessions of gait rehabilitation using the GaitMaster4.

Main outcome measures:

We measured gait speed and timed up-and-go test.

Results:

No differences between the two groups were observed in the baseline clinical data. For the combined groups A and B, the maximum gait and timed up-and-go test speeds improved significantly only in the intervention phase ( P = 0.0001 and P = 0.003, respectively). The percentages of improvement from baseline at the end of GaitMaster training were 16.6% for the maximum gait speed and 8.3% for the timed up-and-go test. The effect size for GaitMaster4 training was 0.58 on the maximum gait speed and 0.43 on the timed up-and-go test.

Conclusions:

This pilot study showed that gait rehabilitation using the GaitMaster4 was a feasible training method for chronic stroke patients. Calculation of the sample size indicated that a sample size of 38 participants would be adequate to test a null hypothesis of nil benefit additional to routine rehabilitation for chronic stroke patients in a future randomized controlled trial.

An ocular form of myasthenia gravis with a high titer of anti-MuSK antibodies during a long-term follow-up

We herein report a case of ocular myasthenia gravis (MG) that was highly positive for anti-muscle-specific tyrosine kinase (MuSK) antibodies. The examined patient exhibited bilateral ptosis and lateral gaze palsy without any generalized symptoms and was diagnosed with ocular MG with anti-MuSK antibodies. She responded to treatment with prednisolone and immunosuppressants and experienced only ocular symptoms for four years and eight months after onset. Ocular MG with anti-MuSK antibodies lasting for a long term has rarely been described. Our findings suggest that it may be reasonable to test for the presence of anti-MuSK antibodies in patients who present with external ophthalmoplegia.

Recurrent isolated abducens nerve paresis associated with persistent trigeminal artery variant

We report a 74-year-old woman who presented with recurrent isolated abducens nerve paresis. Cranial magnetic resonance imaging revealed that the right abducens nerve was sandwiched between the right internal carotid artery and a persistent trigeminal artery (PTA) variant, which might have led to neurovascular compression of the abducens nerve, resulting in abducens nerve damage. Normal variants of PTA, which are cerebellar arteries originating from a precavernous portion of the internal carotid artery, must be carefully observed as such variants can potentially cause a neurovascular compression of the abducens nerve.

Epitope mapping of antibodies against TDP-43 and detection of protease-resistant fragments of pathological TDP-43 in amyotrophic lateral sclerosis and frontotemporal lobar degeneration

TAR DNA-binding protein of 43 kDa (TDP-43) is the major component of the intracellular inclusions in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Here, we show that both monoclonal (60019-2-Ig) and polyclonal (10782-2-AP) anti-TDP-43 antibodies recognize amino acids 203-209 of human TDP-43. The monoclonal antibody labeled human TDP-43 by recognizing Glu204, Asp205 and Arg208, but failed to react with mouse TDP-43. The antibodies stained the abnormally phosphorylated C-terminal fragments of 24-26 kDa in addition to normal TDP-43 in ALS and FTLD brains. Immunoblot analysis after protease treatment demonstrated that the epitope of the antibodies (residues 203-209) constitutes part of the protease-resistant domain of TDP-43 aggregates which determine a common characteristic of the pathological TDP-43 in both ALS and FTLD-TDP. The antibodies and methods used in this study will be useful for the characterization of abnormal TDP-43 in human materials, as well as in vitro and animal models for TDP-43 proteinopathies.

[Molecular dissection of TDP-43 in ALS and FTLD]

Proteomic and immunochemical analyses have shown that hyperphosphorylated TDP-43 is a major component of ubiquitin-positive inclusions from brain of frontotemporal lobar degeneration (FTLD) patients. In 2008, TDP-43 gene mutations were discovered in familial and sporadic amyotrophic lateral sclerosis (ALS), indicating that TDP-43 protein abnormality is associated with neurodegeneration. We raised antibodies against 36 synthetic phosphopeptides and demonstrated that abnormal phosphorylation takes place in the C-terminal region of TDP-43. One antibody, pS409/410, stained the inclusions in both FTLD and ALS brains, with no nuclear staining. Immunoblotting revealed the presence of hyperphosphorylated 45 kDa band, smearing substances and 18-26 kDa fragments in deposits, and the band patterns were different between FTLD and ALS. Overexpression of TDP-43 C-terminal fragments as GFP-fusions resulted in formation of inclusions positive for antibodies to phosphorylated TDP-43 and ubiquitin. We further investigated the protease-resistant TDP-43 and found that it is also different between ALS and FTLD, supporting the idea that the different band patterns reflect different conformations of abnormal TDP-43. Interestingly, the C-terminal band pattern is indistinguishable among brain regions and spinal cord in each individual patient. These results suggest that abnormal TDP-43 produced in a cell may be transferred to different regions and propagated during disease progression.

The immunoreceptor adapter protein DAP12 suppresses B lymphocyte-driven adaptive immune responses

DAP12, an immunoreceptor tyrosine-based activation motif-bearing adapter protein, is involved in innate immunity mediated by natural killer cells and myeloid cells. We show that DAP12-deficient mouse B cells and B cells from a patient with Nasu-Hakola disease, a recessive genetic disorder resulting from loss of DAP12, showed enhanced proliferation after stimulation with anti-IgM or CpG. Myeloid-associated immunoglobulin-like receptor (MAIR) II (Cd300d) is a DAP12-associated immune receptor. Like DAP12-deficient B cells, MAIR-II-deficient B cells were hyperresponsive. Expression of a chimeric receptor composed of the MAIR-II extracellular domain directly coupled to DAP12 into the DAP12-deficient or MAIR-II-deficient B cells suppressed B cell receptor (BCR)-mediated proliferation. The chimeric MAIR-II-DAP12 receptor recruited the SH2 domain-containing protein tyrosine phosphatase 1 (SHP-1) after BCR stimulation. DAP12-deficient mice showed elevated serum antibodies against self-antigens and enhanced humoral immune responses against T cell-dependent and T cell-independent antigens. Thus, DAP12-coupled MAIR-II negatively regulates B cell-mediated adaptive immune responses.

Molecular dissection of TDP-43 proteinopathies

TDP-43 has been identified as a major component of ubiquitin-positive tau-negative cytoplasmic inclusions in frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U) and in amyotrophic lateral sclerosis (ALS). We raised antibodies to phosphopeptides representing 36 out of 64 candidate phosphorylation sites of human TDP-43 and showed that the antibodies to pS379, pS403/404, pS409, pS410 and pS409/410 labeled the inclusions, but not the nuclei. Immunoblot analyses demonstrated that the antibodies recognized TDP-43 at ~45 kDa, smearing substances and 18-26 kDa C-terminal fragments. Furthermore, the band patterns of the C-terminal fragments differed between neuropathological subtypes, but were indistinguishable between brain regions and spinal cord in each individual patient. Protease treatment of Sarkosyl-insoluble TDP-43 suggests that the different band patterns of the C-terminal fragments reflect different conformations of abnormal TDP-43 molecules between the diseases. These results suggest that molecular species of abnormal TDP-43 are different between the diseases and that they propagate from affected cells to other cells during disease progression and determine the clinicopathological phenotypes of the diseases.

A Japanese case with Nasu-Hakola disease of DAP12 gene mutation exhibiting precuneus hypoperfusion

A 38-year-old Japanese man with Nasu-Hakola disease (NHD) had repeated pathological fractures and frontal lobe symptoms which developed when he was 18 and 26 years old, respectively. Neuropsychological testing showed memory impairment, and in particular, visuo-spatial memory at the age of 35. Furthermore, single-photon emission computed tomography revealed precuneus hypoperfusion. The patient later suffered prolonged convulsive seizures, which left him in a persistent vegetative state. Genetic testing confirmed a heterozygous mutation in the DAP12 gene (a single-base deletion of 141 G in exon 3) specific to NHD. Precuneus dysfunction might contribute to characteristic memory impairment of NHD.

CpG demethylation enhances alpha-synuclein expression and affects the pathogenesis of Parkinson's disease

BACKGROUND

Alpha-synuclein (SNCA) gene expression is an important factor in the pathogenesis of Parkinson's disease (PD). Gene multiplication can cause inherited PD, and promoter polymorphisms that increase SNCA expression are associated with sporadic PD. CpG methylation in the promoter region may also influence SNCA expression.

METHODOLOGY/PRINCIPAL FINDINGS

By using cultured cells, we identified a region of the SNCA CpG island in which the methylation status altered along with increased SNCA expression. Postmortem brain analysis revealed regional non-specific methylation differences in this CpG region in the anterior cingulate and putamen among controls and PD; however, in the substantia nigra of PD, methylation was significantly decreased.

CONCLUSIONS/SIGNIFICANCE

This CpG region may function as an intronic regulatory element for SNCA gene. Our findings suggest that a novel epigenetic regulatory mechanism controlling SNCA expression influences PD pathogenesis.

Detection of elevated levels of α-synuclein oligomers in CSF from patients with Parkinson disease

BACKGROUND

To date, there is no accepted clinical diagnostic test for Parkinson disease (PD) that is based on biochemical analysis of blood or CSF. The discovery of mutations in the SNCA gene encoding α-synuclein in familial parkinsonism and the accumulation of α-synuclein in the PD brain suggested a critical role for this protein in PD etiology.

METHODS

We investigated total and α-synuclein oligomers levels in CSF from patients clinically diagnosed with PD, progressive supranuclear palsy (PSP), or Alzheimer disease (AD), and age-matched controls, using ELISA developed in our laboratory.

RESULTS

The levels of α-synuclein oligomers and oligomers/total-α-synuclein ratio in CSF were higher in the PD group (n = 32; p < 0.0001, Mann-Whitney U test) compared to the control group (n = 28). The area under the receiver operating characteristic curve (AUC) indicated a sensitivity of 75.0% and a specificity of 87.5%, with an AUC of 0.859 for increased CSF α-synuclein oligomers in clinically diagnosed PD cases. However, when the CSF oligomers/total-α-synuclein ratio was analyzed, it provided an even greater sensitivity of 89.3% and specificity of 90.6%, with an AUC of 0.948. In another cross-sectional pilot study, we confirmed that the levels of CSF α-synuclein oligomers were higher in patients with PD (n = 25) compared to patients with PSP (n = 18; p < 0.05) or AD (n = 35; p < 0.001) or control subjects (n = 43; p < 0.05).

CONCLUSION

Our results demonstrate that levels of α-synuclein oligomers in CSF and the oligomers/total-α-synuclein ratio can be useful biomarkers for diagnosis and early detection of PD.

Thunderclap headache without hypertension in a patient with pheochromocytoma

Pheochromocytoma is a well known, catecholamine-producing tumor characterized by hypertension, headache, hyperglycemia, hypermetabolism, and hyperhydrosis. Approximately 65% of cases of pheochromocytoma were shown to be associated with hypertension. A case of pheochromocytoma that presented with thunderclap headache (TCH) and palpitations is reported. The patient never showed hypertension during the course of the disease. Paroxysmal headache and palpitations led to the identification of the underlying condition, and the final diagnosis was confirmed by histopathological examination of a surgical specimen. Pheochromocytoma should be identified as a less common although important cause of TCH. In addition, due to its lack of utility in identifying this disorder, negative cranial imaging may impede further investigation of extracranial lesions that may be the cause of a patient's headache. According to the International Classification of Headache Disorders (ICHD)-II, headache attributed to pheochromocytoma usually develops concomitantly with an abrupt increase in blood pressure. In our case, however, hypertension was never observed, even when the patient was symptomatic. This is the first report of a case of pheochromocytoma with TCH without hypertension.

PYROGLUTAMATE FORMATION AT THE N-TERMINI OF ABRI MOLECULES IN FAMILIAL BRITISH DEMENTIA IS NOT RESTRICTED TO THE CENTRAL NERVOUS SYSTEM

Amyloid molecules harboring pyroglutamate (pGlu) residue at the N-termini are considered to be important for the development of cerebral amyloidosis such as Alzheimer's disease and thought to be either spontaneously generated or being catalyzed by glutaminyl cyclase. Familial British dementia (FBD) is an autosomal dominant form of dementia neuropathologically characterized by parenchymal amyloid and preamyloid deposits, extensive cerebral amyloid angiopathy, and neurofibrillary tangles. FBD is caused by a stop to Arg mutation in the BRI2 gene, generating de novo created amyloid molecule ABri which accumulates in FBD brains but is not present in the normal population. Soluble ABri molecules present in the circulation of carriers of the BRI2 mutation are 34 amino acids long exclusively harboring Glu residue at the N-termini (ABri1-34E), whereas water- and formic acid-soluble ABri molecules extracted from FBD brains have abundant ABri species bearing pGlu residue (ABri1-34pE), suggesting that pyroglutamate formation occurs at the site of deposition. In order to further clarify the mechanism (s) of ABri deposition, we studied whether pyroglutamate formation indeed occurs outside the central nervous system taking advantage that FBD is also a systemic amyloidosis. Soluble and fibrillar ABri molecules extracted from systemic organs and analyzed biochemically using a combination of immunoprecipitation, mass spectrometry, and western blot analysis were oligomeric in size and contained a large proportion of ABri1-34pE. The data indicate that pyroglutamate formation at the N-termini of ABri molecules is an early step in the process of FBD amyloid deposition, and its formation is not restricted to the central nervous system.

Oxidative stress up-regulates presenilin 1 in lipid rafts in neuronal cells

Oxidative stress is associated with beta-amyloid peptide (A beta) accumulation in the brains of Alzheimer's disease patients. A beta is generated upon the sequential proteolytic cleavage of transmembrane amyloid precursor protein (APP) by two membrane-bound proteases, beta-secretase (BACE1) and the gamma-secretase complex comprising presenilin 1 (PS1), nicastrin, APH-1 and PEN-2. Recent evidence suggests that significant amounts of BACE1 and gamma-secretase components localize in the cholesterol-rich region of membranes known as lipid rafts, where A beta production occurs preferentially. In this study, we investigated the effects of oxidative stress on the BACE1 and gamma-secretase components in lipid rafts using human neuroblastoma SH-SY5Y cells exposed to ethacrynic acid (EA), a compound that induces cellular glutathione depletion. Following exposure of cells to EA, heme oxygenase-1, a marker protein of oxidative stress, was strongly induced. Moreover, treatment with EA resulted in a significant increase in PS1 protein levels, but not those of nicastrin, APH-1, PEN-2 or BACE1, in both cell lysates and the lipid raft fraction. This increase in PS1 protein expression was prevented by co-treatment with an antioxidant, N-acetylcysteine (NAC). EA additionally induced a significant increase in PS1 mRNA expression, which was inhibited by NAC. Finally, EA treatment was found to promote A beta secretion from cells expressing Swedish mutant APP. It appears that in our cell culture model, oxidative stress enhances PS1 protein levels in lipid rafts via up-regulation of PS1 transcription, which may constitute the mechanism underlying the oxidative stress-associated promotion of A beta production.

Clinical features of non-hypertensive lobar intracerebral hemorrhage related to cerebral amyloid angiopathy

BACKGROUND AND PURPOSE

The present study aims to clarify the clinical features of non-hypertensive cerebral amyloid angiopathy-related lobar intracerebral hemorrhage (CAA-L-ICH).

METHODS

We investigated clinical, laboratory, and neuroimaging findings in 41 patients (30, women; 11, men) with pathologically supported CAA-L-ICH from 303 non-hypertensive Japanese patients aged >OR=55, identified via a nationwide survey as symptomatic CAA-L-ICH.

RESULTS

The mean age of patients at onset of CAA-L-ICH was 73.2 +/- 7.4 years; the number of patients increased with age. The corrected female-to-male ratio for the population was 2.2, with significant female predominance. At onset, 7.3% of patients received anti-platelet therapy. In brain imaging studies, the actual frequency of CAA-L-ICHs was higher in the frontal and parietal lobes; however, after correcting for the estimated cortical volume, the parietal lobe was found to be the most frequently affected. CAA-L-ICH recurred in 31.7% of patients during the average 35.3-month follow-up period. The mean interval between intracerebral hemorrhages (ICHs) was 11.3 months. The case fatality rate was 12.2% at 1 month and 19.5% at 12 months after initial ICH. In 97.1% of patients, neurosurgical procedures were performed without uncontrollable intraoperative or post-operative hemorrhage.

CONCLUSIONS

Our study revealed the clinical features of non-hypertensive CAA-L-ICH, including its parietal predilection, which will require further study with a larger number of patients with different ethnic backgrounds.

TDP-43 M337V mutation in familial amyotrophic lateral sclerosis in Japan

The clinical features of a Japanese family with autosomal dominant adult-onset amyotrophic lateral sclerosis (ALS) are reported. Weakness initially affected the bulbar musculature, with later involvement of the extremities. Genetic studies failed to detect any mutations of the Cu/Zn superoxide dismutase-1 (SOD1) and Dynactin1 (DCTN1) genes, but revealed a single base pair change from wild-type adenine to guanine at position 1009 in TAR-DNA-binding protein (TDP-43), resulting in a methionine-to-valine substitution at position 337. The immunohistochemical study on autopsied brain of the proband's aunt showed TDP-43-positive cytoplasmic inclusions in the anterior horn cells of the spinal cord and in the hypoglossal nucleus, as well as glial cytoplasmic inclusions in the precentral gyrus, suggesting that a neuroglial proteinopathy was related to TDP-43. In conclusion, a characteristic clinical phenotype of familial ALS with initial bulbar symptoms occurred in this family with TDP-43 M337V substitution, the pathomechanism of which should be elucidated.

A Japanese case of fragile-X-associated tremor/ataxia syndrome (FXTAS)

A 71-year-old man developed postural tremor and was treated as an essential tremor patient. Nine years after the tremor onset, he developed symptoms resembling Fragile-X-associated tremor/ataxia syndrome (FXTAS), including exacerbated (increased coarseness and amplitude) tremor in the right arm, ataxic gait, and brain MRI showed lesions in the bilateral middle cerebellar peduncles (MCP). Evidence of premutation in the form of 83 CGG repeats of the Fragile-X-mental retardation 1 (FMR1) gene confirmed the diagnosis of FXTAS. FXTAS causes various neurological symptoms including in some cases tremor resembling essential tremor in the early stages. FMR1 gene premutation should be checked when the patient develops intention tremor, cerebral dysfunction and/or a brain MRI shows MCP lesions.

Diphenylhydantoin-induced severe yet reversible anemia during pregnancy

Diphenylhydantoin (DPH) therapy, often used in treating epileptic seizures, can cause anemia in some patients. A 26-year-old female suffered from convulsions due to encephalitis and was placed on DPH therapy. About two months after the initiation of DPH therapy, her hemoglobin level was 3.8 g/dL. Her anemia improved after the discontinuation of DPH, confirming that the anemia was caused by DPH. Pure red-cell aplasia (PRCA) combined with hemolytic anemia was indicated by results such as erythroid aplasia, an increased LDH level, and a decreased haptoglobin level. PRCA complicated by hemolytic anemia could be responsible for anemia associated with DPH.

A case of idiopathic hypertrophic cranial pachymeningitis presenting high values of matrix metalloproteinase

This report concerns a 53-year-old male patient with idiopathic hypertrophic cranial pachymeningitis who presented with multiple cranial nerve palsies (I, II, III, IV, V, VI). Brain magnetic resonance imaging showed diffuse thickening and gadolinium enhancement of the cerebral dura mater. A biopsy of the cerebral dura mater showed granulomatous vasculitis with histiocyte infiltration. Although both the serum rheumatoid factor (RF) and matrix metalloproteinase-3 (MMP-3) were high, the patient showed no signs of arthritis. He was anti-cyclic citrullinated peptide antibody negative, which makes the presence of comorbid chronic rheumatoid arthritis (RA) unlikely. The aetiology of the pachymeningitis was unknown, which led to the diagnosis of idiopathic hypertrophic cranial pachymeningitis. Steroid pulse therapy successfully diminished the patient's pachymeningitis and lowered both RF and MMP-3. High values of RF suggest the possible involvement of an autoimmune mechanism, and the MMP value may be an important indicator of the aetiology of pachymeningitis with granulomatous vasculitis.

A case of vitiligo vulgaris showing a pronounced improvement after treatment for myasthenia gravis

This is a report of a 64 year-old male patient whose myasthenia gravis (MG) was accompanied by vitiligo vulgaris. Depigmentation of the face, trunk, and hands was noted. He was diagnosed with vitiligo vulgaris according to macroscopic findings and a skin biopsy. He was also found to have blepharoptosis, and proximal dominant muscle weakness of the extremities. He was anti-acetylcholine receptor antibody-positive, with repetitive nerve stimulation showing a waning phenomenon and chest computed tomography showing invasive thymoma, which led to the diagnosis of generalised MG. His myasthenic symptoms were relieved by the use of steroids and the removal of the thymoma. His vitiligo vulgaris began to improve a month after the relief of myasthenic symptoms. Such improvement was pronounced during the next several months. The clinical or immunological relationship between MG and vitiligo vulgaris is still not known, but these findings might indicate clinical correlation between MG and vitiligo vulgaris.

Intravascular large B cell lymphoma with neurological symptoms diagnosed on the basis of a senile angioma-like eruption

Intravascular large B cell lymphoma (IVLBCL) presents various neurological symptoms, and the prognosis frequently deteriorates with a delay in diagnosis. In addition, for the diagnosis of IVLBCL, invasive biopsies are generally performed in main organs, such as the brain. We report a case of IVLBCL in which an early diagnosis was enabled by skin biopsy. The patient in this case had cauda equine syndrome and had developed multiple brain infarctions. She received six cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone) treatment and is currently in complete remission. At the macroscopic level, her lesions resembled senile angioma, commonly observed in normal elderly persons. Eruptions of this type are not currently recognised as IVLBCL lesions and might easily be overlooked. In cases in which IVLBCL could be suspected, an active search and biopsy of skin lesions, including an eruption of this type, are useful for early diagnosis and treatment.

IGF-1 promotes beta-amyloid production by a secretase-independent mechanism

Beta-amyloid peptide (Abeta) is generated via the sequential proteolysis of beta-amyloid precursor protein (APP) by beta- and gamma-secretases, and plays a crucial role in the pathogenesis of Alzheimer's disease (AD). Here, we sought to clarify the role of insulin-like growth factor-1 (IGF-1), implicated in the AD pathomechanism, in the generation of Abeta. Treatment of neuroblastoma SH-SY5Y cells expressing AD-associated Swedish mutant APP with IGF-1 did not alter cellular levels of APP, but significantly increased those of beta-C-terminal fragment (beta-CTF) and secreted Abeta. IGF-1 also enhanced APP phosphorylation at Thr668. Treatment of beta-CTF-expressing cells with IGF-1 increased the levels of beta-CTF and secreted Abeta. The IGF-1-induced augmentation of beta-CTF was observed in the presence of gamma-secretase inhibitors, but not in cells expressing beta-CTF with a Thr668 to alanine substitution. These results suggest that IGF-1 promotes Abeta production through a secretase-independent mechanism involving APP phosphorylation.

Parkinsonism with organophosphate poisoning

Parkinsonism is a primary neurotoxic manifestation of organophosphate pesticide intoxication. We report here the case of a 67-year-old man who developed acute parkinsonism with tremors and rigidity following exposure to fenitrothion, an organophosphate pesticide. His parkinsonism disappeared, and 2 months later he was able to walk alone without antiparkinsonian drug treatment. To identify particular lesions in the brain, Z score images were obtained from SPECT (single photon emission computed tomography) scans of the patient during the acute poisoning and a follow-up scan performed 2 months later. We indicate that reversible parkinsonism correlated with putaminal hyperperfusion as observed in the Z score images obtained during the acute event; this condition resolved later in concert with resolution of the clinical parkinsonism. We believe that the SPECT scan Z score images in this study are an important find in elucidating parkinsonism manifestations due to organophosphate poisoning.

[Intravascular lymphomatosis manifesting clinically as subacute encephalopathy]

We report a 62-year-old woman with intravascular lymphomatosis (IVL) which presented as subacute encephalopathy. She was admitted to our hospital because of loss of consciousness in the middle of February, 2006. Laboratory tests indicated elevated serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and cerebrospinal fluid protein. Magnetic resonance imaging (MRI) of the brain revealed multiple infarct-like lesions mainly in the white matter. After admission, her consciousness was soon improved, but the inflammatory response did not disappear with any antibiotics or virucides. Her consciousness was not exacerbated, and she was discharged in the middle of March, although the reason for loss of consciousness remained unknown. After discharge she developed an abnormal behavior and mental deterioration, and therefore she was readmitted late in March. On second admission, her consciousness was drowsy. Neurological examinations revealed conjugate deviation of her eyes to the left, left hemiparesis, and generalized hyporeflexia. Laboratory tests showed more elevated CRP than that of the last time, and raised soluble IL-2 receptor (sIL-2R). The repeated MRI of the brain disclosed that initial lesions of the white matter progressively enlarged and increased in number. To make an appropriate diagnosis of the lesions on the brain MRI, the open brain biopsy was performed. Microscopic examination showed that many small vessels were occluded by lymphoma cells (B-lymphocytes) with hemorrhage, and IVL was diagnosed. She was treated with regimens of combined chemotherapy with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone). After chemotherapy her consciousness and left hemiparesis were gradually improved and the levels of CRP were normalized. The infarcts-like lesions detected on the brain MRI became reduced and decreased. IVL is a rare disease, and the prognosis is generally poor, with a rapidly fatal outcome, leading to a postmortem diagnosis. In the present report, we successfully treated the patient by rituximab in addition to standard CHOP therapy. Rituximab may play an important role in the treatment of IVL.