Improvement in Diagnosis of Histoplasma Meningitis by Combined Testing for Histoplasma Antigen and Immunoglobulin G and Immunoglobulin M Anti-Histoplasma Antibody in Cerebrospinal Fluid.

Background: Central nervous system (CNS) histoplasmosis is a life-threatening condition and represents a diagnostic and therapeutic challenge. Isolation of Histoplasma capsulatum from cerebrospinal fluid (CSF) or brain tissue is diagnostic; however, culture is insensitive and slow growth may result in significant treatment delay. We performed a retrospective multicenter study to evaluate the sensitivity and specificity of a new anti-Histoplasma antibody enzyme immunoassay (EIA) for the detection of IgG and IgM antibody in the CSF for diagnosis of CNS histoplasmosis, the primary objective of the study. The secondary objective was to determine the effect of improvements in the Histoplasma galactomannan antigen detection EIA on the diagnosis of Histoplasma meningitis. Methods: Residual CSF specimens from patients with Histoplasma meningitis and controls were tested for Histoplasma antigen and anti-Histoplasma immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody using assays developed at MiraVista Diagnostics. Results: A total of 50 cases and 157 controls were evaluated. Fifty percent of patients with CNS histoplasmosis were immunocompromised, 14% had other medical conditions, and 36% were healthy. Histoplasma antigen was detected in CSF in 78% of cases and the specificity was 97%. Anti-Histoplasma IgG or IgM antibody was detected in 82% of cases and the specificity was 93%. The sensitivity of detection of antibody by currently available serologic testing including immunodiffusion and complement fixation was 51% and the specificity was 96%. Testing for both CSF antigen and antibody by EIA was the most sensitive approach, detecting 98% of cases. Conclusions: Testing CSF for anti-Histoplasma IgG and IgM antibody complements antigen detection and improves the sensitivity for diagnosis of Histoplasma meningitis.

Detection of (1,3)-ß-d-Glucan in Cerebrospinal Fluid in Histoplasma Meningitis.

The diagnosis of central nervous system (CNS) histoplasmosis is often difficult. Although cerebrospinal fluid (CSF) (1,3)-ß-d-glucan (BDG) is available as a biological marker for the diagnosis of fungal meningitis, there are limited data on its use for the diagnosis of Histoplasma meningitis. We evaluated CSF BDG detection, using the Fungitell assay, in patients with CNS histoplasmosis and controls. A total of 47 cases and 153 controls were identified. The control group included 13 patients with a CNS fungal infection other than histoplasmosis. Forty-nine percent of patients with CNS histoplasmosis and 43.8% of controls were immunocompromised. The median CSF BDG level was 85 pg/ml for cases, compared to <31 pg/ml for all controls (P < 0.05) and 82 pg/ml for controls with other causes of fungal meningitis (P = 0.27). The sensitivity for detection of BDG in CSF was 53.2%, whereas the specificity was 86.9% versus all controls and 46% versus other CNS fungal infections. CSF BDG levels of ≥80 pg/ml are neither sensitive nor specific to support a diagnosis of Histoplasma meningitis.

Overlapping demyelinating syndromes and anti­N-methyl-D-aspartate receptor encephalitis.

OBJECTIVE: To report the clinical, radiological, and immunological association of demyelinating disorders with anti­Nmethyl- D-aspartate receptor (NMDAR) encephalitis. METHODS: Clinical and radiological analysis was done of a cohort of 691 patients with anti-NMDAR encephalitis. Determination of antibodies to NMDAR, aquaporin-4 (AQP4), and myelin oligodendrocyte glycoprotein (MOG) was performed using brain immunohistochemistry and cell-based assays. RESULTS: Twenty-three of 691 patients with anti-NMDAR encephalitis had prominent magnetic resonance imaging (MRI) and/or clinical features of demyelination. Group 1 included 12 patients in whom anti-NMDAR encephalitis was preceded or followed by independent episodes of neuromyelitis optica (NMO) spectrum disorder (5 cases, 4 anti-AQP4 positive) or brainstem or multifocal demyelinating syndromes (7 cases, all anti-MOG positive). Group 2 included 11 patients in whom anti-NMDAR encephalitis occurred simultaneously with MRI and symptoms compatible with demyelination (5 AQ4 positive, 2 MOG positive). Group 3 (136 controls) included 50 randomly selected patients with typical anti-NMDAR encephalitis, 56 with NMO, and 30 with multiple sclerosis; NMDAR antibodies were detected only in the 50 anti-NMDAR patients, MOG antibodies in 3 of 50 anti-NMDAR and 1 of 56 NMO patients, and AQP4 antibodies in 48 of 56 NMO and 1 of 50 anti-NMDAR patients (p<0.0001 for all comparisons with Groups 1 and 2). Most patients improved with immunotherapy, but compared with anti-NMDAR encephalitis the demyelinating episodes required more intensive therapy and resulted in more residual deficits. Only 1 of 23 NMDAR patients with signs of demyelination had ovarian teratoma compared with 18 of 50 anti-NMDAR controls (p50.011). INTERPRETATION: Patients with anti-NMDAR encephalitis may develop concurrent or separate episodes of demyelinating disorders, and conversely patients with NMO or demyelinating disorders with atypical symptoms (eg, dyskinesias, psychosis) may have anti-NMDAR encephalitis.

Anti-NMDA receptor encephalitis associated with transient cerebral dyschromatopsia, prosopagnosia, and lack of stereopsis.

A 20-year-old woman suffered from anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and was treated with removal of an ovarian teratoma and retroperitoneal ganglioneuroma in addition to immunotherapy. She was incapable of face recognition, had difficulty with object recognition, and lacked color sensation and stereo perception during recovery. These symptoms were transient and completely resolved over 4 months. Our report documents additional aspects of visual impairment associated with anti-NMDAR encephalitis and suggests that the disease can lead to diffuse cerebral dysfunction including the cortical visual system.

An open trial of long-term testosterone suppression in spinal and bulbar muscular atrophy.

INTRODUCTION: We investigated the long-term effects of leuprorelin on leg-muscle strength in spinal and bulbar muscular atrophy (SBMA). We hypothesized that testosterone suppression by leuprorelin would prevent the progression of muscle weakness. METHODS: In a prospective, long duration, open trial, 16 SBMA patients underwent medical castration with leuprorelin for 3.5 years. Chlormadinone was coadministered initially to prevent a testosterone surge. The strength of knee extension and flexion were quantitated using a torque machine. RESULTS: Our hypothesis was rejected. The leg strength measures decreased significantly with the mean reduction of 22.3-27.8%. In a post hoc analysis, the leg strength of 4 patients with higher pretreatment baseline total testosterone levels and short disease duration of 1-6 years were stronger at baseline and decreased by only 12.3-15.7% after treatment. CONCLUSIONS: Leuprorelin was not effective in this small long-term treatment trial in SBMA. The possibility that earlier treatment might be beneficial may deserve further study.

Far-field potentials in hypothenar motor unit number estimation.

INTRODUCTION: Contamination by far-field potentials (FFPs) may interfere with motor unit number estimation (MUNE) in the ulnar nerve. METHODS: Surface motor unit potentials (SMUPs) from 29 spinal and bulbar muscular atrophy (SBMA) patients and 27 control subjects were classified into SMUPs from the abductor digiti minimi muscle (ADM SMUPs) or non-ADM SMUPs, based on the waveform patterns from 3-channel recordings. RESULTS: The mean areas of the ADM SMUPs and non-ADM SMUPs in control subjects were 219.0 ± 131.3 and 63.7 ± 48.5 µVms, respectively. In SBMA patients they were 1988.9 ± 999.4 and 222.7 ± 125.7 µVms, respectively. The percentages of non-ADM SMUPs were 68 ± 22% in controls and 84 ± 15% in SBMA patients. CONCLUSIONS: Non-ADM SMUPs generated mainly by FFPs often had a negative onset in the routine lead and were indistinguishable from ADM SMUPs. More frequent exclusion of smaller non-ADM SMUPs in controls by size criteria would reduce the diagnostic yield of MUNE.

Impact of a Clinical Text-Based Fall Prediction Model on Preventing Extended Hospital Stays for Elderly Inpatients: Model Development and Performance Evaluation.

BACKGROUND: Falls may cause elderly people to be bedridden, requiring professional intervention; thus, fall prevention is crucial. The use of electronic health records (EHRs) is expected to provide highly accurate risk assessment and length-of-stay data related to falls, which may be used to estimate the costs and benefits of prevention. However, no studies to date have investigated the extent to which hospital stays could be shortened through fall avoidance resulting from the use of prediction tools. OBJECTIVE: We first estimated the extended length of hospital stay caused by falls among elderly inpatients. Next, we developed a model that predicts falls using clinical text as input and evaluated its accuracy. Finally, we estimated the potentially shortened hospital stay that would be made possible by appropriate interventions based on the prediction model. METHODS: Patients aged 65 years or older were selected as subjects, and the EHRs of 1728 falls and 70,586 nonfalls were subjected to analysis. The extended-stay lengths were estimated using propensity score matching of 49 associated variables. Bidirectional encoder representations from transformers and bidirectional long short-term memory methods were used to predict falls from clinical text. The estimated length of stay and the outputs of the prediction model were used to determine stay reductions. RESULTS: The extended length of hospital stay due to falls was estimated to be 17.8 days (95% CI 16.6-19.0), which dropped to 8.6 days when there were unobserved covariates at an odds ratio of 2.0. The accuracy of the prediction model was as follows: area under the receiver operating characteristic curve, 0.851; F-value, 0.165; recall, 0.737; precision, 0.093; and specificity, 0.839. When assuming interventions with 25% or 100% effectiveness against cases where the model predicted a fall, the stay reduction was estimated at 0.022 and 0.099 days/day, respectively. CONCLUSIONS: The accuracy of the prediction model using clinical text is considered to be higher than the prediction accuracy of conventional assessments. However, our model's precision remained low at 9.3%. This may be due, in part, to the inclusion of cases in which falls did not occur because of preventative interventions during hospitalization. Nonetheless, it is estimated that interventions for cases when falls were predicted will reduce medical costs by 886 Yen/day (~US $6.50/day) of intervention, even if the preventative effect is 25%. Limitations include the fact that these results cannot be extrapolated to short- or long-term hospitalization cases, and that this was a single-center study.

Evaluation of spinal and bulbar muscular atrophy by the clustering index method.

INTRODUCTION: A reliable electrophysiological marker for clinical trials is increasingly needed in spinal and bulbar muscular atrophy (SBMA). We previously developed a quantitative analysis method for surface electromyography (SEMG), the clustering index (CI) method. Our purpose was to test the utility of the CI method for evaluating lower motor neuron involvement in SBMA patients. METHODS: Subjects included 29 SBMA patients and 27 healthy controls. The recording electrode was placed over the abductor digiti minimi (ADM) muscle with a proximal reference. The Z-score, based on the CI method, was compared with compound muscle action potential (CMAP) amplitude and motor unit number estimation (MUNE), with regard to sensitivity. RESULTS: The Z-scores of the CI method, CMAP amplitude, and MUNE were abnormal in 100%, 72%, and 93% of the patients, respectively. Interrater reliability of the CI method was sufficiently high. CONCLUSION: The CI method is promising as a non-invasive electrophysiological marker in SBMA.

[Neurological syndromes, encephalitis].

The remote effects of malignant tumors in most cases of paraneoplastic neurological syndromes(PNS)are mediated by autoimmune processes against antigens shared by the tumor cells and the nervous tissue(onconeural antigens). Onconeural (or paraneoplastic)antibodies are broadly categorized into two groups according to the location of the corresponding onconeural antigens, inside or on the surface of neurons. Antibodies established as clinically relevant diagnostic markers for PNS are designated as well-characterized onconeural antibodies (or classical antibodies)that target intracellular antigens(Hu, Yo, Ri, CV2/CRMP5,Ma2, and amphiphysin). They also serve as useful markers in detecting primary tumors. Recent identification of new antibodies as markers of subtypes of limbic encephalitis has also expanded the concept of autoimmune limbic encephalitis. These autoantibodies are directed to neuronal cell-surface antigens including neurotransmitter receptors(NMDA, AMPA, and GABAB receptors)and ion channels(VGKC). They are less frequently associated with cancer, so that they cannot be used as specific markers for PNS. Autoimmune limbic encephalitis with anti-neuronal cell surface antobodies and paraneoplastic limbic encephalitis with classical antibodies overlap in some clinical features but are pathophysiologically distinct. Classical antibodies are not simple tumor markers. They seem to be closely related to the disease mechanisms because specific intrathecal synthesis has been shown in PNS patients. However, attempts to produce an animal model of PNS by passive transfer of these antibodies have been unsuccessful, and there is no direct evidence demonstrating the pathogenic role of classical antibodies. Instead, some circumstantial evidence, including pathological studies showing extensive infiltrates of T cells in the CNS of the patients, supports the hypothesis that cytotoxic-T cell mechanisms cause irreversible neuronal damage. On the other hand, humoral immune response is probably the principal mechanism in autoimmune encephalitis associated with antibodies against neuronal cell-surface antigens. Those antibodies are supposed to mediate neural dysfunction which may be reversed by immunosuppression therapy, while the exact mechanism remains to be elucidated. Further accumulation of the cases and longer observation would be necessary to delineate the clinical spectrum of each type of newly-identified autoimmune limbic encephalitis. Early diagnosis and optimal oncological treatment is a prerequisite for better prognosis of PNS patients. Detection of the primary tumor at very early stages including carcinoma in situ is a challenging issue. Optimization of immunosuppression/ immunomodulation therapy for each patient according to the underlying pathophysiological processes is another important clinical issue.

Clinical efficacy of haematopoietic stem cell transplantation for adult adrenoleukodystrophy.

Accumulated experience supports the efficacy of allogenic haematopoietic stem cell transplantation in arresting the progression of childhood-onset cerebral form of adrenoleukodystrophy in early stages. For adulthood-onset cerebral form of adrenoleukodystrophy, however, there have been only a few reports on haematopoietic stem cell transplantation and the clinical efficacy and safety of that for adulthood-onset cerebral form of adrenoleukodystrophy remain to be established. To evaluate the clinical efficacy and safety of haematopoietic stem cell transplantation, we conducted haematopoietic stem cell transplantation on 12 patients with adolescent-/adult-onset cerebral form/cerebello-brainstem form of adrenoleukodystrophy in a single-institution-based prospective study. Through careful prospective follow-up of 45 male adrenoleukodystrophy patients, we aimed to enrol patients with adolescent-/adult-onset cerebral form/cerebello-brainstem form of adrenoleukodystrophy at early stages. Indications for haematopoietic stem cell transplantation included cerebral form of adrenoleukodystrophy or cerebello-brainstem form of adrenoleukodystrophy with Loes scores up to 13, the presence of progressively enlarging white matter lesions and/or lesions with gadolinium enhancement on brain MRI. Clinical outcomes of haematopoietic stem cell transplantation were evaluated by the survival rate as well as by serial evaluation of clinical rating scale scores and neurological and MRI findings. Clinical courses of eight patients who did not undergo haematopoietic stem cell transplantation were also evaluated for comparison of the survival rate. All the patients who underwent haematopoietic stem cell transplantation survived to date with a median follow-up period of 28.6 months (4.2-125.3 months) without fatality. Neurological findings attributable to cerebral/cerebellar/brainstem lesions became stable or partially improved in all the patients. Gadolinium-enhanced brain lesions disappeared or became obscure within 3.5 months and the white matter lesions of MRI became stable or small. The median Loes scores before haematopoietic stem cell transplantation and at the last follow-up visit were 6.0 and 5.25, respectively. Of the eight patients who did not undergo haematopoietic stem cell transplantation, six patients died 69.1 months (median period; range 16.0-104.1 months) after the onset of the cerebral/cerebellar/brainstem lesions, confirming that the survival probability was significantly higher in patients with haematopoietic stem cell transplantation compared with that in patients without haematopoietic stem cell transplantation (P = 0.0089). The present study showed that haematopoietic stem cell transplantation was conducted safely and arrested the inflammatory demyelination in all the patients with adolescent-/adult-onset cerebral form/cerebello-brainstem form of adrenoleukodystrophy when haematopoietic stem cell transplantation was conducted in the early stages. Further studies are warranted to optimize the procedures of haematopoietic stem cell transplantation for adolescent-/adult-onset cerebral form/cerebello-brainstem form of adrenoleukodystrophy.

Postural tremor in X-linked spinal and bulbar muscular atrophy.

Postural tremor is a common initial symptom in spinal and bulbar muscular atrophy (SBMA), but its pathophysiological mechanisms remain to be studied. This study was undertaken to examine the physiological mechanisms underlying postural tremor in SBMA. For eight patients (36-63 years old) with genetically confirmed SBMA, we recorded surface electromyograms (EMGs) from the forearm muscles and hand movements with an accelerometer (ACC) while maintaining a posture with and without a weight load. We then analyzed their power spectra and coherence. The peak tremor frequency was 6-9 Hz in seven patients and 2-3 Hz in one patient. Oscillatory movements were associated with EMG activity in five patients, but not in three patients. Weight loads and postural changes affected the tremor frequency in all patients. Tremor was classified as "reflex tremor" in five patients and "mechanical tremor" in three patients. These results suggest that peripheral factors play important roles in tremor genesis in SBMA, although its clinical features resemble essential tremor. Subclinical sensory disturbance or a decrease of motor unit numbers might be candidates for such peripheral factors contributing to tremor genesis in SBMA.

A Homozygous LAMA2 Mutation of c.818G>A Caused Partial Merosin Deficiency in a Japanese Patient.

A complete loss of merosin, which is encoded by LAMA2, causes congenital muscular dystrophy with leukoencephalopathy. Partial merosin deficiency can be caused not only by primarily LAMA2 mutations, but also secondarily by dystroglycanopathy. Although it can be molecularly diagnosed based on a genetic analysis, this method is labor-intensive because of its huge genome size. A 26-year-old male patient presented with mild muscular weakness, joint contractures, and epilepsy. Double immunofluorescence staining of a muscle biopsy specimen showed mislocalization of merosin, and a genetic analysis revealed a homozygous c.818G>A (p.Arg273Lys) mutation in LAMA2. Double immunofluorescence staining and whole exome sequencing were useful for the diagnosis of partial merosin deficiency.

Primary face motor area as the motor representation of articulation.

No clinical data have yet been presented to show that a lesion localized to the primary motor area (M1) can cause severe transient impairment of articulation, although a motor representation for articulation has been suggested to exist within M1. Here we describe three cases of patients who developed severe dysarthria, temporarily mimicking speech arrest or aphemia, due to a localized brain lesion near the left face representation of the human primary motor cortex (face-M1). Speech was slow, effortful, lacking normal prosody, and more affected than expected from the degree of facial or tongue palsy. There was a mild deficit in tongue movements in the sagittal plane that impaired palatolingual contact and rapid tongue movements. The speech disturbance was limited to verbal output, without aphasia or orofacial apraxia. Overlay of magnetic resonance images revealed a localized cortical region near face-M1, which displayed high intensity on diffusion weighted images, while the main portion of the corticobulbar fibers arising from the lower third of the motor cortex was preserved. The cases suggest the existence of a localized brain region specialized for articulation near face-M1. Cortico-cortical fibers connecting face-M1 with the lower premotor areas including Broca's area may also be important for articulatory control.

[An autopsied case of a woman with rheumatoid arthritis attacked by multiple cerebral emboli].

A 45-year-old woman, who had had rheumatoid arthritis for 12 years, had three attacks of cerebral embolism over two months and died after the final attack. Intensive clinical laboratory investigations did not disclose any specific origins of emboli, but an autopsy revealed a nodule at the base of the aortic valve which was pathologically proved to be a rheumatoid nodule. The thrombi were present from the distal part of left internal carotid artery up to the proximal part of the left middle cerebral artery. They were rich in fiber, but poorly organized endothelial cell, raising the possibility that they originated from other parts and have recently reached there. On the top of the rheumatoid nodule, a thrombus was present. It was easily ablated and a small amount of fibrin stuck the nodule. Based on these results, we concluded that cerebral emboli were originally generated at the top of a rheumatoid nodule in the heart. In patients with RA, rheumatoid nodules are rarely seen in the heart. If present, they usually cause cardiac failure or atrioventricular block, and seldom result in cerebral infarction. This is the first case in which an autopsy proved rheumatoid nodule in the heart which had caused multiple cerebral emboli. We should consider the possibility of rheumatoid nodules in the heart as an origin of cerebral emboli in patients with rheumatoid arthritis.

[A case of early stage CADASIL showing only dizziness and vertigo with a novel mutation of Notch 3 gene].

We report a 39-year-old woman who presented with only dizziness and vertigo for 2 months. Neurological examination revealed no abnormalities except for hypereflexia on the left side extremities. Neurootological examination revealed no abnormalities. MRI of the brain demonstrated patchy hyperintensity areas on FLAIR images in the periventricular white matter and external capsule. Her grandmother had cerebral infarction and her father is suffering from multi-infarct dementia. Her second older sister who similarly had dizziness and vertigo demonstrated similar MRI findings characterized by patchy hyperintensity areas in the white matter and external capsule even though she had no risk factors for atherosclerosis. Her third older sister also had dizziness and vertigo and had patchy hyperintensity areas in the white matter in her brain MRI even though she had no risk factors for atherosclerosis. Based on this family history, we suspected that she had cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Mutational analysis of Notch3 gene disclosed a novel missense mutation substituting arginine for cysteine at codon 206 (C206R) in exon 4 of the Notch3 gene, confirming the diagnosis of CADASIL. Interestingly, similar dizziness and vertigo were present not only in the patient, but also in the other two sisters who had the same gene mutation as the patient. This report supports the idea that the external capsule lesion is one of the signs suggestive of CADASIL as a diagnosis.

[A case of asymmetric demyelinating neuropathy in a patient with chronic graft-versus-host disease].

A 47-year-old man, who suffered from acute lymphocytic leukemia at 45 years old and was treated with hematopoietic stem cell transplantation at 46 years old after the induction of complete remission by the standard chemotherapy, developed the symptoms of chronic graft-versus-host disease (cGVHD) such as dry eyes, dry mouth, skin thickening, skin scaling, skin pigmentation and impaired liver function. He was admitted to our hospital because of the acute development of diplopia and weakness of his left upper extremity accompanying with the exacerbation of other symptoms of cGVHD. Neurological examinations revealed the right abducens nerve palsy and asymmetric muscular weakness of the extremities; the proximal part of the left upper extremity and the distal part of the right upper extremity were markedly involved. Neurophysiological studies including magnetic motor root stimulation revealed demyelinating neuropathy specifically involving the motor nerves. On the basis of these findings, a diagnosis of peripheral neuropathy associated with cGVHD was made. Nighteen reports are available on peripheral neuropathy in cGVHD patients, but to date little is known about the pathophysiology of this condition. Most of those patients have been diagnosed as having symmetric demyelinating polyneuropathy, such as Guillain-Barré syndrome or chronic inflammatory demyelinating polyneuropathy. In this study, contrary to previous reports, the asymmetric involvement of motor nerves is noteworthy. Accumulation and further analyses of the cases like the present case are necessary to elucidate the pathogenesis of peripheral neuropathy in cGVHD.

Successful treatment of an unresectable inflammatory myofibroblastic tumor of the frontal bone using a cyclooxygenase-2 inhibitor and methotrexate.

Inflammatory myofibroblastic tumor (IMT) is a disease characterized by tumorous lesions consisting of myofibroblastic spindle cells and inflammatory cells that occur primarily in the soft tissues and viscera of children and young adults. Total excision is the most effective therapy. Steroids have been used to treat unresectable lesions with some success. We herein report a case of IMT involving the frontal bone accompanied by pachymeningitis. The tumor was characterized by an aggressive clinical course that was refractory to prednisolone. Performing total excision seemed difficult. Celecoxib and methotrexate were effective treatments. Our experience suggests the efficacy of celecoxib and methotrexate as alternatives for treating unresectable IMT.

[Anti-Ma2-associated encephalitis and paraneoplastic limbic encephalitis].

Anti-Ma2-associated encephalitis (or anti-Ma2 encephalitis) is a paraneoplastic neurological syndrome (PNS) characterized by isolated or combined limbic, diencephalic, or brainstem dysfunction. Anti-Ma2 antibodies detected in the serum or cerebrospinal fluid of patients are highly specific for this disease entity and belong to a group of well-characterized onconeuronal antibodies (or classical antibodies). The corresponding antigen, Ma2 is selectively expressed intracellularly in neurons and tumors as is the case with other onconeuronal antigens targeted by classical antibodies. However, in most cases the clinical pictures are different from those of classical PNS and this creates a potential risk of underdiagnosis. Although limbic dysfunction is the most common manifestation in patients with anti-Ma2 encephalitis which is one of the major causes of paraneoplastic limbic encephalitis (LE), it has been reported that less than 30% of the patients with anti-Ma2 LE exhibit clinical presentations typical of the classical description of LE. Of the remaining, many exhibit excessive daytime sleepiness, vertical ophthalmoparesis, or both associated with LE, because of frequent involvement of the diencephalon and/or upper brainstem. Anti-Ma2 LE can also be manifested as a pure psychiatric disturbance such as obsessive-compulsive disorder in a few cases. Some patients develop mesodiencephalic encephalitis with minor involvement of the limbic system, and some may manifest severe hypokinesis. About 40% of the patients with anti-Ma2 antibodies also have antibodies against different epitopes on Ma1, a homologue of Ma2. These patients may have predominant cerebellar and/or brainstem dysfunctions due to more extensive involvement of subtentorial structures. Anti-Ma2 encephalitis is outstanding among other PNS associated with classical antibodies in that the response rate to treatment is relatively high. While it can cause severe neurological deficits or death in a substantial proportion of the patients, approximately one-third show neurological improvement and another 20 - 40% stabilize in response to treatment, including immunotherapy and/or tumor treatment. Patients who have limited CNS involvement and testicular tumors with complete response to therapy are more likely to show neurological improvement. This fact emphasizes the importance of early diagnosis and prompt initiation of therapy. However, it should be noted that even carcinoma in situ, which is difficult to detect can cause severe neurological disorders. In this respect, it is useful to highlight that anti-Ma2 encephalitis is almost always associated with testicular germ cell tumors in men younger than 50 years. We experienced a 40-year-old patient with severe hypokinesis caused by anti-Ma2 encephalitis associated with bilateral intratubular germ-cell neoplasm of the testes. In older men and women, non-small-cell lung cancer is most common but various types of cancers are reported to be associated. In this study,in addition to reviewing the above case we have reviewed the significance of anti-Ma2 antibodies in the diagnosis of anti-Ma2 encephalitis and the clinical features of this disease.