Autoantibodies against NCAM1 from patients with schizophrenia cause schizophrenia-related behavior and changes in synapses in mice.

From genetic and etiological studies, autoimmune mechanisms underlying schizophrenia are suspected; however, the details remain unclear. In this study, we describe autoantibodies against neural cell adhesion molecule (NCAM1) in patients with schizophrenia (5.4%, cell-based assay; 6.7%, ELISA) in a Japanese cohort (n = 223). Anti-NCAM1 autoantibody disrupts both NCAM1-NCAM1 and NCAM1-glial cell line-derived neurotrophic factor (GDNF) interactions. Furthermore, the anti-NCAM1 antibody purified from patients with schizophrenia interrupts NCAM1-Fyn interaction and inhibits phosphorylation of FAK, MEK1, and ERK1 when introduced into the cerebrospinal fluid of mice and also reduces the number of spines and synapses in frontal cortex. In addition, it induces schizophrenia-related behavior in mice, including deficient pre-pulse inhibition and cognitive impairment. In conclusion, anti-NCAM1 autoantibodies in patients with schizophrenia cause schizophrenia-related behavior and changes in synapses in mice. These antibodies may be a potential therapeutic target and serve as a biomarker to distinguish a small but treatable subgroup in heterogeneous patients with schizophrenia.

Otitis Media With Effusion Caused by a Parapharyngeal Tumor Showing Normal Nasopharyngeal Findings.

The objective of this study is to evaluate otitis media with effusion (OME) among patients with parapharyngeal tumor. We have experienced 82 parapharyngeal tumor cases and encountered 14 patients complaining of hearing loss due to OME as the initial symptom. These patients showed normal nasopharyngeal findings and the presence of tumor had been detected long time after the beginning of their hearing symptoms (4 months to 13 years: median 2.5 years). Six patients had undergone ventilation tube insertion on the affected ear, which may lead to delay in diagnosis. Pathological examination was performed in 76 of 82 patients. Among these 76 patients, 13 showed OME. Seven patients had malignant lesions, whereas 6 had benign lesions. Therefore, malignant lesions are prone to occur with OME and its relative risk was 2.26 (95% confidence intervals, 1.16-4.42). This difference was statistically significant (P = .044, Fisher test). Otitis media with effusion is a very common disease and is well-known as a primary symptom of nasopharyngeal carcinoma. Therefore, nasopharyngeal observation is necessary for patients with intractable middle ear effusion. However, present 14 patients with OME showed normal nasopharyngeal findings and finally found after an imaging study. From our data, OME is an important but go-by symptom of parapharyngeal tumors. Imaging studies are potently useful for such patients with intractable OME.

Burden of vertigo at home: Risks for patients with vertigo.

OBJECTIVE: We aimed to clarify the burden of vertigo in patients' homes. METHODS: This was a questionnaire survey among patients with vestibular vertigo. Four main questions were prepared. Q1: Where did you first notice vertigo? Q2: Where have you had the most difficulty with vertigo in your home? Q3: Where do you have difficulty at present? Q4: What household equipment have you used as a countermeasure to prevent further problems with vertigo? RESULTS: Sixty patients completed the questionnaire. Benign paroxysmal positional vertigo (BPPV) was most common among respondents, followed by Ménière's disease. Q1: Most patients with BPPV first noticed vertigo in the bedroom; patients with other diseases first noticed vertigo in the living room. Q2: Both groups previously had the most difficulty with vertigo in the same locations as in Q1; these differences were significant between Q1 and Q2. Q3: Both groups had the most difficulty on stairs. Q4: Handrails were the most often used equipment for vertigo in both groups. There was no significant difference between Q3 and Q4. CONCLUSION: Our data revealed that the locations of risks differ among patients with vestibular disorders. Handrails were considered the most important equipment to prevent problems with vertigo.

Right dominance in the incidence of external auditory canal squamous cell carcinoma in the Japanese population: Does handedness affect carcinogenesis?

OBJECTIVES/HYPOTHESIS: To investigate the relationship between handedness and the incidence of squamous cell carcinoma in the external auditory canal (EACSCC). MATERIALS AND METHODS: Sixty-eight cases of EACSCC were enrolled in this study, and their affected side was checked. Handedness and ear-picking habits were also investigated in 34 EACSCC cases. Handedness was judged based on self-categorization, and the relationship between handedness and the affected side was investigated. RESULTS: Fifty-two cases occurred on the right side, and 16 cases occurred on the left side of patients with EACSCC. The incidence of laterality in EACSCC showed a statistically significant right dominance. Concerning handedness, 29 cases were right-handed, 4 cases were left-handed, and 1 case was ambidextrous. Twenty-seven out of the 29 right-handed cases and 1 ambidextrous case suffered from carcinoma on the right side, whereas 3 left-handed cases suffered from carcinoma on the left side. That is, most of the cases suffered from EACSCC on the same side as their handedness, and this tendency showed a statistically significant difference. Most of the patients with EACSCC experienced itching and habitual ear-picking in the affected side. CONCLUSION: Mechanical stimulations to the EAC, such as ear picking, may plausibly cause EACSCC. In Japan, ear picking, also called "mimikaki," is a popular habit and an established unique culture. Because ear picking requires delicate handling and manipulation, this tends to occur on the same side as the handedness in the Japanese population. This is the first report about the relationship between handedness and carcinogenesis. LEVEL OF EVIDENCE: N/A.

Imaging of neural conduction block by neuromagnetic recording.

OBJECTIVE: For the clinical application of neuromagnetic recordings in neural conduction block, the patterns of magnetic fields in the region should be clarified. Using an experimental in vitro model, the spatiotemporal course of the neuromagnetic fields at the site of complete conduction block was examined. Additionally, the magnetic compound action fields (CAFs) and electric compound action potentials (CAPs) were compared and correlated. METHODS: In a chamber containing Ringer's solution, 10 isolated sciatic nerves of rabbits were electrically stimulated. Both evoked CAPs and CAFs were measured before and after the ligation of the nerve. The sequential positions of the current dipoles and the location of the conduction block were estimated by the least-squares search. RESULTS: The magnetic contour maps of the CAFs showed a characteristic quadrupolar pattern propagating along the nerve. The peak of the leading magnetic field ceased and disappeared at the position of the nerve ligation, while the trailing magnetic field became attenuated before reaching that position. The positions of the conduction blocks were localized by magnetic recordings within a difference of 2mm. CONCLUSIONS: The neuromagnetic recordings could visualize the change of the magnetic fields at the site of the complete conduction block and closely localize that position. SIGNIFICANCE: The neural conduction block was visualized and localized by neuromagnetic recordings.

Dehiscence of the bony roof of the superior semicircular canal in the middle cranial fossa.

Spontaneous dehiscence of the superior semicircular canal (SSC) in the middle cranial fossa is rare and may cause clinical problems. This dehiscence was investigated in cadaveric and dried temporal bone specimens. One cadaveric specimen showed a spontaneous defect: the dehiscence was a symmetrical, elongated ellipse with smooth margins. Four of 244 dry bone specimens showed bony defects in the roof of the SSC, however, only one specimen was thought to have a spontaneous defect. Based on computer-simulation models, we hypothesized that spontaneous defects of the SSC may arise during the fetal period. Although rare, this defect may cause problems in middle cranial fossa surgery and may relate to certain vertiginous disorders.

Transcallosal conduction time measured by visual hemifield stimulation with face images.

Transcallosal conduction time (TCT) in human visual system was estimated from the hemispheric difference of the peak latencies of face-evoked magnetic field (N170m) by left/right hemifield stimulation using 14 8 channel whole-head magnetometers. The estimated TCTwas 18.0 + 6.2 ms (mean +/- s.d.). Although N 170m amplitude was larger in the right hemisphere of seven of nine subjects, no hemispheric asymmetry was observed in the TCT estimate. Transcallosal visual information was likely to be transferred in the higher order (non-retinotopic) visual cortices. Hemifield stimulation with face images is a useful non-invasive method to estimate the TCT in human visual system.