Behçet disease, and its related disorder Sweet disease, are multisystem inflammatory conditions characterized by muco-cutaneous symptoms. When neuropsychiatric symptoms appear, the two conditions are referred to as neuro-Behçet disease and neuro-Sweet disease. While diagnosing these conditions according to their diagnostic criteria, muco-cutaneous symptoms must be observed; however, neuropsychiatric symptoms may precede muco-cutaneous symptoms. In these conditions the dysregulation of cytokines, following the onset of oral muco-cutaneous bacterial infection, may induce an abnormal chemotaxis of neutrophils causing ectopic encephalitis and meningitis. Thus, an initial treatment targeting neutrophils should be considered based on the diagnosis of neuro-neutrophilic disease when symptoms indicating neutrophil hyperactivity are observed, even without muco-cutaneous symptoms. In addition to human leukocyte antigen-B51 and -A26, genome-wide association analyses have identified new susceptibility loci on the genes of various immunological factors in Behçet disease. These findings may help elucidate disease pathogenesis and assist the development of diagnostic modalities and therapeutic agents for neuro-neutrophilic disease.

Autism spectrum disorder (ASD) is characterized by deficits in social interaction and social communication, along with restricted and repetitive sensory-motor behaviors. The diagnosis of ASD includes various phenotypes outlined in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM)-5. The comprehensive evaluation of each individual case with ASD is needed because many of them have comorbidity with number of neuropsychiatric disorders or somatic conditions. The growing number of genetic studies detected multiple rare variants with relatively large effect sizes. The results have revealed their common potential pathology including abnormal chromatin regulation, which induces epigenetic changes. More researches are expected to elucidate the pathogenesis of ASD and to develop therapeutic approaches.

A 69-year-old man was admitted with neck muscle weakness, symmetric proximal muscle weakness, skin rash and elevated serum creatine kinase levels. Muscle biopsy showed perifascicular necrosis and perimysial alkaline phosphatase activity. Chest CT revealed interstitial lung disease and colorectal cancer was diagnosed on colonoscopy. He was serologically positive for anti-EJ antibody, leading to the diagnosis of antisynthetase syndrome (ASS). After laparoscopic low anterior resection of the rectum, he received intravenous methylprednisolone (1,000 mg/d for 3 days) followed by oral prednisolone (50 mg/d). Although his muscle weakness improved after corticosteroid therapy, he developed pericardial effusion with resultant asymptomatic hypotension and arrhythmia possibly due to pericarditis. Corticosteroid monotherapy was insufficient to control the disease, and, we decided to use oral cyclosporin concurrently. After this combined therapy started, pericardial effusion and arrhythmia were improved. We should keep in mind that pericarditis can occur in patients with anti-EJ antibody-positive ASS, and early combined therapy with corticosteroid and immunosuppressive drugs for ASS may improve the patient’s prognosis.

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a rare form of multisystem ataxia defined by a triad of cerebellar impairment, bilateral vestibular hypofunction, and somatosensory deficit. Here we present a patient with CANVAS. A 76-year-old woman whose parents were cousins had noted slowly worsening gait imbalance since age 67. Peripheral sensory impairment was evident since age 73. When examined at 74, she had a frequent cough. The neurologic examinations showed scanning speech, downbeat nystagmus, pursuit eye movements with saccadic features, truncal ataxia, and mild dysmetria of the extremities. The Romberg test was positive. Light touch, pinprick, and vibration sensation were absent in the distal lower limbs, where allodynia could be demonstrated. Ankle jerk reflex was diminished. Muscle strength was normal. Nerve conduction studies disclosed absence of sensory nerve action potentials in all limbs, while motor conduction was normal except for decreased amplitude of left median and bilateral ulnar nerve compound motor action potentials. MRI of the brain demonstrated cerebellar atrophy. The eye tracking test for the smooth pursuit and visually enhanced vestibulo-ocular reflex test demonstrated functional impairments. Both the bithermal caloric test and the video head impulse testing showed sever hypofunction of the bilateral semicircular canal. In sum, somatosensory deficit and otoneurologic examinations indicated bilateral vestibulopathy which, together with the patient^’s and cerebellar impairment, confirmed the diagnosis of CANVAS.

A 48-year-old man with rapid onset of fever elevation developed acute myelitis over a period of a week. MRI of the spinal cord revealed a longitudinal T₂-hyperintense intraspinal lesion extending from C6 to Th8 level. Clinical symptoms and findings resolved with immunotherapy. In serological analysis, no antibodies related to various collagen diseases, anti-aquaporin-4 (AQP4) antibody and anti-myelin oligodendrocyte glycoprotein (MOG) antibody were detected. Anti-lactosylceramide (LacCer) antibodies were detected in the acute phase of serum and cerebrospinal fluid, with titers showing decrements in the recovery phase. The present case supports the notion that acute myelitis can occur as an anti-neutral glycolipid antibody-related disorder. Anti-neutral glycolipid antibodies should be examined in future pertinent cases of myelitis.