Seen by a Glance, But Not by a Stare-A Case Study of a Patient With Simultanagnosia.

OBJECTIVE: Simultanagnosia is a rare neuropsychological symptom characterized by difficulty recognizing global structures while preserving perception of local detail. The condition is classified into ventral and dorsal types. Clinical presentation of ventral simultanagnosia includes a reduced ability to recognize multiple visual stimuli rapidly, that is, part-by-part recognition. Here, we report a case of ventral simultanagnosia with a unique presentation; when short-duration visual stimuli were presented, the patient could perform global recognition by improving his part-by-part approach. To investigate the relationship between local and global perception bias and the duration of the present stimulus, we conducted a visual perception test using hierarchically organized Navon figures. METHODS/RESULTS: The patient was a 62-year-old right-handed man who suffered from cerebral infarction in the right occipitotemporal lobe. He had no language dysfunction but exhibited left unilateral neglect, prosopagnosia, and ventral-type simultanagnosia. We conducted a visual perception test using the Navon figures and control figures as a visual stimulus. We randomly presented the figures for intervals of 0.2 or 20 s and let the patient report all the letters (global and/or local element) that he recognized. Global elements of the Navon letter were recognized a rate of 0% and 78.3% at intervals of 20 and 0.2 s, respectively, indicating that shorter presentation made the part-by-part approach less likely to manifest. CONCLUSIONS: We assumed that the simultanagnosia in this case was caused by failure to maintain the initially perceived global information for a long period of time during visual presentation, due to right occipitotemporal damage.

A variant at 9q34.11 is associated with HLA-DQB1*06:02 negative essential hypersomnia.

Essential hypersomnia (EHS) is a lifelong disorder characterized by excessive daytime sleepiness without cataplexy. EHS is associated with human leukocyte antigen (HLA)-DQB1*06:02, similar to narcolepsy with cataplexy (narcolepsy). Previous studies suggest that DQB1*06:02-positive and -negative EHS are different in terms of their clinical features and follow different pathological pathways. DQB1*06:02-positive EHS and narcolepsy share the same susceptibility genes. In the present study, we report a genome-wide association study with replication for DQB1*06:02-negative EHS (408 patients and 2247 healthy controls, all Japanese). One single-nucleotide polymorphism, rs10988217, which is located 15-kb upstream of carnitine O-acetyltransferase (CRAT), was significantly associated with DQB1*06:02-negative EHS (P = 7.5 × 10-9, odds ratio = 2.63). The risk allele of the disease-associated SNP was correlated with higher expression levels of CRAT in various tissues and cell types, including brain tissue. In addition, the risk allele was associated with levels of succinylcarnitine (P = 1.4 × 10-18) in human blood. The leading SNP in this region was the same in associations with both DQB1*06:02-negative EHS and succinylcarnitine levels. The results suggest that DQB1*06:02-negative EHS may be associated with an underlying dysfunction in energy metabolic pathways.

Bone radiofrequency ablation combined with prophylactic internal fixation for metastatic bone tumor of the femur from hepatocellular carcinoma.

A 64-year-old man with 6-year history of hepatocellular carcinoma (HCC) was referred to us regarding bone metastasis to the right proximal femur. Although he underwent radiotherapy for pain palliation and local tumor control, the pain persisted and the tumor relapsed 3 months after the radiotherapy and he was thought to be at high risk of pathologic fracture. Given hypervascularity and large tumor size, a prophylactic internal fixation combined with adjuvant radiofrequency ablation (RFA) was proposed to reduce blood loss and prevent viable tumor cells being disseminated. His postoperative course was uneventful without requiring blood transfusion and preoperative symptoms immediately disappeared after surgery. He became capable of weight-bearing walk with a single cane and was almost asymptomatic without local progression on the plain radiographs when he died 14 months after surgery. Combination therapy of RFA and internal fixation using intramedullary nailing for metastases of the long bones from HCC seems to be a very promising technique both for sufficient pain relief and for local control of the tumor. Adjuvant RFA may become a potential option for patients with metastases of the long bones for the purpose of prevention of tumor dissemination and reduction of intraoperative blood loss.