Prevalence of Fragile X-Associated Tremor/Ataxia Syndrome in Patients with Cerebellar Ataxia in Japan.

The presence of fragile X mental retardation 1 (FMR1) premutation has been linked to patients with a certain type of cerebellar ataxia, the fragile X-associated tremor/ataxia syndrome (FXTAS). However, its prevalence in Japan has yet to be clarified. The aim of the present study is to determine the prevalence of FXTAS in Japanese patients with cerebellar ataxia and to describe their clinical characteristics. DNA samples were collected from 1328 Japanese patients with cerebellar ataxia, referred for genetic diagnosis. Among them, 995 patients with negative results for the most common spinocerebellar ataxia subtypes were screened for FMR1 premutation. Comprehensive clinical and radiological analyses were performed for the patients harbouring FMR1 premutation. We herein identified FMR1 premutation from one female and two male patients, who satisfied both clinical and radiological criteria of FXTAS (0.3%; 3/995) as well. Both male patients presented with high signal intensity of corticomedullary junction on diffusion-weighted magnetic resonance imaging, a finding comparable to that of neuronal intranuclear inclusion disease. The female patient mimicked multiple system atrophy in the early stages of her disease and developed aseptic meningitis with a suspected immune-mediated mechanism after the onset of FXTAS, which made her unique. Despite the lower prevalence rate in Japan than the previous reports in other countries, the present study emphasises the necessity to consider FXTAS with undiagnosed ataxia, regardless of men or women, particularly for those cases presenting with similar clinical and radiological findings with multiple system atrophy or neuronal intranuclear inclusion disease.

Effect of hypothermia on motor function of adult rats after neonatal hyperthermic hypoxic-ischemic brain insult.

Regarding therapeutic hypothermia for human neonatal hyperthermic hypoxic-ischemic encephalopathy (HIE), we investigated the motor function of a neonatal hyperthermic HIE rat model, and also performed systemic hypothermia using the model. Forty-two neonatal Wistar rats at 7-days-old were used in this study. The left common carotid artery of 34 neonatal rats was ligated under isoflurane anesthesia. We also established a sham group (S group, n = 8). After 1-h recovery, all rats were exposed to 8% oxygen at an ambient temperature (T (a)) of 40 degrees C for 15 min. Following insult, 16 rats were placed in a chamber at a T (a) of 30 degrees C (H group) and the other 18 rats at a T (a) of 37 degrees C after arterial ligation (N group), and all rats in the S group were placed in a chamber at a T (a) of 37 degrees C for 12 h. A Rota-Rod test was performed involving all rats at 8 weeks old. The rod was rotated at 5, 5, and 7 rpm on three consecutive days, respectively. Rats in the N group stayed on the rotating rod for a significantly shorter period than those in S and H groups only on the second day of measurement. The width of the insulted hemisphere in N group rats was significantly smaller than those in S and H groups. There was no significant correlation between S and H groups regarding the motor function and anatomy. These results suggest that neonatal hyperthermic hypoxic-ischemic insult impairs the motor function, which may be rescued by systemic hypothermia after insult.