Inhibitory dysfunction may cause prospective memory impairment in temporal lobe epilepsy (TLE) patients: an event-related potential study.

Introduction: Prospective memory (PM) is the ability to remember future intentions, and PM function is closely related to independence in daily life, particularly in patients with temporal lobe epilepsy (TLE). As PM involves various cognitive components of attention, working memory, inhibition and other executive functions, this study investigated how TLE may affect PM components and the underlying neural mechanisms. Methods: Sixty-four subjects were recruited, including 20 refractory TLE patients, 18 well-controlled TLE patients and 26 age-matched healthy controls. A set of neuropsychological tests was administered to assess specific brain functions. An event-related potential (ERP) task was used to further explore how PM and its components would be differentially affected in the two TLE types. Results: Our findings revealed that: (1) refractory TLE patients scored lower than the healthy controls in the digit span, Verbal Fluency Test and Symbol Digit Modalities Test; (2) refractory TLE patients exhibited impaired PM performance and reduced prospective positivity amplitudes over the frontal, central and parietal regions in ERP experiments when compared to the healthy controls; and (3) decreased P3 amplitudes in the nogo trials were observed over the frontal-central sites in refractory but not in well-controlled TLE patients. Discussion: To our knowledge, this is the first ERP study on PM that has specifically identified PM impairment in refractory but not in well-controlled TLE patients. Our finding of double dissociation in PM components suggests that inhibition dysfunction may be the main reason for PM deficit in refractory TLE patients. The present results have clinical implications for neuropsychological rehabilitation in TLE patients.

Single-nucleotide polymorphism of transient axonal glycoprotein-1 and its correlation with clinical features and prognosis in chronic inflammatory demyelinating polyneuropathy.

The single-nucleotide polymorphism (SNP) rs2275697 in the transient axonal glycoprotein-1 (TAG-1) gene was reported to be associated with responsiveness to intravenous immunoglobulin (IVIG) treatment in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). However, it is not known if this SNP is associated with long-term prognosis. We examined the case records of 32 Chinese CIDP patients. The overall response rate to IVIG, prednisolone, or plasmapheresis was 83%. After 5.4 years, 57% of patients were on maintenance immunotherapy. Patients with higher modified Rankin score and more prolonged distal motor latencies in the upper limbs on presentation had a higher risk (odds ratio [OR] 3.86, 95% confidence interval [CI] 1.23-12.11 and OR 1.04, 95% CI 1.01-1.07, respectively) of being on maintenance immunotherapy. Blood samples from 24 patients and 147 controls were examined for their genotypes of four non-synonymous SNPs (rs41264871, rs36074532, rs5611135, and rs2275697) in the coding region of TAG-1. The G allelic frequency of rs2275697 was similar between CIDP patients and controls (56% and 50%, respectively) and was not associated with treatment responsiveness, treatment dependence, disability, or mortality.

Ischemic stroke related to intracranial branch atheromatous disease and comparison with large and small artery diseases.

BACKGROUND: The mechanism of ischemic stroke in intracranial branch atheromatous disease (BAD) is different from large artery atherothrombotic disease (LAD) or lacunar infarction (LACI). The concept of BAD is underused in clinical practice and research. METHODS: Patients admitted over 24-months with ischemic stroke caused by atherosclerotic disease were reviewed retrospectively and classified according to radiological±clinical criteria into LAD, BAD and LACI. The BAD cases were further divided into 5 BAD syndromes. Clinical characteristics, vascular risk factors, results of vascular workup and outcome among these subgroups were compared. RESULTS: 123 cases of LAD (17% of all stroke patients or 33% of all studied patients), 147 BAD (20% or 40%) and 102 LACI (14% or 27%) presented during the study period. Compared to LAD, BAD patients had milder neurological deficits, were less often diabetic and carotid stenosis was less common, while stenosis of the intracranial arteries was more frequent in BAD as compared with LACI patients. Outcome in BAD patients was intermediate between LAD and LACI. Comparisons among the BAD syndromes indicated they were homogenous conditions. CONCLUSIONS: BAD is the most prevalent ischemic stroke subtype in our cohort. The homogeneity among the BAD syndromes suggests they might represent a distinctive stroke entity.

-459C>T point mutation in 5' non-coding region of human GJB1 gene is linked to X-linked Charcot-Marie-Tooth neuropathy.

Charcot-Marie-Tooth (CMT) neuropathy is inherited with genetic and clinical heterogeneity. The X-linked form (CMTX) is linked to mutations in the GJB1 gene. However, the genotype-phenotype correlation between variants in the non-coding region of GJB1 gene and CMTX is unclear. We found two structural variants (-459C>T and -713G>A) in the 5' non-coding region of a transcript (Ref seq ID: NM_000166) of the GJB1 gene and explored its association with CMTX in two Chinese families. All family members who carried the -459C>T variant either were symptomatic or had abnormal electrophysiological studies compatible with CMTX, whereas all the non-symptomatic family members who had normal electrophysiological studies and 10 healthy unrelated controls did not have this variant. The other variant in the 5'-flanking region of the gene was found to be a benign polymorphism, although it had been earlier reported to be associated with CMTX in a Taiwanese family. Secondary structure prediction analysis of mutant mRNA using M fold and RNA structure softwares indicates that the -459C>T mutation may reduce translation efficiency of the GJB1 gene by changing its 5'-untranslated region secondary structure and abolishing the internal ribosome entry site at the initialization of its translation in Schwann cells. Our study can help clarify the causal mutations of CMTX in the non-protein coding region of GJB1.

Abnormal diffusion tensor in nonsymptomatic familial amyotrophic lateral sclerosis with a causative superoxide dismutase 1 mutation.

PURPOSE: To determine whether diffusion abnormalities can be observed in nonsymptomatic family members with a known causative Cu/Zn superoxide dismutase mutation (asymptomatic familial amyotrophic lateral sclerosis; AFALS(+SOD1)) in a family with autosomal dominant familial amyotrophic lateral sclerosis (ALS) using diffusion tensor imaging (DTI). MATERIALS AND METHODS: A total of eight AFALS(+SOD1) subjects (aged 17-43 years) were age-matched with 13 healthy controls (aged 19-45 years) without SOD1 mutations. DTI was carried out on a 1.5T scanner. The diffusion index maps derived were then normalized spatially for voxel-based analysis. region of interest (ROI)-based analysis was also carried out. RESULTS: Our voxel-based and ROI-based analysis showed that AFALS(+SOD1) subjects have decreased fractional anisotropy (FA) (0.5401 vs. 0.5168, P < 0.05) and increased tensor trace (TT) (2.5854 x 10(-3) mm(2)/second vs. 2.6226 x 10(-3) mm(2)/second, P < 0.04) at the posterior limb of the internal capsule compared to the control subjects. Increased radial diffusivity (E((2,3)/2)) was detected on both sides (right = 0.5710 x 10(-3) mm(2)/second vs. 0.5943 x 10(-3) mm(2)/second, P < 0.05; left = 0.5666 x 10(-3) mm(2)/second vs. 0.5872 x 10(-3) mm(2)/second, P < 0.05). No significant change in axial diffusivity (E(1)) was detected. CONCLUSION: Abnormal diffusivity was found at the posterior limb of the internal capsule in AFALS(+SOD1) subjects, hitherto unreported. Our results suggest that DTI may detect diffusion abnormalities in AFALS(+SOD1) subjects before symptoms develop.

Mah-jong-induced seizures: case reports and review of twenty-three patients.

'Mah-jong epilepsy' is a rare reflex epilepsy syndrome, manifesting as recurrent epileptic seizures triggered by either playing or just watching mah-jong. We present three patients with this condition and review all the reported cases. Mah-jong-induced seizures can be considered a subtype of cognition-induced epilepsy. Nonetheless, these patients have distinctive clinical and electrophysiological features: late age of onset, different seizure patterns, single seizure-trigger, lack of spontaneous seizures, and electroencephalographic findings not supportive of idiopathic generalised epilepsy. The pathophysiological mechanism underlying mah-jong-induced seizures may be different from the other cognition-associated reflex epileptic phenomena.

Clinical phenotypes of a large Chinese multigenerational kindred with autosomal dominant familial ALS due to Ile149Thr SOD1 gene mutation.

About 10% of amyotrophic lateral sclerosis (ALS) cases are familial. We identified a five-generation Chinese family with autosomal dominant familial ALS (FALS). We performed a detailed family study, clinical and electromyographic validation, and SOD1, VEGF and CNTF mutation analyses. Forty-five living members (16 affected) were studied and DNA samples collected. Genealogical data were collected for deceased members. Based on the duration between symptom onset to ventilator dependence, they were divided into rapidly progressive (range 1-18 months, mean (SD) duration = 12.08 (+/-6.10) months, mean (SD) age of symptom onset = 39.75 (+/-9.84) years) and slowly progressive groups (>18 months; mean (SD) age of onset = 37.25 (+/-5.32) years old). We identified a heterozygous mutation of ATT to ACT of SOD1 gene at codon 149 in exon 5 resulting in substitution of isoleucine to threonine. It co-segregated with all affected members and 11 non-symptomatic members. We report a large multigenerational Chinese FALS kindred with I149T mutation in SOD1. No polymorphisms or mutations were found to date in two known modifier genes, namely, VEGF and CNTF, which were associated with heterogeneity in the phenotype within this kindred. Follow-up of the family will be helpful to explore any potential disease markers.