Neutrophil-to-lymphocyte ratio is an independent predictor for neurological disability in patients with idiopathic transverse myelitis.

INTRODUCTION: The neutrophil-to-lymphocyte ratio (NLR) has been found to be useful in the prognostication of immune-mediated neurological disorders because it roughly reflects the systemic innate immune response compared to the adaptive immune response. However, studies on the validity of NLR in demyelinating disorders of the central nervous system have shown conflicting results. Therefore, we aimed to investigate NLR in the idiopathic transverse myelitis (ITM) cohort. METHODS: We retrospectively analyzed the cohort data of patients with ITM between January 2006 and February 2020. The medical data of all patients with myelitis were reviewed to exclude patients with disease-associated myelopathy according to predefined exclusion criteria. The relationship between the natural log-transformed NLR (lnNLR) and the clinical, paraclinical, and imaging data was evaluated. Factors associated with neurological disability were analyzed using a linear mixed-effects model. Predictive factors for moderate-to-severe neurological disability (Expanded Disability Status Scale [EDSS] score ≥ 4) were investigated. RESULTS: A total of 124 participants were included in the analysis. The lnNLR correlated with EDSS and lesion length. Linear mixed-effects analysis showed that age, lesion length, and lnNLR were independently associated with neurological disabilities. Multivariable logistic regression revealed that lnNLR (odds ratio [OR] = 4.266, 95% confidence interval [CI] = 1.220-14.912, p = 0.023) and lesion length (OR = 1.848, 95% CI = 1.249-2.734, p = 0.002) were independent predictive factors of the worst neurological disability. CONCLUSION: NLR may be used as an independent prognostic factor for predicting poor neurological outcomes in patients with ITM.

Characteristics of Diverse Verbal Pain Descriptors in South Korean Patients With Peripheral Neuropathic Pain: 'Jeorim' (Tingling) and 'Sirim' (Cold) as Key Neuropathic Pain Descriptors.

BACKGROUND AND PURPOSE: The description of pain is the most-important indicator leading to the adequate treatment of patients with neuropathic pain (NeP). The purpose of this study was to identify and characterize the unique features of Korean verbal descriptions in patients with peripheral NeP. METHODS: This study included 400 patients (167 males and 233 females) and their 1,387 pain-description responses. Patients with peripheral NeP freely described their symptoms in Korean. Collected verbal descriptions were grouped according to terminologies with similar meanings. Participants completed validated patient-reported outcome scales including the neuropathic pain symptom inventory (NPSI) and painDETECT questionnaire (PD-Q). The frequencies of each verbal pain descriptor were compared between the NPSI and PD-Q scores. RESULTS: 'Jeorim' (tingling) was the most common among 17 types of organized verbal pain descriptors, and the 'Sirim' (cold) symptom had a significantly higher rate of use in the 2 high-severity groups when participants were classified by their total scores on the NPSI and PD-Q. CONCLUSIONS: Korean verbal NeP descriptors were significantly diverse. The Jeorim (tingling) and Sirim (cold) descriptors can be utilized in evaluations of Korean patients with NeP.

Clinical pitfalls and serological diagnostics of MuSK myasthenia gravis.

BACKGROUND: We aimed to evaluate the diagnostic accuracy of enzyme-linked immunosorbent assay (ELISA) for anti-muscle specific tyrosine kinase (MuSK) antibody (Ab) in a large cohort of anti-acetylcholine receptor (AChR) Ab-negative generalized myasthenia gravis (MG), and also to investigate clinical contexts for the diagnosis of MuSK MG. METHODS: A retrospective study of 160 patients with a clinical suspicion of AChR Ab-negative generalized MG was performed. The serum samples were tested for anti-clustered AChR Ab by cell-based assay (CBA), anti-MuSK Ab by ELISA, CBA and/or radioimmunoprecipitation assay (RIPA). Clinical data were compared between anti-MuSK Ab-positive MG and double seronegative (AChR and MuSK) MG groups. RESULTS: After excluding non-MG and clustered AChR Ab-positive patients, we identified 89 patients as a cohort of AChR Ab-negative generalized MG. Anti-MuSK Ab was positive by ELISA in 22 (24.7%) patients. While CBA identified five additional anti-MuSK Ab-positive patients, the results of ELISA were mostly consistent with CBA and RIPA with Cohen's kappa of 0.80 and 0.90, respectively (p < 0.001). The most frequent differential diagnosis was motor neuron disease particularly of bulbar onset which showed remarkably overlapping clinical and electrophysiological features with MuSK MG at presentation. CONCLUSION: While confirming the highest sensitivity of CBA for detecting anti-MuSK Ab, our results highlight the clinical pitfalls in making a diagnosis of MuSK MG and may support a diagnostic utility of MuSK-ELISA in clinical practice.

Corticosteroid-induced bradycardia in multiple sclerosis and maturity-onset diabetes of the young due to hepatocyte nuclear factor 4-alpha mutation: A case report.

BACKGROUND: Intravenous steroid pulse therapy is the treatment of choice for acute exacerbation of multiple sclerosis (MS). Although steroid administration is generally well-tolerated, cases of cardiac arrhythmia have been reported. Herein, we describe a young woman who developed marked sinus bradycardia and T-wave abnormalities after corticosteroid administration. We also present plausible explanations for the abnormalities observed in this patient. CASE SUMMARY: An 18-year-old woman experienced vertiginous dizziness and binocular diplopia 1 wk prior to admission. Neurological examination revealed left internuclear ophthalmoplegia with left peripheral-type facial palsy. The initial laboratory results were consistent with those of type 2 diabetes. Brain magnetic resonance imaging revealed multifocal, non-enhancing, symptomatic lesions and multiple enhancing lesions. She was diagnosed with MS and maturity-onset diabetes of the young. Intravenous methylprednisolone was administered. On day 5 after methylprednisolone infusion, marked bradycardia with T-wave abnormalities were observed. Genetic evaluation to elucidate the underlying conditions revealed a hepatocyte nuclear factor 4-alpha (HNF4A) gene mutation. Steroid treatment was discontinued under suspicion of corticosteroid-induced bradycardia. Her electrocardiogram changes returned to normal without complications two days after steroid discontinuation. CONCLUSION: Corticosteroid-induced bradycardia may have a significant clinical impact, especially in patients with comorbidities, such as HNF4A mutations.

Subgrouping of Peripheral Neuropathic Pain Patients According to Sensory Symptom Profile Using the Korean Version of the PainDETECT Questionnaire.

BACKGROUND: A culturally validated Korean version of the PainDETECT Questionnaire (PD-Q) was used to identify neuropathic pain components (NeP) in patients suffering from chronic pain. The purpose of this study was to determine if the Korean PD-Q can be used to subgroup patients with peripheral NeP according to sensory symptom profiles. METHODS: This study included 400 Korean patients with peripheral neuropathic pain diagnosed as probable or definite NeP. The total scores and subscores for each item in PD-Q were transformed into a Z-score for standardization. Hierarchical cluster analysis was performed to identify clusters of subjects by PD-Q scores. RESULTS: The mean total PD-Q score of the study participants was 14.57 ± 6.46. A hierarchical cluster analysis identified 5 clusters with distinct pain characteristic profiles. Cluster 1 had relatively severe burning and tingling sensations. The mean total PD-Q score for cluster 2 was the lowest of the 5 clusters. Cluster 3 tended to be vulnerable to pain in response to cold/heat stimulation. Cluster 4 showed relatively severe pain induced by physical stimuli, such as light touch or slight pressure. Cluster 5 had high scores for all NeP symptoms. CONCLUSION: This study demonstrates the ability of patients to cluster by symptoms using the Korean PD-Q. Subgrouping of peripheral neuropathic pain by sensory symptom profile may be useful in making effective drug treatment decisions.

A multicenter prospective observational study on the safety and efficacy of tacrolimus in patients with myasthenia gravis.

INTRODUCTION: Several clinical studies using tacrolimus revealed reasonable therapeutic mechanisms and efficacy in patients with myasthenia gravis (MG). However, long-period studies in a large number of patients with MG are limited; therefore, the aim of this study was to investigate the therapeutic efficacies and safety of tacrolimus in patients with MG during a 12-month follow-up period. METHODS: Tacrolimus was administered to 150 patients with MG who were recruited based on the inclusion criteria. Fifteen medical centers in Korea participated in this study. The efficacy of tacrolimus was assessed using MG composite scales (MGCS) and the prednisolone-sparing effect. And the adverse drug reactions (ADRs) of tacrolimus were monitored in each patient from the beginning of tacrolimus treatment to the end of the follow-up period. RESULTS: After starting tacrolimus, the 32 patients were affected by ADRs, and consequentially 134 patients of the enrolled patients were followed up for 12months. They showed that the mean prednisolone dosage significantly decreased (6.1±7.6mg/day), compared to that in the baseline (11.3±9.5mg/day), and MGCS significantly improved after 12months of tacrolimus treatment, compared to that at the baseline. CONCLUSIONS: Our study showed that tacrolimus would be an effective immunosuppressant as an initial therapeutic agent in patients with MG; in addition, it showed tolerable safety profiles during the 12-month follow-up evaluation.

Cigarette smoking is an independent risk factor for post-stroke delirium.

BACKGROUND: Post-stroke delirium is a common problem in the care of stroke patients, and is associated with longer hospitalization, high short-term mortality, and an increased need for long-term care. Although post-stroke delirium occurs in approximately 10 ~ 30% of patients, little is known about the risk factors for post-stroke delirium in patients who experience acute stroke. METHODS: A total of 576 consecutive patients who experienced ischemic stroke (mean age, 65.2 years; range, 23-93 years) were screened for delirium over a 2-year period in an acute stroke care unit of a tertiary referral hospital. We screened for delirium using the Confusion Assessment Method. Once delirium was suspected, we evaluated the symptoms using the Korean Version of the Delirium Rating Scale-Revised-98. Neurological deficits were assessed using the National Institutes of Health Stroke Scale at admission and discharge, and functional ability was assessed using the Barthel Index and modified Rankin Scale at discharge and 3 months after discharge. RESULTS: Thirty-eight (6.7%) patients with stroke developed delirium during admission to the acute stroke care unit. Patients with delirium were significantly older (70.6 vs. 64.9 years of age, P = .001) and smoked cigarettes more frequently (40% vs. 24%, P = .033) than patients without delirium. In terms of clinical features, the delirium group experienced a significantly higher rate of major hemispheric stroke (55% vs. 26%, P < .001), exhibited poorer functional performance at discharge and 3 months after discharge, and stayed in hospital significantly longer. Independent risk factors for delirium were older age, history of cigarette smoking, and major hemispheric stroke. CONCLUSION: Abrupt cessation of cigarette smoking may be a risk factor for post-stroke delirium in ischemic stroke patients. The development of delirium after stroke is associated with worse outcome and longer hospitalization.

Clinical characteristics of late-onset neuromyelitis optica spectrum disorder: A multicenter retrospective study in Korea.

BACKGROUND: There are currently few studies regarding late-onset neuromyelitis optica spectrum disorder (LO-NMOSD). OBJECTIVE: We aimed to describe the characteristic features of patients with LO-NMOSD in Korea. METHODS: Anti-aquaporin-4 antibody-positive patients with neuromyelitis optica spectrum disorder (NMOSD) from nine tertiary hospitals were reviewed retrospectively. The patients were divided into two groups based on age of onset: LO-NMOSD (⩾50 years of age at onset) versus early-onset neuromyelitis optica spectrum disorder (EO-NMOSD) (<50 years of age at onset). Clinical, laboratory, and magnetic resonance imaging (MRI) parameters were investigated. RESULTS: Among a total of 147 patients (125 female; age of onset, 39.4 ± 15.2 years), 45 patients (30.6%) had an age of onset of more than 50 years. Compared to patients with EO-NMOSD, patients with LO-NMOSD had more frequent isolated spinal cord involvement at onset (64.4% vs 37.2%, p = 0.002), less frequent involvement of the optic nerve (40.0% vs 67.7%, p = 0.002), and less frequent brain MRI lesions (31.1% vs 50.0%, p = 0.034). Furthermore, there was a significant positive correlation between age of onset and Expanded Disability Status Scale (EDSS) score at last follow-up ( r = 0.246, p = 0.003). CONCLUSION: Age of onset could be an important predictor of lesion location and clinical course of patients with NMOSD.

The characteristics of chronic pain after non-traumatic, non-compressive myelopathy: Focus on neuropathic pain.

OBJECTIVES: The aim of this study was to assess the characteristics of neuropathic pain after non-traumatic, non-compressive (NTNC) myelopathy and find potential predictors for neuropathic pain. DESIGN: We analyzed 54 patients with NTNC myelopathy. The Short Form McGill Pain Questionnaire (SF-MPQ) and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) were used to assess pain. Health-related QOL was evaluated by the Short Form 36-item (SF-36) health survey. RESULTS: Out of 48 patients with pain, 16 (33.3%) patients experienced neuropathic pain. Mean age was significantly lower in patients with neuropathic pain than in patients with non-neuropathic pain (39.1 ± 12.5 vs. 49.8 ± 9.3, P = 0.002). There were no statistically significant differences in the other variables including sex, etiology of myelopathy, pain and QOL scores between the two groups. A binary logistic regression revealed that onset age under 40, and non-idiopathic etiology were independent predictors of the occurrence of neuropathic pain. Both SF-MPQ and LANSS scores were significantly correlated with SF-36 scores, adjusted by age, sex, presence of diabetes mellitus, and current EDSS scores (r = -0.624, P < 0.0001 for SF-MPQ; r = -0.357, P = 0.017 for LANSS). CONCLUSION: Neuropathic pain must be one of serious complications in patients with NTNC myelopathy and also affects their quality of life. Onset age and etiology of myelopathy are important factors in the development of neuropathic pain in NTNC myelopathy.

Comparison of MSC-Neurogenin1 administration modality in MCAO rat model.

Intracerebral (IC) grafting of mesenchymal stem cells (MSCs) is not currently used in humans due to its potential complications. On the other hand, intra-arterial (IA) administration can be facilitated for engrafting of intensifed MSCs in the injured human brain. The study is designed to compare the two methods of MSC administration using IA and IC routes through the parameters of behavior, infarct volume, cell distribution, and MSC identification. An ischemic stroke model was generated in Sprague Dawley male rats. This experiment used MSCs/Ngn1 that express Neurogenin1 (Ngn1) to ensure grafted MSC maintenance. MSCs/Ngn1 or normal saline was administrated via the IC or IA route on day 3. All animals were randomly assigned into four groups (five rats in each group): IC-control, IA-control, IC-MSCs/Ngn1, or IA-MSCs/Ngn1. Motor behaviors, infarct volume, and distribution of superparamagnetic iron oxide (SPIO)-labeled cells on magnetic resonance imaging (MRI) were compared from each group. There were no baseline differencess in motor behaviors or infarct volume between IC-MSCs/Ngn1 and IA-MSCs/Ngn1. Hovever, the IA-MSCs/Ngn1 group showed the greatest recovery on Rotarod testing and adhesive removal tests (p = 0.003 and p = 0.009 vs. IC-MSCs/Ngn1, respectively). The IA-MSCs/Ngn1 group also had more evenly distributed SPIO-labeled cells on MRI. The results suggest that IA administration is likely to be benefcial for humans based on its ability to improve behavioral outcomes and ensure even MSC engrafting.

Sonographic findings in the ulnar nerve according to the electrophysiologic stage of carpal tunnel syndrome.

OBJECTIVES: Involvement of the ulnar nerve in patients with carpal tunnel syndrome is controversial. The aim of our study was to evaluate sonographic findings in the ulnar nerve in patients with carpal tunnel syndrome. METHODS: We performed median and ulnar nerve conduction studies with sonography in 109 hands of 60 patients with clinically suspected carpal tunnel syndrome. Sonographic findings were analyzed with regard to electrophysiologic stages of carpal tunnel syndrome. RESULTS: We found that the sensory conduction velocity of the ulnar nerve decreased as the electrophysiologic stage of carpal tunnel syndrome increased (P = .038), but there was no change in the cross-sectional area of the ulnar nerve at the wrist. The median-to-ulnar nerve cross-sectional area ratio at the wrist showed a significant correlation with the electrophysiologic stage of carpal tunnel syndrome (Spearman r = 0.431; P < .0001), in addition to the median nerve cross-sectional area at the wrist and the wrist-to- forearm median nerve cross-sectional area ratio. CONCLUSIONS: In our study, ulnar nerve involvement in patients with carpal tunnel syndrome was shown electrophysiologically but not sonographically. These results suggest that morphologic changes in the ulnar nerve do not occur in carpal tunnel syndrome, although functional changes may occur.

Utility of the rio score and modified rio score in korean patients with multiple sclerosis.

OBJECTIVES: Early identification of suboptimal responders to multiple sclerosis (MS) treatment is critical for optimizing therapeutic decisions. The Rio score (RS) and modified Rio score (MRS) were developed to discriminate the responses to interferon-beta (IFNB) treatment in MS patients. This study was performed to evaluate the utility of RS and MRS in daily clinical practice in Korea. METHODS: This was a real-world setting, multicenter, retrospective study of MS patients treated with IFNB from 10 hospitals in Korea. We investigated whether the RS and MRS at the early stage of IFNB therapy could predict treatment responses over 3 years. Suboptimal treatment responses at 3 years were defined as the presence of clinical relapse and/or EDSS progression and/or patients who had been treated with INFB for at least for 1 year and therapy was switched due to perceived treatment failure during the 2 years of follow-up. RESULTS: Seventy patients (50 females and 20 males) were enrolled; 92% (12/13) of patients with high RS and 86% (12/14) of patients with high MRS (score 2 or 3) were suboptimal responders, whereas 93% (53/57) of patients with low RS and 93% (52/56) patients with low MRS (score 0 or 1) showed optimal responses. New active lesions on MRI with clinical relapse in high RS and MRS were the most common combination in suboptimal responders. CONCLUSIONS: We confirmed that RS and MRS at 6-15 months of IFNB therapy were useful for predicting poor responders over 3 years.

Evaluation of coexistence of Alzheimer's disease in idiopathic normal pressure hydrocephalus using ELISA analyses for CSF biomarkers.

BACKGROUND: We investigated levels of the ß-amyloid 1-42 (Aß42), total tau protein (T-tau) and tau phosphorylated at position threonine 181 (P-tau) in cerebrospinal fluid (CSF) of idiopathic normal pressure hydrocephalus (iNPH) patients and tried to find their clinical implications in the evaluation and treatment of iNPH. METHOD: Twenty-five possible iNPH patients were prospectively enrolled and their CSF was collected to analyze levels of Aß42, T-tau and P-tau using ELISA method. Gait disturbance, urinary incontinence, and cognitive impairment were semi-quantified and detailed neuropsychological (NP) test was performed. RESULT: Eight iNPH patients were classified into the lower CSF Aß42 group and 17 patients were classified into the higher CSF Aß42 group. There was no difference in the iNPH grading score and its improvement after LP between the two groups. The lower CSF Aß42 group showed more deficits in attention, visuospatial function and verbal memory in the baseline NP test and less improvement in phonemic categorical naming and frontal inhibitory function after LP. CONCLUSIONS: Our study suggested that concomitant AD in iNPH patients might contribute to lumbar puncture or shunt unresponsiveness, especially in the field of cognitive dysfunction.

Cardiovascular autonomic function in lateral medullary infarction.

Even though the medulla contains the baroreceptor regulatory centers, few studies have focused on the autonomic dysfunction of lateral medullary infarction (LMI). Therefore, cardiac parasympathetic and sympathetic functions were compared in LMI patients and age-matched controls. We prospectively recruited 25 LMI patients who had ipsilateral Horner's sign and cardiac autonomic function testing without a history of diabetes, cardiac disease, or previous stroke. Parasympathetic function tests included beat-to-beat heart rate variation during deep breathing, 30:15 heart rate ratio testing while standing, and the valsalva ratio. Sympathetic function tests included blood pressure during active standing and sustained handgrip. The composite autonomic score (CAS) was measured as a total of 10 points; parasympathetic dysfunction was designated as ≥3 points in the parasympathetic subscores and sympathetic dysfunction as ≥2 points in the sympathetic subscores. Multiple regression analysis was performed to predict parasympathetic or sympathetic dysfunction. The mean age and stroke risk factors of the study population were not significantly different between the LMI group (n = 25) and control group (n = 29). However, cardiac autonomic functions were significantly different in the groups: parasympathetic dysfunction (14 vs. 4 patients, p = 0.011) and sympathetic dysfunction (3 vs. 13 patients, p = 0.008). In univariate analysis, male-gender (p = 0.011), right-side involvement (p = 0.035) and ventral involvement (p = 0.007) were significantly associated with parasympathetic dysfunction (CAS subscore ≥3). In multivariable analysis, the ventral involvement remained to be the independent predictor for parasympathetic dysfunction (OR 16.0; 95% CI 2.2-118.3, p = 0.007). This study suggests that LMI patients are susceptible to cardiac parasympathetic dysfunction, especially in the ventral medulla.

Ticlopidine with Ginkgo Biloba extract: a feasible combination for patients with acute cerebral ischemia.

BACKGROUND: Even though clopidogrel is the most used drug for cardiovascular prevention, resistance occurs in significant numbers. Therefore, we evaluated platelet aggregation ability of thienopyridines in relation with various genotypes. METHOD: The study population was randomly assigned with clopidogrel (n=43), ticlopidine (n=41), or ticlopidine plus Gingko Biloba extract (EGb) (n=43). Dosage was maintained as 75mg clopidogrel daily, 250mg ticlopidine twice daily, and 250mg ticlopidine plus 80mg Gingko Biloba extract twice daily. Using multiple electrodes aggregometry, platelet aggregation was measured by activators of adenosine diphosphate (ADP), arachidonic acid (ASP), and thrombin (TRAP) at baseline (T0), 7days (T1), and 90days (T2). Side-effects were analyzed in the 3 groups. Inhibition of platelet aggregation (IPA) was defined as percent decrease at T0 and T1. Non-responsiveness (

The combined use of mechanical thrombectomy devices is feasible for treating acute carotid terminus occlusion.

BACKGROUND: Mechanical thrombectomy devices have recently been developed and approved for recanalization of intracranial arterial occlusion. Here, we investigated the feasibility of combined stent-assisted and clot aspiration mechanical thrombectomy for effective recanalization of acute carotid terminus occlusion (CTO). METHODS: Ten consecutive patients with acute ischemic stroke secondary to CTO who underwent intra-arterial (IA) treatment with both stent retrieval and negative-pressured clot aspiration systems were enrolled. Periprocedural and radiologic findings and clinical outcomes were evaluated. RESULTS: The median age was 69 years (range, 47-86 years), and the median initial NIHSS score was 17.5 (range, 12-33). Mechanical thrombectomy was performed using a combination of the Solitaire stents and Penumbra system. Thrombolysis in cerebral ischemia [TICI] grade II-III was achieved in eight patients (80.0 %); complete recanalization of the CTO (TICI III) was achieved in three of those patients. Any type of intracranial hemorrhages occurred in four patients (40.0 %), but parenchymal hematoma type 2 was not observed. Four patients died within 3 months (40.0 %). CONCLUSIONS: Combined mechanical thrombectomy treatment was effective for recanalization of acute CTO. The combination of Solitaire and Penumbra devices can be considered as a treatment option for CTO.

Multiple cerebral arterial occlusions related to Mycoplasma pneumoniae infection.

We report the case of a 33-year-old man with a brainstem infarction due to concomitant occlusions in the left internal carotid, both vertebral, and basilar arteries. The patient had experienced a severe Mycoplasma pneumoniae infection about 10 months prior to symptom onset, and his Mycoplasma antibody titre was positive when the stroke occurred. Despite performing meticulous neurological, vascular, and medical evaluations, we were unable to detect other possible causes of the stroke. Therefore, the multiple occlusions in the major cerebral arteries of our patient were concluded to be related to M. pneumoniae infection.

Comparison between clinical disabilities and electrophysiological values in Charcot-Marie-Tooth 1A patients with PMP22 duplication.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth disease (CMT) type 1A (CMT1A) is the demyelinating form of CMT that is significantly associated with PMP22 duplication. Some studies have found that the disease-related disabilities of these patients are correlated with their compound muscle action potentials (CMAPs), while others have suggested that they are related to the nerve conduction velocities. In the present study, we investigated the correlations between the disease-related disabilities and the electrophysiological values in a large cohort of Korean CMT1A patients. METHODS: We analyzed 167 CMT1A patients of Korean origin with PMP22 duplication using clinical and electrophysiological assessments, including the CMT neuropathy score and the functional disability scale. RESULTS: Clinical motor disabilities were significantly correlated with the CMAPs but not the motor nerve conduction velocities (MNCVs). Moreover, the observed sensory impairments matched the corresponding reductions in the sensory nerve action potentials (SNAPs) but not with slowing of the sensory nerve conduction velocities (SNCVs). In addition, CMAPs were strongly correlated with the disease duration but not with the age at onset. The terminal latency index did not differ between CMT1A patients and healthy controls. CONCLUSIONS: In CMT1A patients, disease-related disabilities such as muscle wasting and sensory impairment were strongly correlated with CMAPs and SNAPs but not with the MNCVs or SNCVs. Therefore, we suggest that the clinical disabilities of CMT patients are determined by the extent of axonal dysfunction.

Chronic cerebral hypoperfusion in a mouse model of Alzheimer's disease: an additional contributing factor of cognitive impairment.

The purpose of the present study was to evaluate whether chronic cerebral hypoperfusion would affect cognitive status in an Alzheimer mouse model. Behavioral tests and histological evaluations were performed using female Tg2576 mice eight weeks after right common carotid artery occlusion (rCCAO), which is known to induce a type of vascular dementia without neuronal necrosis in nontransgenic mice. Positron emission tomography with (18)F-fluorodeoxyglucose (FDG-PET) was utilized to evaluate metabolic status in the rCCAO-operated brain of nontransgenic mice. Escape latency from the Morris water maze test was not significantly different between rCCAO- and sham-operated mice. However, the learning curve was impaired in rCCAO-operated transgenic mice while it was preserved in sham-operated transgenic or rCCAO-operated nontransgenic mice. Histological examination revealed no evidence of cell death in the rCCAO-operated brains, and the extent of amyloid deposition was not different in rCCAO- and sham-operated mice. The brain of rCCAO-operated mice showed metabolic deficits in the ipsilateral parietal cortex through FDG-PET. In conclusion, further cognitive decline which is more comparable to typical Alzheimer's disease was induced by chronic cerebral hypoperfusion in an Alzheimer mouse model. This aggravation might be associated with hypometabolism via chronic cerebral hypoperfusion.