Objective To report the clinical and peripheral neuropathological findings in two patients with autosomal recessive Charcot-Marie-Tooth disease 2K(AR-CMT2K).Methods Case one was a nine year-old girl.She had distal weakness of lower limbs for six years, with calf atrophy and contracture of Achilles tendon for three years.Case two was an eight year-old boy.He had distal weakness of lower limbs with contracture of Achilles tendon and calf muscle atrophy for three years, and proximal weakness of low limbs for two years.The motor nerve conduction velocities in median nerves were 48.1 m/s in case one and 47.6 m/s in case two.The compound motor action potential amplitude of median nerves decreased by 46% in case one and 69% in case two.Sural nerve biopsies and gene targeted next-generation sequencing were performed in both patients.Results Density of myelinated fibers was 8 407/mm2 in case one and 7 714/mm2 in case two.The ratio of myelinated fibers with diameter over 8 μm was 2.6% in case one and 0 in case two.Both patients had small regenerating cluster of myelinated fibers.Thin myelinated fibers appeared in case one.In case two, atypical onion bulb formations with focal folded myelin appeared, and electromicroscopy revealed mitochondrial aggregate in axons.Compound heterozygous mutations of ganglioside-induced differentiation associated protein 1 gene were detected in both patients, including c.767A>G(p.H256R) and c.466G>A (p.A156T) in case one and c.767A>G and 845G>A(p.R282H) in case two.Conclusions Contracture of Achilles tendon may appear in early childhood of AR-CMT2K patients.The main pathological changes in sural nerve are loss of large myelinated fibers, mitochondrial aggregate in axons and myelin abnormalities.

Objective:To evaluate the endothelial functions and autoregulation capacity of cerebral blood flow in patients with Fabry disease .Methods:Brachial artery vasodilation was assessed in 8 pa-tients with Fabry disease and 14 healthy controls by means of flow-mediated dilation ( FMD) and Nitro-glycerin-mediated dilation ( NMD) .Cerebrovascular reactivity was calculated in terms of breath-holding index ( BHI) and vascular motor reactivity ( VMR) by TCD-CO2 test in 4 patients and 14 healthy con-trols.Results:Compared with the controls , brachial artery vasodilation experiment showed no difference (the patients:FMD 15.94%±5.03% and NMD 23.92%±7.23%, the controls: FMD 14.57%± 5 .84% and NMD 22 .64%±6 .96%) , there was no relationship between FMD or NMD and the age , course of disease , MSSI or enzyme activity .In respect of cerebrovascular autoregulation capacity , there was no difference in anterior circulation , while cerebrovascular reactivity tended to be impaired in posteri-or circulation .Conclusion:Endothelial function showed no decline in patients with Fabry disease , but cerebrovascular autoregulation capacity tended to be impaired in posterior circulation .

Objective To analyze membrane attack complex (MAC) expression in different types of idiopathic inflammtory myopathy (IIM).Methods We enrolled 57 cases of dermatomyositis (DM) , 37 cases of polymyositis (PM) ,9 cases of sporadic inclusion body myositis (sIBM) and 15 cases of autoimmune necrotizing myopathy with anti-signal recognition particle antibodies (SRP-ANM) in Department of Neurology at Peking University First Hospital from 2011 to 2014, and used x2 test or Fisher exact test to analyze MAC expression in muscle fibers and endomysial capillaries respectively.Results The total MAC expression in DM, PM, sIBM and SRP-ANM was 75.4％ (43/57), 86.5％ (32/37), 4/9 and 13/15 respectively.The MAC expression in muscle fibers was 50.9％ (29/57), 81.1％ (30/37) , 3/9 and 13/15 respectively.The MAC expression in endomysial capillaries was 49.1％ (28/57) , 24.3％ (9/37) , 1/9 and 6/15 respectively.The MAC expression in muscle fibers and endomysial capillaries of sIBM was less than other types of IIM.The MAC expression in muscle fibers of PM and SRP-ANM was higher than DM and sIBM, but there was no statistically significant difference between PM and SRP-ANM.The MAC expression in endomysial capillaries of DM and SRP-ANM was higher than PM and sIBM, while there was no statistically significant difference between DM and SRP-ANM (x2 =0.397, P =0.574).The MAC expression in four types of IIM had regional distribution, of which 11.6％ (5/43) of DM showed bundle distribution.Conclusion There are differences in the damage of MAC in various types of IIM, the damage of MAC in SRP-ANM indicated the pattern of both DM and PM.

Objective To analyze the differences of the clinical and neuropathological features among the common Charcot-Marie-Tooth disease (CMT) subtypes.Methods There were 81 CMT patients confirmed by genetic testing from 2005 to 2015 in Department of Neurology,Peking University First Hospital,including 31 cases of CMT1A (38.3％),19 cases of CMTX1 (23.5％),16 cases of CMT2A2 (19.8％) and 15 cases of 9 rare types of CMT (1.2％-4.9％).We compared the onset age,duration,muscles weakness of legs,frequency of pes cavus,and main pathological changes of the sural nerve biopsy in 48 cases of the common CMT subtypes.Results The mean age of the onset was (12.00 ± 6.77) years in CMT1A patients,(11.81 ±4.65) years in CMTX1 patients and (5.00 ±2.68) years in CMT2A2 patients (Brown-Forsythe test,P =0.001).The duration was (12.00 ± 6.75) years in CMT1A patients,(8.50 ± 4.75) years in CMTX1 patients and (5.00 ± 2.73) years in CMT2A2 patients (Brown-Forsythe test,P =0.001).The muscle force of the dorsi flexors was Ⅳ (0,Ⅴ) in CMT1A patients,Ⅲ + (0,Ⅳ) in CMTX1 patients and 0 (0,Ⅳ) in CMT2A2 patients (H =11.359,P =0.020).The pes cavus appeared in 15/23 cases of CMT1A,10/16 cases of CMTX1 and 1/9 cases of CMT2A2 (Fisher test,P=0.017).The leukoencephalopathy appeared only in 3 cases of CMTX1 and the visual loss appeared only in 3 cases of CMT2A2.The onion-bulb formations of myelinated fibers appeared in 23/23 cases of CMT1 A,5/16 cases of CMTX1 and 2/9 cases of CMT2A2(Fisher test,P =0.000).The axonal regeneration appeared in 16/23 cases of CMT1A,16/16 cases of CMTX1 and 9/9 cases of CMT2A2 (x2 =7.666,P =0.016).There were significant differences among the three common CMT subtypes in the above parameters.Conclusions CMT1A,CMT2A2 and CMTX1 are the most common subtypes of CMT in the present study.For the clinical diagnosis,more attention should be paid to the onset of the disease,duration,muscles weakness,pes cavus,cerebral symptoms and visual loss.The present frequency of onion-bulb and the axonal regeneration of myelinated fibers help the different pathological diagnosis among them.

Objective To summarize the clinical features of Chinese patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes ( MELAS).Methods A total of 190 patients with MELAS who presented to Peking University First Hospital between 1997 and 2015 were recruited.Among 190 patients, 175 were identified carrying mitochondrial DNA mutations, and the remaining 15 patients were diagnosed by muscle biopsy.The clinical features, including predisposing factors of stroke-like episodes, the onset symptoms and frequencies of various manifestations were analyzed and reported.Results In our cohort of MELAS patients, the male-to-female ratio was 1.44∶1.The median age of onset was 14 years ( from 7 months to 45 years).The peak onset ages were 8-12 years.The median onset age of the first stroke-like episode was 16 years ( from 1 to 53 years ).There were 66 ( 46.15%) patients who had predisposing factors before the onset, and fatigue and upper respiratory tract infection were the most common predisposing factors of stroke-like episodes in these patients ( 37.88%, 25/66 and 34.85%, 23/66, respectively).Other predisposing factors included emotional agitation, drinking alcohol, trauma, withdrawal of antiepileptic drugs, being frightened, satiation and hunger.Stroke-like episodes appeared in 70.53%(134/190) patients as an onset symptom and developed in all patients with disease progression.The neurological manifestations included seizure ( 89.42%, 169/189 ) , mental retardation or dementia (82.87%, 150/181), headache (74.30%, 133/179), hemianopia or cortical blindness (67.72%, 107/158), exercise intolerance (50.87%, 88/173), hemiplegia or hemianesthesia (47.44%, 74/156), sensorineural deafness (46.20%, 85/184), aphasia (39.47%, 60/152), behaviour disorder (17.71%, 31/175) and ophthalmoplegia ( 9.60%, 17/177 ).The manifestations of extra-nervous systems included hirsutism (67.57%, 100/148), vomiting (65.58%, 101/154), fever (62.07%, 90/145), short stature (45.32%, 63/139), diarrhea or constipation (43.48%, 70/161), low body mass index (26.62%, 37/139), diabetes mellitus (20.79%, 37/178) and kidney disease (3.16%, 6/190).Conclusions The majority of the patients in this study have the disease onset during childhood.There are more male MELAS patients than females.Most common clinical manifestations are seizure, mental retardation or dementia, headache, cortical blindness, hirsutism, vomiting and fever in this patient group.

Objective:To evaluate the clinical efficacy of cannulated screws with sutures in the treatment of patellar transverse fractures.Methods:A retrospective analysis was performed of the data of 70 patients with patellar transverse fracture who had been admitted to Senior Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital from January 2017 to March 2021. According to the construction methods for the tension band, the patients were divided into 3 groups. In group A of 21 cases subjected to fixation with cannulated screws with sutures (Fiber-Tape), there were 8 males and 13 females with a median age of 55.0 (48.0, 65.0) years; in group B of 32 cases subjected to fixation with Kirschner wire tension band, there were 15 males and 17 females with a median age of 52.5 (41.5, 63.0) years; in group C of 17 cases subjected to fixation with Cable-Pin system, there were 5 males and 12 females with a median age of 55.0 (37.0, 65.0) years. The 3 groups were compared in terms of complications, secondary surgery (removal of internal fixation), operation time, intraoperative blood loss and knee function rated by the Lysholm and B?stman scores at the last follow-up.Results:There were no significant differences in the preoperative general data between the 3 groups, showing they were comparable ( P > 0.05). There was no significant difference in the operation time, intraoperative blood transfusion or follow-up time among the 3 groups ( P > 0.05). The incidence of soft tissue irritation [4.8% (1/21)] and the secondary operation rate [4.8% (1/21)] in group A were significantly lower than those in group B [43.8% (14/32) and 37.5% (12/32)] and group C [41.2% (7/17) and 35.3% (6/17)] ( P < 0.05), but there was no statistically significant difference between group B and group C ( P > 0.05). In groups A, B and C, respectively, the Lysholm knee score was 84.0 (69.0, 88.0), 89.0 (71.5, 95.0) and 82.0 (63.0, 90.0), and the B?stman knee score 26.0 (23.0, 28.0), 26.5 (24.0, 27.5) and 26.0 (22.0, 28.0), showing no significant difference ( P > 0.05). There was no significant difference either in the incidence of other complications among the 3 groups ( P > 0.05). Conclusion:In the treatment of patellar transverse fractures, compared with the Kirschner wire tension band and Cable-Pin system, cannulated screws with sutures (Fiber-Tape) may lead to a lower incidence of soft tissue irritation and a lower rate of secondary surgery, but no significant differences in operation time, intraoperative blood loss, other complications or postoperative functional scores.