遗传性压迫易感性周围神经病(附一家系2例报告)

目的报道一家系2例遗传性压迫易感性周围神经病(HNPP),以提高对本病的认识及诊断水平。方法 2例均行详细肌电图、运动及感觉神经传导速度、运动神经远端潜伏期测定。结果例1,临床表现为右足反复的压迫或牵拉后无力和麻木;例2,为例1姐姐,11 y前发病,现查体无周围神经病表现。2例电生理检查示广泛性神经传导速度减慢,特别是周围神经易嵌压部位运动传导速度减慢更明显,运动神经远端潜伏期延长,包括临床未受累的神经。结论神经电生理检查是诊断HNPP重要的筛选手段,确诊有赖于腓肠神经活检的典型病理表现及基因检测。     

Kennedy病患者电生理、病理学特点及临床误诊分析

目的研究肯尼迪病(Kennedy disease,KD)患者电生理学特征和肌肉病理学特点,探讨临床误诊原因,以加强对此病电生理学改变和肌肉病理学的认识,减少误诊误治。方法对9例经基因确诊的KD患者行针极肌电图、神经传导、F波和H反射检测。肌电图取舌肌、胸锁乳突肌、三角肌、第一骨间肌、胸椎旁肌、股四头肌、胫前肌。神经电图取双侧正中神经、尺神经、腓总神经、腓肠神经和胫神经。1例患者取股四头肌肌肉活检行病理学检查。结果肌电图检查显示9例肯尼迪病患者均表现为广泛的慢性神经源性损害。CMAP和SNAP波幅均显著降低(P0.01),以腓肠神经动作电位波幅异常率最高(88.89%),腓总神经和腓肠神经传导速度减慢(P0.01),正中神经和胫神经远端潜伏期延长(P0.01),正中神经和胫神经F波响应率降低,胫神经的H反射潜伏期延长(P0.01)。肌活检示神经源性肌损害,表现为肌纤维萎缩,萎缩纤维群组化分布。结论 KD患者电生理以广泛的慢性神经源性损害为最主要改变,感觉和运动神经传导异常,且感觉神经受累较运动神经受累更多见,病理学表现为肌肉萎缩及群组化分布。电生理和肌肉活检对该病的早期诊断和减少误诊率有重要指导价值。     

多发性硬化脊髓型合并周围神经病变

目的：评价多发性硬化（MS）脊髓型的临床特征,脊髓磁共振成像（MRI）,神经电生理检查和腓肠神经活检的诊断价值。方法：分析14例MS脊髓型临床表现,脊髓MRI,神经电生理和腓神经活组织病理检查。结果：其临床表现为两侧肢体不对称性运动和感觉障碍的脊髓内部损害,可伴有发作性症状,有缓解和复发,脊髓MRI可以明确脱髓鞘部位,表现髓内纵行条带状或斑片状长T1长T2信号,脊髓略增粗,诱发电位有极高的敏感性,肌电图和腓肠神经病理提示周围神经脱髓鞘改变。结论：MRI、神经电生理检查及周围神经活检对MS脊髓型的早期诊断和治疗起重要作用。     

Kennedy病的临床、电生理及病理特征分析(附2例报道)

目的探讨Kennedy病的临床、神经电生理及病理特征。方法报道2例经基因确诊的Kennedy病患者,分析其临床症状、体征、肌电图和神经传导检查和神经病理等特点。结果两例患者均中年发病,进展缓慢。神经系统表现为以肢体近端无力和延髓受累为主的下运动神经元瘫痪。血清性激素水平正常,但有男性乳腺发育等雄激素功能低下表现。血清肌酸激酶轻度升高。肌电图呈广泛神经源性损害,神经传导检查提示感觉神经动作电位波幅减低,H反射异常,神经活检提示大的有髓纤维减少。雄激素受体基因编码区CAG重复数大于40。结论 Kennedy病有相对独特的临床、电生理及病理特征,确诊有赖于雄激素受体基因编码区CAG重复数的检测。     

腊肠体样周围神经病的临床、电生理和病理特点

目的总结腊肠体样周围神经病的临床、电生理和病理特点。方法收集3例患者病史、体格检查以及电生理检查及病理检查资料。结果3例患者中男2例、女1例,13～28岁发病,阳性家族史2例;机械性压迫或牵拉后导致双侧腓总神经麻痹1例,隐袭和慢性起病各1例。电生理检查可见广泛的周围神经损伤,正中神经运动传导远端潜伏期（DML）均延长。腓肠神经活检均可见少数明显增粗的有髓神经纤维,电镜下可见髓鞘板层数增多。1例患者肌肉活检示轻微病理改变。结论腊肠体样周围神经病为周围神经髓鞘发育障碍所致,神经电生理和神经病理对诊断有特异性。     

腓骨肌萎缩症电生理、病理和基因定位研究

目的研究腓骨肌萎缩症(CMT)临床特征、基因测定、病理及神经电生理检查在其诊断和分型中的价值。方法收集50例CMT患者临床资料,对其进行肌电图检查及腓肠神经活检,并采用PCR技术直接测序进行基因突变分析。结果 40例CMT患者双下肢运动及感觉传导速度减慢(双胫、腓总神经为15~28 m/s,腓肠神经为12~30 m/s),10例双下肢未引出反应电位;50例正中神经运动及感觉传导速度亦减慢分别为19~48 m/s和20~52 m/s。CMT患者神经传导速度减慢的程度和临床表现的严重程度并不平行。腓肠神经活检符合慢性脱髓鞘部分伴轴索改变性周围神经病。PMP22、Cx32、MPZ、MFN2、GDAP1致病基因的突变分析发现14例患者存在PMP22基因的大片段重复突变(28%),13例患者存在Cx32基因的点突变(26%),4例患者存在MPZ基因的点突变(8%),3例患者存在MFN2基因的点突变(6%),未发现GDAP1基因的突变,16例患者未检测出上述基因突变。结论电生理、病理、基因测定在CMT的诊断及分型中有重要价值。     

线粒体肌病合并周围神经病的临床病理研究

目的:分析线粒体肌病合并周围神经病的临床特点、电生理和病理特征。方法:对10例肌肉活检确诊为线粒体肌病同时又合并周围神经病的患者从临床症状与体征、电生理检查和腓肠神经活检等几方面予以分析,并探讨周围神经病的病理基础。结果:本组10例患者中1例仅有临床下受累,另外9例表现为轻中度感觉运动性周围神经病,以感觉症状为重。结论:对线粒体肌病患者应将详细的神经系统查体与神经电生理检查相结合,提高周围神经病的检出率。电生理检查和腓肠神经活检有助于诊断。周围神经病的发病机制可能与线粒体功能异常有关。     

急性和慢性多发性周围神经病的电生理及形态学观察

目的寻找神经、肌肉电生理和腓肠神经病理在急性和慢性炎性脱髓鞘性多发性周围神经病(GBS和CIDP)的诊断价值。方法总结GBS和CIDP(15例和17例)的临床、电生理及病理资料进行回顾性分析。结果EMG异常而神经电生理正常共8例;临床和电生理均未提示感觉异常的患者病理发现髓鞘和轴突的丧失、髓鞘再生及许旺细胞内结构改变。结论腓肠神经活检及神经、肌电生理的测定是本组疾病相辅相成的辅助检查手段。     

腊肠体样周围神经病的临床和病理

报告４例经腓肠神经活检病理证实的腊肠体样周围神经病，以提高该病的临床认识和诊断能力。方法局麻下做腓肠神经活检，活检标本分别做ＨＥ和Ｍａｓｓｏｎ染色；髓鞘染色；剥离单神经；半薄和超薄切片，分别在光镜或电镜下观察。结果４例均为男性，１３～２１岁发病，其中３例有家族史，临床特征为反复发生的轻微机械性压迫或牵拉后单神经麻痹。电生理检查显示广泛性周围神经损害，传导速度明显减慢。临床符合遗传性压迫易感性麻痹神经病和痛性臂丛神经病。腓肠神经活检可见少数明显增粗的有髓纤维，直径达２０～２８μｍ，髓鞘增厚，而轴索正常，还可见到薄髓纤维。剥离单神经纤维可见局灶性髓鞘增厚，形似腊肠样。电镜下见到髓鞘板层层数增多，无轴索变性，雪旺细胞和无髓纤维未见明显异常。结论腊肠体样周围神经病有周围神经髓鞘发育缺陷，使周围神经易于损伤，是多发性单神经病的病因之一。     

慢性酒精性周围神经病的电生理改变

目的探讨慢性酒精性周围神经病的电生理特点和诊断价值.方法检测36例慢性酒精中毒患者与35例正常人肌电图对照,统计分析.结果观察组中确诊为临床或亚临床周围神经病的共30例(83.3 3%).观察组的正中神经、尺神经、胫后神经、腓总神经、腓肠、腓浅神经传导速度(NCV)及波幅明显低于正常对照组,感觉神经异常率高于运动神经,下肢异常率高于上肢.各神经传导速度与酒精摄入总量(TLDE)呈负相关.结论酒精对周围神经的毒性呈剂量依赖性.神经电生理检查能敏感地评价慢性酒精中毒患者的周围神经受损程度.     

Fulminant case of hereditary neuropathy with liability to pressure palsy

Hereditary neuropathy with liability to pressure palsy (HNPP) is typified as isolated nerve palsies caused by trivial compression or trauma. It rarely presents in two extremities and even more infrequently affects all four limbs simultaneously. We present a patient who concurrently experienced right shoulder, left hand, and bilateral foot weakness mimicking several multifocal conditions. Electromyography suggested HNPP and subsequent nerve biopsy and genetic testing were confirmatory. The case demonstrates that HNPP can present in a fulminant manner and should be included in the differential diagnosis of acute multiple mononeuropathies. The possible causes for such a rapid clinical course in our patient are discussed.     

Clinical and electrodiagnostic findings, nerve biopsy and blood group markers in a family with hereditary neuropathy with liability to pressure palsies

Clinical, electrophysiologic and biopsy findings as well as studies of blood group markers in a family with hereditary neuropathy with liability to pressure palsies (HNPP) are reported. There was an autosomal dominant trait without genetic linkage between the HNPP gene and blood group markers controlled by chromosome 1. Reduced motor and sensory nerve conduction velocity was found in clinically affected and unaffected nerves. Characteristic morphological changes in sural nerve biopsy including tomaculous swelling were present.     

Hereditary neuropathy with liability to pressure palsies

Summary Clinical, neurophysiological and pathological investigations were carried out in 11 affected members of 2 families with hereditary neuropathy with liability to pressure palsies (HNPP). The observations were related to findings in 261 cases of 47 families published in the literature. It was concluded that HNPP is a nosological entity characterized by the following diagnostic criteria: (1) an autosomal dominant inheritance; (2) the clinical presentation of a recurrent mononeuropathy simplex or multiplex, frequently related to an inadequate trauma to peripheral nerves; (3) a significant slowing of motor and sensory conduction velocity in clinically affected, but also in clinically unaffected nerves; (4) characteristic morphological findings in sural nerve biopsy featuring tomaculous swellings of myelin sheaths, transnodal myelination and segmental demyelination. The pathogenesis of HNPP is not clear. Hypothetical explanations of the pathogenesis of HNPP are discussed.In memory of Albert Bischoff (1921–1981), Professor of Neurology, University of Berne     

Recurrent familial brachial plexus palsies as the only clinical expression of 'tomaculous' neuropathy

Two familial cases of recurrent brachial plexus are described and similar episodes were noticed in other members of the family. Electrophysiological investigations found impaired motor and sensory nerve conduction velocity in affected and nonaffected members. Tomaculous neuropathy was found at biopsy of peripheral nerve in more than 40% of dissected fibers. In addition, two affected members showed a reduced interpupillary distance, i.e. the most common dysmorphic feature found in the hereditary neuralgic amyotrophy (HNA). A literature review showed only two other instances of recurrent familial brachial plexus palsies as the only manifestation of tomaculous neuropathy (hereditary neuropathy with liability to pressure palsy, HNPP). The dysmorphic feature found in our cases in addition to the clinical, electrophysiological and anatomical data support the hypothesis that these cases of HNPP and the HNA may represent the same disease.     

Peripheral nerve biopsy study in 19 cases with 17p11.2 deletion

In most cases of hereditary neuropathy with liability to pressure palsy (HNPP) the diagnosis is now assessed by molecular detection of 17p11.2 deletion. However, the family history may be missing and the clinical presentation is not always informative. In such cases, a peripheral nerve biopsy showing the characteristic focal myelin sheath thickening ("tomaculae") may be helpful. We present a retrospective study of peripheral nerve biopsies performed in 19 patients suffering from either a mononeuropathy or a generalized sensory-motor polyneuropathy, and for whom the finding of tomaculae led to a search for 17p11.2 deletion, which was confirmed secondarily. Tomaculae and other coexisting neuropathological lesions such as uncompacted myelin, "onion bulb" formations, and axonal degeneration are described and discussed in the view of previously reported data. It appears that demyelinating lesions with tomaculae are strongly suggestive of HNPP but are not specific as they may be observed in other conditions. Moreover, these features may be overlooked if axonal degeneration is marked.     

Hereditary neuropathy with liability to pressure palsies: the same molecular defect can result in diverse clinical presentation

Hereditary neuropathy with liability to pressure palsies (HNPP) is a peripheral nerve disorder characterized by autosomal dominant inheritance, recurrent pressure palsies, reduced motor and sensory conduction velocities and sausage-like swellings (tomacula) of myelin sheaths in nerve biopsy. Two young adult patients are reported as index cases of two families in which HNPP was diagnosed. The first patient presented with recurrent pressure palsies, whereas the second suffered from fasciculations and myokymias in his right hand, with difficulty in writing, and upper and lower limb paraesthesias of 3 years' duration. Electrodiagnostic studies revealed slowing of conduction primarily in common sites of compression in both patients. Sural nerve biopsy revealed the characteristic tomaculous swellings in both patients. DNA analysis showed that both patients have a deletion in chromosome 17p11.2 which is found in the majority of HNPP cases. In light of the common molecular defect, the different clinical symptomatology of the two patients is discussed.     

Inherited focal, episodic neuropathies

Hereditary neuropathy with liability to pressure palsies (HNPP; also called tomaculous neuropathy) is an autosomal-dominant disorder that produces a painless episodic, recurrent, focal demyelinating neuropathy. HNPP generally develops during adolescence, and may cause attacks of numbness, muscular weakness, and atrophy. Peroneal palsies, carpal tunnel syndrome, and other entrapment neuropathies may be frequent manifestations of HNPP. Motor and sensory nerve conduction velocities may be reduced in clinically affected patients, as well as in asymptomatic gene carriers. The histopathological changes observed in peripheral nerves of HNPP patients include segmental demyelination and tomaculous or “sausage-like” formations. Mild overlap of clinical features with Charcot-Marie-Tooth (CMT) disease type 1 (CMT1) may lead patients with HNPP to be misdiagnosed as having CMT1. HNPP and CMT1 are both demyelinating neuropathies, however, their clinical, pathological, and electrophysiological features are quite distinct. HNPP is most frequently associated with a 1.4-Mb pair deletion on chromosome 17p12. A duplication of the identical region leads to CMT1A. Both HNPP and CMT1A result from a dosage effect of the PMP22 gene, which is contained within the deleted/duplicated region. This is reflected in reduced mRNA and protein levels in sural nerve biopsy samples from HNPP patients. Treatment for HNPP consists of preventative and symptom-easing measures. Hereditary neuralgic amyotrophy (HNA; also called familial brachial plexus neuropathy) is an autosomal-dominant disorder causing episodes of paralysis and muscle weakness initiated by severe pain. Individuals with HNA may suffer repeated episodes of intense pain, paralysis, and sensory disturbances in an affected limb. The onset of HNA is at birth or later in childhood with prognosis for recovery usually favorable; however, persons with HNA may have permanent residual neurological dysfunction following attack(s). Episodes are often triggered by infections, immunizations, the puerperium, and stress. Electrophysiological studies show normal or mildly prolonged motor nerve conduction velocities distal to the affected brachial plexus. Pathological studies have found axonal degeneration in nerves examined distal to the plexus abnormality. In some HNA pedigrees there are characteristic facial features, including hypotelorism. The prognosis for recovery of normal function of affected limbs in HNA is good, although recurrent episodes may cause residual deficits. HNA is genetically linked to chromosome 17q25, where mutations in the septin-9 (SEPT9) gene have been found.     

Inherited focal, episodic neuropathies: hereditary neuropathy with liability to pressure palsies and hereditary neuralgic amyotrophy

Hereditary neuropathy with liability to pressure palsies (HNPP; also called tomaculous neuropathy) is an autosomal-dominant disorder that produces a painless episodic, recurrent, focal demyelinating neuropathy. HNPP generally develops during adolescence, and may cause attacks of numbness, muscular weakness, and atrophy. Peroneal palsies, carpal tunnel syndrome, and other entrapment neuropathies may be frequent manifestations of HNPP. Motor and sensory nerve conduction velocities may be reduced in clinically affected patients, as well as in asymptomatic gene carriers. The histopathological changes observed in peripheral nerves of HNPP patients include segmental demyelination and tomaculous or "sausage-like" formations. Mild overlap of clinical features with Charcot-Marie-Tooth (CMT) disease type 1 (CMT1) may lead patients with HNPP to be misdiagnosed as having CMT1. HNPP and CMT1 are both demyelinating neuropathies, however, their clinical, pathological, and electrophysiological features are quite distinct. HNPP is most frequently associated with a 1.4-Mb pair deletion on chromosome 17p12. A duplication of the identical region leads to CMT1A. Both HNPP and CMT1A result from a dosage effect of the PMP22 gene, which is contained within the deleted/duplicated region. This is reflected in reduced mRNA and protein levels in sural nerve biopsy samples from HNPP patients. Treatment for HNPP consists of preventative and symptom-easing measures. Hereditary neuralgic amyotrophy (HNA; also called familial brachial plexus neuropathy) is an autosomal-dominant disorder causing episodes of paralysis and muscle weakness initiated by severe pain. Individuals with HNA may suffer repeated episodes of intense pain, paralysis, and sensory disturbances in an affected limb. The onset of HNA is at birth or later in childhood with prognosis for recovery usually favorable; however, persons with HNA may have permanent residual neurological dysfunction following attack(s). Episodes are often triggered by infections, immunizations, the puerperium, and stress. Electrophysiological studies show normal or mildly prolonged motor nerve conduction velocities distal to the affected brachial plexus. Pathological studies have found axonal degeneration in nerves examined distal to the plexus abnormality. In some HNA pedigrees there are characteristic facial features, including hypotelorism. The prognosis for recovery of normal function of affected limbs in HNA is good, although recurrent episodes may cause residual deficits. HNA is genetically linked to chromosome 17q25, where mutations in the septin-9 (SEPT9) gene have been found.     

Stoichiometric alteration of PMP22 protein determines the phenotype of hereditary neuropathy with liability to pressure palsies

BACKGROUND: Hereditary neuropathy with liability to pressure palsies (HNPP) is caused by a 1.4-megabase deletion at chromosome 17p11.2, which bears the PMP22 gene and other genes. However, whether other genes besides PMP22 contribute to the phenotype is unknown. Whether any mutation within the coding region of the PMP22 gene ultimately causes HNPP by reducing the amount of peripheral myelin protein 22 (PMP22) expressed in myelin is also unknown. OBJECTIVE: To determine whether affected patients develop a phenotype identical to that found in HNPP and whether the leucine 7 frameshift (Leu7fs) mutation reduces PMP22 levels in myelin. DESIGN: We evaluated affected family members by neurological examination, electrophysiology, and skin biopsies. We identified a large family with a Leu7fs mutation of PMP22 (11 affected members across 3 generations) that predicts truncation of the protein prematurely and eliminates PMP22 expression from the mutant allele. RESULTS: We found that PMP22 levels were reduced in peripheral nerve myelin in dermal skin biopsies in patients with an Leu7fs mutation. Through clinical and electrophysiological evaluation, we also found that patients with the Leu7fs mutation were indistinguishable from patients with HNPP caused by deletion. We also found that a length-dependent axonal loss became pronounced in elderly patients with Leu7fs mutations, similar to what has been described in heterozygous knockout mice (pmp22 +/-). CONCLUSIONS: Taken together, these results confirm that the phenotypic expression is identical in patients with Leu7fs mutation and patients with HNPP caused by chromosome 17p11.2 deletion. They also demonstrate that reduction of PMP22 is sufficient to cause the full HNPP phenotype.     

Diagnostic strategy for familial and sporadic cases of neuropathy associated with 17p11.2 deletion

Clinical, electrophysiologic and molecular studies were performed on at-risk members of 14 families with hereditary neuropathy with liability to pressure palsies (HNPP), in order to detect asymptomatic carriers of the 17p11.2 deletion. Sporadic cases due to de novo deletion accounted for 21% of the investigated HNPP families. Approximately one half of deletion carriers were asymptomatic and did not display significant signs on clinical examination. The electrophysiologic hallmark in both symptomatic and asymptomatic deletion carriers was the presence of a nonuniform sensorimotor demyelinating polyneuropathy with conduction abnormalities preferentially located at common entrapment sites and distal nerve segments. A perfect correlation was found between the molecular and electrophysiologic analyses. A reliable screening method to detect clinically unaffected carriers of the deletion in families with HNPP was the evaluation of motor conduction in at least two nerves across usual entrapment sites, especially the ulnar nerve at the elbow, and evaluation of sensory conduction in the sural nerve. In sporadic cases due to a de novo deletion, electrophysiologic studies were suggestive but not sufficient for the diagnosis, and molecular analysis represented the most sensitive diagnostic tool.