周围神经病

周 围 神 经 病 Peripheral Neuropathy,Peripheral neuropathy is a large group of diseases: Damage of nerves outside of the spinal cord and brain. Dysfunction of these nerves. Caused by any of risk factors,Anatomy and function of peripheral nerve basic to understand neuropathy,Anatomy cranial nerve,olfactory nerve optic nerve oculomotor nerve trochlear nerve trigeminal nerve abducent nerve facial nerve vestibulocochlear nerve glossopharyngeal nerve vagus nerve accessory nerve hypoglossal nerve,Spinal nerves,Histology,Electrophysiology,Unmyelinated nerve fiberMyelinated nerve fiber,Functions,Motor nerveSensory nerveAutonomic nervereflex,Step 1: Clinical features of neuropathies history and examination of patient is the clues to diagnosis of neuropathy,Muscle weakness,Weakness in the arms or legs：difficulty walking, running, climb stairs , Stumbling or tiring easily. Difficulties with carrying a load of groceries, opening jars, turning door knobs, or combing hair. Cranial nerve paralysis: ophthalmoplegia, facial weakness, dysarthria, Respiratory insufficientMuscle atrophy. Reflex lost.,tips: Lower motor neurogenic damageAnatomic distributionSymmetric proximal distalAsymmetricsingle nerve multiple nerveplexus nerve root,Sensory abnormalities,Paresthesias Spontaneous sensations, numbness, tingling, pins and needles, prickling, burning, cold, pinching, sharp deep stabs, and electric shocks or buzzing. Dysesthesias Unpleasant abnormal sensations brought on by touching or other stimuli. Anesthesia a lack of sensation, leading to injuries, cuts and burns due to the lack of normal warning sensations. a lack of sensation of position, which leads to uncoordinated and unsteady walking.,tips:Hearing patients descriptionAnatomic distributionSymmetric “Glove and Stocking” distributionAsymmetric single nerve multiple nerve plexus nerve root,Autonomic Nerve Damage,blurred visiondecreased ability to sweat (anhidrosis)decreased ability to regulate body temperaturedisturbances of bladder functionorthostatic hypotensionConstipationdiarrhea, nausea after meals, abdominal bloatingsexual dysfunction (impotence)thinning of the skin, with easy bruisability and poor healing.,Step 2: Laboratory findings,nerve conduction study can confirm neuropathy and distinguish between damage to axons or the myelin sheath. electromyography differentiates myogenic (muscle tissue) from neurogenic (nerve tissue) causes of weakness and can confirm abnormal neuromuscular junctions. nerve biopsy is needed only when other tests are inconclusive.,Step3: causes Disease,炎症性/免疫介导型神经病中毒性神经病维生素缺乏遗传性神经病神经病伴肿瘤异常球蛋白血征相关的神经病感染相关的神经病系统性疾病外伤切割、挤压、嵌压,神经病伴肿瘤肿瘤的远隔效应肿瘤直接浸润异常球蛋白血征相关的神经病感染相关的神经病HIV麻风Lyme 病带状疱疹,系统性疾病糖尿病神经病甲状腺功能低下肾脏、肺、肝脏衰竭危重病神经病器官移植相关神经病外伤切割、挤压、嵌压,Pathomechanism,Wallerian degenerationaxonal degeneration neuronal degenerationsegmental demyelinationonion-bulb formationInterstitial neuropathy Vasculitic neuropathy,周围神经病的临床病理分类,对称性广泛性多神经病四肢远端对称性感觉运动障碍和皮肤植物神经功能异常。电生理检查：广泛神经传导异常和失神经电位。常见病因：中毒，代谢，遗传，免疫，结缔组织病等,单神经病/多发单神经病单个神经支配区域感觉异常，局部肌肉无力萎缩，非对称性。电生理检查：单神经常见原因：外伤，血管病，感染，肿瘤浸润，结缔组织病，甲低，等,吉兰巴雷综合征 Guillain-Barre syndrome,Guillain-Barre syndrome,1859年 Landrys Acending paralysis 1892年 acute febrile polyneuroritis 1918年 acute infective polineuritis 1916年 Guillain- Barre-Strohl syndrome,Pathologic changes of AIDP,MechanismAntecedent events for GBS,Infections viruses E-B virus Cytomegalovirus HIV Infuenza virus Coxsackie viruses Herpes simplex Hepatitis A and C viruses Others,Bacterial infection Campylobacter jejuni Mycoplasma pneumoniac Escherichia coli OthersParastic Mararia Toxoplasmosis,Antecedent events for GBS,Systemic illnesses Hodgkins disease lymphocytic leukemia Hyperthoidism Collagen vascular diseases Sarcoidosis Renal disease,Other medical condition Pregnancy Surgical procedures Bone marrow transplantation Immunizations Envenomization Drug ingestion,Immunopathology Mechanism molecular mimicry,Classification of GBS,AIDP Acute Inflammatory Demyelinating Polyneuropathy,Miller Fisher syndromeAcute panautonomic neuropathy(APN)acute sensory neuropathy, ASN,AMAN/AMSAN Acute Motor / Sensory Axonal Neuropathy,Concept of GBS,Acute or subacute onsetPeripheral neuropathyalbuminocytologic dissociation in CSF Immune-mediated neuropathyspontaneous recovery in most cases Monophasic course,Epidemiology,Incidence 1-2 cases per 100,000 general populationAll ages, mean age is 40yAll races and nationalitiesA slight male predominance,Clinical features of AIDP(1),50% have paresthesias and pain at beginningfollowed by weakness most begin in the legs 10% begin in the arm rarely begins in the faceweakness may involve: proximal of lower limbs upper limbs, facial muscle, pharyngeal and neck muscle， respiratory muscles , 1/3 of patients require ventilator !,Clinical features of AIDP(2),3-5% have complete ophthalmoplegia15% have autonomic manifestation labile blood pressure, cardiac arrhythmias, bladder dysfunction, constipation, abdominal distension, bloating,Neurologic examination,Quadriplegia: Muscle weakness and atrophyMuscle stretch reflexes are absent or depressedCranial nerve paralysis Sensory loss in a stocking-glove distributionPain in low back, buttocks, thigh Exacerbated by straight leg raisingAutonomic dysfunction,CSF,90% of cases, protein is elevated by the nadir of illness without leukocytosis.5% of cases, pleocytosis 10 (10-20) cells/mm3.OB (oligoclonal bands) IgG/24h increasingMBP increasingSpecial Antibodies : GM1,Electro-diagnostic studies,AIDP: Demyelination Axonal,AMAN/AMSAN: Axonal Demyelination,Sural nerve biopsy,demyelinating and remyelinatingaxonal degenerationInfiltration of inflammatory cells : lymphocytes,macrophagesdeposition of Ig and complements,Course,Most patients of AIDP become maximally weak within 11-12 days of onset. AMSN and AMAN usually reach nadir within 6 days.Most patients progress steadily, occasionally, stuttering or stepwise course.The average time to onset of recovery is 4 weeks.,Diagnosis,Clinical feature: acute progressive quadriplegia CSF: dissociation of protein/leukocytesF-wave, NCV, EMG, MEPSural nerve biopsySpecial antibodies in serum and CSF,Differential diagnosis,Periodic paralysisPoliomyelitisMyelitisToxic neuropathyLymes diseaseMyositis,Treatment of GBS （1）,Support carePrevent complicationsRehabilitationPsychology supportimmunotherapy,Treatment of GBS （2）,ImmunotherapyPlasma exchange (PE)Iv IgPE + IV Ig?Corticosteroid? IV Ig Corticosteroid？,Prognosis,80% recovery within 6 months15% have severe residual disabilityMortality rate is 3%-5%. Cause of death: ARDS with or without sepsis, dysautonomia.,Chronic inflammatory demyelinating polyradiculoneuritis (CIDP),Similar with AIDPCourses: chronic progressive 2 months or relapse-remissionPathology: demyelination, axonal degeneration, onion bulb