神经病学英文ppt课件：04--Guillain-Barre-Syndrome.ppt

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1、Guillain-Barre Syndrome吉兰吉兰-巴雷综合征巴雷综合征DefinitionnGuillain-Barre syndrome(GBS)is a spectrum of immune-mediated neuropathies,characterized by acute onset,rapidly evolving,monophasic polyradiculoneuropathy,consisting of demyelinating and acute axonal degenerating forms.nGBS is a common cause of acute f

2、laccid paralysis worldwide,with an average incidence of about 0.6-1.9 per 100,000.PathophysiologynGBS is a postinfectious,immune-mediated disease.nMost patients report an infectious illness in the weeks prior to the onset of GBS.nMolecular mimicrynMany of the identified infectious agents are thought

3、 to induce production of antibodies that cross-react with specific gangliosides and glycolipids,such as GM1 and GD1b,that are distributed throughout the myelin in the peripheral nervous system,resulting in immunologic damage to the peripheral nervous system.nPathologic findings in GBSnlymphocytic in

4、filtration of spinal roots and peripheral nerves(cranial nerves may be involved as well),nfollowed by macrophage-mediated,multifocal stripping of myelin,nresults in defects in the propagation of electrical nerve impulses,with eventual absence or profound delay in conduction,causing flaccid paralysis

5、.Subtypes of Guillain-Barr syndromenClassic GBS nPharyngealcervicalbrachial weakness(3%,5%,1%)nParaparetic GBS(2%,6%)nBifacial weakness with paraesthesias(1%,5%,)nMiller Fisher syndrome(MFS)(5%,7%)nBickerstaff brainstem encephalitis(BBE)(7%)Clinical Manifestationn Classic GBSnWeakness and areflexia/

6、hyporeflexia in all four limbs,symmetric or asymmetric.nWeakness usually starts in the legs and ascends but may start in the armsnWeakness may be mild,moderate or complete paralysisnCranial-nerve-innervated muscles or respiratory muscles may be involved nMuscle stretch reflexes may be normal or exag

7、gerated in 10%of casesnElectrophysiological evidence of neuropathy.nPharyngealcervicalbrachial weaknessnOropharyngeal,neck and arm weakness and arm areflexia/hyporeflexianAbsence of leg weaknessnParaparetic GBSnLeg weakness and leg areflexia/hyporeflexianAbsence of arm weaknessnBifacial weakness wit

8、h paraesthesiasnFacial weakness and limb areflexia/hyporeflexianAbsence of ophthalmoplegia,ataxia and limb weaknessnMiller Fisher syndrome(MFS)nOphthalmoplegia,ataxia and areflexia/hyporeflexianAbsence of limb weakness and hypersomnolencenPresence of anti-GQ1b IgG antibodies(83%)nBickerstaff brainst

9、em encephalitis(BBE)nHypersomnolence and ophthalmoplegia and ataxianAbsence of limb weaknessnPresence of anti-GQ1b IgG antibodies(68%)Core features for GBS spectrum disordersnMostly symmetric pattern symmetric pattern of limb and/or motor cranial-nerve weaknessweaknessn nMonophasic disease course Mo

10、nophasic disease course with interval between onset and nadir of weakness of 12 h to 28 days,followed by clinical plateaunAbout 73%of patients reach a nadir of clinical function at one week,80%within 2 weeks and 98%at four weeks.nApproximately 25-30%of patients will require ventilatory assistance at

11、 some time during the illness,with a mortality rate as high as 20%occurring primarily in patients who require mechanical ventilation.Other features of GBSnPresence of distal paraesthesia at or before the onset of weakness.nTwo-thirds of cases of GBS are associated with an antecedent infection.nGBS c

12、an occur at any age,but there appears to be a bimodal distribution,with peaks in young adulthood(15-35 ys)and in the elderly(50-75 ys).Axonal variant of GBSnAcute motor axon neuropathy(AMAN)nA summer epidemics in Northern China of the axonal variant with Campylobacter Jejuni infection were reported,

13、this variant is much more common in Northern China,Japan and the rest of America.nFeatures of AMAN nacute onset,symptoms develop in 24-48 hrs,flaccid limbs weakness,rarely involved with sensation,severe and disable.n20-30%GM1 and GD1b antibody positivenElectrophysioligy demostrates axonal degneratio

14、n with decreased CMAPLaboratory featuresnAnalysis of the CSFnAlbuminocytologic dissociation-normal number of cells with an elevated protein concentration(greater than 45 mg/dL,with 3 cells/mm3).nThis finding may be delayed to the end of the first week,50%of the patients punctured in the first week a

15、nd 80%punctured in the second week(prior to treatment)had increased total protein.nMaximum protein values may be seen in third or fourth week.nElectrophysiologic studiesnBe essential to confirm the diagnosis and exclude its mimics.nThe earliest finding is prolongation or absence of the F-wave and ab

16、sent H reflex,which indicates demyelination of the proximal nerve roots.nMost patients demonstrate typical demyelination features 2-3 weeks after the onset of symptoms,which include slowed motor nerve conduction velocities,prolonged distal latencies and F-wave latency,and abnormal temporal dispersio

17、n.Median motor stimulationLeft:Two compound muscle action potentials were recorded from stimulation at the wrist and then at the elbow.The latencies of the responses were respectively 3.6 ms and 8 ms.The distance between elbow and wrist was measured at 24 cm.The conduction velocity is therefore:24 c

18、m/4.4 ms=54.5 m/s.Right:Patient with a demyelinating neuropathy.Note how the first response(wrist stimulation)has a long latency(7.6 ms)and how the second response(elbow stimulation)has a smaller amplitude,indicating partial conduction block.nSerum antibodies to specific gangliosides and glycolipids

19、 in myelin of peripheral nervenGM1 AMANnGD1b MFS and BBEDiagnosisnDiagnosis of GBS can be made clinically in the majority of patients,the features strongly support diagnosisn nAcute wAcute weakness,which may affect the limbs eakness,which may affect the limbs and/and/or the or the territories served

20、 by motor cranial nerves,territories served by motor cranial nerves,tends to be tends to be symmetric.symmetric.n nT The clinical course should be monophasic.he clinical course should be monophasic.nAntecedent infectious symptomsnDistal limb numbness,paraesthesia or pain,any of which becomes initial

21、 symptom.nAlbuminocytologic dissociationnTypical electrodiagnostic featuresnAlternative diagnosis should be excluded.However,other causes for rapidly developing flaccid weakness should be highly unlikely based upon history and if necessary additional tests.Differential DiagnosisnSpinal cord lesions(

22、poliomyelitis,transverse myelitis)nNeuromuscular junction disorders(botulism,myasthenia gravis)nPeripheral Neuropathies(toxic,infections,critical illness polyneuropathy)nMyopathies(periodic paralysis,dermatomyositis,critical illness myopathy)nFunctional paralysisTreatmentnTreatment of GBS has two co

23、mponents:supportive care and specific therapy.nGeneral supportive care remains the cornerstone of therapy.nAll GBS patients should be admitted to a hospital for close observation for respiratory compromise,cranial nerve dysfunction,and autonomic instability.nAs respiratory muscles weaken,elective en

24、dotracheal intubation and mechanical ventilation should be considered.nPatients with severe dysphagia may require nasogastric or feeding tubes.nPain and psychologic stress should be treated.nPhysiotherapy(passive limb movements and rehabilitation program),preventing deep vein thrombosis.nSpecific tr

25、eatment should be initiated soon after diagnosis.nHigh-dose intravenous immunoglobulin(IVIg administered at 0.4 g/kg/day for 5 days)nPlasmapheresis(40mg/kg,4-6 plasm exchanges over 5-8 days)nSpecific treatment has been shown to hasten recovery.Prognosis and RecoverynApproximately 80%patients with GB

26、S achieve a full and functional recovery within 6-12 months.nApproximately 7-15%patients have permanent neurologic sequelae including bilateral footdrop,intrinsic hand muscle wasting,and sensory ataxia.nThe mortality rate is 5%in tertiary care centers with a team of medical professionals who are familiar with GBS management.Thanks!