Effect of conduction block in classification and prognosis of Guillain-Barre syndrome

Aim:The aim was to investigate the electro-physiological characteristics in disease progression of Guillain-Barre syndrome(GBS)and observe the effect of conduction block(CB)in classification and severity of the disease.Methods:Two hundred and ninety-four patients with GBS were divided into acute inflammatory demyelinating poly-neuropathy(AIDP)group,acute motor axonal neuropathy(AMAN)group and equivocal group according to their electro-physiological results and then reclassificated after electro-physiological review.All of the patients were followed for 6 months since their attacks.Results:Bad prognosis is more pronounced in AMAN group than in AIDP group(P<0.05).Most of the patients classificated as AIDP transformed into AMAN when CB occurred in the early phase of the disease.There is a positive relationship between CB in the early phase of the disease and severity of illness(P<0.05),but CB showed no correlation with prognosis of the patients(P>0.05).Conclusion:CB in the early phase of GBS indicates the probability of AIDP transforming into AMAN;it suggests that patients with CB in the early phase of the disease might be in serious conditions in a certain extent.

Arrhythmic syncope: From diagnosis to management

Syncope is a concerning symptom that affects a large proportion of patients.It can be related to a heterogeneous group of pathologies ranging from trivial causes to diseases with a high risk of sudden death.However,benign causes are the most frequent,and identifying high-risk patients with potentially severe etiologies is crucial to establish an accurate diagnosis,initiate effective therapy,and alter the prognosis.The term cardiac syncope refers to those episodes where the cause of the cerebral hypoperfusion is directly related to a cardiac disorder,while arrhythmic syncope is cardiac syncope specifically due to rhythm disorders.Indeed,arrhythmias are the most common cause of cardiac syncope.Both bradyarrhythmia and tachyarrhythmia can cause a sudden decrease in cardiac output and produce syncope.In this review,we summarized the main guidelines in the management of patients with syncope of presumed arrhythmic origin.Therefore,we presented a thorough approach to syncope work-up through different tests depending on the clinical characteristics of the patients,risk stratification,and the management of syncope in different scenarios such as structural heart disease and channelopathies.

Clinical and Brain Magnetic Resonance Imaging Features in a Cohort of Chinese Patients with Kearns-Sayre Syndrome

Background： Kearns-Sayre syndrome （KSS） is a mitochondrial DNA （mtDNA） deletion disorder characterized by a triad of onset before 20 years of age, ophthalmoplegia, and pigmentary retinopathy. The heart and central nervous system are commonly involved. We summarized clinical and brain magnetic resonance imaging （M RI） features of a cohort of Chinese KSS patients. Methods： Nineteen patients confirmed by muscle biopsy and mtDNA analysis were enrolled. We examined clinical profiles, mainly focusing on changes in electrocardiogram （ECG） and brain MRI. The correlation between genotype and phenotype was statistically analyzed. Results： The mean age of onset was 9.6 ＋ 4.3 years, with all developing the classic triad at the time of diagnosis. Heart conduction block was detected in 63.2%, with four initially presenting as bundle branch block and developing into complete atrioventricular block over 3-72 months. Brain MRI showed symmetric high-T2 signals in 100% of cerebral and cerebellar white matter, as well as brainstem, 46.7% of basal ganglia, and 53.3% of thalamus. There were two patterns of cerebral white matter involvements, one with selective subcortical U-fibers and the other with periventricular white matter. The size of mtDNA deletion did not significantly correlate with age of onset or percentage of ragged blue fibers on muscle pathology. Conclusions： The clinical features of KSS evolve dynamically, affecting the cardiac conduction system predominantly, highlighting the significance of ECG monitoring. Brain MRI showed changes involving both the white matter and deep gray nuclei. Clinical presentation or severity of muscle pathological changes is not related to the size of mtDNA deletions.

Relevance of muscle biopsy for diagnosing multifocal motor neuropathy

Multifocal motor neuropathy （MMN） is a rare,.focal,inflammatory,demyelinating disease of the peripheral nerves with pure motor involvementJ MMN is clinically characterized by slowly progressive,asymmetric,distal,upper limb predominant weakness,in the absence of sensory disturbances） Weakness is usually multifocal and connected to a distinct motor nerve,such as the musculocutaneous nerve resulting in biceps weakness,the posterior interosseus nerve resulting in finger drop,the median,ulnar,or radial nerve resulting in dexterity problems or grip weakness,or the peroneal nerve resulting in a foot drop.Onset of clinical manifestations is between 20 and 50 years of age.The prevalence of MMN is reported as 1-2 per 100 000.2 MMN is three times more frequent in men as compared to women.

Different distributions of nerve demyelination in chronic acquired multifocal polyneuropathies

Background:Multifocal motor neuropathy(MMN),Lewis-Sumner syndrome(LSS),and many chronic inflammatory demyelinating polyradiculoneuropathies(CIDPs)are representative of acquired multifocal polyneuropathy and are characterized by conduction block(CB).This retrospective study aimed to investigate the demyelinating distribution and the selective vulnerability of MMN,LSS,and CIDP with CB(CIDP-CB)in nerves.Methods:Fifteen LSS subjects(107 nerves),24 MMN subjects(176 nerves),and 17 CIDP-CB subjects(110 nerves)were included.Their clinical information was recorded,blood and cerebrospinal fluid tests were conducted,and nerve conductions of the median,ulnar,radial,peroneal,and tibial nerves were evaluated.CB,temporal dispersion,distal motor latency(DML),and F-wave latency were recorded,and nerve conduction velocity,terminal latency index,and modified F-wave ratio were calculated.Results:CB was more likely to occur around the elbow in CIDP-CB than in MMN(78.6%vs.6.8%,P<0.01)but less likely to occur between the wrist and the elbow than in LSS(10.7%vs.39.3%,P<0.05).Tibial nerve CB was most frequently observed in MMN(47.4%,P<0.05).CIDP-CB was characterized by a prolonged DML in all nerves,and slow motor nerve velocity of the upper limb was significant when CB nerves were excluded(P<0.05).Conclusions:We report the different distributions of segmental and diffuse demyelination of the ulnar and tibial nerves in LSS,MMN,and CIDP-CB.These distinct distributions could help in differentiating among these conditions.

Role of the neuromuscular ultrasound in the diagnostic of the multifocal motor neuropathy

Multifocal motor neuropathy(MMN)is the one of the most common acquired immune-mediated inflammatory disorders of the peripheral nervous system.The diagnosis is based on the distribution pattern of the neurological semiology and the pathological changes of nerve conduction studies(NCS)in classical cases.However,in cases with subtle clinical presentation,an extended diagnostic workup may be needed,such as cerebrospinal fluid examination,laboratory tests,and nerve biopsy.NCS remain nowadays fundamental not only for the diagnosis,but also for the follow-up and measurement of response to immune-treatment in MMN.New challenges arose though,on how best to acquire a static and dynamic imaging of the peripheral nerves,aiming to provide a holistic approach to the nerve impairment.According to the literature,neuromuscular ultrasound is able to detect in MMN patients thickened or swollen cervical roots,peripheral nerves or brachial plexus,findings that suggest ongoing inflammation.This review provides a timely update on the nerve ultrasound findings in MMN.