Motor nerve conduction and clinical characteristics of POEMS syndrome / 中华神经科杂志

Objective@#To summarize the clinical characteristics and nerve conduction damage in patients with early POEMS syndrome, and to explore the value of segment nerve conduction velocity in the diagnosis of POEMS syndrome. @*Methods@#A total of 73 patients with POEMS syndrome and 27 healthy controls in Peking Union Medical College Hospital from September 2009 to June 2019 were recruited in this study. The motor and sensory nerve conduction characteristics of median, ulnar, tibial, and peroneal nerves and the clinical features of the participants were analyzed. The analysis parameters included: (1) distal motor latency (DML), compound muscle action potential (CMAP); (2) the median velocity from elbow to wrist, the median velocity from axillary to elbow, the ulnar velocity from the site below elbow to wrist, the ulnar velocity from the site above elbow to below elbow, the ulnar velocity from axillary to the site above elbow, the tibial velocity from ankle to knee, the peroneal velocity from ankle to fibulae capitulum; (3) sensory nerve conduction velocity and amplitude of these nerves; (4) terminal latency indices (TLI) of median; (5) motor nerve conduction blocks. @*Results@#Peripheral nerve damages were the initial symptoms in thirty-two patients in this group, accounting for 43.8% (32/73), and 81.3% (26/32) of these patients only showed numbness in lower extremities. All POEMS syndrome patients with numbness had abnormal sensory nerve conduction, and 9.5% (7/73) of patients without sensory symptoms also had abnormal sensory nerve conduction. On the other hand, the decrease of CMAP amplitude corresponded to clinical muscle strength decline and motor dysfunction. In the patients with POEMS syndrome, motor nerve conduction in the lower limbs were more likely to be affected and the damages were more severe than in the upper limbs: the proportion of CMAP disappearance in the lower limbs and upper limbs was 47.6% (112/235) vs 2.8% (7/252; χ2=133.698, P<0.01). Sensory nerve conduction damage was more severe than motor nerve conduction: the proportion of amplitude disappearance in sensory and motor conduction was 43.0% (141/328) vs 24.4% (119/487; χ2=133.698, P<0.01). The slowing of motor nerve conduction velocity was more common than the decrease of CMAP amplitude: the rate of slowing down of motor nerve conduction was 88.7% (432/487), and the rate of decrease of amplitude was 52.8% (257/487; χ2=151.905, P<0.01). The DML of median and ulnar nerve in the POEMS syndrome group was longer than that in the control group (median nerve: 4.4 (3.7, 5.0) ms vs 3.2 (3.0, 3.5) ms, U=854.000, P<0.01; ulnar nerve: 3.1 (2.7, 3.8) ms vs 2.5 (2.2, 2.7) ms, U=1 077.500, P<0.01). The TLI of median nerve in patients with POEMS syndrome was significantly higher than that of healthy controls (0.40±0.11 vs 0.35±0.06, t=3.466, P=0.001). There was no statistically significant difference in nerve conduction velocity between the forearm segment and the upper arm segment in the POEMS group. @*Conclusions@#Neurological damages were common in patients with POEMS syndrome with sensory nerve damage often being the initial clinical manifestation. In patients with POEMS syndrome, the nerve damage in the lower limbs was more severe than in the upper limbs, and sensory nerve damage was more severe than motor nerve damage. Segmental motor nerve conduction results suggested that demyelination damage occurred earlier than axonal damage, and proximal lesions were slightly heavier than distal lesions. No conduction block was detected in these patients. These characteristics of segmental nerve conduction can provide more evidence for clinical diagnosis of POEMS syndrome.

Low frequency repetitive nerve stimulation in anti-muscle specific tyrosine kinase receptor antibody positive myasthenia gravis / 中华神经科杂志

Objective To describe the repetitive nerve stimulation ( RNS) in anti-muscle specific tyrosine kinase (anti-MuSK) receptor antibody positive myasthenia gravis (MG), and compare with anti-acetylcholine receptor ( AChR ) positive myasthenia gravis , to figure out characteristics of anti-MuSK receptor MG.Methods We analyzed clinical and RNS data of nine anti-MuSK receptor MG and 19 age-and sex-matched anti-AChR MG.RNS was performed to the abductor digiti minimi , orbicularis oculi or musculus frontalis and trapezius .Results In anti-MuSK receptor MG , abnormal RNS in facial nerve was seen in 6/9 and in trapezius was 5/9, in limbs was 0.In anti-AChR MG, abnormal RNS in facial nerve was seen in 13/19, in trapezius was 18/19 and in limbs was 7/19.Abnormal in any of three parts was 8/9 and 19/19 in anti-MuSK receptor MG and anti-AChR MG, respectively.The RNS decrementing was more obvious in facial nerve in anti-Musk receptor MG than in anti-AChR MG.Negative prostigmin test was independently associated with anti-MuSK receptor MG (OR=4.25,95% CI 2.19 -15.25, P=0.015). Conclusions Abnormal RNS in any of three parts is more pronounced in anti-AChR MG compared with anti-MuSK receptor MG.RNS decrementing in facial nerve is more obvious in anti-AChR MG.Negative prostigmin test can aid in early suspicion in anti-MuSK receptor MG.

Characteristics of giant F-waves in amyotrophic lateral sclerosis / 中华神经科杂志

Objective To investigate the characteristics of giant F-waves in patients with amyotrophic lateral sclerosis ( ALS ) and the relationship between giant F-waves and disease phenotype . Methods Motor nerve conduction study and F-waves were performed to the median , ulnar, tibial and peroneal nerves of 55 patients with ALS and 52 healthy volunteers.A series of 100 electrical stimuli were employed to obtain F-waves.The following F-wave variables were estimated: frequency of giant F-waves, frequency of patients with giant F-waves, the relationship between giant F-waves and lower motor neuron dysfunction , the relationship between giant F-waves and upper motor neuron dysfunction , the relationship between giant F-waves and disease duration , the relationship between giant F-waves and disease severity , and the relationship between giant F-waves and disease progression rate ( DPR).Results The frequencies of giant F-waves ( ALS: median nerve 0.00 ( 0.00 )%, ulnar nerve 0.00 ( 1.02 )%, tibial nerve 0.00 (0.00)%,peroneal nerve 0.00(0.00)%.Normal controls:median nerve 0.00(0.00)%,Z=-2.360, P=0.018;ulnar nerve 0.00(0.00)%,Z=-3.997,P<0.01;tibial nerve 0.00(0.00)%,Z=-3.006, P=0.003;peroneal nerve 0.00(0.00)%,Z=-3.006,P=0.003) and the frequencies of patients with giant F-waves (ALS:median nerve 13/55,23.6%,ulnar nerve 26/55,47.2%,tibial nerve 18/55,32.7%, peroneal nerve 16/55, 29.1%.Normal controls:median nerve 4/52,7.7%,χ2 =0.024,P=0.024;ulnar nerve 7/52,13.5%, χ2 =14.326,P<0.01; tibial nerve 6/52,11.5%, χ2 =6.897,P=0.009; peroneal nerve 6/52,11.5%,χ2 =5.042,P=0.025) in the median nerve, ulnar nerve, tibial nerve and peroneal nerve were significantly increased compared with those of the normal controls .No significant differences were found in the frequencies of upper motor neuron dysfunction between nerves with giant F -waves and nerves without giant F-waves in the median nerves , ulnar nerves , tibial nerves and peroneal nerves of ALS patients . The compound muscle action potential amplitude of nerves with giant F-waves was significantly higher than those of nerves without giant F-waves in the median nerves (11.20(5.80) mV vs 5.90(8.50) mV,t=2.883,P=0.004)and tibial nerves ((13.20 ±4.61) mV vs (10.69 ±4.76) mV,t=-2.222,P=0.028) of the ALS patients.No significant correlation was detected between the frequency of giant F-waves and disease duration or ALS functional rating scale in the ALS patients , while the frequency of giant F-waves correlated inversely with the DPR(r=-0.287,P=0.034).No significant differences were detected in disease duration between ALS patients with giant F-waves and those without giant F-waves.Compared with those in ALS patients without giant F-waves, the revised ALS Functional Rating Scale score (37.00(3.00) vs 42.00(4.75),Z=3.197,P=0.001) was more, the DPR (0.50(0.35)vs 0.90(0.43),Z=-3.033, P=0.002 ) was slower in ALS patients with giant F-waves. Conclusions The giant F-waves were significantly increased in the ALS patients than those in the healthy volunteers and were distributed asymmetrically between the left and right sides .These electrophysiological characteristics of ALS patients fitted well with progressive loss of anterior horn cells , and indicated differential involvement of different spinal motoneuron pools in the ALS patients .No correlations were found between the frequency of giant F-waves and disease duration .The appearance of giant F-waves may indicate loss of spinal motoneuron early in the disease course , and may suggest that the degree of reinnervation and functional compensation are relatively good after motoneuron loss .

Low frequency repetitive nerve stimulation in anti-muscle specific tyrosine kinase receptor antibody positive myasthenia gravis / 中华神经科杂志

Objective To describe the repetitive nerve stimulation ( RNS) in anti-muscle specific tyrosine kinase (anti-MuSK) receptor antibody positive myasthenia gravis (MG), and compare with anti-acetylcholine receptor ( AChR ) positive myasthenia gravis , to figure out characteristics of anti-MuSK receptor MG.Methods We analyzed clinical and RNS data of nine anti-MuSK receptor MG and 19 age-and sex-matched anti-AChR MG.RNS was performed to the abductor digiti minimi , orbicularis oculi or musculus frontalis and trapezius .Results In anti-MuSK receptor MG , abnormal RNS in facial nerve was seen in 6/9 and in trapezius was 5/9, in limbs was 0.In anti-AChR MG, abnormal RNS in facial nerve was seen in 13/19, in trapezius was 18/19 and in limbs was 7/19.Abnormal in any of three parts was 8/9 and 19/19 in anti-MuSK receptor MG and anti-AChR MG, respectively.The RNS decrementing was more obvious in facial nerve in anti-Musk receptor MG than in anti-AChR MG.Negative prostigmin test was independently associated with anti-MuSK receptor MG (OR=4.25,95% CI 2.19 -15.25, P=0.015). Conclusions Abnormal RNS in any of three parts is more pronounced in anti-AChR MG compared with anti-MuSK receptor MG.RNS decrementing in facial nerve is more obvious in anti-AChR MG.Negative prostigmin test can aid in early suspicion in anti-MuSK receptor MG.

Characteristics of giant F-waves in amyotrophic lateral sclerosis / 中华神经科杂志

Objective To investigate the characteristics of giant F-waves in patients with amyotrophic lateral sclerosis ( ALS ) and the relationship between giant F-waves and disease phenotype . Methods Motor nerve conduction study and F-waves were performed to the median , ulnar, tibial and peroneal nerves of 55 patients with ALS and 52 healthy volunteers.A series of 100 electrical stimuli were employed to obtain F-waves.The following F-wave variables were estimated: frequency of giant F-waves, frequency of patients with giant F-waves, the relationship between giant F-waves and lower motor neuron dysfunction , the relationship between giant F-waves and upper motor neuron dysfunction , the relationship between giant F-waves and disease duration , the relationship between giant F-waves and disease severity , and the relationship between giant F-waves and disease progression rate ( DPR).Results The frequencies of giant F-waves ( ALS: median nerve 0.00 ( 0.00 )%, ulnar nerve 0.00 ( 1.02 )%, tibial nerve 0.00 (0.00)%,peroneal nerve 0.00(0.00)%.Normal controls:median nerve 0.00(0.00)%,Z=-2.360, P=0.018;ulnar nerve 0.00(0.00)%,Z=-3.997,P<0.01;tibial nerve 0.00(0.00)%,Z=-3.006, P=0.003;peroneal nerve 0.00(0.00)%,Z=-3.006,P=0.003) and the frequencies of patients with giant F-waves (ALS:median nerve 13/55,23.6%,ulnar nerve 26/55,47.2%,tibial nerve 18/55,32.7%, peroneal nerve 16/55, 29.1%.Normal controls:median nerve 4/52,7.7%,χ2 =0.024,P=0.024;ulnar nerve 7/52,13.5%, χ2 =14.326,P<0.01; tibial nerve 6/52,11.5%, χ2 =6.897,P=0.009; peroneal nerve 6/52,11.5%,χ2 =5.042,P=0.025) in the median nerve, ulnar nerve, tibial nerve and peroneal nerve were significantly increased compared with those of the normal controls .No significant differences were found in the frequencies of upper motor neuron dysfunction between nerves with giant F -waves and nerves without giant F-waves in the median nerves , ulnar nerves , tibial nerves and peroneal nerves of ALS patients . The compound muscle action potential amplitude of nerves with giant F-waves was significantly higher than those of nerves without giant F-waves in the median nerves (11.20(5.80) mV vs 5.90(8.50) mV,t=2.883,P=0.004)and tibial nerves ((13.20 ±4.61) mV vs (10.69 ±4.76) mV,t=-2.222,P=0.028) of the ALS patients.No significant correlation was detected between the frequency of giant F-waves and disease duration or ALS functional rating scale in the ALS patients , while the frequency of giant F-waves correlated inversely with the DPR(r=-0.287,P=0.034).No significant differences were detected in disease duration between ALS patients with giant F-waves and those without giant F-waves.Compared with those in ALS patients without giant F-waves, the revised ALS Functional Rating Scale score (37.00(3.00) vs 42.00(4.75),Z=3.197,P=0.001) was more, the DPR (0.50(0.35)vs 0.90(0.43),Z=-3.033, P=0.002 ) was slower in ALS patients with giant F-waves. Conclusions The giant F-waves were significantly increased in the ALS patients than those in the healthy volunteers and were distributed asymmetrically between the left and right sides .These electrophysiological characteristics of ALS patients fitted well with progressive loss of anterior horn cells , and indicated differential involvement of different spinal motoneuron pools in the ALS patients .No correlations were found between the frequency of giant F-waves and disease duration .The appearance of giant F-waves may indicate loss of spinal motoneuron early in the disease course , and may suggest that the degree of reinnervation and functional compensation are relatively good after motoneuron loss .

The characteristics of F-waves in patients with Kennedy's disease / 中华神经科杂志

Objective To investigate the characteristics of F-waves in patients with Kennedy's disease.Methods Thirty two patients with Kennedy's disease and 30 male healthy volunteers,who visited the Department of Neurology,Peking Union Medical College Hospital between August 2013 and July 2014,were recruited consecutively for this study.Motor nerve conduction study and F-wave examination were performed on the median,ulnar,tibial and peroneal nerves of all participants.A series of 100 electrical stimuli were employed to obtain F-waves.The F-wave parameters in all tested nerves were compared between patients with Kennedy's disease and normal controls including F-wave minimum latency,F-wave persistence,mean and maximum F-wave amplitude,the frequency of giant F-waves.Results The mean Fwave amplitude (median nerve:patients with Kennedy's disease 375.0 (298.3) μV,healthy volunteers 297.0(145.0) μV,Z =-3.378,P ＜0.01;ulnar nerve:patients with Kennedy's disease 397.5(295.0) μV,healthy volunteers 293.0 (101.8) μV,Z =-3.968,P ＜ 0.01;tibial nerve:patients with Kennedy's disease 374.5 (227.3) μV,healthy volunteers 294.0 (160.5) μV,Z =-3.144,P =0.002;peroneal nerve:patients with Kennedy's disease 346.5 (292.8) μV,healthy volunteers 146.5 (69.3) μV,Z =-6.864,P ＜ 0.01),maximum F-wave amplitudes (median nerve:patients with Kennedy's disease 1 291.0 (952.0) μV,healthy volunteers 846.5 (523.0) μV,Z =-4.823,P ＜ 0.01;ulnar nerve:patients with Kennedy's disease 1 663.5 (1 374.0) μV,healthy volunteers 760.5 (341.8) μV,Z =-6.813,P ＜ 0.01;tibial nerve:patients with Kennedy's disease (1 054.1 ± 451.6) μV,healthy volunteers (652.5-± 172.5) μV,t =5.380,P ＜ 0.01;peroneal nerve:patients with Kennedy's disease (840.4 ± 494.1) μV,healthy volunteers (370.2 ± 202.0) μV,t =6.475,P ＜ 0.01),frequency of giant F-waves (median nerve:patients with Kennedy's disease 0.0％ (7.2％),healthy volunteers 0.0％ (0.0％),Z =-5.149,P ＜ 0.01;ulnar nerve:patients with Kennedy's disease 3.1％ (10.5％),healthy volunteers 0.0％ (0.0％),Z =-7.026,P ＜0.01;tibial nerve:patients with Kennedy's disease 0.0％ (3.3％),healthy volunteers 0.0％ (0.0％),Z =-4.651,P ＜0.01;peroneal nerve:patients with Kennedy's disease 3.3％ (28.2％),healthy volunteers 0.0％ (0.0％),Z =-5.532,P ＜0.01),and frequencies of patients with giant F-waves (median nerve:patients with Kennedy's disease 78.1％ (25/32),healthy volunteers 10.0％ (3/30),x2 =29.016,P ＜ 0.01;ulnar nerve:patients with Kennedy's disease 87.5％ (28/32),healthy volunteers 10.0％ (3/30),x2 =37.200,P ＜ 0.01;tibial nerve:patients with Kennedy's disease 62.5％ (20/32),healthy volunteers 6.7％ (2/30),x2 =21.085,P ＜ 0.01;peroneal nerve:patients with Kennedy's disease 68.8 ％ (22/32),healthy volunteers 10.0％ (3/30),x2 =22.209,P ＜ 0.01) in all nerves examined were significantly higher in patients with Kennedy's disease than in the normal controls.The F-wave persistence in all nerves examined was significantly lower than in the normal controls (median nerve:patients with Kennedy's disease 52.5％ (36.3％),healthy volunteers 98.0％ (7.0％),Z =9.010,P ＜ 0.01;ulnar nerve:patients with Kennedy's disease 71.0％ (28.3％),healthy volunteers 100.0％ (1.0％),Z =9.455,P ＜ 0.01;tibial nerve:patients with Kennedy's disease 100.0％ (2.0％),healthy volunteers 100.0％ (0.0％),Z =4.255,P ＜ 0.01;peroneal nerve:patients with Kennedy's disease 33.1％ ± 23.9％,healthy volunteers 46.9％ ± 27.2％,t =-2.848,P =0.007).Giant F-waves were detected in multiple nerves and often appeared symmetrically on the same nerves between the left and right sides in patients with Kennedy's disease.No significant correlations were found between the pooled frequency of giant F-waves and disease duration in patients with Kennedy's disease(r =0.162,P =0.418).Conclusions The results showed increased F-wave amplitudes,increased number of giant F-waves,especially giant F-waves detected in multiple nerves or appearing symmetrically combined with low persistence,consistent with the pathologic features of chronic and unselected loss of anterior horn cells in patients with Kennedy's disease.