Diagnostic value of F wave changes in patients with Charcot-Marie-Tooth1A and chronic inflammatory demyelinating polyneuropathy / 北京大学学报(医学版)

OBJECTIVE@#To analyze and compare the characteristics and causes of F wave changes in patients with Charcot-Marie-Tooth1A (CMT1A) and chronic inflammatory demyelinating polyneuropathy (CIDP).@*METHODS@#Thirty patients with CMT1A and 30 patients with CIDP were enrolled in Peking University Third Hospital from January 2012 to December 2018. Their clinical data, electrophysiological data(nerve conduction velocity, F wave and H reflex) and neurological function scores were recorded. Some patients underwent magnetic resonance imaging of brachial plexus and lumbar plexus, and the results were analyzed and compared.@*RESULTS@#The average motor conduction velocity (MCV) of median nerve was (21.10±10.60) m/s in CMT1A and (31.52±12.46) m/s in CIDP. There was a significant difference between the two groups (t=-6.75, P < 0.001). About 43.3% (13/30) of the patients with CMT1A did not elicit F wave in ulnar nerve, which was significantly higher than that of the patients with CIDP (4/30, 13.3%), χ2=6.65, P=0.010. Among the patients who could elicit F wave, the latency of F wave in CMT1A group was (52.40±17.56) ms and that in CIDP group was (42.20±12.73) ms. There was a significant difference between the two groups (t=2.96, P=0.006). The occurrence rate of F wave in CMT1A group was 34.6%±39%, and that in CIDP group was 70.7%±15.2%. There was a significant difference between the two groups (t=-5.13, P < 0.001). The MCV of median nerve in a patient with anti neurofascin 155 (NF155) was 23.22 m/s, the latency of F wave was 62.9-70.7 ms, and the occurrence rate was 85%-95%. The proportion of brachial plexus and lumbar plexus thickening in CMT1A was 83.3% (5/6) and 85.7% (6/7), respectively. The proportion of brachial plexus and lumbar plexus thickening in the CIDP patients was only 25.0% (1/4, 2/8). The nerve roots of brachial plexus and lumbar plexus were significantly thickened in a patient with anti NF155 antibody.@*CONCLUSION@#The prolonged latency of F wave in patients with CMT1A reflects the homogenous changes in both proximal and distal peripheral nerves, which can be used as a method to differentiate the CIDP patients characterized by focal demyelinating pathology. Moreover, attention should be paid to differentiate it from the peripheral neuropathy caused by anti NF155 CIDP. Although F wave is often used as an indicator of proximal nerve injury, motor neuron excitability, anterior horn cells, and motor nerve myelin sheath lesions can affect its latency and occurrence rate. F wave abnormalities need to be comprehensively analyzed in combination with the etiology, other electrophysiological results, and MRI imaging.

Diagnostic value of tremor analysis in identifying the early Parkinson's syndrome / 北京大学学报(医学版)

OBJECTIVE@#To investigate the diagnostic value of tremor analysis in early stages of Parkinson's syndrome, when the clinical symptoms of tremor onset are not unilaterally often able for a definite diagnosis to be made.@*METHODS@#We included 70 patients with unilateral tremor, under 45 years old and disease duration within 3 years enrolled in Peking University Third Hospital from January, 2014 to December 2015. We recorded clinical features, unified Parkinson's disease rating scale (UPDRS)-III, non-motor symptom (NMS) scores. Tremor analysis and transcranial sonography were performed for all the patients. Based on the results of tremor analysis, we arbitrarily divided the patients into 3 groups: (1) The patients with classical Parkinson's syndrome manifestations on one side (25 cases); (2) The patients with classical Parkinson's syndrome manifestations on both sides (15 cases); (3) The patients with no classical Parkinson's syndrome manifestations (30 cases). The patients were monitored every 6 months to 3 years, until the final diagnosis was made.@*RESULTS@#There was no significant difference in age, gender distribution, Hamilton depression scale (HAMD) scores and H-Y scores among the three groups (P>0.05). The average UPDRS-III motor scores of the three groups were significantly different (P=0.001), with 18.23, 18.79 and 14.67, respectively. The average scores of NMS were significantly different, with 15.81, 17.07 and 9.90, respectively (P<0.001). The positive rates of transcranial sonography (TCS) in the three groups were 48.0%, 60.0% and 26.67%, with no significant difference (P=0.702). After three years of follow-up, 35 patients (50%) met the diagnostic criteria of Parkinson's disease of International Parkinson and Movement Disorder Society (MDS) in 2015, 19 patients (27.1%) met the criteria of idiopathic tremor, and 7 patients (10%) met the criteria of Parkinson's plus syndrome. The sensitivity and specificity of tremor analysis for early diagnosis of Parkinson's disease were 82.8% and 68.6%, respectively. Compared with TCS, the sensitivity and specificity of TCS were 65.7% and 62.9%. There were consistency (Kappa=0.568) and significant difference (P=0.031) between the two methods.@*CONCLUSION@#Tremor analysis is sensitive and a superior way in identifying early Parkinson's syndrome patients with tremor dominant manifestation. The combination of non-motor symptoms and transcranial sonography are also needed at diagnosis.