肛门括约肌肌电图、体位性低血压和头晕对多系统萎缩的诊断价值

Value of Anal Sphincter Electromyography,Orthostatic Hypotension and Dizziness in Diagnosing Multiple System Atrophy

目的探讨肛门括约肌肌电图(ASEMG)、体位性低血压和头晕对多系统萎缩(MSA)的鉴别诊断价值。方法检索我院ASEMG数据库,分别以头晕患者(MSA组和非MSA组)、卧立位血压不达标患者(MSA组和非MSA组)以及很可能MSA患者(卧立位血压达标组和不达标组)为目标人群,比较ASEMG和卧立位血压的特点。结果476例患者曾行ASEMG检查,其中以头晕为首发症状的69例,MSA组(33例)和非MSA组(36例)的平均时限[(14.6±2.1)和(12.8±2.0)ms,P<0.01]和卫星电位出现率[(22.7±11.8)%和(12.2±8.9)%,P<0.01]差异具有显著性,卧立位血压达标率(84.6%和55.2%)及收缩压和舒张压的差值两组差异均无显著性。162例有头晕症状的患者中,MSA组(90例)和非MSA组(72例)的平均时限[(15.3±2.7)和(12.8±1.9)ms,P<0.001]、卫星电位出现率[(25.4±12.8)%和(13.5±10.4)%,P<0.001]和舒张压差[(18.5±17.0)和(11.7±12.7)mmHg,P<0.05]差异均有显著性,卧立位血压达标率(60%和41.9%)和收缩压的差值两组差异无显著性。146例卧立位血压未达到标准,MSA组(61例)和非MSA组(85例)的平均时限[(15.0±2.4)和(12.8±1.7)ms,P<0.001]和卫星电位出现率[(22.0±12.2)%和(10.6±8.5)%,P<0.001]差异均有显著性。125例很可能MSA患者中,卧立位血压达标组(44例)与未达标组(36例)的平均时限[(15.5±2.4)和(15.9±2.2)ms]和卫星电位出现率[(24.3±12.6)%和(22.7±12.4)%]差异无显著性。达标组出现头晕的比例和以头晕为首发症状的比例分别为93.2%(41例)和52.3%(23例),未达标组分别为44.4%(16例)和8.3%(3例)。结论当怀疑头晕患者为MSA时,ASEMG的诊断价值优于体位性低血压。无论MSA患者的卧立位血压是否达到标准,ASEMG均可表现为神经源性损害,有助于MSA的早期诊断。

Objective To explore the value of anal sphincter electromyography （ASEMG） , orthostatic hypotension （ OH）, and dizziness in diagnosing multiple system atrophy （ MSA ）. Method The characteristics of ASEMG and OH were compared among patients with dizziness （ MSA and non-MSA）, patients without OH （ MSA and non-MSA） , and patients with probable MSA （ OH and non-OH）. Results Totally 476 patients underwent ASEMG examinations. Dizziness was the onset symptom in 69 patients. Between the MSA group and non-MSA group, the mean duration of dizziness [ （ 14.6 ±2.1 ） vs. （ 12.8 ±2.0） ms, P 〈 0.01 ] and satellite potential occurrence rate [ （ 22.7 ±11.8 ） % vs. （ 12.2 ±8.9 ） %, P 〈 0. 01 ] were significantly different, while the OH rate （84.6% vs. 55.2% ） and the difference of the blood pressure between standing and supine positions were not significantly different. In 162 patients with symptom of dizziness, the mean duration of dizziness [ （ 15.3 ± 2.7 ） vs. （ 12.8 ± 1.9 ） ms, P 〈 0. 001 ], satellite potential occurrence rate [（25.4± 12.8）% vs. （13.5 ± 10.4）%, P 〈0.001], and difference of the diastolic blood pressure [ （ 18.5 ± 17.0） vs. （ 11.7 ± 12.7 ） mmHg, P 〈 0.05 ] were significantly different between the MSA group and non-MSA group, while the normal rate of blood pressure at standing position （60% vs. 41.9% ） and the difference of systolic blood pressure were not significantly different. In 146 patients with abnormal blood pressure at standing and supine positions, the mean duration of dizziness [ （ 15.0 ± 2. 4 ） vs. （ 12.8 ± 1.7 ） ms, P 〈 0. 001 ] and satellite potential occurrence rate [ （22.0 ± 12.2） % vs. （ 10.6 ± 8.5 ） %, P 〈 0. 001 ] were significantly different between the MSA group （ n = 61 ） and non-MSA group （ n = 85 ）. In 125 patients with probable MSA, the mean duration of dizziness [ （ 15.5 ± 2.4） vs. （ 15.9 ± 2.2） ms, P 〉 0.05 ] and satellite potential occurrence rate [ （ 24.3 ± 12.6 ） % vs. （ 22.7 ± 12.4 ） %, P 〉 0.05 ] were not significantly different between those with OH and those without OH. The rates of dizziness and the percentage of dizziness as the onset symptom were 93.2% and 52.3% in OH group and 44.4% and 8.3% in non-OH group. Conclusions ASEMG is better than OH in diagnosing patients with dizziness suspected as MSA. Neurogenic lesion can be found by ASEMG in patients without OH, which is helpful in the early diagnosis of MSA.