PREDICTIVE FACTORS FOR MYASTHENIC CRISIS AFTER VIDEOSCOPIC THYMECTOMY IN PATIENTS WITH MYASTHENIA GRAVIS HYUNG SEOK LEE, MD,1 HYE SUN LEE, MS,2 HYO EUN LEE, MD,1 MI KYUNG BAE, MD,3 KYUNG YOUNG CHUNG, MD,3 HA YOUNG SHIN, MD,1 YOUNG-CHUL CHOI, MD,1 and SEUNG MIN KIM, MD1 1
Department of Neurology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea Department of Biostatistics, Yonsei University College of Medicine, Seoul, Republic of Korea 3 Department of Thoracic and Cardiovascular Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea Accepted 25 November 2014 2
ABSTRACT: Introduction: Predictive factors for myasthenic crisis after transsternal thymectomy have been reported, but little is known about myasthenic crisis after videoscopic thymectomy (MCAVT). Methods: We investigated 146 myasthenia gravis patients who underwent videoscopic thymectomy. Results: Patients with MCAVT had a lower forced vital capacity (FVC) (2.1 vs. 3.0 L, P < 0.001) than those without. Low-frequency repetitive nerve stimulation showed decremental responses of the orbicularis oculi (47.1% vs. 18.1%, P 5 0.001) and nasalis muscles (54.1% vs. 21.4%, P < 0.001), which were more pronounced in patients with MCAVT than those without. According to multivariate analysis, FVC (OR 0.144, 95% confidence interval [CI], 0.044–0.479, P 5 0.002) and decremental response of orbicularis oculi (odds ratio, 1.029; 95% CI, 1.001–1.058, P 5 0.044) were independently associated with MCAVT. Conclusions: FVC and decremental response of orbicularis oculi were associated with MCAVT. Muscle Nerve 52: 216–220, 2015
Myasthenia
gravis (MG) is an autoimmune disorder affecting neuromuscular transmission. Approximately 75% of MG patients have abnormal histopathology of the thymus,1 which may play an important role in the pathogenesis. Thymectomy is one of the therapeutic options in MG, and thymectomy is performed in patients with thymoma, or it can be performed to improve long-term outcomes in patients without thymoma. Although transsternal thymectomy is a common, traditional surgical technique, videoscopic thymectomy recently became popular with its minimally invasive and superior cosmetic advantages, especially because MG occurs more commonly in young women.2,3 Myasthenic crisis, which is a severe exacerbation in weakness, often life threatening, may be precipitated by various factors, including infection, emotional stress, high-dose corticosteroid therapy, or surgery. MG patients who undergo thymectomy Abbreviations: AChR-Ab, anti-acetylcholine receptor binding antibody; ADM, abductor digiti minimi; BMI, body mass index; CI, confidence interval; CMAP, compound muscle action potentials; FCU, flexor carpi ulnaris; FVC, forced vital capacity; IVIg, intravenous immunoglobulin; LF-RNS, low-frequency repetitive nerve stimulation; MCAT, myasthenic crisis after thymectomy; MCAVT, myasthenic crisis after videoscopic thymectomy; MG, myasthenia gravis; PLEX, plasma exchange; QMGS, quantitative myasthenia gravis score. Key words: myasthenia gravis; myasthenic crisis; prognosis; thymectomy; videoscopic thymectomy Correspondence to: H. Y. Shin; e-mail: [email protected] C 2014 Wiley Periodicals, Inc. V
Published online 2 December 2014 in Wiley Online Library (wileyonlinelibrary. com). DOI 10.1002/mus.24531
216
Myasthenic Crisis after VATS
occasionally have myasthenic crisis immediately after thymectomy. Myasthenic crisis often requires intensive care with prolonged mechanical ventilatory support during hospitalization for thymectomy. The ability to predict patients at high risk for myasthenic crisis after thymectomy (MCAT) would be clinically useful, because it may be preventable with careful perioperative management, including preoperative intravenous immunoglobulin (IVIg) or plasma exchange (PLEX).4,5 Previous studies have shown several predictive factors for MCAT, such as preoperative bulbar symptoms, low preoperative vital capacity, history of previous myasthenic crisis, high serum antiacetylcholine receptor binding antibody (AChRAb) level, large preoperative doses of pyridostigmine, and significant blood loss during the operation.6–10 However, these predictive factors were obtained through studies using transsternal thymectomy, not videoscopic thymectomy. Therefore, little is known about the predictive factors for myasthenic crisis after videoscopic thymectomy (MCAVT). Thus, we investigated the clinical characteristics of MG patients with MCAVT to identify predictive factors. PATIENTS AND METHODS
The institutional review board of Severance Hospital, Yonsei University Health System approved this study and waived the requirement for informed consent from study subjects. We conducted a retrospective review of all MG patients who underwent videoscopic thymectomy at our institution between October 2007 and March 2012. One hundred forty-seven MG patients underwent videoscopic thymectomy using a previously described technique.11 Of these patients, we excluded 1 patient who underwent thymectomy for tuberculosis of the thymus, not for MG. Thymectomy was performed in 41 MG patients with thymoma and in 105 MG patients without thymoma. The diagnosis of MG was made based on the signs and symptoms of muscle fatigue, responses to lowfrequency repetitive nerve stimulation (LF-RNS), serum levels of AChR-Ab, and improvement in muscle fatigue after intramuscular injection of neostigmine. Subjects.
MUSCLE & NERVE
August 2015
MCAVT was defined as delayed extubation (more than 48 h) after videoscopic thymectomy or need for reintubation during the admission in patients who were successfully extubated without critical postoperative cardiopulmonary complications.10 Data Collection. Patient medical records were reviewed, and we recorded the duration of mechanical ventilation after thymectomy, thymus pathology, and the pre and intra-operative factors listed below. Preoperative factors included age at thymectomy, gender, body mass index (BMI), MGFA clinical classification, history of myasthenic crisis, history of cardiopulmonary disease, presence of bulbar symptoms, disease duration between MG symptom onset and thymectomy, daily dose of pyridostigmine, use of corticosteroids and other immunosuppressants, preoperative management with IVIg or PLEX, baseline quantitative myasthenia gravis score (QMGS), forced vital capacity (FVC), serum level of AChR-Ab, and decrement in compound muscle action potentials (CMAP) to LF-RNS. The intraoperative factors were operation time, intraoperative blood loss volume, and phrenic nerve injury during thymectomy. RNS Testing and QMGS. LF-RNS was performed according to previously described methods on the abductor digiti minimi (ADM) and flexor carpi ulnaris (FCU) muscles by ulnar nerve stimulation at the elbow, on the orbicularis oculi and nasalis muscles using stimulation of the facial nerve, and on the trapezius muscle by stimulation of the spinal accessory nerve.12 All RNS procedures used the Neuroscreen system (Toennies, Germany) or the Schwarzer topas EMG system (Natus, Germany). The nerves were stimulated at a rate of 3 HZ supramaximally, while the surface temperature over tested muscles was controlled to remain above 32 C. A decrement from the first to fifth CMAP 10% was considered to be abnormal. In patients taking pyridostigmine bromide, RNS was performed at least 12 h after the last dose. Baseline QMGS was performed on the same day of RNS testing by neurologists trained in neuromuscular disease, as previously described.13 In the patients treated with IVIg or PLEX before thymectomy, baseline QMGS was measured before the preoperative management.
The Mann-Whitney and Fisher exact tests were performed to compare continuous and categorical variables between groups with and without MCAVT, respectively. Multivariate analysis was applied using a logistic regression model to identify the independent predictors for MCAVT. Factors with P-values less than 0.05 in the univariate analysis were included in a stepwise multiple logistic regression analysis. The results are preStatistical Analysis.
Myasthenic Crisis after VATS
sented as odds ratios and 95% confidence intervals (CIs). All statistical analyses were performed using SPSS version 18.0 software (Chicago, Illinois). A 2-tailed P-value < 0.05 was considered statistically significant. RESULTS
The demographic and clinical characteristics of patients with and without MCAVT are summarized in Table 1. Of 146 patients, 10 (6.8%) developed MCAVT. Among the 10 patients, 3 required reintubation and mechanical ventilatory support after successful extubation in the operating room. Reintubation was performed 1, 4, and 5 days after thymectomy. The median duration of mechanical ventilator support was 4.5 days (range, 2.1–11.6 days). All 10 patients recovered from MCAVT and were extubated successfully. Patients with MCAVT had a higher frequency of bulbar symptoms (90.0% vs. 54.4%, P 5 0.043) and higher baseline QMGS (21 vs. 12, P 5 0.001) than those without MCAVT. In addition, FVC was significantly lower in patients with MCAVT than those without MCAVT (2.1 vs. 3.0 L, P < 0.001). On LF-RNS, the CMAP decrement of the FCU (28.6 vs. 13.4%, P 5 0.039), orbicularis oculi (47.1 vs. 18.1%, P 5 0.001), and nasalis (54.1 vs. 21.4%, P < 0.001) muscles were significantly more pronounced in patients with MCAVT than in those without. No significant differences in age at thymectomy, gender, BMI, history of myasthenic crisis, history of cardiopulmonary disease, disease duration, daily dose of pyridostigmine, use of corticosteroids and other immunosuppressants, preoperative management with IVIg or PLEX, serum level of AChR-Ab, operation time, volume of intraoperative blood loss, presence of phrenic nerve injury, and thymoma were observed between patients with and without MCAVT. A stepwise multivariate logistic regression analysis revealed that the FVC [odds ratio (OR), 0.144; 95% CI, 0.044–0.479; P 5 0.002] and the decrement in CMAP in the orbicularis oculi on LF-RNS (OR 1.029, 95% CI 1.001–1.058, P 5 0.044) were independently associated with MCAVT (Table 2). DISCUSSION
In this study, MCAVT occurred in 10 of 146 MG patients who underwent videoscopic thymectomy between October 2007 and May 2012. In patients with MCAVT, the preoperative baseline QMGS, bulbar symptoms, FVC, and response to LF-RNS (FCU, orbicularis oculi, and nasalis muscles) were more abnormal compared with those without MCAVT. Of these clinical findings, the preoperative FVC and the orbicularis oculi response to LF-RNS were independent predictors MUSCLE & NERVE
August 2015
217
Table 1. Comparison of demographics and clinical characteristics between patients with and without myasthenic crisis after videoscopic thymectomy Characteristics Thymectomy age (years), median (IQR) Women, n (%) BMI (kg/m2), median (IQR) Previous cardiopulmonary disease, n (%) Myasthenic crisis before thymectomy, n (%) Disease duration before thymectomy (months), median (IQR) AChR-Ab positive, n (%) AChR-Ab titer (nmol/L), median (IQR) Thymoma, n (%) MGFA clinical classification I, n (%) IIa, n (%) IIb, n (%) IIIa, n (%) IIIb, n (%) IVa, n (%) IVb, n (%) V, n (%) Bulbar symptoms, n (%) Baseline QMGS, median (IQR) FVC (L), median (IQR) Decremental response on RNS FCU (%), median (IQR) ADM (%), median (IQR) Orbicularis oculi (%), median (IQR) Nasalis (%), median (IQR) Trapezius (%), median (IQR) Medication for MG before thymectomy PB dose (mg/day), median (IQR) Corticosteroids, n (%) Immunosuppressants, n (%) Preoperative IVIg, n (%) Preoperative PLEX, n (%) Intraoperative factors Operation time (min), median (IQR) Blood loss (mL), median (IQR) Phrenic nerve injury, n (%)
With MCAVT (n 5 10)
Without MCAVT (n 5 136)
P*
25.0 (15.5 - 48.0) 9 (90.0) 20.5 (19.0 - 21.5) 0 (0) 2 (20.0) 8.5 (4.8 - 16.3)
35.0 (27.0 - 46.0) 101 (74.3) 21.7 (19.8 - 24.5) 2 (1.5) 8 (5.9) 16.0 (5.0 - 36.0)
0.162 0.452 0.126 1.000 0.141 0.251
10 (100) 13.2 (7.8 - 15.1) 3 (30.0)
136 (100) 10.0 (6.9–14.1) 38 (27.9)
1.000 0.278 1.000
0 (0) 0 (0.0) 1 (10.0) 1 (10.0) 2 (20.0) 2 (20.0) 2 (20.0) 2 (20.0) 9 (90.0) 21.0 (16.0 - 26.3) 2.1 (1.5 – 2.7)
11 (8.1) 38 (27.9) 28 (20.6) 28 (20.6) 6 (4.4) 9 (6.6) 8 (5.9) 8 (5.9) 74 (54.4) 12.0 (8.0 - 15.0) 3.0 (2.6 - 3.6)
1.000 0.064 0.687 0.687 0.095 0.166 0.141 0.141 0.043 0.001
Department of Neurology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea Department of Biostatistics, Yonsei University College of Medicine, Seoul, Republic of Korea 3 Department of Thoracic and Cardiovascular Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea Accepted 25 November 2014 2
ABSTRACT: Introduction: Predictive factors for myasthenic crisis after transsternal thymectomy have been reported, but little is known about myasthenic crisis after videoscopic thymectomy (MCAVT). Methods: We investigated 146 myasthenia gravis patients who underwent videoscopic thymectomy. Results: Patients with MCAVT had a lower forced vital capacity (FVC) (2.1 vs. 3.0 L, P < 0.001) than those without. Low-frequency repetitive nerve stimulation showed decremental responses of the orbicularis oculi (47.1% vs. 18.1%, P 5 0.001) and nasalis muscles (54.1% vs. 21.4%, P < 0.001), which were more pronounced in patients with MCAVT than those without. According to multivariate analysis, FVC (OR 0.144, 95% confidence interval [CI], 0.044–0.479, P 5 0.002) and decremental response of orbicularis oculi (odds ratio, 1.029; 95% CI, 1.001–1.058, P 5 0.044) were independently associated with MCAVT. Conclusions: FVC and decremental response of orbicularis oculi were associated with MCAVT. Muscle Nerve 52: 216–220, 2015
Myasthenia
gravis (MG) is an autoimmune disorder affecting neuromuscular transmission. Approximately 75% of MG patients have abnormal histopathology of the thymus,1 which may play an important role in the pathogenesis. Thymectomy is one of the therapeutic options in MG, and thymectomy is performed in patients with thymoma, or it can be performed to improve long-term outcomes in patients without thymoma. Although transsternal thymectomy is a common, traditional surgical technique, videoscopic thymectomy recently became popular with its minimally invasive and superior cosmetic advantages, especially because MG occurs more commonly in young women.2,3 Myasthenic crisis, which is a severe exacerbation in weakness, often life threatening, may be precipitated by various factors, including infection, emotional stress, high-dose corticosteroid therapy, or surgery. MG patients who undergo thymectomy Abbreviations: AChR-Ab, anti-acetylcholine receptor binding antibody; ADM, abductor digiti minimi; BMI, body mass index; CI, confidence interval; CMAP, compound muscle action potentials; FCU, flexor carpi ulnaris; FVC, forced vital capacity; IVIg, intravenous immunoglobulin; LF-RNS, low-frequency repetitive nerve stimulation; MCAT, myasthenic crisis after thymectomy; MCAVT, myasthenic crisis after videoscopic thymectomy; MG, myasthenia gravis; PLEX, plasma exchange; QMGS, quantitative myasthenia gravis score. Key words: myasthenia gravis; myasthenic crisis; prognosis; thymectomy; videoscopic thymectomy Correspondence to: H. Y. Shin; e-mail: [email protected] C 2014 Wiley Periodicals, Inc. V
Published online 2 December 2014 in Wiley Online Library (wileyonlinelibrary. com). DOI 10.1002/mus.24531
216
Myasthenic Crisis after VATS
occasionally have myasthenic crisis immediately after thymectomy. Myasthenic crisis often requires intensive care with prolonged mechanical ventilatory support during hospitalization for thymectomy. The ability to predict patients at high risk for myasthenic crisis after thymectomy (MCAT) would be clinically useful, because it may be preventable with careful perioperative management, including preoperative intravenous immunoglobulin (IVIg) or plasma exchange (PLEX).4,5 Previous studies have shown several predictive factors for MCAT, such as preoperative bulbar symptoms, low preoperative vital capacity, history of previous myasthenic crisis, high serum antiacetylcholine receptor binding antibody (AChRAb) level, large preoperative doses of pyridostigmine, and significant blood loss during the operation.6–10 However, these predictive factors were obtained through studies using transsternal thymectomy, not videoscopic thymectomy. Therefore, little is known about the predictive factors for myasthenic crisis after videoscopic thymectomy (MCAVT). Thus, we investigated the clinical characteristics of MG patients with MCAVT to identify predictive factors. PATIENTS AND METHODS
The institutional review board of Severance Hospital, Yonsei University Health System approved this study and waived the requirement for informed consent from study subjects. We conducted a retrospective review of all MG patients who underwent videoscopic thymectomy at our institution between October 2007 and March 2012. One hundred forty-seven MG patients underwent videoscopic thymectomy using a previously described technique.11 Of these patients, we excluded 1 patient who underwent thymectomy for tuberculosis of the thymus, not for MG. Thymectomy was performed in 41 MG patients with thymoma and in 105 MG patients without thymoma. The diagnosis of MG was made based on the signs and symptoms of muscle fatigue, responses to lowfrequency repetitive nerve stimulation (LF-RNS), serum levels of AChR-Ab, and improvement in muscle fatigue after intramuscular injection of neostigmine. Subjects.
MUSCLE & NERVE
August 2015
MCAVT was defined as delayed extubation (more than 48 h) after videoscopic thymectomy or need for reintubation during the admission in patients who were successfully extubated without critical postoperative cardiopulmonary complications.10 Data Collection. Patient medical records were reviewed, and we recorded the duration of mechanical ventilation after thymectomy, thymus pathology, and the pre and intra-operative factors listed below. Preoperative factors included age at thymectomy, gender, body mass index (BMI), MGFA clinical classification, history of myasthenic crisis, history of cardiopulmonary disease, presence of bulbar symptoms, disease duration between MG symptom onset and thymectomy, daily dose of pyridostigmine, use of corticosteroids and other immunosuppressants, preoperative management with IVIg or PLEX, baseline quantitative myasthenia gravis score (QMGS), forced vital capacity (FVC), serum level of AChR-Ab, and decrement in compound muscle action potentials (CMAP) to LF-RNS. The intraoperative factors were operation time, intraoperative blood loss volume, and phrenic nerve injury during thymectomy. RNS Testing and QMGS. LF-RNS was performed according to previously described methods on the abductor digiti minimi (ADM) and flexor carpi ulnaris (FCU) muscles by ulnar nerve stimulation at the elbow, on the orbicularis oculi and nasalis muscles using stimulation of the facial nerve, and on the trapezius muscle by stimulation of the spinal accessory nerve.12 All RNS procedures used the Neuroscreen system (Toennies, Germany) or the Schwarzer topas EMG system (Natus, Germany). The nerves were stimulated at a rate of 3 HZ supramaximally, while the surface temperature over tested muscles was controlled to remain above 32 C. A decrement from the first to fifth CMAP 10% was considered to be abnormal. In patients taking pyridostigmine bromide, RNS was performed at least 12 h after the last dose. Baseline QMGS was performed on the same day of RNS testing by neurologists trained in neuromuscular disease, as previously described.13 In the patients treated with IVIg or PLEX before thymectomy, baseline QMGS was measured before the preoperative management.
The Mann-Whitney and Fisher exact tests were performed to compare continuous and categorical variables between groups with and without MCAVT, respectively. Multivariate analysis was applied using a logistic regression model to identify the independent predictors for MCAVT. Factors with P-values less than 0.05 in the univariate analysis were included in a stepwise multiple logistic regression analysis. The results are preStatistical Analysis.
Myasthenic Crisis after VATS
sented as odds ratios and 95% confidence intervals (CIs). All statistical analyses were performed using SPSS version 18.0 software (Chicago, Illinois). A 2-tailed P-value < 0.05 was considered statistically significant. RESULTS
The demographic and clinical characteristics of patients with and without MCAVT are summarized in Table 1. Of 146 patients, 10 (6.8%) developed MCAVT. Among the 10 patients, 3 required reintubation and mechanical ventilatory support after successful extubation in the operating room. Reintubation was performed 1, 4, and 5 days after thymectomy. The median duration of mechanical ventilator support was 4.5 days (range, 2.1–11.6 days). All 10 patients recovered from MCAVT and were extubated successfully. Patients with MCAVT had a higher frequency of bulbar symptoms (90.0% vs. 54.4%, P 5 0.043) and higher baseline QMGS (21 vs. 12, P 5 0.001) than those without MCAVT. In addition, FVC was significantly lower in patients with MCAVT than those without MCAVT (2.1 vs. 3.0 L, P < 0.001). On LF-RNS, the CMAP decrement of the FCU (28.6 vs. 13.4%, P 5 0.039), orbicularis oculi (47.1 vs. 18.1%, P 5 0.001), and nasalis (54.1 vs. 21.4%, P < 0.001) muscles were significantly more pronounced in patients with MCAVT than in those without. No significant differences in age at thymectomy, gender, BMI, history of myasthenic crisis, history of cardiopulmonary disease, disease duration, daily dose of pyridostigmine, use of corticosteroids and other immunosuppressants, preoperative management with IVIg or PLEX, serum level of AChR-Ab, operation time, volume of intraoperative blood loss, presence of phrenic nerve injury, and thymoma were observed between patients with and without MCAVT. A stepwise multivariate logistic regression analysis revealed that the FVC [odds ratio (OR), 0.144; 95% CI, 0.044–0.479; P 5 0.002] and the decrement in CMAP in the orbicularis oculi on LF-RNS (OR 1.029, 95% CI 1.001–1.058, P 5 0.044) were independently associated with MCAVT (Table 2). DISCUSSION
In this study, MCAVT occurred in 10 of 146 MG patients who underwent videoscopic thymectomy between October 2007 and May 2012. In patients with MCAVT, the preoperative baseline QMGS, bulbar symptoms, FVC, and response to LF-RNS (FCU, orbicularis oculi, and nasalis muscles) were more abnormal compared with those without MCAVT. Of these clinical findings, the preoperative FVC and the orbicularis oculi response to LF-RNS were independent predictors MUSCLE & NERVE
August 2015
217
Table 1. Comparison of demographics and clinical characteristics between patients with and without myasthenic crisis after videoscopic thymectomy Characteristics Thymectomy age (years), median (IQR) Women, n (%) BMI (kg/m2), median (IQR) Previous cardiopulmonary disease, n (%) Myasthenic crisis before thymectomy, n (%) Disease duration before thymectomy (months), median (IQR) AChR-Ab positive, n (%) AChR-Ab titer (nmol/L), median (IQR) Thymoma, n (%) MGFA clinical classification I, n (%) IIa, n (%) IIb, n (%) IIIa, n (%) IIIb, n (%) IVa, n (%) IVb, n (%) V, n (%) Bulbar symptoms, n (%) Baseline QMGS, median (IQR) FVC (L), median (IQR) Decremental response on RNS FCU (%), median (IQR) ADM (%), median (IQR) Orbicularis oculi (%), median (IQR) Nasalis (%), median (IQR) Trapezius (%), median (IQR) Medication for MG before thymectomy PB dose (mg/day), median (IQR) Corticosteroids, n (%) Immunosuppressants, n (%) Preoperative IVIg, n (%) Preoperative PLEX, n (%) Intraoperative factors Operation time (min), median (IQR) Blood loss (mL), median (IQR) Phrenic nerve injury, n (%)
With MCAVT (n 5 10)
Without MCAVT (n 5 136)
P*
25.0 (15.5 - 48.0) 9 (90.0) 20.5 (19.0 - 21.5) 0 (0) 2 (20.0) 8.5 (4.8 - 16.3)
35.0 (27.0 - 46.0) 101 (74.3) 21.7 (19.8 - 24.5) 2 (1.5) 8 (5.9) 16.0 (5.0 - 36.0)
0.162 0.452 0.126 1.000 0.141 0.251
10 (100) 13.2 (7.8 - 15.1) 3 (30.0)
136 (100) 10.0 (6.9–14.1) 38 (27.9)
1.000 0.278 1.000
0 (0) 0 (0.0) 1 (10.0) 1 (10.0) 2 (20.0) 2 (20.0) 2 (20.0) 2 (20.0) 9 (90.0) 21.0 (16.0 - 26.3) 2.1 (1.5 – 2.7)
11 (8.1) 38 (27.9) 28 (20.6) 28 (20.6) 6 (4.4) 9 (6.6) 8 (5.9) 8 (5.9) 74 (54.4) 12.0 (8.0 - 15.0) 3.0 (2.6 - 3.6)
1.000 0.064 0.687 0.687 0.095 0.166 0.141 0.141 0.043 0.001
