Pinto S, Pinto A, De Carvalho M
Faculty of Medicine, University of Lisbon, Lisbon, Portugal.
Eura Medicophys. 2007 Dec;43(4):505-9.
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving limbs and bulbar muscles. The major cause of death in these patients is respiratory insufficiency. However, bulbar-onset ALS patients have a shorter survival than those with spinal-onset. It is not established if this difference is related to an earlier respiratory dysfunction in bulbar-onset patients. The aim of the present study was to determine if bulbar-onset patients have an earlier respiratory impairment as compared with the spinal-onset ones.
From the population of ALS patients followed in our centre, we studied 82 patients (45 spinal-onset and 37 bulbar-onset, group 1 and 2 respectively), all evaluated between 6-18 months after disease onset. We investigated forced vital capacity, maximal inspiratory (PI max) and expiratory (PE max) pressures, mouth occlusion pressure at 100 ms after inspiration, arterial blood gases, percutaneous nocturnal oxymetry, phrenic nerve conduction, needle electromyography (EMG) of the right diaphragm and right internal intercostals muscles and functional ALS scale (ALS-FRS).
No statistical difference was found for gender and disease duration between both groups, but bulbar-onset patients were older. PI max and PE max were statistically lower (P<0.001 and P<0.006, respectively) in group 2. However, no correlation was found between bulbar ALS-FRS subscore and PI max or PE max.
Our results support that PI max and PE max are sensitive measurements of respiratory dysfunction in bulbar patients. Probably, this finding cannot be solely explained by the oro-facial weakness of bulbar-patients. We speculate that respiratory accessory muscles weakness can contribute for this observation.
肌萎缩侧索硬化症（ALS）是一种累及肢体和延髓肌肉的进行性神经退行性疾病。这些患者的主要死因是呼吸功能不全。然而，延髓起病的ALS患者比脊髓起病的患者生存期更短。目前尚不清楚这种差异是否与延髓起病患者更早出现的呼吸功能障碍有关。本研究的目的是确定延髓起病患者与脊髓起病患者相比是否更早出现呼吸功能损害。
从我们中心随访的ALS患者群体中，我们研究了82例患者（45例脊髓起病和37例延髓起病，分别为1组和2组），所有患者均在疾病发作后6至18个月进行评估。我们调查了用力肺活量、最大吸气（PI max）和呼气（PE max）压力、吸气后100毫秒时的口腔闭合压力、动脉血气、经皮夜间血氧饱和度测定、膈神经传导、右侧膈肌和右侧肋间内肌的针极肌电图（EMG）以及功能性ALS量表（ALS-FRS）。
两组之间在性别和病程方面未发现统计学差异，但延髓起病患者年龄更大。2组的PI max和PE max在统计学上更低（分别为P<0.001和P<0.006）。然而，延髓ALS-FRS子评分与PI max或PE max之间未发现相关性。
我们的结果支持PI max和PE max是延髓起病患者呼吸功能障碍的敏感测量指标。可能，这一发现不能仅用延髓起病患者的口面部无力来解释。我们推测呼吸辅助肌无力可能导致了这一观察结果。
