The objective of this study was to establish the reliability and validity of an assessment battery for the evaluation of pulmonary and muscle strength and function in late onset Pompe disease. This was a multi-center, multinational, 12-month observational study. Eligible patients were ambulatory and non-invasively ventilated. Measurements included quantitative muscle testing (QMT) of seven muscle groups, manual muscle testing (MMT) of 34 muscle groups, timed functional activity assessments (FAA), a 6-min walk test (6MWT) and pulmonary function testing (PFT). Intra-class correlation coefficients ranged from .93 to .99 for the QMT muscle groups, .98 to .99 for FAAs, and .93 to 1.0 for PFTs. Test-retest reliability was .98 for the two administrations of the 6MWT. Almost all patients (93%) presented with lower limb proximal muscle weakness. Fifty-two of Fifty-eight (89.7%) patients had QMT Leg scores of <80% of predicted normal values and 57 of 58 (96%) patients had 6MWT distances <80% of predicted normal values. Mean QMT Leg and Arm scores were 44.6% and 72.7% of predicted normal values, respectively. Lower % predicted QMT Leg scores were associated with shorter 6MWT distances (r = .52, p < .01), longer stair climb times (r = −.42, p < .01), lower functional leg grades (r = −.51, p < .01), lower MMT scores (r = .64, p < .01) and increased use of walking devices (r = −.30, p < .05). Shorter walking distances and the use of walking devices were associated with lower SF-36 PCS scores, (r = −.36, r = −.28, p < .05). Lower % predicted QMT Arm scores were associated with lower functional arm grades (r = −.45, p < .01). Lower FVC, MIP and MEP % predicted values were associated with increased use of nocturnal noninvasive ventilation (r = −.58, r = −.38, r = −.37, p < .01). The outcome measures in this study were reliable, sensitive and predictive of the functional status of late onset Pompe patients and appropriate for use in future clinical trials.

Objective: The objective of this study was to evaluate the impact of the clinical manifestations of late onset Pompe disease on the health-related quality of life of affected patients. Methods: This was a multi-center, multinational, 12-month observational study. Eligible patients were ambulatory and non-invasively ventilated. Measurements included quantitative muscle testing (QMT), timed functional activity assessments (FAA), a 6-min walk test (6MWT), pulmonary function testing (PFT) and QOL assessment using a late onset Pompe disease Questionnaires and the SF-36. Results: Fifty-eight patients (22 males and 36 females), aged 24—69 years completed the study. Age at symptom onset was 29.2 ± 11.5 years. Disease duration was 14.7 ± 9.1 years. The most commonly experienced signs and symptoms were neuromuscular and respiratory in nature and included fatigue/low energy (94.8%), hypotonia (93.1%), generalized muscle weakness (84.5%), back pain (81.0%), shortness of breath (72.4%), muscle pain or spasms (70.7%), joint pain (63.8%), sleep disturbances (55.2%), morning headache (48.3%), and neck pain (50.0%). Mean 6MWT distance and QMT Leg score were 52.3% and 41.5% of predicted normal, respectively. Shorter 6MWT distances, lower QMT Leg scores, and the use of walking devices were associated with SF-36 PCS (Physical Component Summary) and PF (Physical Function) subscale scores 2 SDs below 1998 US general population norms. Mean FVC, MIP and MEP % predicted values were 63.4%, 50.1%, and 37.9%, respectively. Lower FVC, MIP and MEP % predicted values and the use of nocturnal noninvasive ventilation were associated with SF-36 PCS and PF subscale scores 2 SDs below 1998 US general population norms. Disease duration (defined as time since symptom onset) predicted clinical status and SF-36 PCS and PF scores. Conclusion: Late onset Pompe disease causes progressive pulmonary and muscle weakness that impairs function and significantly diminishes the physical health status of patients.

Common symptoms of neuromuscular disease (NMD) include weakness, difficulty walking, contractures, and scoliosis, all of which can contribute to chronic pain. This study was designed to address the gap in our understanding of the occurrence and impact of pain in youths with NMD. A convenience sample of 33 youths from the greater Seattle metropolitan area that have a primary diagnosis of NMD was obtained for this study through mailings from a children’s hospital, public postings, and referrals. The semi-structured interviews took place over-the phone or in person. The participants ranged in age from nine to twenty years (mean 15.0 3.0) and 60% were male. The majority of youths had a diagnosis of Duchenne muscular dystrophy (n=10, 30%), followed by myotonic dystrophy (n=6, 18%) and Charcot-Marie Tooth neuropathy (n=5, 15%). Participants completed several questionnaires that were developed for this study including demographic and disability-specific information, an eleven-point numerical rating scale for pain intensity, questions from the Child Health Questionnaire and a modified Brief Pain Inventory interference scale. Fifty eight percent of the youths reported experiencing chronic pain (average 2.7 on a scale of 0-10) and 67% indicated they experienced pain daily or weekly. Pain in the following body locations were the most frequently reported: back (68%), legs (63%), buttocks/hips (53%), and feet (53%). Pain interfered most with mobility, school, work or chores, and general activity as measured by the modified Brief Pain Inventory. Parents of 68% of the youths have sought treatment for their child’s pain and have tried non-steroidal anti-inflammatories (71%), acetaminophen (58%), and physical/occupational therapy (46%). These findings indicate the need for more specific inquiries into the chronic pain experiences of youths with NMD. Common symptoms of neuromuscular disease (NMD) include weakness, difficulty walking, contractures, and scoliosis, all of which can contribute to chronic pain. This study was designed to address the gap in our understanding of the occurrence and impact of pain in youths with NMD. A convenience sample of 33 youths from the greater Seattle metropolitan area that have a primary diagnosis of NMD was obtained for this study through mailings from a children’s hospital, public postings, and referrals. The semi-structured interviews took place over-the phone or in person. The participants ranged in age from nine to twenty years (mean 15.0 3.0) and 60% were male. The majority of youths had a diagnosis of Duchenne muscular dystrophy (n=10, 30%), followed by myotonic dystrophy (n=6, 18%) and Charcot-Marie Tooth neuropathy (n=5, 15%). Participants completed several questionnaires that were developed for this study including demographic and disability-specific information, an eleven-point numerical rating scale for pain intensity, questions from the Child Health Questionnaire and a modified Brief Pain Inventory interference scale. Fifty eight percent of the youths reported experiencing chronic pain (average 2.7 on a scale of 0-10) and 67% indicated they experienced pain daily or weekly. Pain in the following body locations were the most frequently reported: back (68%), legs (63%), buttocks/hips (53%), and feet (53%). Pain interfered most with mobility, school, work or chores, and general activity as measured by the modified Brief Pain Inventory. Parents of 68% of the youths have sought treatment for their child’s pain and have tried non-steroidal anti-inflammatories (71%), acetaminophen (58%), and physical/occupational therapy (46%). These findings indicate the need for more specific inquiries into the chronic pain experiences of youths with NMD.