Table 1 Retrospective chart review
From: Misdiagnosis of inclusion body myositis: two case reports and a retrospective chart review
Patient | Age (yr) | Time to diagnosis (mo) | Sex | Symptoms | Examination at initial presentationa | Electrodiagnostic studies | Muscle biopsy | Diagnosis before referral |
|---|---|---|---|---|---|---|---|---|
1 | 56 | 24 | M | Gait difficulty, then grip weakness | WE 4− (L), FF 2, HF 5− (L), KE 3, DF 2 | Myopathic | End-stage muscle wasting | Possible myopathy |
2 | 70 | 60 | M | Asymmetric leg weakness, recurrent falls | HF 4− (L), HE 4−; HF 3 (R), KE 4−, KF 5−, DF 4, | Myopathic | s-IBM strongly confirmed by p62-positive fibers | Unknown |
3 | 76 | 36 | M | Difficulty getting up from chair then difficulty opening jars; mild dysphagia | SA 5−, EF 4−, EE 4−, FE 4; digits 4 and 5 FF 4 (L), HF 4−, KE 4 | Mixed proximal myopathy | End-stage muscle wasting, no inclusion bodies or lymphocytic infiltrates | Probable myopathy |
4 | 81 | 48 | M | Leg weakness, falls, difficulty getting up from chair | Mild digit 5 flexion weakness, HF 4 | Myopathic | Fibers with adjacent lymphocytes, inclusions in fibers, interstitial fibrosis, COX-negative fibers | Comorbid RA |
5 | 85 | 72 | M | Difficulty climbing stairs, then asymmetric grip weakness | Distal FF 2, KE 3, PF 4+ (L) | Length dependent axonopathy, myopathy | Atrophy with scattered morula, with mild chronic inflammation | Peripheral neuropathy |
6 | 67 | 60 | M | Grip weakness, then difficulty getting up from chair | FF 3, HF 3, KE 2, PF 4 | NA | Intramyofiber inclusions | Unknown |
7 | 77 | 48 | F | Getting up from chair and gait difficulty, then difficulty opening jars | SA 2, EF 2, EE 4, FF 2, FE 4+, HE 4, HA 4, KE 2, KF 4−, DF 4−, PF 4− | Myopathic | NA | Unknown |
8 | 55 | 48 | M | Proximal leg weakness, difficulty getting up from chair, climbing stairs | FF 4, HF 5−, HE 5−, KF 4−, KE 4 | Myopathic | Chronic and active vacuolar myopathy, severe IBM | ALS |
9 | 54 | 145 | M | Grip weakness, then leg weakness, getting up from chair and ambulation difficulty | FF 3 (R); 4 (L), KE 3 (L), KE 4− (R) | Myopathic | 2003: polymyositis | Polymyositis |
2013: chronic and active vacuolar myopathy | ||||||||
10 | 68 | 48 | M | Weakness with grip, opening jars, handling coins, then proximal leg weakness | EF 5−, EE 4+, FF 3 (R) 2 (L), KE 4− (R); 2 (L), HF 4+ | Myopathic | Intramyofiber inclusions with fibrosis, absent oxidative positivity | Neuropathy vs. myopathy |
11 | 63 | 36 | F | Proximal leg weakness, then finger flexor weakness, some difficulty swallowing solids. | Digits 4 and 5 FF 2 (R); digits 2–5 FF 2 (L), KE 4−, DF 4+ (R); 4− (L), PF 4+ | Myopathic | Prominent lymphocytic infiltration | Unknown |
12 | 73 | 120 | M | Proximal leg weakness | HE 4, KE 3 | Chronic denervation in the L4 muscles | Biceps with minimal denervation changes, quadriceps too atrophic to biopsy | Possible myopathy |
13 | 43 | 60 | M | Finger flexor and proximal leg weakness | HE 4−, KE 3+ (R); 4− (L) | NA | Lymphocytes, myopathy | Inflammatory myopathy vs. IBM |
14 | 67 | 24 | M | Proximal leg weakness, then finger flexors | HF R 4, KE R 4 (R); 4+ (L), DF R 2 (R); 4+ (L) | Myopathic | Multifocal endomysial inflammation and fibrosis, intramyofiber inclusions | Extrapyramidal disease vs. lumbosacral radiculopathy |
15 | 75 | 6 | M | L leg weakness, L hand weakness, b/l arm weakness | SA 4, FF 4−, HF 3, HA 4, KF 4+, DF 4+, KE 4− | Myopathic | Atrophic myofibers, minimal endomysial inflammation, rimmed vacuoles | Unknown |
16 | 71 | 120 | F | Leg weakness, then hand weakness, then difficulty swallowing | B 4+ (R); 4 (L); WE 4 (R), FE 3, FF 3, KE 4− | Myopathic | Intramyofiber inclusions | IBM |
17 | 81 | 240 | F | Proximal leg weakness, then finger flexor weakness; some difficulty swallowing | SA 3 (R); 4− (L), FE 4−, WE 4−, WF 4−, FF 4−, HF 2, HE 3, KE 3, DF3, PF 3 | NA | Severe inflammatory myopathy | Polymyositis |
18 | 82 | 24 | M | R hand weakness, then L hand weakness | FF 3R (R); 2 (L) | Myopathic | Ragged red fibers, COX-negative fibers | ALS |
19 | 56 | 60 | M | Progressive weakness in hand grip | WF 5−, FF 4 | Myopathic | NA | Possible ALS |
20 | 55 | 120 | M | Difficulty holding heavy objects, then difficulty getting up from chair | EE 4, FF 4, HF 4−, KE 5− | NA | Endomysial mononuclear infiltration, internal nuclei in many fibers, ragged red fibers with rimmed vacuoles, COX-negative fibers | IBM |