1. Pattern Recognition of Myopathic Disorders
Richard J. Barohn, MD
Chair, Department of Neurology
Gertrude and Dewey Ziegler Professor of Neurology
University Distinguished Professor
Vice Chancellor for Research
University of Kansas Medical Center
Kansas City, KS

2. Pattern Recognition of Myopathic Disorders
Pattern MP1:
Proximal “limb-girdle” weakness
Acute/subacute – acquired
Inflammatory (PM/DM) - pain/rash/CTD
Endocrine
Toxic drugs
Chronic/congenital/painless – hereditary
Most dystrophies
Congenital
Mitochondrial
Pompe’s disease
Carnitine deficiency
Neuromuscular junction
Overlap with SMA

3. Pattern Recognition of Myopathic Disorders
Pattern MP2:
Distal weakness
Distal muscular dystrophies:
Late adult onset: Welander; Markesbery/Udd
Early adult onset: Nonaka; Miyoshi; Laing
Myofibrillar (Desmin) myopathy
Myotonic dystrophy
Congenital myopathies
Other: NMJ disease - MG, congenital MG
Overlap with CMT/hereditary motor neuropathy
Barohn RJ et al. Autosomal recessive distal dystrophy. Neurology 1991;41:
Dimachkie MM, Barohn RJ. Neurol Clin 2014;32(3):817-42

4. Pattern Recognition of Myopathic Disorders
Pattern MP3:
Proximal arm/distal leg weakness (Scapuloperoneal)
Facioscapulohumeral dystrophy
With facial weakness
Scapuloperoneal myopathy
Emery-Dreifuss humeroperoneal dystrophy
Pompe’s disease
Barohn et al. Adult acid maltase deficiency. Muscle Nerve 1993;16:
Congenital myopathy
From: Barohn et al. Adult acid maltase deficiency. Muscle Nerve 1993;16:

5. Pattern Recognition of Myopathic Disorders
Pattern MP4:
Distal arm/proximal leg weakness
Inclusion body myositis
Common presentation
Finger & wrist flexor weakness
Knee extensor weakness
Asymmetric
Occasionally myotonic dystrophy
Amato AA, et al. Ann Neurol 1996;40(4):581-6.;Dimachkie MM, Barohn RJ. Neurol Clin 2014;32(3):817-42

6. Pattern Recognition of Myopathic Disorders
Pattern MP5: Eyeball Pattern
Ptosis / ophthalmoplegia
Ptosis without ophthalmoplegia
Myotonic dystrophy
Congenital myopathies
Ptosis with ophthalmoplegia
Oculopharyngeal dystrophy
Mitochondrial myopathy
Centronuclear myopathy
Neuromuscular junction disease:
MG, LEMS, congenital MG, botulism*
*Diplopia

7. Pattern Recognition of Myopathic Disorders
Pattern MP6:
Prominent neck and trunk extensor weakness
Isolated neck extensor myopathy (INEM)
Isolated trunk extensor myopathy (ITEM)
Myasthenia gravis
IBM / PM/ DM
Myotonic dystrophy
FSH dystrophy
Congenital myopathy
Carnitine deficiency
Hyperparathyroidism
Overlap pattern with ALS
Katz JS, Wolfe GI, Bryan WW, Burns DK, Barohn RJ. Neurology 1996;47:917-21; Barohn RJ, Dimachkie MM, Jackson CE. Neurol Clin 2014;32(3):569-93

8. Pattern Recognition of Myopathic Disorders
Pattern MP7:
Bulbar weakness – tongue/pharyngeal/ diaphragm (dysarthria or dysphagia, SOB)
MG, LEMS
Oculopharyngeal dystrophy
LGMD 1A myotilinopathy
Myotonic dystrophy
IBM
Pompe (respiratory)
Overlap pattern with: ALS, Kennedy’s

9. Pattern Recognition of Myopathic Disorders
Pattern MP8:
Episodic pain, weakness, myoglobinuria with trigger
Related to exercise
Glycogenoses (McArdle’s, etc)
Lipid disorders (CPT def)
Couch potatoes & exercise
Not related to exercise
Malignant hyperthermia
Drugs/toxins
Trauma (crush injury)
Other: Neuroleptic malignant syndrome
Epileptic status
Sharp LJ, Haller RG. Neurol Clin 2014;32(3):777-99

10. Pattern Recognition of Myopathic Disorders
Pattern MP9:
Episodic weakness delayed or unrelated to exercise
Myasthenia gravis
Periodic paralysis
Na+ channelopathies (hyperkalemic)
Ca++ channelopathies (hypokalemic)
Andersen’s syndrome
Secondary PP (thyrotoxicosis)
Matthews E, et al. Brain 2010;133(Pt 1):9-22.

11. Pattern Recognition of Myopathic Disorders
Pattern MP10:
Stiffness/decreased ability to relax
Improves with exercise
Myotonia – usually Cl- channelopathy
Worsens with exercise/cold sensitivity
Paramyotonia - Na+ channelopathy
Brody’s disease
With fixed weakness
Myotonic dystrophy (DM 1)
Proximal myotonic myopathy (DM 2)
Becker’s disease (AR Cl- channelopathy)
Other: rippling muscle, neuromyotonia, stiff-person
Statland JM, et al. JAMA 2012;308: ; Trivedi JR, et al. Brain 2013;136(Pt 7): ;
Statland J, Phillips L, Trivedi JR. Neurol Clin 2014;32(3):

12. Clinical Patterns of Muscle Disorders
Weakness
PATTERN
Proximal
Distal
Asymmetric
Symmetric
Episodic
Trigger
Diagnosis
MP1 - Limb girdle +
Most myopathies –
hereditary and acquired
MP2 – Distal*
Distal myopathies
(also neuropathies)
MP3 - Proximal arm / distal leg
“scapuloperoneal”
Arm
Leg
(FSH)
(others)
FSH, Emery-Dreifuss,
acid maltase, congenital scapuloperoneal
MP4 - Distal arm / proximal leg
IBM
Myotonic dystrophy
MP5 - Ptosis / Ophthalmoplegia
(MG)
OPD, MG, myotonic dystrophy, mitochondria
MP6 - Neck – extensor*
INEM, MG
MP7 - Bulbar (tongue, pharyngeal, diaphragm)*
MG, LEMS, OPD
(also ALS)
MP8 - Episodic weakness/
Pain/rhabdo + trigger
McArdle’s, CPT, drugs, toxins
MP9 - Episodic weakness
Delayed or unrelated to exercise
+/-
Primary periodic paralysis
Channelopathies:
Na+
Ca++
Secondary periodic paralysis
MP10 - Stiffness/ Inability to relax
Myotonic dystrophy, channelopathies, PROMM, rippling (also stiff-person, neuromyotonia)
*Overlap patterns with neuropathic disorders Adapted from Barohn RJ, Dimachkie MM, Jackson RJ. Neurol Clin 2014;32(3):