Questions
Is trunk extensor muscles weakness an elderly disorder?
Are they clinical specific signs
Are usefull ancillary examination?
What are the muscles involved?
Pathophysiology?
Primary vs. secondary syndromes?
Dropped head and bent spine same disease?
Familial cases?
Excessive activation of the abdominal wall muscles. Trunk flexion. Viscera support
Mitochondrial respiratory chain. Complex I and III deficiency
Pathophysiology
Destabilization in the complex interaction of spinae muscles
Multifidi. Short, deep, stabilisator, rotator
Intrinsic muscles of spine
1. Muscular parameters
Myopathy of the antigravity muscles of trunk, loss of elasticity
Weakness of erector spinae muscles, prime movens.
Reduced EMG activity when body bending
Weak multifidi: stabilizers and rotatores
Normal neck extensors
Imbalance between erectors and abdominalis, stabilizers, flexors, rotatores
Excessive activation of the abdominal wall muscles: trunk flexion, viscera support
2. Postural parameters
Permanent stabilization of the trunk impaired
Resistance to gravity continuously monitored by longissimus
Other muscles: intermittent activity with shifts of center of gravity
Increased instability of stance when leaning forward
Dyssynergy due to elderly (Ferrandez, Serratrice)
Decrease of stride length, of walking velocity
Increase of stride duration, of double-support duration
3. Interlimbs coordination parameters
Relationships between normal head movements and trunk weakness
Diagonal backward deplacement of center of body mass after unilateral hand and leg forces
Primary vs. secondary
Primary
Atypical: exertional camptocormia
Unusual pathology: RRF, inflammation, myoadenylate
Secondary
Hysterical war nevrosis (Souques 1915) PD
Neonatal hypotonia
Phosphorylase, carnitine
NMD: FSHD, IBM, Vulpian, PROMM …
An unrecognized form of secondary camptocormia (Serratrice et al., 2000)
Progressive painful paraspinal muscle weakness exagerated by exercise
Slight myotonia
Cataracte
Gamma GT
Angular fibers, type II atrophy
Dropped head and Bent spine no separate entities. Oerlemans et al.
Secondary Dropped Head
Spasmodic antecolis
Dermatomyositis
I B M
Myasthenia gravis
Myotonic dystrophy
A L S
Post polio
| Dropped Head | Bent spine | |
| Primary | Rare | Not unfrequent |
| Muscles | Neck extensors | Erector spinae |
| Pathophysiology | Phasic > tonic | Phasic + tonic |
| Muscle CT Scan | Hypodensities | Myopathic |
| Coronal MRI | ? | Loss of paraspinal muscles |
| Muscle biopsy | Inflammatory, IBM | Rather myogenic |
| Onset | Subacute | Insidious |
| Outcome | Unchanged or Improved | Progressive relentless |
| Handicap | Moderate | Stick or wheelchair |
| Secondary | Systemic disease | NMD |
| Familial case | Exceptional | Some but no informative |
Familial cases (10)
Autosomal Dominant Inheritance
Late onset
Low back pain
Normal CK
Myopathic EMG
No specific morphological changes
Progressive course
Difficult genetic study due to late onset
Conclusion
A Primary Progressive Axial Muscle Disease
Late sporadic or familial myopathy or related to aging?
A relentless disease no responsive to treatments: drugs, rehabilitation, surgery
Different from neck muscles weakness