Table 2

Classification of “dropped head syndrome”

(A) Myogenic
Myasthenia gravis1
Polymyositis2
Isolated neck extensor myopathy7,8
Facio-scapulo-humeral muscular dystrophy4
Nemaline myopathy5
Proximal myotonic myopathy13
Inclusion body myositis14
Carnitine deficiency6
Adult onset acid maltase deficiency15
Acute hypokalaemic myopathy16
Congenital myopathy17
Focal myositis of extensor neck muscles18
(B) Neurogenic
Amyotrophic lateral sclerosis3,8–10
Spinal muscular atrophy3
Chronic inflammatory demyelinating polyneuropathy12
(C) Miscellaneous
Hypothyroidism19
Cervical dystonia20
(D) Local causes
Cervical spondylosis with neurogenic weakness of neck extensors20
Ankylosing spondylitis20