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 |
