Dropped Head Syndrome
Dropped head syndrome (head droop or head drop) refers to forward flexion of the head on the neck, such that the chin falls on to the chest (cf. antecollis) and the head cannot be voluntarily extended. This syndrome has a broad differential diagnosis, encompassing disorders which may cause axial truncal muscle weakness, especially of upper thoracic and paraspinous muscles.
- Motor neurone disease (the author has also seen this syndrome in a patient with frontotemporal dementia with motor neurone disease, FTD/MND)
- Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy
- Paraneoplastic motor neuronopathy.
- Neuromuscular junction disorder:
- Myasthenia gravis
- Myotonic dystrophy
- Myopathy with rimmed vacuoles
- "Dropped head syndrome", or "isolated neck extensor myopathy", a condition of uncertain etiology but which may on occasion be steroid-responsive ("bent spine syndrome" or camptocormia may be a related form of axial myopathy).
- Extrapyramidal disorders:
- Parkinson’s disease
- Multiple system atrophy
- Progressive supranuclear palsy.
Of these, probably MND and myasthenia gravis are the most common causes.
Treatment of the underlying condition may be possible, hence investigation is mandatory. If not treatable (e.g., MND), a head brace may keep the head upright.
Katz JS, Wolfe GI, Burns DK, Bryan WW, Fleckenstein JL, Barohn RJ. Isolated neck extensor myopathy. A common cause of dropped head syndrome. Neurology 1996; 46: 917-921
Nicholas RS, Lecky BRF. Dropped head syndrome: the differential diagnosis. Journal of Neurology, Neurosurgery and Psychiatry 2002; 73: 218 (abstract 26)
Rose MR, Levin KH, Griggs RC. The dropped head plus syndrome: quantitation of response to corticosteroids. Muscle Nerve 1999; 22: 115-118
Swash M. Dropped-head and bent-spine syndromes: axial myopathies? Lancet 1998; 352: 758