Dropped Head Syndrome Results In Neck Pain, Trouble Eating & Interferes With Vision
Dropped head syndrome causes a recognizable deformity with varying degrees of “chin on chest” posture. There is usually weakness of the neck muscles that results in the head dropping forward, sometimes called ptosis of the head. The fixed flexion or forward bending of the neck is often painful, interferes with feeding and horizontal eye gaze. The head is typically able to be passively ranged or moved up by hand.
It is most often associated with problems of the nerves and/or muscles, however; in some cases there is no obvious cause even after extensive evaluation, or muscle biopsy may indicate a cause that is isolated to the neck extensor muscles and non-inflammatory. These cases are called isolated neck extensor myopathy or may be described as idiopathic head ptosis, where neck muscle weakness is the only symptom.
There are many potential and varied causes: central or peripheral nerve disorders like myasthenia gravis or Parkinson’s disease, autoimmune problems of muscle and connective tissue such as polymyositis and systemic sclerosis; they may be systemic and progressive with a poor prognosis like amyotrophic lateral sclerosis (ALS).
The most common cause of dropped head syndrome is isolated neck extensor myopathy and may have a benign clinical course.
The 4 Most Common Causes Of Dropped Head Syndrome
A 2019 systematic review in Clinical Spine Surgery lists the top 20 causes. Of these, 4 stand out as the most common – with approximate percentages.
- Isolated Neck Extensory Myopathy (32%)
- Parkinson’s Disease (20%)
- Myasthenia Gravis (12%)
- Amyotrophic Lateral Sclerosis (7%)
Finishing out the remaining (28%) of the top 20 causes of dropped head syndrome in descending order of prevalence as above. The percentages are not included, but decline rapidly from 5% to 1%:
- MEK inhibitor
- Endocrine/Electrolyte Abnormality
- Postoperative Myopathy
- Spinal Cord Injury
- Anti-GAD (Gadolinium) Inflammatory Myopathy
- Lipid Storage Disease
- Neuroendocrine Tumor
- Neurofibromatosis Type 1
- Inflammatory Polyneuropathy
- Cervical Myelopathy
Treatment For Dropped Head Syndrome
It is both a challenging and complex condition to diagnose and treat. Management necessitates comprehensive multi-disciplinary diagnosis to ascertain the primary cause. Many of the conditions are medically treatable and it is possible that the deformity can be decreased to an acceptable level. Conditions like Parkinson disease, inflammatory myositis, and secondary myopathies related to endocrine or metabolic dysfunction may show substantial improvement with medications. Other causes resulting in structural changes like radiation fibrosis may respond poorly to medical treatment.
The best treatment methods are often vague and based on case reports. For symptoms that persist even with treatment of an underlying pathology, steroids, bracing and strengthening exercises with other conservative forms of physiotherapy are suggested and surgical options as a viable last resort.
Options for orthotic stabilization and varying degrees of correction of dropped head syndrome include removable hard or soft collars, corset or vest combinations, banding systems, and special wheelchair headrests. While some may offer a type of nuromuscular re-education toward correction or prevention of atrophy, these devices are often only a temporary or partial solutions, achieving long term satisfaction only in select patients. However, they can help maintain horizontal gaze/eye contact, assist in proper feeding and facilitate other daily living activities.
While head supports may be cumbersome, irritate the skin, and may cause further deconditioning or deterioration of neck muscles, they should be instituted early. Why? Because a secondary deformity due to compression, neck muscle contractures or degenerative changes may result in conditions like cervical myelopathy and neurological decline that contributes to disability, even after reasonable recovery of neck strength. This highlights the importance of attempts to maintain proper neck posture during the period of weakness.
- A 2020 study in the European Spine Journal indicates cervical spine involvement (kyphosis) can be supported by only a cervical brace like the Headmaster Collar, but where there is significant thoracic spine involvement (kyphosis) and global positive imbalance including pelvic imbalance, this requires an additional thoracic support, like the Head Support System.
- While treatment of dropped head syndrome is based on an appropriate diagnostic entity, for neuromuscular diseases that are commonly associated like Parkinson’s and myasthenia gravis, there are accepted pharmacologic protocols which should be trialed first, offering the patient an effective alternative to surgery.
- Patients are often referred to a rheumatologist or neurologist for evaluation of possible autoimmune or neuromuscular causes. If no subsequent diagnosis is made, then the condition is attributed to isolated neck extensor myopathy (INEM) and a course of immune-modulating therapy like corticosteroids may be initiated by a medical internists.
- If a rheumatologic or neurological diagnoses fails to respond to appropriate primary treatment, a course of immune-modulating therapy is often considered as second line treatment.
- If the patient fails to respond to both primary medical treatment and secondary immune-modulating therapy, the patient may consult a spine surgeon for subaxial fusion across the cervicothoracic junction. In the above referenced study, the authors indicated positive clinical outcomes using this method in selected patients.
Fusion from C2 to T2 is promoted to preserve motion in the upper cervical spine, while extending the into the thoracic spine to minimize thoracic kyphosis which moves the center of gravity of the head forward and can contribute to fatigue of the the neck extensor muscles.
The study indicated response to medical and immuno-modulatory therapy treatment in over 70% of patients, and surgery was was an independent predictor of a positive clinical outcome. Fusion across the cervicothoracic junction was a primary factor to success of the surgery and to minimize complications and/or revision surgery resulting from limiting fusion to the cervical spine alone.
A 2019 study in Neuromuscular Disorders indicated a wide spectrum of both hereditary and acquired myopathies may present with head drop as the predominant clinical feature. In the study, the average presenting age was 68 with 53% achieving a specific diagnosis, with the predominant diagnosis of inflammatory myopathy.
53% of patients responded to treatment and those reporting neck flexion weakness and limb weakness on physical examination were associated with good response to treatment. 89% of patients had abnormal pulmonary function tests, 50% abnormal swallow evaluation, 37% abnormal electrocardiogram and 13% abnormal transthoracic echocardiogram.
Other relevant dianoses were: myopathy with rimmed vacuoles, radiation-induced myopathy, sporadic late-onset nemaline myopathy, myofibrillar myopathy, facioscapulohumeral dystrophy, inclusion body myositis, mitochondrial myopathy and others. Regarding myopathy associated head drop syndrome, the authors concluded, “Establishing a diagnosis is crucial for timely treatment administration, screening for swallowing and cardiorespiratory involvement, and counseling regarding prognosis.”