ABSTRACT
Dropped head syndrome (DHS) is a relatively rare condition, with a broad differential
diagnosis. This deformity has significant implications on the health and quality of
life of affected individuals. While surgery seems to be an obvious therapeutic option,
there is a paucity of information on surgical intervention with no clear consensus
on an optimal approach or timing.
We present a case of DHS in a young woman to illustrate this condition, and review
the current literature. Although at present the only definitive solution for correction
and stabilization of DHS is surgical intervention involving multilevel instrumented
fixation and fusion, this condition requires a persistent medical workup and treatment
of reversible causes before surgical intervention is contemplated.
BACKGROUND
Dropped head syndrome (DHS) is characterized by severe kyphotic deformity of the cervico-thoracic
spine. It is a relatively rare condition with a broad differential diagnosis [1]. The conditions linked with DHS can be categorized into neurological, neuromuscular,
muscular, and other causes (Table [1]). This deformity has significant implications on the quality of life of affected
individuals, resulting in considerable restrictions to ambulation, activities of daily
living, and social interactions. While surgery seems to be an obvious therapeutic
option, there is a paucity of information on surgical intervention with no clear consensus
on an optimal approach or timing.
CASE REPORT
A 38-year-old woman presented to the senior author's spinal cord clinic with a history
of severe chronic cervical pain and a recent history of cervical deformity and gait
abnormalities. She gave a decade long history of gradually worsening intense tightness
around the neck and muscular contractions. Her neck deformity had been slowly progressive
over the last 3 to 4 years but had worsened in recent months. She also described trouble
ambulating, primarily due to difficulty holding up her head. However, she testified
no motor or sensory dysfunction in any extremity.
On examination she was found to have pronounced cervical kyphosis with hypertrophic
neck extensors. The deformity was completely reducible by the examiner. Active cervical
flexion and extension were reduced to 50% of normal and painful at extremes. Muscle
bulk, tone, and power were normal in all four limbs. She had mild global hyperreflexia
and positive Hoffmann reflexes bilaterally, but downward Babinski reflexes bilaterally.
Tests of sensation were normal.
X-ray of cervical spine (Fig [1]) indicated marked cervical kyphosis centered on the mid-cervical spine, and evidence
of spondylosis. Magnetic resonance imaging (MRI) (Fig [2]) showed multilevel cervical spondylosis with cerebrospinal fluid effacement at the
mid-cervical levels but no evidence of cord signal change. A preliminary diagnosis
of cervical dystonia causing DHS with subtle signs of myelopathy was considered, and
further investigations to determine the primary pathology were organized.
Initial electrodiagnostic findings were nonspecific. A muscle biopsy from the trapezius
showed no evidence of inflammatory myopathy and nonspecific atrophic changes with
fibrosis which were considered nondiagnostic.
Over 2 years she became progressively disabled with decline in her functional state
such that she could only ambulate short distances while holding her head up with both
hands. Clinical examination showed an increase in hyperreflexia of the left arm but
was otherwise unchanged. Repeated MRI (Fig [3]) showed distinct T2 hyperintensity of the cord at C3 – C4 and atrophy with fat infiltration
of the paraspinal muscles in the lower cervical spine. Repeated electrodiagnostic
assessment showed fibrillation and small amplitude polyphasic potentials in the paraspinal
muscles suggesting myopathy as the cause of DHS.
The patient consented to surgical intervention to achieve the goals of decompression
of neural structures, and correction of the cervical deformity with stabilization.
She underwent a C2 to T1 decompressive laminectomy, and occiput to T6 posterior instrumented
fixation and fusion. Good reduction of the cervical deformity with neutral head alignment
was achieved via direct visualization and image intensification. The surgical procedure
was uncomplicated, with motor and sensory-evoked potentials maintained throughout.
Intraoperative electromyographic recordings showed transient-spiking activity during
the procedure but this resolved fast.
Postoperatively she recovered well with no neurological deficits. Computed tomography
confirmed good positioning of all hardware, and anatomical alignment with increased
space in the spinal canal. She was managed for 8 weeks postoperatively in a cervico-thoracic
orthosis. She regained full mobility, and at 8 months follow-up she reported increased
energy and a significantly improved ability to carry out daily activities. Imaging
at follow-up shows the correction and stabilization of the deformity (Fig [4]).
DISCUSSION
Dropped head syndrome is a complex and challenging condition. Optimal management of
a patient with DHS requires a comprehensive multidisciplinary workup to establish
the primary cause before surgical decision making. Many of the underlying conditions
are medically treatable and in some cases the extent of the deformity may be decreased
to an acceptable level without invasive intervention. In particular, Parkinson disease,
inflammatory myositis, and secondary myopathies due to metabolic or endocrine dysfunction
are likely to show substantial improvement when treated with appropriate medications.
Other etiologies that cause focal structural changes are poorly suited to medical
treatment, such as neck radiation therapy causing extensor myopathy and anterior scar
contracture.
When investigations including electromyographic studies and muscle biopsy show a myopathic
cause of DHS that is noninflammatory and isolated to the neck extensors, a diagnosis
of isolated neck extensor myopathy can be made. While isolated neck extensor myopathy
and some other causes of DHS may not be medically treatable, benefit may be gained
with physiotherapy, massage, and acupuncture to maximize function and slow progression
of symptoms. However, the natural history of this condition usually involves progression
to a complete inability to lift the head in a seated or standing position, and this
severe kyphosis can lead to secondary degenerative changes including vertebral compression
and anterior muscle contraction. This development can later lead to cervical myelopathy
and neurological decline. Thus, when medical and physical treatment options have been
exhausted, mechanical correction of DHS may be needed to maintain a reasonable quality
of life for the patient.
Options for mechanical stabilization and correction of DHS include removable soft
or hard collars, Somi brace, halo-vest, or surgical fixation [1], [2], [3]. External orthotic devices may provide stabilization and partially correct the deformity;
however, they may be cumbersome, irritating the skin, and may cause further deconditioning
and deterioration of neck extensor musculature. Therefore these devices are often
only temporary solutions, and are likely to achieve long-term satisfaction in only
a select patient group – those too old or unwell to undergo major surgical intervention.
At present, the only definitive solution for correction and stabilization of DHS is
surgical intervention involving multilevel instrumented fixation and fusion.
Several articles have documented surgical correction of DHS. Dating back to 1988,
Simmons and Bradley described a case series of six patients who underwent surgical
intervention for what they termed „chin-on-chest deformity” [3]. They advocated halo traction and anterior muscle release to help reverse anterior
muscle contraction when the condition was longstanding. They also suggested that posterior
resection of the inferior facets could be useful to achieve restoration of normal
extension. In four cases, posterior instrumented spinal fusion was performed from
mid-cervical (C3 – C4) to upper thoracic (T1 – T3) levels with good bony fusion, but
the authors did not provide long-term follow-up data. They did report that two of
these procedures had caused anterior wedge separation, requiring subsequent keystone
strut-grafting.
Gerling and Bohlman [4] reported nine cases of DHS in the context of cervical myopathy that were managed
with posterior instrumented fusion. The primary complaint of all nine patients was
loss of horizontal gaze, and five patients also complained of axial neck pain. Only
one was myelopathic, and this patient was not decompressed during surgery. The surgical
constructs for all patients spanned C2 to upper thoracic levels (T1 – T5) [4], [5]. Four also required anterior cervical releases. The average follow-up was 6 years,
and overall the authors found good outcomes at the 2-year follow-up in seven patients
and fair outcomes in the other two. This was despite frequent complications including
construct failure in one case; two revision surgeries in another; camptocormia in
two cases; dysphagia in two cases; and pneumonia in two cases.
Petheram et al [1] described a series of seven patients with DHS, six of whom were treated nonoperatively
and one with a C4 to T2 instrumented fusion at another institution. The 79-year-old
patient was unhappy with the outcome because of decreased neck mobility and difficulty
walking after surgery. The six patients treated nonoperatively also did not fare well,
with only one showing marked improvement with physiotherapy and temporary use of a
neck collar.
Amin et al presented a patient with long-standing DHS and osteoporosis who was managed
with instrumented fusion spanning C2 – T11 after suffering a fall and multiple thoracic
vertebral fractures [6]. Their rationale for the lengthy construct was due to extremely poor-quality bone
and the need for stabilization of the thoracic fractures. The patient recovered well
and after 3 months of rehabilitation was able to live independently, walking without
aids, and maintaining a functionally useful head position.
Kawaguchi et al reported a case of DHS caused solely by cervical myelopathy secondary
to spondylosis [7]. In this scenario, they found that decompressive laminectomy alone was sufficient
to improve neck extensor function to allow return to normal posture.
A final case describes a patient with Parkinson disease who had undergone DBS placement
but continued to have falls and sustained an odontoid fracture. Initial surgical intervention
consisted of C1 – C2 internal fixation, but the patient sustained a vertebral artery
injury and continued to experience painful spasmodic anterocollis and torticollis.
This patient subsequently received occiput to T1 posterior instrumented fusion, which
resulted in complete resolution of neck pain and a subjective improvement in overall
functioning [8].
We need to consider several key issues in the surgical management of DHS. First, the
decision to operate is based on numerous patient factors, including age, functional
status, and current quality of life reported by the patient. This has to be weighed
against the expected functional status and quality of life after intervention, which
will be affected if an occipito-cervico-thoracic fusion is performed.
Second, is the number of levels that need to be stabilized. While most published reports
of instrumented fusion spared the craniocervical junction, our construct did not due
to the patient’s extremely poor extensor musculature. In general, if function of moderate
neck extensor remains, it is preferable to limit the rostral level of fusion to C2
to preserve some head mobility. It is also important to consider the status of the
thoracic extensor musculature and the bone quality to determine how caudal the fusion
needs to be extended. In our case due to poor-density bone the integrity of a shorter
construct would have been questionable. In other individuals with high-quality bone
and relatively normal thoracic extensor muscles, fusion down to T3 would likely be
sufficient.
Third, is the question whether or not to perform a laminectomy in the context of mild
cervical myelopathy. It is possible that the mechanical correction of the severe kyphosis
itself may decompress the spinal cord. In our case, laminectomy was indicated as the
patient had clinical and radiological signs of myelopathy. Given the presence of canal
stenosis and cord signal change, the safest method to protect the spinal cord during
the correction of deformity was to ensure that it was decompressed first.
Finally, the timing of surgery is vital in this degenerative condition. While it is
desirable to delay surgery until it is absolutely necessary, it is essential to intervene
before cervical myelopathy and neurological deficits become established. The recommended
approach is to monitor closely for clinical or radiological evidence (via serial MRIs)
of cervical myelopathy, and intervene if this becomes apparent.
In summary, we report a case of DHS secondary to cervical myopathy. Such a presentation
requires a persistent medical workup and treatment of reversible causes before surgical
intervention is contemplated. Surgical issues to consider include the optimal timing
of intervention, the need for anterior muscle release, the choice of approach (anterior
vs posterior vs 360), and the levels which will involve decompression and instrumented
fusion.
