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“Dropped head syndrome” is characterised by weakness of the extensor muscles of the neck, with or without involvement of the neck flexors, and is commonly caused by a variety of neuromuscular disorders, including myasthenia gravis, polymyositis, amyotrophic lateral sclerosis, facio–scapulo–humeral dystrophy, nemaline myopathy, carnitine deficiency, spinal muscular atrophy, and isolated neck extensor myopathy.1,2 There are isolated reports of dropped head syndrome occurring in cervical spondylitis and ankylosing spondylitis.3 In this report, we describe the clinical and imaging findings of two patients who had dropped head syndrome as a rare neurological sign secondary to syringomyelia.
Case report 1
A 46 year old right handed man presented during May 2002 with insidious onset, gradually progressive weakness and wasting of the small muscles of the left hand since August 1998. This deficit stabilised after a period of one year. At the onset of illness, he had also developed mild difficulty in using his right hand for performing fine work but this symptom remained stable. He noticed occasional fasciculations over the arms for one year. After two years and nine months he developed rapidly progressive head drop and required assistance of the hand to maintain the head in an erect posture, and he also had mild difficulty in lifting his head off the bed while rising from the supine position. There was no history of impaired sensation to touch, pain, or temperature, or inadvertent burns over the hands or shoulders. There were no features to suggest Horner’s syndrome or symptoms referring to the cranial nerves, lower limbs, cerebellar system, or sphincters. There was no nuchal pain, restricted neck movements, or symptoms of raised intracranial pressure.
Examination revealed mild cerebellar dysarthria and fasciculations over the tongue. There were no features of Horner’s syndrome and the eye movements, facial sensations, palatal reflexes, and pharyngeal reflexes were normal. Occasional fasciculations were present over the arms. There was Medical Research Council grade 2 weakness of the neck extensor muscles with head drop and grade 4 weakness of the neck flexors. There was mild wasting of the erector spinae muscles in the neck and asymmetric wasting of the small muscles of the hand, including the thenar, hypothenar, and interossei muscles bilaterally, with the left side being affected more severely. Power in the lower limbs was normal. Deep tendon reflexes were sluggish in the upper limbs and exaggerated in the lower limbs, with a bilateral flexor plantar response. The sensory system revealed bilateral C2 hypoesthesia, with impaired pain and temperature sensations in both upper limbs and in the shoulder girdle region. Magnetic resonance imaging of the spine and brain revealed a septate intrinsic cord hypointensity in T1 weighted images, becoming hyperintense in T2 weighted images extending from the C2 to C7 (fig 1) levels, associated with low lying cerebellar tonsils and brainstem reaching the lower border of C1. Brain images revealed evidence of hydrocephalus. There was no evidence of myelomeningocele. Electromyography of the distal muscles in the upper limbs showed fibrillation and fasciculation potentials. Motor and sensory conduction studies were normal. Investigations including serum chemistry and haemogram were normal.
Case report 2
A 30 year old man presented in December 2003 with progressive weakness and atrophy of the right shoulder girdle muscles with a duration of one year, followed by similar symptoms on the left side for 10 months; at presentation he was unable to raise his arms. In the last six months he had developed head drop, with difficulty in maintaining the head in the erect posture, and since this time he had noticed weakness and atrophy of the hand muscles. There were no symptoms of pain or restricted neck movements, and there was no sensory impairment, sphincter disturbance, or cerebellar ataxia. Neurological deficits were present in the form of thoracic kyphoscoliosis and wasting of the extensor muscles of the neck, resulting in severe weakness and dropped head (fig 2). Power in the neck flexors was grade 4. Severe asymmetric wasting of the shoulder girdle muscles, in addition to moderate wasting of the arm, forearm, and hand muscles was noted, with bilateral clawing. There was grade 2 power in the proximal muscles, including the arm, and grade 3 in the small muscles. Deep tendon reflexes were absent in the upper limbs and exaggerated in the lower limbs, with a bilateral extensor plantar response. Temperature sensation was impaired in the entire body except for the face. Posterior column and spinothalamic sensations were normal. Contrast magnetic resonance imaging of the spine, including T1 weighted and T2 weighted images, revealed a cerebrospinal fluid signal intensity lesion involving the entire cord, with expansion of the cord, and no evidence of abnormal contrast enhancement, suggestive of holocord syringomyelia.
Dropped head syndrome is a well known feature in a variety of neuromuscular disorders, and is also described in diseases of the bone and joints, such as ankylosing spondylitis and cervical spondylitis.3 Neck flexion weakness is typical in most conditions, but prominent neck extensor weakness has been described in several reports. In the recent review article on dropped head syndrome in amyotrophic lateral sclerosis, 19 different conditions are listed as causes for dropped head syndrome, but syringomyelia is not mentioned as a cause.4 Our patients presented with classic features of cervical intrinsic cord lesion suggestive of syringomyelia and had the typical features of dropped head syndrome.
Competing interests: none declared
The patient gave consent for reproduction of the photograph.
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