Upper-limb Dystonia Secondary to Atlantoaxial Dislocation - a Rare Case Report

Introduction:progressive cervical myelopathy, foramen magnum
The Atlantoaxial dislocation (AAD) is a fracture of thesyndrome and sudden death due to compression of
odontoid process, in such a way that the end thatvital structures at cervico- medullary junction.
forms a joint with the atlas is separated from itsDystonia is a rare neurological disorder characterized
base and kept in position only by the ligaments, whichby sustained muscle contraction with resultant bizarre
are not strong, joining it to the atlas. Usually AADmuscle movements and hence bizarre posturing.
presents with occipital pain, others develop vertigo,Broadly dystonia can be classified as focal,
brainstem signs, lower cranial nerve palsies. Thegeneralized, early onset or late onset. [2] Though
brainstem findings occur with either basilardystonia due to diverse etiologies like drugs,
invaginations or with the alteration of the path of thedegenerative diseases like progressive supra nuclear
vertebral artery with changing of normal anatomy.palsy and even cortical oligoastrocytoma have been
Though Idiopathic Cervical Dystonia as a sequel todescribed. [3] There has been a frequently reported
AAD has been reported in literature. [1] Upper limbassociation between peripheral injuries or pain and
dystonia is unusual in such cases and has never beensubsequent development of dystonia. Although this
reported from India as well as from any part ofhas been noted for many years, the mechanism is
world and we report a 19-year-old male with AADunclear and causative link is speculative. Most cases
who presented with limb dystonia and hemiparesishave been in patients who develop various forms of
Case History:focal adult onset primary torsion dystonia after local
A 19-year-old boy born of a non-consanguineousinjuries. Some patients may have pre-existing genetic
marriage, following a trivial trauma to the nape ofliability to dystonia but this has been unproven.
neck before 2 years developed progressive spasticOccasionally Dystonia have been described in
right hemiparesis. Three months prior to admission, hesurprising clinical settings like spinal cord lesions and
developed urinary urgency, precipitancy andbrainstem hemorrhage. [4,5] In the contrary, cervical
constipation, and abnormal posturing of right upperdystonia itself may result in orthopedics and
limb predominantly of the hand.There was history ofneurological complications including cervical spine
right hemiparesis when he was four years old, whichdegeneration, spondylosis, disk herniation, vertebral
improved spontaneously over two months. He deniedsubluxation and fractures, radiculopathies and
history of fever, accident or vaccination prior to themyelopathy. [6] AAD leading to dystonia could be due
present illness.to multiple factors like limb pain and cervical cord
His neurological examination revealed short neck, lowlesion. Our case report is exceptional and AAD leading
hairline and spastic right-sided hemiparesis. There wasto limb dystonia has probably never been described in
marked hyper-reflexia and clonus with posteriorliterature.
column impairment without signs of spinothalamicThe exact mechanism of movement disorders in
tract involvement. This was associated withcervical cord lesions is yet not clearly understood.
restriction of neck movements and neck spasm.However, various hypotheses have been proposed
There were abnormal movements of right upper limbwhich includes altered sensory input, abnormal
predominantly distal, in form of repetitive sustainedprocessing of both input and output signals in the
posturing suggestive of dystonia.spinal interneurons and increased excitability of the
The clinical, biochemical and radiological examinationspinal motor neurons. Disruption of the
revealed neither evidence of rheumatoid arthritis norsomatosensory pathways or motor cortex to the
any inflammatory, connective tissue disorder.striatum also may produce abnormal movements
Magnetic Resonance Imaging (MRI) of craniovertebralwithout sensory loss.
junction showed a mobile Atlantoaxial dislocation withHand dystonia in our patient was ascribed to AAD
a well-developed posterior arch of atlas and thewith cord compression because the abnormal
absence of the lamina of the axis.The MRI of brainmovements of hand completely disappeared after
was normal.the correction of AAD.
Discussion:References:
Atlantoaxial dislocation (AAD) constitutes an1.Kanekar S. Atlantoaxial dislocation in idiopathic
important group of Cranio-Vertebral Junctioncervical dystonia. Neurol India 2004 ;52:124-5.
anomalies frequently requiring emergency2.Jowi JO, Musoke SS.Dystonia: case series of twenty
decompression and stabilization of joints to preventtwo patients.East Afr Med J 2005 ;82:463-7.
morbidity and mortality resulting from compression of3.Koch MW, Luijckx GJ, Leenders KL.Paroxysmal focal
neurovascular bundles. Although present since birth,dystonia with sensory symptoms secondary to
patients become symptomatic at a later age (oftencortical oligoastrocytoma.J Neurol2006;253:1227-8.
in third decade) usually following a trauma. The4.Cammarota A, Gershanik OS, Garcia S, Lera G.
trauma may be so trivial, so as to be forgotten byCervical dystonia due to spinal cord ependymoma:
the patient himself. When present, the severity ofinvolvement of cervical cord segments in the
symptoms and its progression bears no relationshippathogenesis of dystonia. Mov Disord1995;10:500-3.
to the injury sustained. It is suggested that chronic5.Esteban Munoz J, Tolosa E, Saiz A, Vila N, Marti MJ,
recurrent trauma during neck movements and dailyBlesa R. Upper-limb dystonia secondary to a midbrain
activities is an important factor for making the illnesshemorrhage. Mov Disord 1996;11:96-9.
symptomatic and its sudden aggravation. Because of6.Konrad C, Vollmer-Haase J, Anneken K, Knecht S.
its varied clinical presentation and an unpredictableOrthopedic and neurological complications of cervical
course the AAD is often misdiagnosed. Its usualdystonia- review of the literature. Acta Neurol Scand
manifestations include nuchal pain and rigidity,2004;109:369-73.