Athetosis-dystonia in intramedullary lesions of spinal cord

Pseudochoreoathetosis secondary to progressive spondylotic cervical myelopathy

Pseudochoreoathetosis is a rare movement disorder associated with loss of proprioception. Culprit lesions may occur at any point between the cerebral cortex and the peripheral nerve. Seldom is the underlying cause reversible or prone to improvement. An elderly man presented to our tertiary centre with choreoathetoid movements secondary to spondylotic subaxial cervical myelopathy. His myelopathy fulminated and he was emergently treated with posterior decompressive neurosurgery. Unexpectedly, his choreoathetoid movements improved significantly post-operatively. There are a multitude of reports of pseudochoreoathetosis secondary to lesions of various aetiologies; however, few have reported this disorder secondary to cervical spondylosis. To our knowledge, there is only one other report in the medical literature. Herein, we report a second case, for the purposes of raising awareness of this disorder, and to highlight relevant clinical pearls for clinicians who encounter this rare pathology.

Cervical demyelinating lesion presenting with choreoathetoid movements and dystonia

Pseudoathetosis and dystonia are rare manifestations of spinal cord disease that have been already reported in lesions involving the posterior columns at the cervical level. We report two patients with a cervical demyelinating lesion at C3-C4 level presenting with hand dystonia and pseudoathetoid movements. The movement disorder disappeared after steroid treatment. The cases we described highlight the importance of identifying secondary causes of movement disorders that can be reversible with appropriate therapy.

The anatomical basis of upper limb dystonia: lesson from secondary cases

Upper limb dystonia is a focal dystonia that may affect muscles in the arm, forearm and hand. The neuroanatomical substrates involved in upper limb dystonia are not fully understood. Traditionally, dysfunction of the basal ganglia is presumed to be the main cause of dystonia but a growing body of evidence suggests that a network of additional cortical and subcortical structures may be involved. To identify the brain regions that are affected in secondary upper limb dystonia may help to better understand the neuroanatomical basis of the condition. We considered only patients with focal upper limb dystonia associated with a single localized brain lesion. To identify these patients, we conducted a systematic review of the published literature as well as the medical records of 350 patients with adult-onset dystonia seen over past 15 years at our movement disorder clinic. The literature review revealed 36 articles describing 72 cases of focal upper limb dystonia associated with focal lesions. Among patients at our clinic, four had focal lesions on imaging studies. Lesions were found in multiple regions including thalamus (n = 39), basal ganglia (n = 17), cortex (n = 4), brainstem (n = 4), cerebellum (n = 1), and cervical spine (n = 7). Dystonic tremor was not associated with any particular site of lesion, whereas there was a trend for an inverse association between task specificity and thalamic involvement. These data in combination with functional imaging studies of idiopathic upper limb dystonia support a model in which a network of different regions plays a role in pathogenesis.

Long-term surgical outcome and risk factors in patients with cervical myelopathy and a change in signal intensity of intramedullary spinal cord on Magnetic Resonance imaging

OBJECT

The goal of this study was to determine the long-term clinical significance of and the risk factors for intramedullary signal intensity change on MR images in patients with cervical compression myelopathy (CCM), an entity most commonly seen with cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament (OPLL).

METHODS

One hundred seventy-four patients with CCM but without cervical disc herniation, severe OPLL (in which the cervical canal is < 10 mm due to OPLL), or severe kyphotic deformity (> 15 degrees of cervical kyphosis) who underwent surgery were initially selected. One hundred eight of these patients were followed for > 36 months, and the 71 patients who agreed to MR imaging examinations both pre- and postsurgery were enrolled in the study (the mean follow-up duration was 60.6 months). All patients underwent cervical laminoplasty. The authors used the Japanese Orthopaedic Association (JOA) score and recovery ratio for evaluation of pre- and postoperative outcomes. The multifactorial effects of variables such as age, sex, a history of smoking, diabetes mellitus, duration of symptoms, postoperative expansion of the high signal intensity area of the spinal cord on MR imaging, sagittal arrangement of the cervical spine, presence of ventral spinal cord compression, and presence of an unstable cervical spine were studied.

RESULTS

Change in intramedullary signal intensity was observed in 50 of the 71 patients preoperatively. The pre- and postoperative JOA scores and the recovery ratio were significantly lower in the patients with signal intensity change. The mean JOA score of the upper extremities was also significantly lower in these patients. Twenty-one patients showed hypointensity in their T1-weighted images, and a nonsignificant correlation was observed between intensity in the T1-weighted image and the mean JOA score and recovery ratio. The risk factors for signal intensity change were instability of the cervical spine (OR 8.255, p = 0.037) and ventral spinal cord compression (OR 5.502, p < 0.01). Among these patients, 16 had postoperative expansion of the high signal intensity area of the spinal cord. The mean JOA score and the recovery ratio at the final follow-up were significantly lower in these patients. The risk factor for postoperative expansion of the high signal intensity area was instability of the cervical spine (OR 5.509, p = 0.022). No significant correlation was observed between signal intensity on T1-weighted MR images and postoperative expansion of the intramedullary high signal intensity area on T2-weighted MR images.

CONCLUSIONS

Long-term clinical outcome was significantly worse in patients with intramedullary signal intensity changes on MR images. The risk factors were instability of the cervical spine and severe ventral spinal compression. The long-term clinical outcome was also significantly worse in patients with postoperative expansion of the high signal intensity area. The fact that cervical instability was a risk factor for the postoperative expansion of the high signal intensity indicates that this high signal intensity area occurred, not only from necrosis secondary to ischemia of the anterior spinal artery, but also from the repeated minor traumas inflicted on the spinal cord from an unstable cervical spine. The long-term neurological outcome found in the preliminary study of patients with CCM who had cervical instability and intramedullary signal intensity changes on MR images suggests that surgical treatment should include posterior fixation along with cervical laminoplasty or anterior spinal fusion.

Hemidystonia secondary to cervical demyelinating lesions

Hemidystonia is usually associated with a structural lesion in the contralateral basal ganglia. We report a patient with definite multiple sclerosis, according to Poser's criteria, presenting with an acute-onset sustained left hemidystonia. Cranial T2-weighted magnetic resonance imaging (MRI) showed several hyperintense lesions in the centri semiovali and in the periventricular area without basal ganglia involvement. Moreover cervical spinal cord T2-weighted MRI showed two hyperintense lesions in the left posterolateral spine at C2 and C3, and one lesion in the right posterolateral spine at C4 levels. The hemidystonia improved completely after daily treatment with 1000 mg of methylprednisolone, and cervical MRI was performed after the improvement which showed that the lesions had become smaller and less intense. Finally we consider that the hemidystonia may be caused by the cervical spinal cord lesions of multiple sclerosis.

Painful tonic/dystonic spasms in Sjogren's syndrome

Three patients with Sjogren's syndrome are presented in whom frequent tonic/dystonic spasms of the limbs developed during the course of the illness. These patients' clinical findings suggested spinal cord involvement, a localization that was confirmed by magnetic resonance imaging in two patients. In one patient the painful movements responded to treatment with phenytoin and in one other to baclofen. Sjogren's syndrome should be considered in the differential diagnosis of conditions that produce tonic/dystonic limb spasms.

Syringomyelic dystonia and athetosis

Two patients with movement disorders associated with syringomyelia are described, one of whom developed unusual torticollis, and the other had choreoathetoid-dystonic movements of the hand and arm. In each case, the movements resolved with decompression of the syrinx. The literature is reviewed and possible mechanisms explored.

[Ataxic instable Alajouanine-Akerman's hand: recovery of a semiologic sign]

It is aimed to recover, considering its historical value, a semiological sign described in 1931 by an eminent neurologist of Rio de Janeiro, together with a master of the French neurology. In the article by Alajouanine and Akerman, named "Attitude of the hand in an astereognostic monobrachial crisis of multiple esclerosis", a semiologic alteration was described which was characterized by "an instability in the attitude of the fingers, which is observed mainly with the hand extended in the attitude of swearing". This attitude of hand worsened a lot with the eyes closed and was accompanied by sensory ataxia, astereognosis, and impaired deep sensation in the affected member. From the original article, it is possible to consider at the present time the described semiologic alteration as a form of pseudoathetosis localized in the hand.

Sternocleidomastoid muscle responses to transcranial magnetic stimulation in patients with cervical dystonia

Ten cervical dystonia (CD) patients, with involuntary head rotation to one side and contralateral sternocleidomastoid muscle (SCM) hypertrophy, were investigated with transcranial magnetic stimulation, and the results were compared to those of 10 healthy subjects. Monopolar needle electrodes with isolated shafts were used for bilateral electromyographic recordings in the SCMs of the motor evoked potentials (MEPs) elicited by the magnetic stimulator. The latencies of ipsilateral SCM MEPs were shorter in the CD patients than in the control subjects (P < 0.001). The latencies of SCM activity suppression by TMS were longer in the CD patients than in the control group when stimuli were given on the contralateral side (P < 0.05). Both the clinically dystonic and the contralateral SCM of the CD patients exhibited significantly abnormal latencies of the ipsilateral SCM MEPs (P < 0.01) and of the SCM suppression (P < 0.05). Three CD patients also had consistent activity in the SCM counteracting the direction of head rotation during the suppression experiments. The latencies of the suppression of this abnormal activation were shorter (P < 0.05), than the latencies of the suppression in the SCM during normal voluntary activation by these CD patients (i.e. rotation of the head in the contrary direction). The results suggest bilaterally enhanced motoneuronal excitability and disturbed inhibitory regulation in patients with CD.