Correspondence Address: Dr. Gurusidheshwar M Wali Neurospecialities Centre, Club Road, Belagavi 590001, Karnataka, India. India
Source of Support: None, Conflict of Interest: None
Insidious-onset progressive dystonias are rarely described as a sequelae of stroke. Their pathological basis consists of axonal degeneration and neuronal plasticity secondary to the initial vascular damage. This case series describes four cases of poststroke dystonias. Although clinical and radiological findings suggest their cause–effect relationship, we have performed genetic testing using clinical exome sequencing to rule out incidental co-occurrence of genetic dystonic syndrome in a patient with stroke. We have documented the clinical evolution of the dystonic features and attempted clinico-radiological correlations using magnetic resonance imaging. A video document of all the cases is provided, highlighting the clinical distribution of the dystonic features and unusual findings. Treatment aspects are briefly discussed.
Keywords: Botulinum toxin in stroke, cerebral perforating vessel disease, poststroke dystonia, white matter hyperintensities
How to cite this article: Wali GM. Poststroke dystonia: A video-based case series. Ann Mov Disord 2019;2:28-31
Poststroke movement disorders may appear in approximately 4% of all patients with stroke, either ischemic or hemorrhagic. Such movement disorders may be either of the hypokinetic type ( Parkinsonism More Details) or of the hyperkinetic type. The latter may include conditions such as chorea, athetosis, dystonia, tremor, myoclonus, stereotypies, and akathisia. Some of these may occur immediately after stroke, whereas others may occur later, and a few may present as delayed-onset progressive movement disorders, possibly as a result of neuronal plasticity.Several locations within the brain have been identified as areas that result in abnormal movements following a stroke. Most often lesions of the basal ganglia or disruption of the direct or indirect pathways of the basal ganglia motor circuitry lead to the appearance of various movement disorders. There are no specific sites or arterial territories for any of the hyperkinetic movement disorders. Lesions in different parts of the motor pathways may lead to the same movement disorder.Vascular damage to these areas of interest may occur due to cardio-embolism, atherothrombosis of the large- or medium-sized vessels, and pathologies affecting the perforating small vessels of the brain., Diseases affecting the perforating small vessels may be of hereditary type or of the acquired type occurring in the background of hypertension, diabetes, or smoking.
Dystonia is a hyperkinetic movement disorder characterized by involuntary sustained muscle spasms causing twisting movements and abnormal posturing of one or multiple body parts. It is classified on the basis of etiology, age at onset, and distribution of affected body parts. Etiologically, dystonia is classified as primary dystonia, heredo-degenerative dystonia, and secondary dystonia. In secondary dystonia, the disorder is a symptom of an identified neurological condition such as focal brain lesion (tumor, infarct, bleed, etc.) or exposure to drugs or chemicals. On the basis of age at onset, dystonia is classified as early onset (onset below the age of 30 years) or late onset. On the basis of distribution of affected body parts, it is classified as focal, segmental, multifocal, generalized, or hemidystonia. Although poststroke dystonias are not uncommon, the subgroup of delayed-onset progressive dystonias is rare. We present a series of four such cases.
All the cases presented here had normal birth and developmental history. None had a family history of vascular disorders or dystonia. They had no history of exposure to neuroleptics or clinical features to suggest neurodegenerative diseases such as Huntington disease or late-onset Wilson’s disease. Clinical exome sequencing studies were performed for all the cases to rule out possible genetic cause for their dystonic disorders. None of the cases showed pathogenic or likely pathogenic gene variants causative of the identified phenotypes (MedGenome, India).
We documented the history of each case with special attention to conditions such as hypertension, diabetes, smoking, and past stroke. Magnetic resonance imaging (MRI) scans of the brain were performed for all the patients with an intention to identify the nature, location, and extent of the vascular lesions. Any associated changes in the cerebral cortex or the cerebellum, if present, were documented. The radiological findings in the regions of interest (basal ganglia and the brain stem) for all the cases are shown in [Figure 1], whereas all affected locations are listed casewise in [Table 1]. Spinal MRI scans were performed to look for any changes in the spinal cord, which could contribute to the clinical findings. A video document highlighting the clinical pattern of dystonias is provided for all the cases [Video 1].
Figure 1: (A) Magnetic resonance imaging (MRI) of Case 1 brain, which is a coronal T2-weighted image, shows evidence of lacunar hyperintense signals in both basal ganglia (caudate/lentiform nucleus). (B) MRI of Case 2 brain is an axial T2-weighted image showing evidence of hyperintense signal in the left thalamus. (C) MRI of Case 3 brain is an axial T2-weighted image revealing evidence of hyperintense signals, involving both gangliocapsular regions with peripheral blooming. Lacunar hyperintense signals are seen in both the thalami as well. (D) MRI of Case 4 brain is a sagittal T1-weighted image of the pons showing two lacunar infarcts
This 68-year-old man, a diabetic, hypertensive, and smoker, presented with a 3-year history of insidious onset and slowly progressive neurological disability. He had a remote history of right hemiparesis, which cleared completely in 2 weeks. The initial features of his present illness included forgetfulness, difficulty in naming, poor attention, and lack of interest in surroundings. Over the next 6 months, he was noticed to have poor utility and abnormal posturing of the right upper extremity, which gradually worsened and spread to involve the right lower extremity affecting his gait. During the same period, he developed features of progressive dysarthria and urinary–bowel urgency. When examined by us, 2 years through his illness, he was found to have significant cognitive failure, anarthria, vacant searching looks, right hemidystonia, and a slow gait with short steps. During further follow-up, he developed features of lingual dyskinesia and stereotypic movements of the left upper extremity. The latter consisted of frequent raising of the left arm and sweeping it across his head [Video 1]. MRI findings at the level of the basal ganglia are shown in [Figure 1A].
This 58-year-old man with hypertension presented with a 2-year history of slowly progressive neurological disability. His illness started insidiously with symptoms of non-vertiginous dizziness and subjective gait imbalance. Over the next 6 months, he developed mild right hemidystonia and a slow gait. Gradually, he developed truncal laterocormia toward the right side. Both the motor symptoms worsened with walking leading to Pisa syndrome [Video 1]. MRI findings in the region of interest are shown in [Figure 1B].
This 70-year-old man with hypertension presented with a 7-year history of slowly progressive involuntary movements of the neck and trunk. The symptoms first appeared in the form of a tremulous cervical dystonia with chin pointing toward his right shoulder. This could be suppressed briefly with a geste phenomenon. As the symptom worsened over the next 3 years, he developed abnormal posturing of the trunk in the form of right laterocormia leading to Pisa syndrome, which worsened during walking [Video 1]. MRI findings in the region of interest are shown in [Figure 1C].
This 58-year-old man with hypertension presented with a 6-year history of insidious onset of slowly progressive difficulty in walking. His initial symptoms included a feeling of dizziness and subjective imbalance. Gradually over the years, he experienced slowness of gait and abnormal posturing of the right upper extremity induced by walking. Over the next few years, his family members pointed out that his trunk deviated to one side during walking. Examination revealed poor facial expressions and a slow wide-based gait. He had walking-induced left-sided truncal laterocormia leading to Pisa syndrome. The dystonic arm abduction also worsened while he walked. MRI scan revealed the presence of two lacunar infarcts in the middle of the pons [Figure 1D].
All the four cases were treated with a combination of antiplatelet drugs, clonazepam and/or diazepam. However, in view of the short duration of follow-up, we are unable to comment on the effectiveness or otherwise of the treatment. The patients are kept under regular follow-up. Botulinum toxin injection therapy is planned for all the cases.
On the basis of background history of hypertension/diabetes/smoking, clinical assessment, negative genetic findings on clinical exome sequencing, and presence of cerebral vascular lesions on MRI, we strongly believe that the dystonic manifestations noted in our cases are secondary to vascular insults to the brain. Incidentally, all the cases presented here had radiological proof of parenchymal changes scattered in multiple territories because of pathologies in the perforating vessels supplying the brain. Previous studies have also observed that both small vessel diseases and small deep infarcts represent the most common subtype of strokes leading to abnormal movements., The resultant parenchymal lesions are visible as white matter hyperintensities (WMHs). Capillary endothelial dysfunction is considered to be the basis of such hyperintensities. Varying intensities of the lesions indicate that they have appeared at different periods. Such lesions may remain “silent” over a period and lead to progressive dystonic disorders because of secondary axonal degeneration and neuronal plasticity.
Our cases reveal that a wide range of delayed-onset progressive dystonias can appear in the poststroke period [Video 1]. Case 1 had progressive right hemidystonia followed by appearance of lingual dyskinesia and stereotypic movement involving the left upper extremity. The other three cases had evidence of segmental dystonia, wherein the trunk was uniquely involved. Cases 2 and 4 had truncal dystonia associated hemidystonia, whereas Case 3 had truncal dystonia associated with tremulous cervical dystonia. The truncal dystonia worsened with walking in all these cases leading to Pisa syndrome. This phenomenon of worsening of poststroke dystonia with walking has been described in the past and is considered to be related to proprioceptive dysfunction.Previous studies have documented that dystonias are most often seen with lesions of the putamen but also reported with lesions involving the thalamus, caudate nucleus, globus pallidus, internal capsule frontal lobe, parieto-occipital lobe, brain stem, cerebellum and the spinal cord, and cerebellothalamic pathways. Truncal dystonia often occurs as a manifestation of neurodegenerative disease or as a neuroleptic syndrome. Three of our cases had truncal dystonia, indicating that it can occur as a poststroke complication. Case 1 had stereotypic movements of the left upper extremity. This presentation, which is mostly unilateral, is often seen with lesions involving the parietal, lenticulostriate, thalamic, midbrain, or the left middle cerebral artery territory. Case 4 had well-defined two lacunar infarcts of varying sizes, involving the pons. Such cases are rarely described. Dysregulation of the pallidal efferents to the pedunculo-pontine and/or pontine afferents to the thalamus may be the mechanism underlying this phenomenon.The treatment of poststroke dystonias is aimed at control of factors such as hypertension/diabetes/smoking and use of antiplatelet drugs in ischemic cases. The symptomatic management of the poststroke dystonia is possible with the use of injections of botulinum toxin. The toxin acts by blocking the release of acetylcholine. Selection of the appropriate muscles using electromyographic guidance can provide good results. Oral agents useful in its treatment include benzodiazepines, baclofen, anticholinergic drugs, and dopamine-depleting drugs. The anticholinergic drugs, which also act by blocking the release of acetylcholine, deactivate muscle contractions, leading to symptomatic relief from dystonia. Their use in elderly patients is limited because of potential adverse effects such as confusion and constipation.
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