Cervical dystonia caused by focal putaminal ischemia.

We describe a 48-year-old woman with putaminal gliosis and a sphenoid wing meningioma at the left, who developed dystonia restricted to cervical regions. We propose the following causal chain: the meningioma led to an occlusion of a lenticulo-striatal branch of the middle cerebral artery that caused ventral putaminal ischemia and finally resulting in symptomatic dystonia. The previously reported relevance of the infarcted regions to the pathophysiology of dystonia supports this assumption. Implications for the diagnostic procedure of dystonia will be discussed.

Introduction

Dystonia is a group of movement disorders characterized by involuntary, repetitive movements, or abnormal postures.1 A recently published consensus suggests a bi‐axial classification with clinical characteristics (focal, segmental, hemidystonia, generalized) on the first and the etiology (primary, secondary) on the second axis.2

The current pathophysiological concept of dystonia assumes that abnormal alterations in the sensorimotor integration accompanied by an increase in motor cortex excitability finally leads to sustained muscle contractions. The abnormalities were charged to be secondary to a shortage of inhibitory control in the basal ganglia.3 This approach is in line with the lesion analyses which emphasize the particular, albeit not exclusive, relevance of striatal or thalamic regions for the etiology of dystonia.4, 5

In 256–40%7 of all patients, a secondary dystonia is assumed. Causes differ widely from tardive dystonia secondary to neuroleptic treatment7 to vascular etiologies as stroke8, 9 or subdural hematoma.10 Neoplasms are a known source of secondary dystonia as well: reported cases focused on tumors in children,4, 11, 12, 13, 14, 15 whereas only four cases in adults have been described yet4, 12, 14, 16 (for a complete overview of all identified causes for secondary dystonia see 17).

Here, we report a case of secondary cervical dystonia caused by ventral putaminal ischemia after vascular occlusion due to a sphenoid wing meningioma.

Case Report

In 2007, a 48‐year‐old woman presented at an outpatient medical center after developing an antero‐ and laterocollis with a tilt of 45° to the right, a hypertonic right sternocleidomastoid and a dystonic lifted shoulder, resulting in a Tsui Score of 8 (solely considering cervical symptoms, range from 0 to 25). The patient reported a slight relief under usage of a sensory trick maneuver, cervical symptoms seemed to improve by touching the right shoulder. There was no relevant medical history and family history was negative for movement disorders. Except arterial hypertension, no other comorbidities were reported. Cervical dystonia was diagnosed and regular injections with abobotulinum toxin type A (Dysport®, Ipsen Ltd, Paris, France, 800 MU) were conducted at intervals of 3 months, resulting in a good but dropping response. However, a cranial magnetic resonance imaging (MRI) was not performed. Within 3 years, an outspread of dystonic symptoms to the right dorsal trunk became manifest. Therefore, the patient was admitted to our medical care center to consider a treatment with deep brain stimulation (DBS).

Extensive laboratory diagnostics of the patients' blood and cerebrospinal fluid revealed no indications for inflammatory or neurodegenerative processes. Doppler sonography of intra and extracranial vessels and electroencephalography were unremarkable. Cranial MRI revealed a circumscribed gliosis of the left ventral putamen, adjacent to the left capsula externa (see Fig. 1A) that corresponds to the supply area of a lenticulo‐striatal branch of the middle cerebral artery. Further, a 13 × 15 mm sized extra‐axial mass was observed at the left sphenoid wing with homogeneous contrast enhancement (see Fig. 1B) and direct spatial relation to the lenticulo‐striatal branches of the middle cerebral artery. We decided to fully resect the mass next to the infarct via a pterional approach. Histological examination led to the pathological diagnosis of a meningeothelial psammomatous meningioma (WHO‐I).

Figure 1

(A) Preoperative coronal magnetic resonance imaging (FLAIR, TR: 9000 msec, TE: 118 msec) showing a circumscribed gliosis of the ventral putamen, corresponding to the area of a lenticulo‐striatal branch. (B) Axial MRI (contrast‐enhanced T1‐MPRAGE, TR: 1900 msec, TE: 3.37 msec) reveals a homogeneously enhancing meningioma located at the left sphenoid wing comprising the left middle cerebral artery in the height of lenticulo‐striatal branches. (C) Axial CT showing the middle cerebral artery after successful tumor resection.

Postoperatively, the patient noticed no more progression of truncal dystonic symptoms. During a 3‐year clinical follow‐up, the cervical component of dystonia (Tsui Score of 8) remained stable. After an attempt with anticholinergic medication (trihexyphenidyl) proved ineffective, the treatment with abobotulinum toxin type A was resumed, leading to a moderate benefit (see Video S1).

Discussion

The typical clinical characteristics and the absence of additional neurologic symptoms initially led to the diagnosis of primary dystonia. The presence of sensory tricks seems to be rare in patients with secondary dystonia,6 supporting the initial assumption. However, the lesions found upon structural brain imaging clearly suggest a secondary dystonia due to a meningioma‐induced ventral putaminal ischemia. The ischemic region presumably affected sensorimotor pathways in the striatum which were accounted for being a pathophysiological substrate of dystonia.3 This conclusion is in line with a case of left segmental dystonia affecting the face and hand after embolic occlusion of the middle cerebral artery.5 A direct genesis of dystonia by the meningioma as previously reported in a case by Soland and coworkers16 seems to be implausible as the meningioma described here was distinctly smaller, just slightly infiltrated the adjacent cortex, and was not accompanied by a perifocal edema which could affect the basal ganglia. However, a coincidental occurrence of primary dystonia cannot fully be excluded.

The diagnostic criteria of the European Federation of Neurological Societies stated the need of structural brain imaging as MRI in the diagnosis of primary dystonia for the screening of secondary forms.18 Geyer and Bressman suggest to perform brain imaging as an obligatory part of the diagnosis if the patient is older than 26 or, if younger, after a hereditary genesis can be ruled out.17 Our case emphasizes the necessity of structural brain imaging in the diagnosis of dystonia – particularly with regard to a potentially treatable underlying cause as described here.

Due to the fact that several studies indicate a weaker effect of DBS for the treatment of secondary dystonia in comparison to primary forms,18, 19 conventional treatment regimen with botulinum toxin was preferred.

In summary, our case provides a new facet for the pathophysiological substrate of dystonia consisting of a putaminal lesion induced by a neoplasm–vascular cascade which underlines the need for a cranial MRI in the diagnosis of dystonia.

Conflict of Interest

None declared.

Video S1. The described cervical dystonia with an antero‐ and laterocollis to the right, before and 3 years after tumor resection.

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