Acquired Movement Disorders Secondary to Giant Tumefactive Perivascular Spaces

Abstract

Dear Editor, Perivascular spaces (PVSs), commonly known as VirchowRobins spaces, are interstitial cystic spaces filled with cerebrospinal fluid (CSF). PVSs generally accompany deep branches of cerebral vessels within the white matter and, in healthy individuals, are < 2 mm in diameter.1 Traditionally, these spaces are asymptomatic and benign; however, in rare instances, these spaces can expand into giant tumefactive PVSs (GTPVSs) that compress nearby structures, causing neurologic disorders and hydrocephalus.1,2 PVSs > 15 mm in diameter are considered GTPVSs and may require neurosurgical intervention for symptomatic relief.1,3 A 17-year-old man with a history of congenital hypothyroidism presented with chronic, nonprogressive left upper extremity shaking and dysconjugate gaze with compensatory tilt since the age of 11 years. On examination, he had vertical nystagmus, saccadic upward gaze, left hyperopia with skew deviation and trace bilateral papilledema. Initial MRI revealed a 4 cm multicystic lesion in the left midbrain that extended into the thalamus and partially obstructed the third ventricle, causing dilatation of the third ventricle with mild lateral ventricular dilatation (Figure 1A and B). At the age of 12 years, he underwent open biopsy with soft tissue at the superior portion of the brainstem and cystic fenestration. Pathology showed minute fragments of gray and white matter without neoplastic cells (Figure 1E and F). He has yearly MRI scans of the brain that show stable ventricular size and no evolution of GTPVSs. Because his symptoms do not bother daily living activities, the decision was to clinically and radiologically monitor (Figure 1C and D). Physical examination (at the age of 17 years) revealed left head tilt and mild scanning speech. The left eye had an elevated gaze compared to the right eye with skewed lateral left and right gaze as well as intermittent horizontal and rotatory nystagmus. He had a 4–6 Hz proximal postural tremor in the left upper extremity with dystonic posturing of the left hand. Handwriting with the left hand was jerky, ataxic and required purposeful force to keep the pen stable on the paper. When asked to pour water from a cup in one hand to the other, the left-sided tremor worsened. Finger-to-nose testing showed ataxia without dysmetria; however, when he used his right hand to stabilize the left arm, finger-to-nose testing showed a marked improvement in ataxia. Mild left-sided bradykinesia was noted, but tone was normal. There was no postural instability. Ataxia was also noted with heel-to-shin testing on the left and tandem gait (Supplementary Video 1 in the online-only Data Supplement). A DATscan [preprocedure intravenous infusion of I-123 ioflupane as well as SPECT and CT images of the brain were acquired and processed using Symbia Intevo 16 SPECT/CT hybrid technology (Siemens Healthineers, Malvern, PA, USA)], which revealed normal uptake in the left striatum, decreased uptake in the right putamen and mild decreased uptake in the right caudate nucleus (Figure 1G). The levodopa trial did not help the tremor. We present a rare case of an acquired movement disorder in a pediatric patient secondary to GTPVSs. Our patient’s complex movement disorder and abnormal extraocular movements cor-