Figure of Eight Stereotypies in a Young Girl With a Prenatal Cerebellar Injury

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Rhythmic repetitive head‐nodding movements can be a “primary” condition in otherwise normal children or a “secondary” manifestation associated with autism, visual or oculomotor dysfunction, genetic syndromes, use of drugs, autoimmune encephalitis, psychiatric conditions, tumors, and developmental brain malformations.1 Whereas the precise underlying pathophysiological mechanism for these stereotypic head movements remains unknown, several reports have suggested an association with abnormalities of the cerebellum and posterior fossa. Either an up‐and‐down (“yes”), side‐side (“no”), or shoulder‐to‐shoulder movement has been reported in children with lesions of the third ventricle (bobble‐headed doll syndrome)2 and in those with Dandy Walker syndrome.3 A persistent “figure of eight” head‐nodding stereotypy is well described in association with rhombencephalosynapsis (RES), a brain malformation with partial or complete absence of the cerebellar vermis with fusion of the cerebellar hemispheres across the midline.4 The latter has also been described in a child with a unilateral cerebellar lesion on CT.5

Case Report

We report on a 9‐year‐old girl who presented with hypotonia and a variety of rhythmic, repetitive, fixed (form, amplitude, and location) movements that stopped with distraction. Her initial movement, which began at 3 months of age, included figure of eight head stereotypies. At age 3 years, she developed complex motor stereotypies consisting of rhythmic, individual, right greater than left finger movements, at times accompanied by flapping/waving activity of the wrist, elbow, or shoulder, as well as tapping foot movements that occasionally appeared when seated (see Video). Stereotypies were exacerbated by excitement and boredom, disappeared with distraction, and were absent during sleep. She had normal intelligence, affect, and an unremarkable mental status exam. Examination was notable for hypometric saccades, right greater than left hypotonia, and right‐sided dysmetria and dysdiadochokinesia. Review of her MRI showed extensive right greater than left cerebellar atrophy, possibly attributed to an early in‐utero vascular insult (Fig. 1A,B). The cerebral cortex and basal ganglia were normal in appearance (Fig. 1C).

Figure 1.

Axial (A) and sagittal (B) T₂‐weighted MR images show profound right greater than left cerebellar atrophy. Axial T₁ image (C) demonstrates that the cortex and basal ganglia are normal in appearance.

Although most commonly described in association with RES, this is the second report of figure of eight head stereotypies in a child with a unilateral cerebellar lesion, likely secondary to infarction.5 It is difficult to estimate how frequently this specific stereotypy occurs in children with no evidence of cerebellar dysfunction on exam or imaging. In one previous report of 6 patients with both figure of eight stereotypies and imaging, 2 had a posterior fossa malformation, 1 had ventricular asymmetry, 1 had mild ventriculomegaly, and 2 had normal imaging.5 Although complex motor movements and stereotypies of the limbs have been described in children with figure of eight stereotypies, to our knowledge, this is the first report of an accompanying asymmetric arm stereotypy. This may be associated with a greater degree of atrophy in the right cerebellum.

Classification of repetitive head movements in children is controversial. For example, head movements in bobble headed doll syndrome are viewed by some as a tremor, rather than a stereotypy.6 Figure of eight movements observed in RES are generally considered a stereotypy. Some investigators, however, hypothesized that they were secondary to disruption of central vestibular processing, based on the presence of subtle eye movement abnormalities such as hypometric saccades and deficits in smooth pursuit.4 Nevertheless, these same researchers acknowledged that their subjects frequently had complex motor stereotypies involving the limbs as well as the presence of common comorbidities observed in children with stereotypies, for example, tics, attention deficit hyperactivity disorder ADHD, and obsessive‐compulsive disorder OCD7—symptoms not explainable solely as a deficit in vestibular processing.

The pathophysiology of complex motor stereotypies has traditionally been proposed to lie within habitual behavioral pathways, more specifically in cortical (premotor/supplementary motor area) to basal ganglia (putamen) connections.8 The influence of the cerebellum on this motor network has only begun to be appreciated. The cerebellum sends excitatory projections directly to the thalamus, amygdala, ventral tegmental area, and dorsal raphe nuclei and indirectly to the basal ganglia through the thalamus and amygdala.9, 10 Furthermore, there are multiple reports, including this case, of stereotypies associated with cerebellar malformation.3, 4, 5 Cerebellar strokes in adults have also been reported to cause stereotypic movements, including rubbing thumbs against the index finger11 and unilateral movements of the hand and extremity.12 The cerebellum is capable of rapidly modulating basal ganglia activity in real time, leading to more‐precise motor control.13 This rapid modulation can instead lead to abnormal movements when cerebellar input is abnormal13 and may explain the roles for the cerebellum in several different motor disorders.14, 15, 16, 17 Although this report provides additional support for an association between cerebellar pathology and head nodding/complex motor stereotypies, it is recognized that a direct causative effect has not been proven. Future animal and human studies are required to better understand the pathophysiology of motor stereotypies and especially the role of the cerebellum.

Author Roles

(1) Case Report Project: A. Conception, B. Organization, C. Execution; (2) Manuscript: A. Writing of the First Draft, B. Review and Critique; (3) A. Radiological Interpretation.

S.D.: 1A, 1B, 1C, 2A

T.A.G.M.H.: 1A, 2B, 3A

A.P.: 1A, 3A

H.S.: 1A, 1B, 2A, 2B

Disclosures

Ethical Compliance Statement

We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines. The authors confirm that the approval of an institutional review board was not required for this work. Written parental permission to publish the case description, MRI images, and patient videos was obtained prior to submission.

Funding Sources and Conflicts of Interest

Harvey Singer is supported by a grant from the Tourette Association of America and is a consultant for Teva Pharmaceuticals and Clear View Healthcare Partners. Shannon Dean is supported through a training grant from the NIH (T32 GR 50382) and a pilot grant through the University of Rochester Harry T. Mangurian Jr. Foundation. The authors report no conflicts of interest.

Financial Disclosures for previous 12 months

The authors declare that there are no disclosures to report.

Supporting information

Video S1. Video taken by the patient's family showing both typical head and arm stereotypies. Note the greater prominence of arm/hand/finger movements on the right.