Persistent figure‐eight and side‐to‐side head shaking is a marker for rhombencephalosynapsis

Abstract

Background Head-shaking stereotypies have been described in patients with neurological impairment. We noted an unusual preponderance of head shaking in patients with rhombencephalosynapsis (RES). We sought to delineate the movements further and determine whether oculomotor and vestibular testing could reveal their cause. Methods Information was collected from direct observation, video review and parental questionnaire from 59 patients with RES. Oculomotor and vestibular testing was performed in 4 children. Results 50 of 59 patients had persistent head shaking that was often observed years before RES was recognized. Three affected children demonstrated abnormal central vestibular processing. Conclusions Head-shaking is common in RES. These characteristic movements may provide input to a defective vestibular system or may represent a motor pattern that is usually suppressed by vestibular feedback. Persistent head shaking should alert clinicians to the possible presence of a congenital hindbrain abnormality that affects the vestibulocerebellum, particularly RES.

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

“…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 . Furthermore, there are multiple reports, including this case, of stereotypies associated with cerebellar malformation . Cerebellar strokes in adults have also been reported to cause stereotypic movements, including rubbing thumbs against the index finger and unilateral movements of the hand and extremity .…”

“…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 . 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 OCD—symptoms not explainable solely as a deficit in vestibular processing.…”

“…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) and in those with Dandy Walker syndrome . 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 . The latter has also been described in a child with a unilateral cerebellar lesion on CT …”

Hidrocefalia Congénita: Síndrome de Gómez-López-Hernández, un síndrome subdiagnosticado. Caso clínico

“…Some research have demonstrated a deficit in the central vestibular processing, thus, this stereotype is an involuntary movement to obtain additional sensorial information. The pattern of movement, would activate semicircular canals and afferent nerve fibers, which increases the inputs in an abnormal vestibular system 23 . The cerebral magnetic resonance, a study of choice in GLHS besides showing rhombencephalosynapsis ( Figure 1) and triventricular hydrocephalus, it can highlight corpus callosum hypoplasia, absence or septum pellucidum lipoma and septo-optic dysplasia with hypothalamic-pituitary dysfunction.…”

Horizontal head titubation in infants with Joubert syndrome: a new finding

“…Rhombencephalosynapsis is defined by agenesis of the vermis and fusion of the cerebellar hemispheres across the midline . About 85% of patients with rhombencephalosynapsis have head‐shaking movements characterized by a rhythmic, repetitive, figure‐of‐eight or occasionally side‐to‐side swinging motion that may be intermittent or almost constant . As with head titubation in Joubert syndrome, the movements occur most frequently during times of fatigue or excitement, but their frequency is lower and amplitude larger compared to the head titubation in Joubert syndrome .…”