Bobble head doll syndrome: A rare case report.

Bobble - head syndrome (BHDS) is a complex and rare syndrome with repetitive anteroposterior head movements. It is usually associated with expansile lesions in the third ventricular region. We present a 9 year old child with a giant suprasellar arachnoid cyst causing involuntary head movements.

Introduction

Introduction: Bobble-head doll syndrome (BHDS) was first described by Benton et al. in the year 1966.[1] BHDS is a rare clinical entity usually associated with an expansion in the area of the third ventricle.[2] It has been observed among patients with suprasellar or third ventricle cysts, aqueductal stenosis, or patients with a malfunctioning shunt. Only 57 patients are quoted in the literature. Rarity of this case leads to this case report.

Case Report

A 9-year-old child came to hospital with the chief complaints of involuntary movements of head as excessive head nodding since 1 year, gradual in onset, progressive in nature. Patient is able to control head movements voluntarily [Video 1]. Movements are increased with emotions and stress, decreased during sleep. No other positive significant history. Clinical examination shows patient is conscious and coherent and fundus examination showed temporal pallor, more on the right side. The remainder of the nervous system examination was normal. Computed tomography scan and magnetic resonance imaging (MRI) [Figures 1–6] of the brain was done, which shows a cystic lesion arising from suprasellar region extending upwards causing compression of the third ventricle leading to obstructive hydrocephalous at the level of the third ventricle. The cystic fluid shows signal intensity equal to the cerebrospinal fluid (CSF) intensity in all sequences in MRI suggestive of giant suprasellar arachnoid cyst causing involuntary head movements.

Figure 1

T2-weighted axial image showing cystic lesion in suprasellar region causing obstructive hydrocephalous

Figure 6

(a and b) Axial diffusion-weighted imaging and apparent diffusion coefficient maps showing cystic lesion with facilitated diffusion indicating arachnoid cyst

T1-weighted axial image showing cystic lesion in suprasellar region causing obstructive hydrocephalous

Fluid-attenuation inversion recovery axial image showing cystic lesion with fluid intensity equal to cerebrospinal fluid

T1-weighted mid-sagittal image showing cyst arising from suprasellar region extending upwards and into prepontine area causing compression of the third ventricle and obstructive hydrocephalous

T2-weighted mid-coronal section showing suprasellar cyst causing compression of thalami

Discussion

The “bobble-head doll syndrome (BHDS)” is a rare and an interesting movement disorder characterized by continuous or episodic forward and backward head nodding at times associated with side to side movements of the head of 2-3 Hz frequency. These movements are absent during sleep and transiently disappear or attenuate on volitional activities, often accompanied with truncal tremors. These movements are very sensitive to sensory stimuli. This condition is commonly associated with a lesion in and around the third ventricle. Third ventricular tumors or suprasellar arachnoid cysts are the most common lesions encountered, followed by aqueductal stenosis. Other lesions cited include communicating hydrocephalus, cyst of the cavum pellucidum and interpositum, trapped fourth ventricle, aqueductal and third ventricular choroid plexus papilloma and developmental cerebellar disorders.

Bobble-head doll syndrome is a complex syndrome with the dominant symptom of repetitive anteroposterior head movement. It is presumed that this movement disorder is due to the pressure effect of dilated third ventricle, which distorts the dorsomedial red nucleus and dentatorubrothalamic pathways.[345] In addition, there is compression of medial thalamus, the latter having their somatotropic motor representation of head and neck area.[5] The pressure over the medial thalamus leads to head and neck tremors, and as the lesion progresses, it gives rise to truncal and appendicular tremors also by affecting thalamic area. Attenuation of tremors on volitional activities and their presence at rest suggest a possible role of basal ganglia in the genesis of this disorder. It is also suggested that the movement develops as a learned phenomenon as it stops on volitional activities. This probably helps in improving the CSF circulation and is supported by the observation of disappearance of head movements and headache on extreme flexion or extension of neck in a case with BHDS.[6]

Neuroimaging is essential for evaluation of these patients. Mid-sagittal plane MRI is the best modality for the delineation of CSF pathways and soft tissue. A neuroendoscopic ventriculocystocisternostomy is the treatment of choice for BHDS. In our case, after surgical decompression of the cyst through endoscope movements were decreased.