Bobble-head doll syndrome with supra-sellar arachnoid cyst

A 19-year-old woman reported progressively worsening involuntary head movements since the age of 7. She had visited multiple hospitals and been labelled as having a functional disorder. Detailed evaluation identified a large supra-sellar arachnoid cyst with hydrocephalus. We made a diagnosis of bobble-head doll syndrome, which is only very rarely associated with suprasellar arachnoid cyst. Her symptoms improved rapidly following endoscopic third ventriculostomy with cyst fenestration and gradual decompression of the ventricles. Clearly, not all suppressible movements should be labelled as psychogenic.

Endoscopic approach of suprasellar arachnoid cyst

A male 3-year-old child was referred to our service due to increasing head size and mild headache. On physical examination, head circumference was 55 cm (bigger than 97th percentile), the child was conscious, alert and oriented to person, place, time and event, his pupils were isochoric, the light reflex was bilaterally positive, eye movements showed a slight palsy on the abduction of the left eye, and a partial vision loss on the left eye was detected. Gait was also impaired. MRI presented a cystic lesion in the suprasellar region suggesting arachnoid cyst, associated with hydrocephalus. An endoscopic ventricular approach was performed through a straight incision over Kocher’s point. The cyst was easily identified, coagulated with cautery and incised with endoscopic scissors. A ball-valve mechanism was well visualized. Prepontine cistern was also sharply opened and the whole cyst wall was coagulated. The patient was discharged on the second postoperative day showing a clinical improvement. Late head CT presented also a radiologic improvement.

Prenatal diagnosis of a large suprasellar arachnoid cyst

Arachnoid cysts represent 1% of all intracranial lesions and appear on the arachnoid membrane (subarachnoid space). The etiology and pathogenesis of arachnoid cysts remain unclear and in their majority they are asymptomatic. Due to the developmental origin of arachnoid cysts, these formations can be identified on prenatal fetal imaging. In this report we presented a case of an enlarged suprasellar arachnoid cyst detected incidentally during a routine fetal sonographic examination at 33 weeks of gestation. The cyst remained stable in size prenatally and postnatally without compressive symptoms and signs and the patient has been set under expectant management with serial clinical evaluation and serial imaging of the cyst.