Cerebellar mutism after posterior fossa tumor resection in children: a multicenter international retrospective study to determine possible modifiable factors.

PURPOSE: A preliminary survey of pediatric neurosurgeons working at different centers around the world suggested differences in clinical practice resulting in variation in the risk of pediatric cerebellar mutism (CM) and cerebellar mutism syndrome (CMS) after posterior fossa (PF) tumor resection. The purposes of this study were (1) to determine the incidence and severity of CM and CMS after midline PF tumor resection in children treated at these centers and (2) to identify potentially modifiable factors related to surgical management (rather than tumor biology) that correlate with the incidence of CM/CMS. METHODS: Attending pediatric neurosurgeons at British Columbia's Children's Hospital (BCCH) and neurosurgeons who completed a pediatric neurosurgery fellowship at BCCH were invited to provide data from the center where they currently practiced. Children aged from birth to less than 18 years who underwent initial midline PF tumor resection within a contemporary, center-selected 2-year period were included. Data was obtained by retrospective chart and imaging review. Modifiable surgical factors that were assessed included pre-resection surgical hydrocephalus treatment, surgical positioning, ultrasonic aspirator use, intraoperative external ventricular drain (EVD) use, surgical access route to the tumor, and extent of resection. CM was defined as decreased or absent speech output postoperatively and CMS as CM plus new or worsened irritability. RESULTS: There were 263 patients from 11 centers in 6 countries (Canada, Germany, the Netherlands, India, Indonesia, and the USA). Median age at surgery was 6 years (range < 1 to 17 years). The overall incidence of postoperative CM was 23.5% (range 14.7-47.6% for centers with data on ≥ 20 patients). The overall incidence of CMS was 6.5% (range 0-10.3% for centers contributing data on ≥ 20 patients). A multivariate logistic regression on the full data set showed no significant association between pre-resection surgical hydrocephalus treatment, prone position, ultrasonic aspirator use, EVD use, telovelar approach, complete or near total resection, or treating center and either postoperative CM or CMS. CONCLUSIONS: While there was variation in surgical management of midline PF tumors among centers participating in this study, the factors in management that were examined did not predict postoperative CM or CMS.

Bobble-head doll syndrome: report of 2 cases and a review of the literature, with video documentation of the clinical phenomenon.

Bobble-head doll syndrome (BHDS) is a rare pediatric movement disorder presenting with involuntary 2- to 3-Hz head movements. Common signs and symptoms also found on presentation include macrocephaly, ataxia, developmental delay, optic disc pallor or atrophy, hyperreflexia, tremor, obesity, endocrinopathy, visual disturbance or impairment, headache, and vomiting, among others. The syndrome is associated with suprasellar cysts, third ventricular cysts, or aqueductal obstruction, along with a few other less common conditions. The cause of involuntary head motions is not understood. Treatment is surgical. The authors present 2 cases of BHDS. The first is a 14-year-old boy with BHDS associated with aqueductal obstruction and triventricular hydrocephalus secondary to a tectal tumor. He was successfully treated by endoscopic third ventriculostomy, and all symptoms resolved immediately in the recovery room. This case is unusual in its late age of symptom onset, the primacy of lateral ("no-no") involuntary head rotations, and the associated tectal tumor. The second case is a 7.5-year-old girl with BHDS associated with a suprasellar cyst. She was successfully treated with an endoscopic fenestration but preexisting endocrinopathy persisted, and the patient was diagnosed with autism spectrum disorder at age 12 years. This second case is more typical of BHDS. A comprehensive and up-to-date review of the literature of BHDS and video documentation of the phenomenon are presented.