Transient cerebellar eye closure and mutism after cerebellar tumor surgery: long-term clinical follow-up of neurologic and behavioral disturbances in a 14-year-old girl

Cerebellar mutism syndrome

Cerebellar mutism most commonly, but not exclusively, develops in children after surgery for midline cerebellar or intraventricular tumors in the posterior fossa, typically medulloblastoma. Cerebellar mutism syndrome (CMS) comprises a complex set of neurologic and neurocognitive signs and symptoms, the cardinal and central component of which is an initially profound but usually reversible speech disorder. As such, CMS is currently recognized as an extreme form of the so-called cerebellar cognitive affective syndrome (Schmahmann syndrome). The putative cause of CMS is a substantial surgical injury to the proximal components of the bilateral efferent cerebellar pathways, disrupting cerebellar input to the supratentorial brain. The resultant cerebellocerebral diaschisis may lead to supratentorial cortical perfusion depression with frontal predominance. The speech disorder is, therefore, likely an apraxia. As our understanding of the mechanism and the clinical spectrum of CMS evolves, clinically useful preoperative risk stratification schemes, adjustments to surgical strategies and techniques, and possible early therapeutic-rehabilitative measures are being sought and developed to reduce the burden of this severe and particularly handicapping chronic morbidity on affected individuals and their families.

Cause and outcome of cerebellar mutism: evidence from a systematic review

PURPOSE

Cerebellar mutism is a serious neurosurgical complication after posterior fossa surgery, but the cause, incidence and outcome remain incompletely defined. The aim of this paper was to identify and review all reports of this phenomenon to better delineate and improve the evidence base.

METHODS

A systematic search and retrieval of databases was conducted using advanced search techniques. Review/outcomes criteria were developed, and study quality was determined.

RESULTS

The retrieval identified 2,281 papers of which 96 were relevant, identifying 650 children with cerebellar mutism. Causative factors, clinical features and outcomes were reported variably; papers focussed on multiple areas, the majority reporting incidence in single or series of case studies with little or no analysis further than description.

CONCLUSIONS

The complexity and variability of data reporting, likely contributing factors and outcomes make cerebellar mutism difficult to predict in incidence and the degree of impact that may ensue. A clear and accepted universal definition would help improve reporting, as would the application of agreed outcome measures. Clear and consistent reporting of surgical technique remains absent. Recommendations for practice are provided.

Auditory-perceptual speech analysis in children with cerebellar tumours: a long-term follow-up study

Mutism and Subsequent Dysarthria (MSD) and the Posterior Fossa Syndrome (PFS) have become well-recognized clinical entities which may develop after resection of cerebellar tumours. However, speech characteristics following a period of mutism have not been documented in much detail. This study carried out a perceptual speech analysis in 24 children and adolescents (of whom 12 became mute in the immediate postoperative phase) 1-12.2 years after cerebellar tumour resection. The most prominent speech deficits in this study were distorted vowels, slow rate, voice tremor, and monopitch. Factors influencing long-term speech disturbances are presence or absence of postoperative PFS, the localisation of the surgical lesion and the type of adjuvant treatment. Long-term speech deficits may be present up to 12 years post-surgery. The speech deficits found in children and adolescents with cerebellar lesions following cerebellar tumour surgery do not necessarily resemble adult speech characteristics of ataxic dysarthria.

Cerebellar mutism: review of the literature

PURPOSE

Cerebellar mutism is a common complication of posterior fossa surgery in children. This article reviews current status with respect to incidence, anatomical substrate, pathophysiology, risk factors, surgical considerations, treatment options, prognosis and prevention.

METHODS

We reviewed all peer-reviewed English publications on cerebellar mutism between the years of 1985 and 2009. The majority were found by searching for ‘cerebellar mutism’ and ‘posterior fossa syndrome’ in PubMed. Additional cases were identified by cross-checking reference lists.

RESULTS

The overall incidence of postoperative cerebellar mutism is 11-29%, and patients with medulloblastomas and/or brainstem invasion are at a greater risk of developing it than those with other kinds of tumors and/or without brainstem invasion. Permanent sequelae in the form of both motor- and non-motor-related speech deficits are common, especially when the right cerebellar hemisphere is involved. The mutism is caused by bilateral pertubation of the dentate nuclei and their efferent pathways, which emphasizes the need to explore surgical methods that spare these structures. The pathophysiological mechanisms of delayed onset and resolution of cerebellar mutism are not clear, but axonal damage, edema, perfusional defects and metabolic disturbances may be involved.

CONCLUSION

The incidence of cerebellar mutism is well documented in children with medulloblastoma, but precise figures for those with astrocytoma and ependymoma are lacking. Further anatomical, functional imaging and neuropsychological studies are needed to clarify the pathophysiological mechanisms in order to define preventive measures during surgery. Randomized, controlled trials of the effects of different medication and post-operative speech therapy are necessary for improving treatment.

Transient cerebellar eye closure after posterior fossa surgery in a 5-year-old child

INTRODUCTION

Transient cerebellar eye closure (TCES) is a rare complication of cerebellar tumor surgery in children. The pathogenesis of this problem remains unclear, and controversy exists regarding whether it is a purely psychogenic disorder or an organic syndrome. The anatomical substrate for this transient eye closure remains unknown. Most of the cases reported were associated with the syndrome of mutism.

CASE REPORT

We encountered a case of post-operative TCES in a 5-year-old girl with posterior fossa tumor.

RESULTS

We are presenting this rare complication with the hope of elucidating further on clinical course of illness and literature review on the possible pathophysiological mechanism.

Postoperative motor speech production in children with the syndrome of 'cerebellar' mutism and subsequent dysarthria: a critical review of the literature

Transient cerebellar mutism is a well-known clinical entity which may develop after surgery to the cerebellum. As the period of mutism is followed by motor speech deficits, the condition has also been termed the syndrome of (cerebellar) Mutism and Subsequent Dysarthria (MSD). In children, its incidence is estimated between 8% and 31%. Unfortunately, the literature provides contradictory information regarding motor speech production post-mutism. We therefore critically reviewed data on 283 childhood cases to chart the mode of recovery of motor speech production after the mute period. After applying stringent exclusion criteria, we found that 98.8% of the children displayed motor speech deficits. This percentage is much higher than commonly reported in the literature. In addition, recovery of speech appeared to be less favourable than previously ascertained. Future studies should investigate more carefully the patients' speech characteristics in order to be able to offer children an adequate and complete rehabilitation program.

Posterior fossa syndrome after a vermian stroke: a new case and review of the literature

The posterior fossa syndrome (PFS) is a well-known clinical consequence of posterior fossa surgery that has only been reported in a limited number of cases with a nontumoral etiology. It consists of transient cerebellar mutism, behavioral abnormalities and personality changes. We describe a 12-year-old child who developed transient cerebellar mutism associated with behavioral and emotional symptoms following rupture of a vermis arteriovenous malformation (AVM). Following the stroke, the girl experienced a 24-hour symptom-free interval. After that, she became mute and her emotional state was characterized by severe anxiety, irritability and withdrawal. After 3 days, mutism resolved and dysarthria became apparent. Two weeks after stroke, the AVM was surgically removed and the postoperative course was uneventful. This case is the first reported in which the PFS occurred after focal nonsurgically induced cerebellar damage.

Neurobehavioral alterations in an adolescent following posterior fossa tumor resection

The posterior fossa syndrome (PFS) consists of a variety of symptoms, including cerebellar mutism, behavioral disturbances and personality changes. We report longitudinal clinical, neuroradiological and neurobehavioral findings in a 19-year-old left-handed patient, diagnosed with attentional deficit hyperactivity disorder (ADHD) at the age of 12, who underwent posterior fossa tumor resection. Although the patient did not develop cerebellar mutism after surgery, marked apathy and emotional indifference, urinary retention, eye-lid apraxia and visual hallucinosis became apparent after a brief interval of normal functioning. Based on these findings it is argued that the PFS might be considered a semiological heterogeneous condition with variable clinical expressions. Long-term follow-up investigations revealed subtle, but significant cognitive and affective deficits, resembling the cerebellar cognitive affective syndrome in adults. As demonstrated by functional neuroimaging studies with SPECT, symptoms were associated with perfusional deficits in the anatomoclinically suspected supratentorial regions, reflecting the distant impact of the cerebellum on cognitive and affective functions.

Supratentorial arterial ischemic stroke following cerebellar tumor resection in two children

We describe two children who developed ischemic strokes in the territory of the middle cerebral artery, one 7 days and one 11 days after resection of a cerebellar tumor. In the first child, another infarction occurred in the territory of the contralateral middle cerebral artery 5 days after the first stroke. No specific cause or underlying risk factor other than the surgical procedure was found. The subacute clinical course at stroke onset resembled that of the 'posterior fossa syndrome', suggesting a common underlying mechanism.