Cerebellar Mutism/Posterior Fossa Syndrome Following Resection of Posterior Fossa Tumor in Pediatric Patients: Assessing Pathophysiology, Risk Factors, and Neuroradiographic Features

Abstract

Background

Cerebellar mutism syndrome (CMS) is a postoperative syndrome of decreased speech seen in children associated with neurobehavioral abnormalities, the incidence of which is up to 40%.

Objectives

To evaluate pediatric patients with posterior fossa tumors for incidence, clinical characteristics, pathophysiology, risk factors, and neuroradiographic features of this syndrome.

Materials and Methods

The study included 60 pediatric patients with a posterior fossa tumor who underwent surgery by a telovelar approach. Detailed pre- and postoperative clinical and radiological evaluations were done. Patients with CMS were analyzed and compared with those without mutism to find risk factors for CMS. The presentation and characteristics of cerebellar mutism were studied along with the following risk factors:

• Clinical—age, sex, cranial nerve deficit, and adjuvant treatment.

• Radiological—tumor location, hydrocephalus, brainstem invasion, extent of tumor resection, peduncular and brainstem edema, and atrophy of posterior fossa structures.

• Pathological—histopathology of tumor.

The preoperative, immediate postoperative, and 1-year postoperative imaging results were reviewed to assess the neuroradiographic features in the two groups.

Results

The incidence of this syndrome was 20%. The mutism was accompanied by some neurobehavioral abnormalities (p-value = 0.05). The most significant finding was the presence of a period of cerebellar dysarthria after the resolution of the muteness (p-value < 0.001) in all cases. Brainstem and related structures' involvement was the most significant risk factor (p-value = 0.03). The presence of brainstem and peduncular edema in the immediate postoperative period (p-value = 0.04) and gross atrophy of posterior fossa structures at 1 year (p-value = 0.01) showed significance toward the development of CMS. There was delayed neurological recovery in patients with CMS with a poor Glasgow Outcome Score at 1 year of follow-up.

Conclusion

The clinical presentation of this syndrome in context with neuroradiographic features suggests that it results from transient impairment of the afferent and/or efferent pathways of dentate nuclei that are involved in initiating complex volitional movements and are associated with brainstem involvement of tumor and poor functional outcome.

Keywords

mutism - neurobehavioral - dysarthria - posterior fossa tumors in children - posterior fossa syndrome

Ethical Approval

The study has been approved by the Ethics Committee of Maulana Azad Medical College, New Delhi, India.

Patients' Consent

All participants gave written informed consent to participate prior to enrolment in the study.

Publikationsverlauf

Artikel online veröffentlicht:
13. Januar 2025

• References

• 1 Korah MP, Esiashvili N, Mazewski CM. et al. Incidence, risks, and sequelae of posterior fossa syndrome in pediatric medulloblastoma. Int J Radiat Oncol Biol Phys 2010; 77 (01) 106-112
• 2 Dimova PS, Bojinova VS, Milanov IG. Transient mutism and pathologic laughter in the course of cerebellitis. Pediatr Neurol 2009; 41 (01) 49-52
• 3 Robertson PL, Muraszko KM, Holmes EJ. et al; Children's Oncology Group. Incidence and severity of postoperative cerebellar mutism syndrome in children with medulloblastoma: a prospective study by the Children's Oncology Group. J Neurosurg 2006; 105 (6, suppl): 444-451
• 4 Pollack IF. Neurobehavioral abnormalities after posterior fossa surgery in children. Int Rev Psychiatry 2001; 13: 302-312
• 5 Gudrunardottir T, Sehested A, Juhler M, Schmiegelow K. Cerebellar mutism: incidence, risk factors and prognosis. Childs Nerv Syst 2011; 27 (04) 513-514 , author reply 515
• 6 Wells EM, Khademian ZP, Walsh KS. et al. Postoperative cerebellar mutism syndrome following treatment of medulloblastoma: neuroradiographic features and origin. J Neurosurg Pediatr 2010; 5 (04) 329-334
• 7 Ildan F, Tuna M, Erman T, Göçer AI, Zeren M, Cetinalp E. The evaluation and comparison of cerebellar mutism in children and adults after posterior fossa surgery: report of two adult cases and review of the literature. Acta Neurochir (Wien) 2002; 144 (05) 463-473
• 8 Küpeli S, Yalçın B, Bilginer B, Akalan N, Haksal P, Büyükpamukçu M. Posterior fossa syndrome after posterior fossa surgery in children with brain tumors. Pediatr Blood Cancer 2011; 56 (02) 206-210
• 9 Catsman-Berrevoets CE, Aarsen FK. The spectrum of neurobehavioural deficits in the posterior fossa syndrome in children after cerebellar tumour surgery. Cortex 2010; 46 (07) 933-946
• 10 Turkstra LS, Bayles KA. Acquired mutism: physiopathy and assessment. Arch Phys Med Rehabil 1992; 73 (02) 138-144
• 11 Murdoch BE. The cerebellum and language: historical perspective and review. Cortex 2010; 46 (07) 858-868
• 12 Riva D, Giorgi C. The cerebellum contributes to higher functions during development: evidence from a series of children surgically treated for posterior fossa tumours. Brain 2000; 123 (Pt 5): 1051-1061
• 13 Miller NG, Reddick WE, Kocak M. et al. Cerebellocerebral diaschisis is the likely mechanism of postsurgical posterior fossa syndrome in pediatric patients with midline cerebellar tumors. AJNR Am J Neuroradiol 2010; 31 (02) 288-294
• 14 Frassanito P, Massimi L. Cerebellar mutism: review of the literature. Childs Nerv Syst 2011; 27 (06) 867-868
• 15 Fabozzi F, Margoni S, Andreozzi B. et al. Cerebellar mutism syndrome: from pathophysiology to rehabilitation. Front Cell Dev Biol 2022; 10: 1082947
• 16 Schmahmann JD. Pediatric post-operative cerebellar mutism syndrome, cerebellar cognitive affective syndrome, and posterior fossa syndrome: historical review and proposed resolution to guide future study. Childs Nerv Syst 2020; 36 (06) 1205-1214
• 17 Ozgur BM, Berberian J, Aryan HE, Meltzer HS, Levy ML. The pathophysiologic mechanism of cerebellar mutism. Surg Neurol 2006; 66 (01) 18-25
• 18 Grill J, Viguier D, Kieffer V. et al. Critical risk factors for intellectual impairment in children with posterior fossa tumors: the role of cerebellar damage. J Neurosurg 2004; 101 (2, suppl): 152-158
• 19 Cobourn K, Marayati F, Tsering D. et al. Cerebellar mutism syndrome: current approaches to minimize risk for CMS. Childs Nerv Syst 2020; 36 (06) 1171-1179
• 20 Sergeant A, Kameda-Smith MM, Manoranjan B. et al. Analysis of surgical and MRI factors associated with cerebellar mutism. J Neurooncol 2017; 133 (03) 539-552
• 21 Pols SYCV, van Veelen MLC, Aarsen FK, Gonzalez Candel A, Catsman-Berrevoets CE. Risk factors for development of postoperative cerebellar mutism syndrome in children after medulloblastoma surgery. J Neurosurg Pediatr 2017; 20 (01) 35-41