Postoperative cerebellar mutism syndrome following treatment of medulloblastoma: neuroradiographic features and origin.
OBJECTIVE
The origin and long-term outcome of cerebellar mutism syndrome (CMS), a postoperative syndrome of diminished speech, hypotonia, and ataxia that affects approximately 25% of patients with medulloblastoma, is poorly elucidated. The current study was undertaken to determine factors associated with development of CMS, a means to determine its severity or cause, and outcomes of patients with this syndrome.


METHODS
The study included 28 children with medulloblastoma who either underwent an operation or were referred to the authors' institution soon after surgery. Eleven (39%) of these children had CMS. The preoperative, immediate postoperative, and 1-year postoperative MR images were reviewed by a neuroradiologist blinded to diagnosis of CMS. The severity of mutism and neurological and neurocognitive outcomes were examined.


RESULTS
Preoperative MR images showed no differences in tumor size, hydrocephalus, or peritumoral edema in patients with and without CMS. An association with brainstem invasion was significant (p < 0.05), and there was a trend toward an association with involvement of the cerebellomedullary angle (p = 0.08). Images obtained immediately postoperatively showed cerebellar edema in 92% of all patients; there were trends for more middle and superior cerebellar peduncle edema in patients with CMS (p = 0.05 and 0.07, respectively). At 1 year postoperatively, patients with CMS showed more moderate to severe atrophy/gliosis of total cerebellum (p < 0.01), vermis (p < 0.01), and brainstem (p < 0.05). Mean IQ was 16 points lower in patients with CMS (IQ = 84.2 +/- 15.8) compared with those without CMS (IQ = 100.4 +/- 17.4), with a trend toward significance (p = 0.07).


CONCLUSIONS
This study demonstrates that CMS is associated with postoperative damage to the cerebellum and brainstem, damage not predicted by immediate postoperative MR imaging, and with poorer associated functional outcome.
Wells
Elizabeth M
EM
Division of Neurology, Children's National Medical Center, Washington, DC 20010, USA.
Khademian
Zarir P
ZP
Walsh
Karin S
KS
Vezina
Gilbert
G
Sposto
Richard
R
Keating
Robert F
RF
Packer
Roger J
RJ
D001284:Atrophy; D002528:Cerebellar Neoplasms / Q000473:pathology / Q000601:surgery*; D002530:Cerebellopontine Angle / Q000473:pathology; D002531:Cerebellum / Q000473:pathology / Q000601:surgery; D002648:Child; D003388:Cranial Fossa, Posterior / Q000473:pathology; D005260:Female; D005911:Gliosis / Q000473:pathology; D006801:Humans; D007360:Intelligence; D008279:Magnetic Resonance Imaging; D008297:Male; D008527:Medulloblastoma / Q000473:pathology / Q000601:surgery*; D009155:Mutism / Q000209:etiology / Q000473:pathology*; D009483:Neuropsychological Tests; D011183:Postoperative Complications / Q000473:pathology*; D012720:Severity of Illness Index