Bilateral crossed cerebello-cerebral diaschisis and mutism after surgery for cerebellar medulloblastoma

A 7-year-old boy developed mutism after surgery for cerebellar medulloblastoma. Postoperative magnetic resonance imaging (MRI) showed atrophy of the cerebellar vermis and both cerebellar hemispheres, predominantly on the right side. Single photon emission computed tomography (SPECT) with technetium-99m-ethyl cysteinate dimer (Tc-99m ECD) revealed decreased cerebral blood flow (CBF) in the bilateral thalami, bilateral medial frontal lobes, and left temporal lobe in addition to the cerebellar vermis and both cerebellar hemispheres when mutism was manifest, indicating the existence of bilateral crossed cerebello-cerebral diaschisis (BCCCD). Circulatory disturbance in both cerebellar hemispheres secondary to tumor resection probably caused BCCCD in both cerebral hemispheres, predominantly in the left, via the dentatothalamocortical pathway (DTCP). With recovery of his mutism, CBF increased in the right thalamus, bilateral medial frontal lobes and left temporal lobe. Thus BCCCD was improved, with only a slight decrease in CBF still persisting in the left thalamus. The mechanism of mutism may have involved damage to the cerebellar vermis (the site of incision at operation), the left dentate nucleus (heavily infiltrated by the tumor) and the right dentate nucleus of the cerebellum (affected by circulatory disturbance secondary to acute postoperative edema). The SPECT findings suggested that mutism was associated with BCCCD-induced cerebral circulatory and metabolic hypofunction in the supplementary motor area mediated via the DTCP.Link_to_subscribed_fulltex

A modified “far-lateral” approach for safe resection of retroodontoid dural cysts

Cystic mass lesions at the ventral craniocervical junction have been described only rarely in the past, however, they have received more attention with improved imaging modalities in recent years. These lesions have been approached by various operative procedures. A modified “far-lateral” approach combined with a C1 hemilaminectomy without fusion was used to safely remove the cyst and decompress the cervical medulla in a 72-year-old woman with cervicooccipital pain and paresthesia in both arms. Following surgery, complete resolution of symptoms was achieved, and no recurrence at 1 year follow-up was detected. A modified “far-lateral” approach offers several advantages when compared with other operation techniques

Post atlantoaxial fusion for unilateral cleft of atlas posterior arch associated with os odontoideum: case report and technique note

A case of a 34-year-old female with unilateral cleft of atlas posterior arch associated with os odontoideum is reported. The patient had experienced neck pain for 6 months. Five days earlier to admission the pain aggravated as a result of mild head trauma from behind. Imaging examinations revealed C1–2 subluxation as well as the deformity. After 3 days of skull traction, a sound C1–2 reduction was achieved. Post atlantoaxial fusion using bilateral transarticular screws combined with C1 laminar hook on the intact side and autogenous bone graft was performed. On the sixth month of postoperative follow-up, CT revealed solid fusion was achieved. No related complications were detected within 3 years of follow-up. The clinical manifestations and imaging findings were presented. The incidence and etiopathogenesis of hypoplastic posterior arch of the atlas were concisely introduced. Techniques of post atlantoaxial fusion under circumstances of unilateral C1 posterior elements defects were discussed. The authors believe bilateral transarticular screws combined with C1 laminar hook on the intact side and autogenous bone graft can be applicable to atlantoaxial fusion on the premise of preoperative C1–2 reduction and C1 posterior arch remaining >1/2 of its full length