Management of Subependymal Giant Cell Astrocytomas in Children
Initial Management at Presentation
Early surgical removal: Early tumor resection is advocated in asymptomatic children having SEGA with TSC, primarily when there is evidence of growth on successive MRIs (2, 7, 10, 18, 24, 26, 27). Growth can lead to sudden death due to acute hydrocephalus and intraventricular bleeding (33).
Management complicated by growth: Major complications occur in operated symptomatic children with TSC when increased ICP is already present (14, 16, 26). Large lesions cause deformation of the foramen of Monro, leading to difficulties in operative hemostasis and problems of tumor dissection from surrounding structures such as the fornix, the head of caudate nucleus, the ependyma and TSC veins, and the intraventricular septum. Additionally, a worsening of epileptic seizures in terms of frequency and intensity can occur over time.
Management of hydrocephalus
Tumor removal: Removal of the tumor is the best treatment for the hydrocephalus.
Medications: Steroids and diuretics can be administered in the perioperative period since elevated ICP may be present even in the absence of ventriculomegaly in children with TSC. This is due to the abnormal architecture of the subependymal region, which modifies cerebral compliance (14).
EVD: EVD is needed if the patient is sick and moribund due to life-threatening hydrocephalus.
Ventriculoperitoneal shunt: Shunting is not routinely indicated prior to the tumor’s removal unless life-threatening hydrocephalus is present and EVD not feasible for logistical reasons CSF diversion devices tend to block because SEGAs cause an abnormally high level of proteins in the CSF.
Management of residual hydrocephalus after tumor removal: Although the CSF protein level normalizes after complete resection of the tumor, hydrocephalus can evolve. The hydrocephalus leads to postoperative deaths in 10–20% of patients from whom SEGAs were removed.. Endoscopic fenestration of the septum pellucidum can be performed as a supplementary measure after resection of the tumor near the foramen of Monro in cases of asymmetric hydrocephalus. ETV can be performed as a staged procedure after resection of the tumor if the patient develops a symptomatic persistent or progressive hydrocephalus.
Imaging: MRI at 3 months postoperatively and then surveillance imaging on an annual basis are indicated to look for tumor regrowth and to detect developing hydrocephalus.
Neuropsychological tests: These tests could be done as a baseline study and 3–6 months after surgery. Findings would help in prognostication, counseling, and rehabilitation. Testing is of relevance since a postoperative cognitive impairment may occur that may be attributable to damage to the fornix during surgery. However, these young children may have cognitive impairment before surgery, and it may not be always imputable to surgical damage to the fornix.