Clinical characteristics of and treatment protocol for trapped temporal horn following resection of lateral ventricular trigone meningioma: a single-center experience

OBJECTIVE Trapped temporal horn (TTH) is a rare subtype of loculated hydrocephalus that is often managed surgically. The natural history of TTH is not well understood, and there are few data on the outcomes of conservative management of this condition. The aim of this study was to analyze the clinical features and outcomes of conservatively and surgically managed cases of TTH. METHODS The authors retrospectively reviewed the clinical data for 19 consecutive cases of TTH that developed after microsurgical resection of lateral ventricular trigone meningioma between 2011 and 2015. RESULTS The 19 cases involved 6 male and 13 female patients (mean age [± SD] 39.9 ± 13.8 years). The mean time interval from tumor resection to onset of TTH was 3.2 ± 3.0 months (range 3 days–10 months). Symptoms of intracranial hypertension were the most common complaints at presentation. The mean Karnofsky Performance Scale (KPS) score at onset was 52.1 ± 33.3 (range 10–90). Midline shift was observed in 15 cases (78.9%), and the mean amount of midline shift was 6.0 ± 4.8 mm (range 0–15 mm). Eleven cases (57.9%) were managed with surgical intervention, while 8 cases (42.1%) were managed conservatively. All patients (100%) showed improved clinical status over the course of 4.8 ± 1.0 years (range 2.8–6.3 years) of follow-up. The mean KPS score at last follow-up was 87.9 ± 11.3 (range 60–100). Eighteen patients (94.7%) showed signs of radiographic improvement, and 1 patient (5.3%) exhibited stable size of the temporal horn. Significant differences were observed between the surgical and nonsurgical cohorts for the following variables: KPS score at onset, presence of intracranial hypertension, and midline shift. The mean KPS score at onset was greater (better) in the nonsurgical group than in the surgical group (82.5 ± 8.9 vs 30 ± 25.7, p = 0.001). A greater proportion of patients in the surgical group presented with symptoms of intracranial hypertension (81.8% vs 0%, p = 0.001). The extent of midline shift was greater in the surgical group than in the nonsurgical group (9.0 ± 3.8 mm vs 2.0 ± 2.4 mm, p = 0.001). CONCLUSIONS The majority of patients with TTH presented in a delayed fashion. TTH is not always a surgical entity. Spontaneous resolution of TTH may be under-reported. Conservative management with clinical and radiological follow-up is effective in selected patients.