High frequency of spinal involvement in patients with basal subarachnoid neurocysticercosis

Objective: To determine the frequency of spinal neurocysticercosis (NCC) in patients with basal subarachnoid NCC compared with that in individuals with viable limited intraparenchymal NCC (≤20 live cysts in the brain). Methods: We performed a prospective observational case-control study of patients with NCC involving the basal cisterns or patients with only limited intraparenchymal NCC. All patients underwent MRI examinations of the brain and the entire spinal cord to assess spinal involvement. Results: Twenty-seven patients with limited intraparenchymal NCC, and 28 patients with basal subarachnoid NCC were included in the study. Spinal involvement was found in 17 patients with basal subarachnoid NCC and in only one patient with limited intraparenchymal NCC (odds ratio 40.18, 95% confidence interval 4.74-340.31; p < 0.0001). All patients had extramedullary (intradural) spinal NCC, and the lumbosacral region was the most frequently involved (89%). Patients with extensive spinal NCC more frequently had ventriculoperitoneal shunt placement (7 of 7 vs 3 of 11; p = 0.004) and tended to have a longer duration of neurologic symptoms than those with regional involvement (72 months vs 24 months; p = 0.062). Conclusions: The spinal subarachnoid space is commonly involved in patients with basal subarachnoid NCC, compared with those with only intraparenchymal brain cysts. Spinal cord involvement probably explains serious late complications including chronic meningitis and gait disorders that were described before the introduction of antiparasitic therapy. MRI of the spine should be performed in basal subarachnoid disease to document spinal involvement, prevent complications, and monitor for recurrent disease.