Development and characterization of an adult model of obstructive hydrocephalus

While hydrocephalus is common in adults its pathophysiology is not fully understood and its treatment remains problematic. Previous animal models have been acute, developmental, or involved non-specific blockage or inflammation and are not suitable for study of chronic adult-onset hydrocephalus. In this study, we describe the development of a canine model which allows basic physiological studies along with diagnostic and treatment procedures via surgical occlusion of the fourth ventricle with a bolus injection of cyanoacrylic gel glue. A total of 26 adult male canine mongrels were used for the induction of chronic hydrocephalus and were monitored for 1-12 weeks post-induction using magnetic resonance imaging (MRI), intracranial pressure measurements, and neurological fitness assessments. Of these, 81% (21/26) developed hydrocephalus that was mild (N=6), moderate (N=7), or severe (N=8). Pressures were mild and transiently elevated, and brain compliance decreased. Clinical symptoms were also mild and transient. This model is unique in its focal obstruction without local compression or general inflammation and should facilitate the study of the pathophysiology and treatment of chronic adult-onset hydrocephalus.