ABSTRACT
Hypertrophic olivary degeneration (HOD) is a unique form of transneuronal degeneration caused by a disruption of the dentato-rubro-olivary pathway, also known as the triangle of Guillain-Mollaret. The triangle of Guillain-Mollaret is involved in fine voluntary motor control and consists of both the inferior olivary nucleus and the red nucleus on one side and the contralateral dentate nucleus. Clinically, patients classically present with symptomatic palatal myoclonus. Typical magnetic resonance imaging findings include T2-hyperintensity and enlargement of the inferior olivary nucleus evolving over time to atrophy with residual T2-hyperintensity. In this article, we provide a case-based illustration of the anatomy of the Guillain-Mollaret-triangle and the typical imaging findings of hypertrophic olivary degeneration.
ABSTRACT
BACKGROUND: A 1-year-old girl was referred to the neurosurgery department. The patient presented with a swelling on the vertex of the head which was present at birth but increased gradually over time. There were no perinatal problems and the child developed normally. The swelling produced no discomfort nor pain, and measured 2 cm Å~ 3 cm. The child was followed during 6 months because there was a chance of involution. The patient was reevaluated 6 months later.