What is the Relationship between Chiari I and Obesity
What is the Relationship between Chiari I and Obesity
Harold L Rekate*
Department of Neurosurgery, Zucker Hofstra Northwell School of Medicine, USA
Introduction
As a pediatric neurosurgeon for forty years and more recently as director of the Chiari Institute on Long Island New York I have been treating patients of all ages who present with symptoms related to a mechanical distortion of the cerebellum in which the cerebellar tonsils have herniated below the foramen magnum. Generally, if this descent of the cerebellar tonsils is at least 5 mm the condition is called the Chiari I malformation (CM1). The nomenclature here is quite controversial and attempts to obtain a consensus on the definition of the term have been unsuccessful and frustrating. For most neuroradiologists the diagnosis depends on a measurement of 5 mm of descent. This number derives from the work of Barkovich who noted that the majority of patients with this degree of descent were symptomatic [1].
Prior to the routine availability of magnetic resonance imagine (MRI) CM1 was considered a very rare condition. From the late 1980’s it has become clear that the majority of patients who have significant degrees of tonsillar descent are asymptomatic and that tonsillar ectopia is not rare. It is estimated that as many as 0.5% of individuals would have scans that would be read as having CM1 [2].
What makes the difference between individuals with cerebellar dystopia with incapacitating symptoms and others with identical imaging who are asymptomatic? Does obesity play a role?
In order to understand the relationship between obesity and symptomatic CMI a Boolean search was conducted on Pubmed using the search strategy of Chiari and obesity. The search yielded 4 references [2-5]. As well studies dealing with the outcomes of treatment for CM1 were included if they considered obesity as defined using BMI and/or intracranial pressure in the assessment [6-13].