Sudden unexpected nocturnal death in Chiari type 1 malformation and potential role of opioid analgesics

Determinants of Chiari I progression in pregnancy

Chiari Malformation type 1 (CM-I) is congenital or an acquired anomaly of the hind brain; develops when the cerebellar tonsils recede downwards below the foramen magnum. Recurrent post tussive suboccipital headache is the common presentation in a pregnant woman and the diagnosis is usually missed or delayed due to lack of formal understanding of this neurological pathology. Much has been written regarding presentation, morphology and the treatment of CM-I; however, little is known when the etiology is acquired or an iatrogenic in its evolution. Similarly, unknown is the progression of CM-I (diagnosed or undiagnosed) in pregnancy. The objective of this study is to elucidate the causes of progression of CM-I in pregnancy, and how this can be avoided. A detailed literature review has been conducted to find the case reports or case studies on association of CM-I in pregnancy; therefore, the risk factors regarding the progression have been sought. There is a lack of literature on timing, mode of anesthesia, and the management of CM-I. Moreover, authors have sought a questionnaire to screen these patients at pre-conception, intrapartum visits if, the initial diagnosis is delayed. Crucial points of concern including but not limited to the diagnosis, pre-conception counseling, timing of intervention during pregnancy, and mode of anesthesia, have been discussed in detail. In summary, a formal management algorithm has been proposed to avoid the rapid progression of this complex neurological pathology especially, in women of child bearing age and/or during pregnancy.