Comprehensive comparative study ofChiari-like malformation inveterinary and human medicine.

Abstract

This review aims toenrich our understanding ofChiari-like malformation (CLM) bycombining human and veterinary insights, and providing adetailed cross-species overview. CLM isadevelopmental abnormality characterised bycaudal displacement ofthe hindbrain into the foramen magnum due toan entire brain parenchymal shift caused byinsufficient skull volume. This malformation leads toaprogressive obstruction atthe craniocervical junction, which disrupts the normal cerebrospinal fluid flow, leading tosecondary syringomyelia. The clinical signs ofCLM and syringomyelia include phantom scratching, head tilt, head tremor, ataxia, tetraparesis, pain, muscle atrophy, and scoliosis ortorticollis. Magnetic resonance imaging remains the gold standard for diagnosing CLM, since itallows the visualisation ofabnormal findings such asthe caudal cerebellar herniation, caudal cerebellar compression from occipital dysplasia, and attenuated cerebrospinal fluid cisternae. Although various medical and surgical interventions, including foramen magnum decompression, can provide temporary symptomatic/clinical sign relief, current literature shows alack ofsustained long-term efficacy. Therefore, additional research isneeded toevaluate the long-term effects ofexisting treatment strategies and tocompare different techniques utilised inconjunction with foramen magnum decompression.