Chiari type 1 deformity may present due to any of the following:
They may cause sensory loss, ataxia, weakness, nystagmus, limb spasticity to name a few 1). Although the most common presentation of Chiari type 1 deformity is occipital headache, the association of audio-vestibular symptoms is not rare.
The headache is commonly aggravated by Valsalva and sensory and motor deficits.
In a series of 71 patients, pain was the commonest symptom (69% of patients); other symptoms included weakness (56%), numbness (52%), and unsteadiness (40%). The presenting physical signs consisted of a foramen magnum syndrome (22%), central cord syndrome (65%), or a cerebellar syndrome (11%) 2).
The appearance of audio-vestibular manifestations in CM-I makes it common to refer these patients to neurotologists. Unsteadiness, vertiginous syndromes and sensorineural hearing loss are frequent. Nystagmus, especially horizontal and down-beating, is not rare. It is important for neurotologists to familiarise themselves with CM-I symptoms to be able to consider it in differential diagnosis 3).
Feinberg et al present a case of Chiari malformation manifesting as isolated trismus, describe the typical symptoms associated with Chiari malformation, and discuss the potential anatomical causes for this unique presentation. A 3-year-old boy presented with inability to open his jaw for 6 weeks with associated significant weight loss. The results of medical and radiological evaluation were negative except for Chiari malformation type 1 with cerebellar tonsils 12 mm below the level of the foramen magnum. The patient underwent Chiari decompression surgery. Postoperatively, his ability to open his mouth was significantly improved, allowing resumption of a regular diet. Postoperative MRI revealed almost complete resolution of the syringobulbia. To the best of the authors' knowledge, this is the first reported case of isolated trismus from Chiari malformation with syringobulbia 4).