Arnold-Chiari Malformation

Arnold-Chiari malformation is a constellation of congenital anomalies related to the hindbrain and base of the brain. It consists of cerebellar tonsils herniation through the foramen magnum into the cervical spinal canal. Chiari malformation is a rare entity and its etiology is not clearly known but said to be genetic. We report a case of Arnold Chiari Malformation type 1 with holocord syrinx.
Chiari malformation is a rare disease with prevalence rates of 0.1-0.5% with a female predominance.[1] Chiari malformation is of four types, in which chiari 1, commonly diagnosed in adulthood, is least severe and most common type of malformation. Chiari 1 malformation is characterized by abnormal protrusion of the cerebellar tonsils from the base of
As a result, cerebellum development takes places in this small posterior compartment which leads to overcrowding and not only results in abnormal protrusion of cerebellar tonsils but also its impaction with foramen magnum. This theory has been found to be consistent with the association of Chiari 1 malformation with other hereditary mesodermal connective tissue diseases i.e Ehlers-Danlos syndrome.[6] Pathophysiology leading to symptoms of Chiari 1 are as follows: (A) compression of cerebellum, (B) compression of upper spinal cord and medulla, and (C) CSF flow disruption through foramen magnum due to which patient may present with a headache, progressive cerebellar ataxia, progressive spastic quadriparesis, downbeating nystagmus, segmental atrophy and sensory loss in the hands and arms with or without pain. Lower cranial nerve & nuclear dysfunction with myelopathy may occur due to compression of medulla and cord. Symptoms such as dysmetria, ataxia, disequilibrium and nystagmus may result due to cerebellum compression. Pain being the most common symptom arise due to CSF flow disruption through the