Hey, you reading! Welcome to my blog post on StemSocial. Today, I will be discussing Chiari Malformation and Syringomyelia which in literal terms means "Cavity in the spinal cord". It is referred to as an abnormal or pathological neurological condition caused by a fluid-filled cavity within the parenchyma of the spinal cord, or the central canal. Normally, cerebrospinal fluid (CSF) circulates through the lateral ventricles which are the first and second ventricle to the third ventricle, then to the cerebral aqueduct then to the fourth ventricle before finding its way down to the central canal. The CSF goes to the foramen magendie and exits to the subarachnoid space.
With Syringomyelia, it can be caused by conditions such as abnormal dilation of the central canal causing hydromyelia, or where there is an abnormal cavity of the syrinx within the substance of the spinal cord where the cavity may communicate or may not communicate with the central canal. The syringomyelia might exist at the epidermal or gliotic tissue and it can extend into the lower part of the medulla (brainstem), although it usually occur in the cervical cord, and that is when the cavity is regarded as syringobulbia. Let's put down the grammer a little, a syrinx is a cystic cavitation that occur in the spinal cord, and it is often progressive. It can present from being asymptomatic, to being progressive, causing pain, and could lead to scoliosis. Syrinx occur as a result of chiari malformations where the lower part of the brain puts pressure on the opening of the skull and spinal cord which can be as a of ligametous abnormalities, craniocervical instability, developmental mismatch, and so on. Syrinx can also be caused by tethered cord, trauma, hydrocephalus, and intradural scarring. Chiari malformation has to do the structural defect where the cerebelum protrudes below the foramen magnum.
Chiari malformation can be of two types or three depending on where your source, with type one patients being people who had the malformation from birth which would over years create a syrinx which would then create a myelopathy. Type 1 chiari malformation has to do with the extension of the cerebellar tonsils into the foramen magnum without the involvement of the brainstem. Like I said it is always congenital and can be acquired in few cases. Another type is the Chiari 1.5 which is a chiari type 1 with an additional caudal herniation of the brainstem down through the foramen magnum. Chiari malformation type 2 has to do with an open neural tube or close neural tube defect where there is an extension of the cerebellar tonsils, brain stem tissue, cerebellar vermis, and the 4th ventricle into the foramen magnum and it is associated with myelomeningocele. There can also be type 3 and type 4 chiari malformation, with type three where the cerebellum and the brain stem protrude through the foramen magnum along with 4th ventricle, cenvical, and or occipital encephalocele. The type 4 is very rare and it has to do with cerebellar hypoplasia.
Chiari malformation can be genetic and it can also be acquired. Chiari type malformation is usually associated with small posterir fossa, space occupying lesion, lumboperitoneal shunt, arachnoid web, scar or fibrosis in the brainstem, upper cervical spine abnormalities, and Craniosynothosis-pan. In type 2 malformation there can be breaking of the tectum, absence of septum pellucidum, microgyria, hydromyelia, degeneration of lower cranial nerve nuclei, and hypoplasia of falx. Patients with chiari malformation and syringomyelia will have symptoms that includes headache, spasticity, loss of sensitivity, muscle weakness, hyperreflexia, ankle clonus, tremors, pain in the neck, numbness in the hands and feet, pain in the back, and scolliosis.
Understanding the cause of a syrinx is still not clear but there are multiple theories such as chiari malformation, subarachnoid scarring, tethered core and chanage in the flow dynamics of cerebral spinal fluid but the causes are not still clear. Syrinxes can vary depending on the location, such as a syringomyelia which is a cystic cavitation outside the central canal, hydromyelia and syringobulbia like I mentioned above, but it is better to use Syringomyelia as a general word. Other ways to identify different syrinxes includes the etiology, the size, the progression, and etiology. This is why treating a syrinx has to do with treating the underlying cause (reversing the cause of the syrinx, such as in cases like hydrocephalus, tethered cord, posterior fossa decompression, tumor resection, lysis of adhesions, and syrinx shunt).
Syringomyelia is a progressive condition that affect both children and adults, and it can be congenital or acquired due to trauma of the spinal cord. It is important to treat the underlying cause, and it is usually diagnosed using MRI scanning. Surgery is often done to treat these conditions.