What is Hydromyelia?
Hydromyelia is quite an uncommon neurological disorder in which an individual develops fluid-filled cavity named as syrinx within the spinal cord. This fluid filled cavity or syrinx is usually noted in the neck region. As the disease advances, this cavity enlarges thus causing significant damage to the nerve fibers resulting in numerous symptoms. The classic presenting features of Hydromyelia are muscle stiffness and weakness along with severe pain. There is also sensory alteration where the patient loses the ability to differentiate between what is hot or cold. The severity of the symptoms of Hydromyelia progress with the passage of time and may be different for different individuals. How severe the symptoms may become depends on the location of the syrinx and how much it has enlarged and distended. It is recommended that if Hydromyelia is diagnosed then it be treated promptly so as to avoid further potentially serious neurologic complications. Hydromyelia usually occurs in males more than females and is seen between the ages of 20-30.
What Causes Hydromyelia?
What exactly causes Hydromyelia is still a matter of ongoing study at the present time, although it is almost always caused due to obstruction of the flow of the cerebrospinal fluid which is a fluid which protects the brain and spinal cord. Once the flow of CSF is obstructed, it results in accumulation of the CSF causing distention of the spinal cord causing pressure on the nerves resulting in symptoms. Hydromyelia may be present at the time of birth or may develop much later in life. It is usually divided into two groups
Congenital Form of Hydromyelia: This is a form of Hydromyelia which is present since birth and is associated with a medical condition known as Arnold Chiari malformation. In this form of Hydromyelia, the brain tissue extends into the spinal cord obstructing flow of the CSF.
Acquired Form of Hydromyelia: This form of Hydromyelia develops as a result of some medical condition namely tumor or any type of injury to the spinal cord.
Some other medical conditions which can cause Hydromyelia are:
Scoliosis: This is a medical condition in which there is a curvature in the spine giving it a bent appearance.
Klippel-Feil Syndrome: This is a medical condition in which there is congenital fusion of the vertebrae of the neck limiting its movement.
What are the Symptoms of Hydromyelia?
In almost all the cases of Hydromyelia, the patients develop symptoms quite gradually with time. Hydromyelia which is associated with Arnold Chiari malformation begins to show up symptoms during the teenage years of the patient. If Hydromyelia is caused due to a tumor or a trauma then symptoms will be caused with any type of straining activities. The symptoms of Hydromyelia are different for different people and depend on the location of the syrinx and the extent of damage caused to the nerve fibers. Some of the symptoms of Hydromyelia are:
- Muscle weakness.
- Sensory loss
- Excruciating pain on palpation of the affected region like the neck
- Stiffness of back, shoulders, and the upper and lower extremities
- Bowel and bladder disturbance
- As the disease advances the patient may develop joint contractures, scoliosis as well as osteoporosis.
How is Hydromyelia Diagnosed?
In order to diagnose Hydromyelia, the physician will first conduct a detailed history of the patient as to when the symptoms started and any prior history of trauma or injury to the spinal cord. The physician will then conduct a detailed physical examination looking for presenting signs of Hydromyelia like muscle weakness and areflexia along with muscle weakness and pain with palpation of the neck region. The physician may order blood test to rule out other infectious processes which may cause similar symptoms to that of Hydromyelia. Once Hydromyelia is suspected the best way to confirm the diagnosis is by conducting an MRI of the brain and spinal cord, which will clearly show development of syrinx. It will also show how much the syrinx has enlarged and to what extent the CSF flow is obstructed.
How is Hydromyelia Treated?
Treating Hydromyelia will depend on the severity and progression of the disease and what is the severity of the symptoms. In case if the disease (Hydromyelia) is completely asymptomatic, then the physician may just recommend observing the condition with serial MRIs to look for any progression of the disease and no treatment is recommended.
In case if Hydromyelia is causing symptoms which are quite bothersome to the patient then the most preferred route of treatment is surgery. The main aim of the surgical procedure for Hydromyelia is to relieve the pressure the cysts are putting on the spinal cord and restore normal flow of the CSF. The surgical procedure required will depend on what is causing Hydromyelia. Some of the surgical procedures done are as follows:
Surgery for Arnold-Chiari Malformation: If Hydromyelia is caused by this condition then surgery called posterior fossa decompression is performed in which the surgeon will take out a bit of bone from behind the skull to create more room for the brain to expand and hence reduce the pressure being put on the brain and spinal cord and thus treating this condition along with Hydromyelia.
Draining the Cyst: In order to drain the fluid form the cyst the surgeon inserts a shunt containing a tube and a valve with one end of the tube being attached to the cyst and the other end being attached to other part of the body, which is usually the abdomen and the fluid is drained from the cyst using this shunt.
Removal of Obstruction: In case if there is a tumor or an abnormal growth restricting the slow of the CSF then removal of the tumor is done so as to restore normal flow of the CSF and allowing the fluid from the cysts to drain.
In case if Hydromyelia is being caused due to a tethered cord then correcting the abnormality is useful in restoring normal flow of the CSF and draining the fluid from the cyst and resolving the symptoms which arises from Hydromyelia.