Some CMs are asymptomatic and do not interfere with a person’s activities of daily living. In other cases, medications may ease certain symptoms, such as pain.
Surgery is the only treatment available to correct functional disturbances or halt the progression of damage to the central nervous system. Most individuals who have surgery see a reduction in their symptoms and/or prolonged periods of relative stability. More than one surgery may be needed to treat the condition.
Posterior fossa decompression surgery is performed on adults with CM to create more space for the cerebellum and to relieve pressure on the spinal column. Surgery involves making an incision at the back of the head and removing a small portion of the bottom of the skull (and sometimes part of the spinal column) to correct the irregular bony structure. The neurosurgeon may use a procedure called electrocautery to shrink the cerebellar tonsils. This surgical technique involves destroying tissue with high-frequency electrical currents.
A related procedure, called a spinal laminectomy, involves the surgical removal of part of the arched, bony roof of the spinal canal (the lamina) to increase the size of the spinal canal and relieve pressure on the spinal cord and nerve roots.
The surgeon may also make an incision in the dura (the covering of the brain) to examine the brain and spinal cord. Additional tissue may be added to the dura to create more space for the flow of CSF.
Infants and children with myelomeningocele may require surgery to reposition the spinal cord and close the opening in the back.
Hydrocephalus may be treated with a shunt system that drains excess fluid and relieves pressure inside the head. A sturdy tube that is surgically inserted into the head is connected to a flexible tube that is placed under the skin, where it can drain the excess fluid into either the chest wall or the abdomen so it can be absorbed by the body. An alternative surgical treatment to relieve hydrocephalus is third ventriculostomy, a procedure that improves the flow of CSF. A small perforation is made in the floor of the third ventricle and the CSF is diverted into the subarachnoid space to relieve pressure.
Similarly, surgeons may open the spinal cord and insert a shunt to drain a syringomyelia or hydromyelia. A small tube or catheter may be inserted into the syrinx for continued drainage.