Types and what happens
Normally, the cerebellum is located above the foramen magnum, and cerebrospinal fluid circulates freely around the brain stem. With this anomaly, the posterior cranial fossa is tight, and the lower parts of the cerebellum are displaced into the foramen, partially blocking the flow of fluid. The pressure pulse wave is transmitted to the spinal cord, and a fluid-filled cavity can form inside it. The type is determined by which structures are displaced and how much, and whether there are associated developmental defects.
- Type 1 - prolapse of the cerebellar tonsils, most often detected in adolescents and adults
- Type 2 - displacement of the cerebellum and brainstem, combined with spina bifida in children
- Types 3 and 4 - rare and severe forms
- Syringomyelia - a cavity in the spinal cord as a common complication
- Hydrocephalus with severe impairment of liquor flow
Symptoms
The most characteristic symptom is pain in the back of the head and upper neck, which occurs or sharply intensifies with coughing, sneezing, laughing, straining and physical effort, lasting seconds or minutes. Dizziness, tinnitus, instability, and visual impairment are often associated. When a cavity forms in the spinal cord, there is a loss of pain and temperature sensitivity in the hands while maintaining the sense of touch: the person does not feel hot and gets burns. May cause weakness in the hands, muscle loss, difficulty swallowing and sleep apnea.
- Pain in the back of the head when coughing and straining
- Dizziness, tinnitus, unsteadiness
- Numbness and weakness in the hands
- Loss of temperature and pain sensitivity
- Swallowing difficulty, hoarseness
- Impaired fine motor skills, loss of hand muscles
- Sleep apnea, snoring with pauses in breathing
Diagnostics
The main method is MRI of the brain with targeted assessment of the craniovertebral junction. The doctor measures the degree of prolapse of the tonsils, assesses the patency of the cerebrospinal fluid tract and necessarily examines the cervical spinal cord to look for syringomyelia. MRI of all parts of the spine is often performed, since the cavity can be extensive. CT helps evaluate the bony features of the skull base and associated vertebral anomalies. For a complete picture, a neurological examination is important, and in case of respiratory complaints, a sleep study.
- MRI of the brain with assessment of the craniovertebral junction
- MRI of the cervical spine to exclude syringomyelia
- MRI of the thoracic and lumbar spine if necessary
- CT scan of the craniovertebral junction for bone assessment
- Neurological examination over time
- Polysomnography for suspected sleep apnea
When is surgery needed?
If tonsil prolapse is discovered by chance, there are no complaints and the spinal cord is not changed, observation with a repeat MRI is usually sufficient. Surgical treatment is discussed for persistent characteristic headaches that disrupt life, with neurological deficits and especially with syringomyelia, which is increasing. Surgery - decompression of the posterior cranial fossa: the bone window is expanded and, if necessary, plastic surgery of the dura mater is performed to restore fluid flow. The goal of intervention is to stop progression; functions that have already been lost do not always return, so there is no point in delaying treatment if symptoms increase.
- Asymptomatic finding - observation and control MRI
- Persistent cough headache - an indication for discussing surgery
- Increasing syringomyelia - active tactics
- Respiratory and swallowing disorders - urgent consultation with a neurosurgeon
- Decompression of the posterior cranial fossa - the main technique
- In case of hydrocephalus, the issue of fluid drainage is first decided.
Life with a diagnosis and what is possible
In asymptomatic cases, no restrictions are usually required, only observation is needed. If you have a cough headache, it is wise to avoid situations of sudden straining: lifting heavy objects, holding your breath during effort, deep bends and headstands. It is useful to treat chronic cough and constipation, which provoke attacks. A doctor should select painkillers. After the operation, the load is gradually increased, and a control MRI is performed according to the schedule established by the neurosurgeon.
- Avoid heavy lifting and straining if symptomatic.
- Treat chronic cough and constipation
- Avoid headstands and sharp bends
- Manual manipulation of the neck - only after consultation with a doctor
- Control MRI as prescribed
- Contact us immediately if you experience weakness or numbness in your hands.