Arnold-Chiari malformation (ACM) is a rare, congenital disorder that affects the brain and spinal cord. It is diagnosed through a combination of medical history, imaging tests, and physical examination.
Medical history: A doctor will ask about any family history of the disorder, as well as any symptoms the patient may have experienced since birth. Common symptoms include headache, neck pain, dizziness, trouble swallowing, and a feeling of pressure in the back of the head.
Imaging tests: A doctor will use imaging tests such as an MRI or CT scan to look for signs of ACM. These scans can reveal the abnormal size and shape of the cerebellar tonsils in the back of the brain, which is a hallmark of ACM.
Physical examination: A doctor will perform a physical examination to look for signs of ACM. This includes checking for impaired coordination and muscle strength, as well as any physical deformities or abnormalities.
Once ACM is suspected, a doctor will confirm the diagnosis by performing a lumbar puncture. This procedure involves inserting a needle into the lower back to collect cerebrospinal fluid (CSF), which is then tested for signs of ACM.
In some cases, a doctor may also order an electromyogram (EMG) to measure electrical activity in the muscles and nerves. An EMG can help identify nerve damage or other issues that may be caused by ACM.
In summary, ACM is diagnosed through a combination of medical history, imaging tests, and physical examination. In some cases, a lumbar puncture and/or an EMG may be needed to confirm the diagnosis.