How to Diagnose Guillain-Barré Syndrome (GBS)?
Guillain-Barré syndrome (GBS) diagnosis relies on a combination of methods focusing on clinical presentation and supportive tests. There's no single definitive test.
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Detailed Medical History and Physical Examination: A doctor will thoroughly review your medical history, paying close attention to the onset and progression of symptoms. The physical exam assesses muscle weakness, reflexes (often diminished or absent), and sensory changes. Symmetrical weakness is a key indicator.
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Electrodiagnostic Studies: These tests evaluate nerve and muscle function:
- Nerve Conduction Studies (NCS): Electrodes placed on the skin measure the speed of nerve signals. Slowed conduction speeds suggest nerve damage characteristic of GBS.
- Electromyography (EMG): Thin needles inserted into muscles assess muscle and nerve activity. EMG findings in GBS reflect the impact of nerve damage on muscle function.
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Lumbar Puncture (Spinal Tap): A small sample of cerebrospinal fluid (CSF) is collected from the spinal canal. Analysis reveals elevated protein levels (without a significant increase in white blood cells), a hallmark of GBS.
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Other Tests: While not specific to GBS, blood tests may rule out other conditions with similar symptoms. In some cases, additional imaging (e.g., MRI) might be used to exclude other neurological disorders.
Interpreting the Results:
The diagnosis of GBS is made by integrating the findings from the history, physical examination, and the electrodiagnostic studies and CSF analysis. The characteristic combination of clinical features and supportive test results confirms the diagnosis.
