From the Guidelines
A comprehensive laboratory workup for seizures should include an electroencephalogram (EEG), complete blood count, basic metabolic panel, and other tests to identify underlying causes and determine appropriate treatment strategies. When evaluating a patient with a seizure, it is essential to consider the potential causes and consequences of the seizure, including the risk of recurrence, morbidity, and mortality. According to the American Heart Association/American Stroke Association guideline 1, new-onset seizures in the context of spontaneous intracerebral hemorrhage are relatively common, and continuous electroencephalographic monitoring for at least 24 hours is probably reasonable. The laboratory workup should include:
- Complete blood count to check for infections or blood disorders
- Basic metabolic panel to evaluate electrolyte imbalances, glucose levels, and kidney function
- Electrolyte studies to check for sodium, calcium, or glucose imbalances that could trigger seizures
- Liver and kidney function tests to evaluate potential organ damage
- Toxicology screening to identify potential substance-induced seizures
- Drug levels if the patient is on antiepileptic medications
- Thyroid function tests to evaluate potential thyroid-related seizures
- Inflammatory markers to evaluate potential inflammatory causes
- Cerebrospinal fluid analysis if infection is suspected
- Neuroimaging studies like MRI or CT scan to identify structural abnormalities
- Autoimmune encephalitis screening with antibody panels for new-onset seizures in adults
- Metabolic and genetic testing in children with seizures. The Annals of Emergency Medicine study 1 suggests that no laboratory test was significantly associated with the final diagnosis of seizure, but this study is older and has limitations. In contrast, the more recent guideline from the American Heart Association/American Stroke Association 1 provides a more comprehensive approach to evaluating and managing patients with seizures. Therefore, a comprehensive laboratory workup, including an EEG and other tests, is essential for identifying the underlying cause of seizures and determining appropriate treatment strategies.
From the Research
Laboratory Workup for Seizures
The laboratory workup for seizures typically includes a range of tests to help diagnose and manage the condition. Some of the key tests include:
- Electroencephalogram (EEG) 2, 3, 4, 5: This test measures the electrical activity of the brain and can help diagnose seizure disorders.
- Complete Blood Count (CBC) 6: This test can help identify any underlying infections or inflammatory conditions that may be contributing to the seizure.
- Basic Metabolic Panel (BMP) 2, 6, 3: This test measures various electrolyte and metabolic levels in the blood, including sodium, glucose, and calcium.
- Serum glucose testing 2, 3: This test can help identify hypoglycemia or hyperglycemia, which can contribute to seizures.
- Creatine kinase (CK) levels 6: This test can help identify muscle damage or rhabdomyolysis, which can occur after a seizure.
- Electrolyte panel 6: This test measures the levels of various electrolytes, including sodium, potassium, and calcium.
- Liver and renal function tests 6: These tests can help identify any underlying liver or kidney disease that may be contributing to the seizure.
- Prolactin testing 6: This test can help differentiate between epileptic and non-epileptic seizures.
- Brain imaging tests, such as MRI or CT scans 3, 4, 5: These tests can help identify any structural abnormalities in the brain that may be contributing to the seizure.
Additional Tests
In some cases, additional tests may be ordered to help diagnose and manage the seizure disorder. These may include:
- Long-term electroencephalography (LT-EEG) 4: This test involves continuous EEG monitoring over a longer period of time to help diagnose and characterize seizure activity.
- Ambulatory EEG 5: This test involves portable EEG monitoring over a longer period of time to help diagnose and characterize seizure activity.
- Video/EEG monitoring 5: This test involves simultaneous video and EEG monitoring to help diagnose and characterize seizure activity.
- Positron emission tomography (PET) scan 5: This test can help identify any abnormal areas of brain activity that may be contributing to the seizure.
- Single photon emission computed tomography (SPECT) scan 5: This test can help identify any abnormal areas of brain activity that may be contributing to the seizure.