From the Guidelines
A comprehensive laboratory workup for seizures should include a complete blood count, comprehensive metabolic panel, electrolyte studies, liver and kidney function tests, toxicology screening, and an electroencephalogram (EEG) to detect abnormal electrical activity in the brain. This approach is supported by recent guidelines and studies, such as the 2022 guideline for the management of patients with spontaneous intracerebral hemorrhage, which emphasizes the importance of monitoring patients with ICH for seizures and using continuous electroencephalographic monitoring for at least 24 hours 1.
When evaluating a patient with a seizure, it is essential to consider the underlying cause and tailor the laboratory workup accordingly. For example, if the patient has a history of alcohol or drug use, toxicology screening may be particularly important. Additionally, if the patient has a history of autoimmune or infectious diseases, screening for these conditions with tests like erythrocyte sedimentation rate, C-reactive protein, and cerebrospinal fluid analysis may be warranted.
The use of neuroimaging such as MRI or CT scan can also help identify structural abnormalities that may be contributing to the seizures. According to a study published in the Annals of Emergency Medicine in 2014, CT results were abnormal in 19% of patients who received a CT scan, highlighting the importance of neuroimaging in the evaluation of seizures 1.
In terms of specific tests, the following should be considered:
- Complete blood count to check for anemia or infection
- Comprehensive metabolic panel to check for electrolyte imbalances or kidney dysfunction
- Electrolyte studies to check for sodium, calcium, or glucose imbalances
- Liver and kidney function tests to check for underlying organ dysfunction
- Toxicology screening to check for substance use
- Antiepileptic drug levels if the patient is on medication
- Thyroid function tests to check for thyroid dysfunction
- Ammonia levels to check for hepatic encephalopathy
- Screening for autoimmune or infectious causes with tests like erythrocyte sedimentation rate, C-reactive protein, and cerebrospinal fluid analysis.
Overall, a comprehensive laboratory workup is essential for identifying the underlying cause of seizures and determining appropriate treatment and management strategies.
From the Research
Laboratory Workup for Seizures
The laboratory workup for seizures typically includes a range of tests to help determine the cause and guide management. Some of the key tests include:
- Electroencephalogram (EEG) 2, 3, 4: This test measures the electrical activity of the brain and can help diagnose and monitor seizure disorders.
- Complete blood count (CBC) 5, 6: This test can help identify any underlying infections or inflammatory conditions that may be contributing to the seizures.
- Basic metabolic panel (BMP) 5, 6: This test measures various electrolyte and metabolic levels in the blood, including sodium, glucose, and creatinine.
- Prolactin testing 5: This test can help differentiate between epileptic and non-epileptic seizures.
- Creatine kinase (CK) levels 5: Elevated CK levels can be indicative of generalized tonic-clonic seizures.
- Metabolic markers such as ammonia and lactate 5: These tests can help identify any underlying metabolic disorders that may be contributing to the seizures.
- Liver and renal function tests 5, 6: These tests can help identify any underlying liver or kidney disease that may be contributing to the seizures.
- Brain imaging tests such as magnetic resonance imaging (MRI) or computed tomography (CT) scans 2, 3, 4: These tests can help identify any structural abnormalities in the brain that may be contributing to the seizures.
Additional Tests
In some cases, additional tests may be ordered, such as:
- Long-term electroencephalography (LT-EEG) 3: This test can help monitor seizure activity over an extended period.
- Ambulatory EEG 4: This test can help monitor seizure activity in a more natural setting.
- Video/EEG 4: This test can help monitor seizure activity and correlate it with behavioral changes.
- Positron emission tomography (PET) or single photon emission computed tomography (SPECT) scans 4: These tests can help identify any areas of abnormal brain activity.
- Serum evaluation 4: This test can help identify any underlying infections or inflammatory conditions that may be contributing to the seizures.