//fpnotebook.com/
Neuroimaging after First Seizure
Aka: Neuroimaging after First Seizure, Seizure Indications for Neuroimaging
- Epidemiology
- Incidence: Neuroimaging in first non-febrile Seizure Evaluation identifies a structural Brain Lesion
- Adults: 33%
- Infants <6 months: 50%
- Techniques: Imaging Studies after first Seizure
- Step 1: Urgent CT Head (acute to exclude Hemorrhage)
- Indicated urgently for at risk patients to exclude conditions that change acute management
- Structural cause found in 17% of adults and 8% of children
- New onset convulsive Status Epilepticus
- New Focal Seizures
- Persistently abnormal Neurologic Exam (or symptoms that do not resolve)
- Failure to return to neurologic baseline or persistent neurologic deficits
- New, non-Febrile Seizure in age <1 year old
- Suspected Traumatic cause (e.g. suspected Child Abuse or neglect)
- Patient without risk factors for intracranial pathology
- May wait for outpatient imaging typically with MRI Brain
- Contrast needed only in HIV or cancer history where tumor or abscess is suspected
- Step 2: Routine MRI Head (preferred for structural exam)
- Higher efficacy than Head CT in identifying underlying Brain Lesions
- No radiation exposure (see Cancer Risk due to Diagnostic Radiology)
- Even a greater concern in children in whom radiation exposure carries higher lifetime cancer risk
- Indications: Adults
- All adults should have Neuroimaging after First Seizure (per ACEP and AAN)
- Timing of neuroimaging depends on presentation
- At risk patients, should undergo urgent Head CT, followed by later MRI Brain
- Stable patients may wait to undergo outpatient MRI Brain (if no contraindication for delay)
- Urgent neuroimaging indications (typically CT Head)
- Acute Head Trauma
- Age over 40 years
- AIDS
- Altered Mental Status persists
- Anticoagulation
- Fever
- Focal neurologic deficit of new onset
- Headache persists
- Malignancy
- Partial Seizure (Focal Seizure)
- Deferred outpatient neuroimaging indications (typically MRI Head)
- Stable patient and
- No urgent neuroimaging indications (see above) and
- Reliable patient for follow-up and
- Returned to baseline mental status during emergency department evaluation
- Indications: Children
- All patients under age 6-12 months
- Cognitive or Motor Developmental Delay
- EEG with primary Generalized Epilepsy
- Head Trauma
- Malignancy
- Brain Tumor
- Prior Cerebrovascular Accident
- HIV Infection
- Bleeding Disorder or Coagulopathy
- Sickle Cell Disease
- Hydrocephalus
- Prior CNS surgery with shunt
- Neurocutaneous Syndrome (e.g. Neurofibromatosis, Tuberous Sclerosis)
- Hemihypertrophy
- Cysticercosis exposure (e.g. travel to endemic regions)
- Abnormal Neurologic Exam
- Focal neurologic deficits
- Mental status changes persist
- Partial Seizure (Focal Seizure)
- Postictal neurologic deficit that persists
- References
- Nocera, Valente, Amanullah (2018) Crit Dec Emerg Med 32(11): 3-9
- Dayan (2015) Pediatrics 136(2): e351-60 +PMID:26195538 [PubMed]
- Wilden (2012) Am Fam Physician 86(4): 334-40 [PubMed]
- Harden (2007) Neurology 69(18): 1772-80 [PubMed]