How do you workup adult patients who present with a new-onset seizure and now neurologically back to normal?

There unfortunately is very little recent literature about the best workup approach. In 1994, the American College of Emergency Physicians (ACEP) published a Clinical Policy based on expert consensus. The EM Clinics of North America series also just published a review on the topic. The bottom-line is that there are two types of workup approaches.

For the uncomplicated cases (age less than 40 years, afebrile, no comorbidities, no neurologic deficits), the workup is fairly minimal, which includes:

• Glucose and electrolytes
• Urine pregnancy test, if appropriate
• +/- Urine toxicology screen
• Head CT (noncontrast)

Otherwise, the more complex cases require a more extensive workup, which may include a lumbar puncture in the setting of a fever, severe headache, immunocompromised status, or persistent altered mental status.

Pearl

Be sure you obtain a head CT for patients who you think are presenting with a simple new-onset, alcohol-withdrawal seizure. One study showed that 6.2% of these patients actually have a significant lesion on CT (eg. bleed, mass).

PV Card: Workup for First Time Seizure

Adapted from [1, 2]
Go to ALiEM (PV) Cards for more resources.

References

1. ACEP C, Clinical P. Clinical policy: Critical issues in the evaluation and management of adult patients presenting to the emergency department with seizures. Ann Emerg Med. 2004;43(5):605-625. [PubMed]
2. Jagoda A, Gupta K. The emergency department evaluation of the adult patient who presents with a first-time seizure. Emerg Med Clin North Am. 2011;29(1):41-49. [PubMed]

In Wednesday’s post about the Colorado Compendium, Graham mentioned a new 2010 BMJ article on the high-risk signs suggestive of subarachnoid hemorrhage by the gurus in clinical prediction rules in Canada.

We excessively work-up patients for a subarachnoid hemorrhage with a nonspecific headache and no neurologic deficitis. This is because it’s difficult to predict who is high, medium, and low risk for such a bleed. So we throw a wider net so that we don’t miss such a devastating diagnosis. This usually means a CT and LP for many patients with a headache.

In this 5-year multicenter study, the investigators identified clinical decision rules to help identify the higher-risk groups for a subarachnoid hemorrhage. They derived 3 models, based on recursive partitioning. Each has a negative predictive value of 100%.

Before thinking about seeing if your headache patient has any of these high-risk features, pay special attention to see if s/he would have met the inclusion and exclusion criteria of this study.

Inclusion criteria:

• Neurologically intact adults (age ≥ 16 years) with a non-traumatic headache peaking within an hour.

Exclusion criteria:

• History of ≥3 recurrent HA’s of same character/intensity
• Referred from another hospital with confirmed SAH
• Returned for reassessment of same HA which was already evaluated for SAH
• Papilledema
• New focal neurologic deficits
• Previous dx of cerebral aneurysm or SAH
• Previous dx of brain neoplasm
• Known hydrocephalus

Although none of the models are validated as of yet, the cumulative list of clinical characteristics from these 3 models may be able to help you understand who may be at higher risk:

• Age ≥ 40 years
• Witnessed loss of consciousness
• Neck pain or stiffness
• Onset of HA with exertion
• Arrival by ambulance
• Vomiting
• DBP ≥ 100 mmHg or SBP ≥ 160 mmHg

PV Card: Subarachnoid Hemorrhage – High Risk Characteristics