WHAT ARE THE SIGNS?
--review by Avbersek & Sisodiya in J Neurol Neurosurg Psychiatry (link below)
--looked at 34 studies
--tried to tease out what signs distinguish epileptic vs. non-epileptic seizure
WHAT DID THEY FIND?
--signs that favor psychogenic non-epileptic seizures (specificity)
- fluctuating course (96%)
- asynchronous movements (93-96%)
- pelvic thrusting (96-100%)
- side-to-side head/body movement (96-100%)
- closed eyes (74-100%)
- ictal crying (100%)
- memory recall (96%)
--signs that favor epileptic seizures (specificity)
- occurance from sleep (100%)
- post-ictal confusion (88%)
- stertorous (snoring) breathing (100%)
FYI:
--the sensitivities for all of these signs were horrible, so can't use them to rule anything out
--sometimes excluded frontal lobe partial seizures
--insufficient evidence: gradual onset, flailing/thrasing, opisthotonus, tongue biting, urinary incontinence
Reference(s): review article, picture
STUDY 1:
--37 syncope and 26 generalized tonic–clonic seizure patients
--tested serum CK and myoglobin at ED presentation and 4 hrs after the event
--no statistically significant different in myoglobin at any time
--no statistically significant different in CK at ED presentation
--CK drawn 4 hrs after the event:
- elevated in four of 37 (10.8%) patients with syncope
- elevated in nine of 26 (34.6%) patients with seizure activity
- statistically significant difference in CK between seizure and syncope groups (P<0.05)
- sensitivity 34%
- specificity 89%
STUDY 2:
--Sequential sample of 205 patients with transient loss of consciousness. The study group consisted of 96 patients who had CK measurements in the ED
--Mean (+/- SE) CK significantly higher in the seizure group (231.1 +/- 34.8 U/L vs. 70.5 +/- 5.6 U/L, p less than 0.001).
--elevated CK: sensitivity of 0.43, specificity of 0.98--elevated CK >3hrs after event: sensitivity was 0.80, specificity was 0.94
10-SECOND TAKEAWAY:
--serum CK level after seizure: not too sensitive (better after 3 hrs), pretty specific
--may be useful to confirm suspected seizure if elevated >3-4 hours s/p event
Reference(s): study 1, study 2, picture
STUDY:
--200 patients with seizure-like activity, 109 ultimately diagnosed with seizure
--31% (of 200 patients) had abnormal prolactin (upper limit of normal ~30mg/dL)
--the numbers:
- sensitivity of this serum prolactin was 42%
- specificity was 82%
- positive predictive value (PPV) of 74%
- negative predictive value (NPV) of 54%
- overall accuracy of 60% in the diagnosis of seizure,
- likelihood ratio of 2.4
--their conclusion: "The measurement of serum prolactin is helpful as a confirmatory test, but not as screening test in the emergency department setting."
REVIEW ARTICLE:
--most studies used 2x baseline serum prolactin level as 'elevated'
--the numbers:
- pooled sensitivity for generalized tonic-clonic seizures (60.0%); for complex partial seizures (46.1%)
- pooled specificity was similar for both (approximately 96%)
- 2 Class II studies were consistent in showing prolactin elevation after tilt-test-induced syncope.
--their conclusion: "Elevated serum prolactin assay, when measured in the appropriate clinical setting at 10 to 20 minutes after a suspected event, is a useful adjunct for the differentiation of generalized tonic-clonic or complex partial seizure from psychogenic nonepileptic seizure among adults and older children (Level B). Serum prolactin assay does not distinguish epileptic seizures from syncope (Level B)"
META-ANALYSIS:
--usefulness of raised serum prolactin in diagnosing generalised tonic-clonic seizures (GTSC) in patients presenting to the ED after a single episode of syncope
--13 relevant studies only 3 met the criteria for evaluation
--the numbers: if a serum prolactin concentration is > 3x the baseline when taken within one hour of syncope, then...
- LR (likelihood ratio) of GTSC vs pseudoseizure = 8.92, sensitivity 0.62, specificity 0.89
- LR of GTSC vs. syncope = 4.60, sensitivity 0.71, specificity 0.85
10-SECOND TAKEAWAY:
--serum prolactin in seizure: not too useful in the ED
--generally poor sensitivity, better specificity, but only if tested early (~10-60 min s/p episode)
--so if you can draw it fast, and if its significantly elevated, it might be useful (a lot of if's), but if its low, doesn't mean it's not a seizure
--serum prolactin in seizure: not too useful in the ED
Reference(s): study, review, meta-analysis, picture
QUESTION:
--my patient had some sort of 'episode', story is unclear
--does their tongue lac tell me anything? was this a seizure?
PUBMED BIOPSY (not a ton out there):
STUDY 1: "Value of tongue biting in the diagnosis of seizures"
--study of 106 patients admitted to epilepsy unit + 45 patients with syncope
--small sample size, but interesting
--8/106 seizure patients had a tongue lac: all on the side
--1/45 syncope patients had a tongue lac: at the tip.
--sensitivity of 24% and a specificity of 99% for the diagnosis of generalized tonic-clonic seizures.
--Lateral tongue biting was 100% specific to grand mal seizures.
STUDY 2: The diagnostic value of oral lacerations and incontinence during convulsive "seizures".
--84 patients on EEG
--trying to tell seizure from pseudoseizure (a.k.a. psychogenic non-epileptic seizure, or PNES)
--oral lacs: (p=0.01)
- seizure: 26% (17/66) --14 side of tongue, 1 tip of tongue, 2 cheek, 3 lip
- not a seizure: 0% (0/18)
- sensitivity 26%, specificity 100%
--Incontinence: (p = 0.09)
- seizure: 23% (15/66)
- not a seizure: 6% (1/18) --!!! (now that's commitment)
- sensitivity 23%, specificity 94%
BOTTOM LINE:
--side-of-tongue lac is near 100% specific for seizure, not very sensitive
--if the story fits, and you bit the side of your tongue and/or pissed yourself, you probably earned a seizure workup
Reference(s): tongue biting, oral lacs and incontinence, picture
