Distinguishing sleep disorders from seizures: diagnosing bumps in the night.
BACKGROUND
Abnormal paroxysmal events in sleep may be parasomnias or epileptic seizures. In nocturnal frontal lobe epilepsy (NFLE), the unusual seizure features often lead to diagnostic confusion with nonepileptic parasomnias; video-electroencephalography monitoring is usually required to make the diagnosis.


OBJECTIVE
To examine the reliability of the clinical history in diagnosing NFLE, using the Frontal Lobe Epilepsy and Parasomnias (FLEP) scale.


METHODS
The FLEP scale, comprising specific questions reflecting the diagnostic features of NFLE and parasomnias, was developed by an expert panel following review of the literature. It was then validated in a sample of individuals with firmly diagnosed nocturnal events.


METHODS
Patients were recruited after appropriate diagnostic workup in tertiary sleep and epilepsy referral centers in Melbourne, Australia.


METHODS
Sixty-two patients (45 males) [corrected] with paroxysmal nocturnal events. Intervention Two independent interviews were conducted in each case, with the patient and a witness, by researchers blinded to the diagnosis.


METHODS
The diagnosis obtained from scores on the FLEP scale was compared with the confirmed diagnosis in each patient.


RESULTS
Nocturnal frontal lobe epilepsy was correctly diagnosed from the FLEP score in 31 of 31 patients, with a sensitivity of 1.0 (95% confidence interval [CI], 0.85-1.00), specificity of 0.90 (95% CI, 0.73-0.97), positive predictive value of 0.91 (95% CI, 0.75-0.97), and negative predictive value of 1.00 (95% CI, 0.85-1.00).


CONCLUSIONS
A diagnosis of NFLE can be made reliably using the clinical features identified in the FLEP scale. This may reduce the requirement for tertiary referral and extensive inpatient monitoring.
Derry
Christopher Paul
CP
Epilepsy Research Centre, Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia.
Davey
Margot
M
Johns
Murray
M
Kron
Katie
K
Glencross
Deborah
D
Marini
Carla
C
Scheffer
Ingrid E
IE
Berkovic
Samuel F
SF