A hypothesis for how non-REM sleep might promote seizures in partial epilepsies: a transcranial magnetic stimulation study.
OBJECTIVE
To investigate alterations of inhibitory and excitatory cortical circuits during non-rapid eye movement (NREM) sleep in drug-naive patients with partial epilepsies and sleep-bound seizures only.


METHODS
A paired-pulse TMS paradigm was used to test intracortical inhibition (ICI) and facilitation (ICF) in the hemisphere of the epileptic focus in three untreated patients with nonlesional, nongenetic frontal lobe epilepsy in NREM2 (three patients), NREM3/4 (one patient), and wakefulness (three patients).


RESULTS
All three patients exhibited a major decrease of ICI in NREM sleep as opposed to the physiological enhancement of ICI with the progression of NREM sleep.


CONCLUSIONS
Decreased ICI might reflect a substrate for the association of epileptic processes with thalamocortical networks that propagate sleep. Thus our findings contribute to a hypothesis of how NREM sleep could promote seizures.
Salih
Farid
F
Neurologische Klinik und Poliklinik, and Interdisziplinäres Schlafmedizinisches Zentrum, Charité-Universitätsmedizin Berlin, Augustenburgerplatz 1, 13353 Berlin, Germany. Farid.Salih@charite.de
Khatami
Ramin
R
Steinheimer
Saskia
S
Kretz
Rebekka
R
Schmitz
Bettina
B
Grosse
Pascal
P
D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography / Q000706:statistics & numerical data; D004828:Epilepsies, Partial / Q000503:physiopathology; D017034:Epilepsy, Frontal Lobe / Q000503:physiopathology; D005133:Eye Movements / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology*; D009434:Neural Pathways / Q000503:physiopathology; D012640:Seizures / Q000503:physiopathology*; D012890:Sleep / Q000502:physiology; D012894:Sleep Stages / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000503:physiopathology; D009435:Synaptic Transmission / Q000502:physiology; D013788:Thalamus / Q000503:physiopathology; D050781:Transcranial Magnetic Stimulation; D014851:Wakefulness / Q000502:physiology