Degenerative pontine lesions in patients with familial narcolepsy.
OBJECTIVE
Narcolepsy is characterized by chronic excessive daytime sleepiness with episodic sleep attacks. There are several associated symptoms of narcolepsy: cataplexy (bilateral muscle weakness without loss of consciousness provoked by an emotional trigger, e.g. laughter), sleep paralysis and hypnagogic-hypnopompic hallucinations. Most cases are sporadic; familial narcolepsy contributes to only 1-5% of all cases. While most cases of narcolepsy are idiopathic and are not associated with clinical or radiographic evidence of brain pathology, symptomatic or secondary narcolepsy may occur occasionally in association with lesions caused by tumours, demyelination or strokes of the diencephalon, midbrain, and pons. There are some examples of non-specific brainstem lesions found in magnetic resonance imaging (MRI) in patients with idiopathic narcolepsy.


METHODS
The authors present eleven patients from a five-generation family with many members who suffer from episodic excessive daytime sleepiness. Narcolepsy was diagnosed in 9 patients. Sleepiness was frequently associated with cataplexy, hypnagogic-hypnopompic hallucinations and sleep paralysis. Improvement in their clinical state was observed during the treatment with modafinil. All probands had MRI of the brain, routine blood tests, EEG, polysomnography, examination of the level of hypocretin in cerebrospinal fluid and evaluation by means of Epworth and Stanford Sleepiness Scales.


RESULTS
In 9 patients with narcolepsy, decreased thickness of the substantia nigra was found and in six of them degenerative lesions in the pontine substantia nigra were also noticed.


CONCLUSIONS
The significance of these changes remains unclear. No data have been published until now concerning the presence of any brain lesions in patients with familial narcolepsy.
Stepień
Adam
A
Clinic of Neurology, Military Medical Institute, Szaserów St., Warsaw, Poland. astepien@wim.mil.pl
Staszewski
Jacek
J
Domzał
Teofan M
TM
Tomczykiewicz
Kazimierz
K
Skrobowska
Ewa
E
Durka-Kesy
Marta
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D001933:Brain Stem / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000134:cerebrospinal fluid; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000235:genetics*; D009479:Neuropeptides / Q000134:cerebrospinal fluid; D000068797:Orexins; D010375:Pedigree; D017286:Polysomnography; D011149:Pons / Q000473:pathology*; D012154:Reticular Formation / Q000473:pathology*; D013378:Substantia Nigra / Q000473:pathology*; D055815:Young Adult
D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins