Postlingual hearing loss as a mitochondrial 3243A>G mutation phenotype.

BACKGROUND: The prevalence of isolated hearing loss (HL) associated with the m.3243A>G mutation is unknown. The aim of this study was to assess the frequency and heteroplasmy level of the m.3243A>G mutation in a large group of Polish patients with postlingual bilateral sensorineural HL of unidentified cause. METHODOLOGY/PRINCIPAL FINDINGS: A molecular search was undertaken in the archival blood DNA of 1482 unrelated patients with isolated HL that had begun at ages between 5 and 40 years. Maternal relatives of the probands were subsequently investigated and all carriers underwent audiological tests. The m.3243A>G mutation was found in 16 of 1482 probands (an incidence of 1.08%) and 18 family members. Of these 34 individuals, hearing impairment was detected in 29 patients and the mean onset of HL was at 26 years. Some 42% of the identified m.3243A>G carriers did not develop multisystem symptomatology over the following 10 years. Mean heteroplasmy level of m.3243A>G was lowest in blood at a level of 14% and highest in urine at 58%. These values were independent of the manifested clinical severity of the disease. CONCLUSIONS: A single m.3243A>G carrier can usually be found among each 100 individuals who have postlingual hearing loss of unknown cause. Urine samples are best for detecting the m.3243A>G mutation and diagnosing mitochondrially inherited hearing loss.

Evaluation of the function of the vestibular system in patients with migraine.

BACKGROUND AND PURPOSE: Migraine is a common disorder with 1-year prevalence of 17.2% in women and 6% in men. Otoneurological symptoms such as phonophobia, tinnitus, vertigo, and dizziness are quite common in migraine. It is estimated that vertigo and dizziness are associated with migraine in 10% of all dizzy patients. The aim of the study was to evaluate the function of the vestibular system using electronystagmography (ENG) and videonystagmography (VNG) in patients with migraine compared to healthy controls. MATERIAL AND METHODS: Sixty-two patients (46 women and 16 men) aged 20-35 years (mean age: 28.4 years) with migraine were qualified to the study. All other illnesses that can cause dysfunction of the vestibular system were excluded. The control group consisted of 31 healthy volunteers fulfilling the same demographic criteria as the migraine group (mean age: 29.2 years). RESULTS: Vertigo or dizziness was reported by 41 patients with migraine (66.1%). In ENG/VNG examination changes suggesting impairment of the peripheral or central part of the vestibular system were found in 34 patients (54.8%). In the control group, any abnormalities in ENG/VNG examination were present in 22.6% of individuals (p=0.0031). No statistical significance was found in the frequency of any ENG/VNG abnormalities in subgroups of patients with migraine with aura and migraine without aura. Factors predisposing to dysfunction of the vestibular system in our group of migraineurs were the frequency and duration of the migraine. CONCLUSIONS: Vertigo and dizziness are frequent co-existing symptoms in patients with migraine. ENG/VNG abnormali-ties are significantly more frequent in migraineurs than in healthy controls.

Familial narcolepsy.

BACKGROUND AND PURPOSE: Narcolepsy is a disease 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 (isolated loss of muscle tone associated with rapid eye movement [REM] in normal sleep) and hypnagogic-hypnopompic hallucinations (vivid dreaming occurring at the time of sleep onset and awakening that can be difficult to distinguish from reality). MATERIAL AND METHODS: The authors present eleven patients with suspected narcolepsy, who were members of a five-generation family with many cases of episodic excessive daytime sleepiness. Some of them experienced sleep attacks which were occasionally associated with a sudden loss of muscle tone (cataplexy), as well as with sleep paralysis and hypnagogic hallucinations. All probands had magnetic resonance (MR) of the brain performed, along with routine blood tests, EEG, polysomnography, examination of the level of hypocretin in the cerebrospinal fluid and evaluation by means of Epworth and Stanford Sleepiness Scales. RESULTS: Narcolepsy was diagnosed in nine patients. Improvement in their clinical state was observed during the treatment with modafinil.

[Trigemino-autonomic cephalalgias. Report of two cases]. / Trójdzielno-autonomiczne bóle glowy. Opis dwóch przypadków.

Trigemino-autonomic cephalalgias (TAC) constitute a rare group of primary headache conditions associated with unilateral fluctuating head pain and autonomic symptoms. These syndromes, including cluster headache, hemicrania continua, paroxysmal hemicrania and SUNCT, are much less prevalent than migraine and tension-type headache. The pathogenesis of TAC is unknown. Similar neuropeptide changes seen in all TAC syndromes suggest a shared underlying pathophysiology in these headaches. Some of them respond to the treatment with indomethacin and sumatriptan. Two patients suffering from one of the trigemino-autonomic cephalalgias are presented in the paper.