Treatment of habitual snoring with botulinum toxin: a pilot study

The objective of this study was to investigate whether injections of botulinum toxin into the soft palate reduce snoring in a subgroup of patients that present an active process causing habitual snoring. The study was conducted in eight patients with habitual snoring but without evidence of obstructive sleep apnea. Polysomnography was performed for diagnostic purposes and to monitor sleep quality before and after treatment. The patients and their partners completed a questionnaire before and after treatment. Recordings of snoring noise before and after treatment were evaluated on a visual analog scale by a blinded assessor. Doses of 20 U of botulinum toxin type A (Dysport) were injected unilaterally into the muscles of the soft palate. Snoring was reduced in eight cases. The patients reported no major adverse effects. These results justify further studies of botulinum toxin therapy in patients with habitual snoring. The scheme presented for injections of botulinum toxin into the levator veli palatini muscle provides a rational basis for the design of such studies. Therapy with botulinum toxin for habitual snoring is safe, non-invasive, easy to perform, fully reversible, and thus warrants investigation under placebo-controlled, double-blind conditions. This treatment is appropriate for a disorder that is of paramount social importance but does not pose a medical threat to the individuals affected.

Sumatriptan and corneal reflexes in headache-free migraine patients: a randomized and placebo-controlled crossover study

A temporary sensitization of central trigeminal neurones in migraine patients during acute attacks has been described in previous studies using the electrically evoked nociceptive blink reflex. The cornea is innervated by small myelinated A-delta and unmyelinated C-fibres only. Stimulation with air puffs activates peripheral nociceptors and allows the investigation of peripheral trigeminal nerve structures. Our objective was to investigate whether corneal reflex examinations with air puff stimulation detect abnormalities in migraineurs during their pain-free interval and if the corneal reflex may be modulated by the administration of an oral triptan. After validation of the nociceptive air puff technique by investigating the corneal reflexes before and after a local anaesthesia of the cornea, we recorded corneal reflexes in 25 migraineurs during their pain-free period and 25 healthy controls before and after the oral administration of 100 mg sumatriptan in a randomized, placebo-controlled, crossover study. Baseline response areas under the curve (AUCs) and latencies of the R2 components of the corneal reflexes did not show any significant differences between patients and controls. Patients did not show any significant differences regarding their headache and non-headache side. The use of an oral triptan had no significant influence on latencies or AUCs in both patients and controls. Our data suggest that there is no facilitation of the trigeminal system in the headache-free interval among patients with migraine. The stable corneal reflexes after the oral administration of 100 mg sumatriptan suggest that there was no inhibition of the trigeminal system, both in patients during their headache-free period and in healthy controls.

Autonomic involvement in tick-borne encephalitis (TBE): report of five cases

BACKGROUND

Tick-borne encephalitis (TBE) is a viral infection of the CNS with significant acute and long-term morbidity. Dysfunction of the autonomic nervous system may be a potentially harmful complication of TBE.

MATERIAL AND METHODS

In a retrospective case series, 5 patients with acute TBE were evaluated for clinical signs of autonomic dysfunction and subject to autonomic testing. Heart rate variability (HRV) with 6 per minute deep breathing was performed between day 9 to 31 after onset of meningitis. Follow-up data were available in three cases.

RESULTS

All patients showed clinical signs of autonomic dysfunction, including upper and lower gastrointestinal tract symptoms, orthostatic hypotension, and urinary retention. A reduced HRV was observed in 4 patients, with sustained sinus tachycardia in 2 of them. The minimum of the HRV was reached 9 to 20 days after onset of meningitis. In one patient, normalization of the HRV occurred within 3 months.

CONCLUSION

Acute TBE can be associated with autonomic dysfunction including reduced HRV and tachycardia. Prospective studies are needed to analyze the incidence of autonomic dysfunction in TBE, and to clarify which patients have the highest risk for autonomic failure.

Functional connectivity between trigeminal and occipital nerves revealed by occipital nerve blockade and nociceptive blink reflexes

Headache syndromes often suggest occipital and neck involvement, although it is still unknown to what extent branches of segment C1-C3 contribute actively to primary headache. Pain within the occipital area may be referred to the trigeminal territory. However, a modulation of trigeminal transmission by affecting cervical input in humans has not been elucidated so far. A convergence of cervical and trigeminal input at the level of the caudal part of the trigeminal nucleus in the brainstem has been suggested due to anatomical and neurophysiological studies in animals. We examined the R2 components of the nociceptive blink reflex responses in 15 healthy subjects before and after unilateral nerve blockade of the greater occipital nerve with 5 ml prilocain (1%). R2 response areas (AUC) decreased and the R2 latencies increased significantly after the nerve blockade only on the side of injection. AUC and latencies on the non-injection side remained stable. Thresholds for sensory or pain perception did not differ significantly between the repeated measurements on both sides. Our findings extend previous results related to anatomical and functional convergence of trigeminal and cervical afferent pathways in animals and suggest that the modulation of this pathway is of potential benefit in primary headache disorders.

Persistent ocular motor disturbances in migraine without aura

Activation in the brain stem during attacks of migraine has been detected with the use of functional imaging, suggesting an important role of the brain stem in this disorder. Recent findings showed permanent cerebellar signs in common forms of migraine. Both structures are involved in generating smooth pursuit eye movements. The aim of this study was to investigate migraine patients by electrooculography to identify persisting abnormalities that may provide a clinical sign of continuous dysfunction of these structures. We investigated 25 patients with migraine without aura and 15 controls. Smooth pursuit was pathologically changed, velocity gain was reduced and phase was significantly altered in migraineurs as compared to controls. The data provide clinical evidence of a persistent dysfunction in the brain stem and certain cerebellar structures in migraine patients. This is consistent with previous studies indicating an important role of the brain stem in generating migraine attacks.