| Author/Editor | Kržan, M | |
| Title | Spremljanje živčno-mišičnega prenosa pri bolnikih s fokalno distonijo, zdravljenih z botulinom | |
| Translated title | Study of neuromuscular transmission in botulinum toxin treated patients with focal dystonia | |
| Type | monografija | |
| Place | Ljubljana | |
| Publisher | Medicinska fakulteta | |
| Publication year | 1992 | |
| Volume | str. 39 (68) | |
| Language | slo | |
| Abstract | SFEMG with axonal microstimulation was used to measure human neuromuscular transmission in vivo and in situ in muscles treated with botulinum toxin (sternocleidomastoid - SCM and orbicularis oculi - OOC muscles) and those distant from the injection site (extensor digitorum communis muscle -EDC). Compared to pre-injection values, the neuromuscular jitter increased significantly (p less th. 0.001) in the injected (SCM) and distant (EDC) muscles in the whole group of 6 torticollis patients (18.6 micros vs. 33.0 micros in SCM and 16.8 micros vs. 26.6 micros in EDC, respectively). This confirms disturbed neuromuscular transmission in distant muscles wich however remained subclinical. No correlation between dosage and degree of transmission disturbance was found. Presynaptic potentiation and depression was studied at individual motor endplates (MEPs) as a function of activation rate. Jitter and blocking was measured at stimulation frequencies ranging from 0.5 to 50 Hz. Forty MEPs of botulin injected SCM and OOC muscles were studied at two or more stimulation Frequencies 7 to 38 days after injection. Stimulations at higher rates produced a decrease of jitter in 13 and increase in 9 MEPs. Blocking was less frequent at higher rates in 12 MEPs, and more frequent in 2. Mean jitter was highest at 5 and 10 Hz, followed by a marked decrease at 20 Hz. The mean frequency of blocking was highest between 2 and 5 Hz. The most prominent and consistent finding was a marked decline of blocking frequency from 2 to 20 Hz. This is interpreted is suggestive of the expected presynaptic lesion. to be due to rate dependent presynaptic potentiation. The pattern of jitter and blocking changes with stimulation frequency was more similar to that reported myasthenia than that in the myasthenic syndrome, suggesting more pronounced postsynaptic dysfunction. This may be due to immaturity of the newly formed neuromuscular junctions. Only the marked decline in blocking from 2 to 20 Hz | |
| Descriptors | DYSTONIA BOTULINUM TOXINS ELECTROMYOGRAPHY MOTOR ENDPLATE TORTICOLLIS BLEPHAROSPASM NEUROMUSCULAR JUNCTION |