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Biomedical subjects

T Dalager

Publications and source records attributed to T Dalager.

5 recordsLinked to original sources

Reduced jaw opening from paradoxical activity of mandibular elevator muscles treated with botulinum toxin.

The aim of the study was the effect of injections with botulinum toxin A (BTX-A) on reduced jaw opening, caused by paradoxical, antagonistic activity of jaw elevator muscles after brain stem lesions. The study included a male (51 years) and a female (69 years) patient. Subjective assessment, clinical recordings, muscle blocks and electromyography (EMG) were used to diagnose paradoxical activity, and to plan, guide and evaluate the treatment. The paradoxical innervation pattern was unilateral in the male and bilateral in the female. The paradoxical activity during jaw opening amounted to 24-109% of the level during maximum biting, and bursts of paradoxical activity were also present during chewing. EMG-guided blocks and later BTX-A injections of the affected muscles increased the opening by 9-23 mm from pre-treatment values of 15-18 mm, and normalized chewing. The study proved BTX-A to be an effective treatment for reduced jaw opening caused by paradoxical activity. Treatment was optimized by EMG evaluation of the current activity of the jaw elevator muscles, permitting individual treatment plans with longer intervals between BTX-A injections and lower doses than with conventional treatment for oromandibular dystonia. Thus the treatment only had to be repeated one to two times per year to maintain acceptable jaw mobility.

Aged↗

Long-term botulinum toxin treatment of cervical dystonia--EMG changes in injected and noninjected muscles.

OBJECTIVE: To evaluate changes in quantitative EMG of injected and noninjected sternocleidomastoid muscles following long-term unilateral botulinum toxin treatment of cervical dystonia. METHODS: We investigated 27 patients with cervical dystonia, who received repeated unilateral botulinum toxin injections of the sternocleidomastoid muscle, with quantitative EMG at rest and at maximal voluntary contraction. The patients had on the average 7.1 botulinum toxin treatments and the follow-up period was on the average 31 months (SD 16). RESULTS: After the first treatment, the injected sternocleidomastoid muscles showed a significant decrease in turns/s (mean 45%) and amplitude (mean 52%) at rest, and in amplitude at maximal flexion (mean 24%) and rotation (mean 39%). Except for a reduction in turns/s at rotation (mean 19%) no further reductions in EMG parameters were seen after long-term treatment. The contralateral noninjected sternocleidomastoid muscles showed no significant change in EMG activity after the first BT treatment, but after long-term treatment a significant reduction in turns/s and amplitude at both maximal flexion (turns: mean 28%; amplitude: mean 25%) and rotation (turns/s: mean 32%; amplitude: mean 25%) were seen as compared to pretreatment values. CONCLUSION: The results indicate that there seems to be no cumulative chemodenervation by repeated botulinum toxin injections of sternocleidomastoid muscles measured by quantitative EMG. Contralateral noninjected sternocleidomastoid muscles however, seem to be affected following long-term treatment. The mechanism behind this finding is unknown.

Adolescent↗

[Myotonic dystrophy].

Myotonic dystrophy (MD) is illustrated by a characteristic case report. MD is a dominantly inherited multi-organic disease with complete penetrance, but with highly variable expression illustrated by the near relatives of this patient. The disease usually follows a slow, progressive course. The cardinal symptoms are myotonia, muscle atrophia, cataract and a characteristic facial appearance. Cardial arrhythmias, endocrine and mental changes also occur. The liability to arrhythmias and the weakened respiratory muscles of the patients which lead to ventilatory insufficiency makes anesthesia and surgical operation risky. The diagnosis, which is made by electromyography, is easy in typical cases, but suspicion that the disease is present is seldom raised in very mild cases if there is no recognition of familial cases. Meticulous examination of near relatives of severe cases is therefore essential to take advantage of the possibilities of prenatal diagnosis recently made possible through developments in DNA technology.

Adult↗

Spasm index in subarachnoid haemorrhage: consequences of vasospasm upon cerebral blood flow and oxygen extraction.

A spasm index, defined as transcranial Doppler detected flow velocity in the middle cerebral artery divided by regional cortical cerebral blood flow (CBF), was used on 24 patients with subarachnoid haemorrhage (SAH). The aim was to estimate degree and time course of vasospasm, even in cases with great day-to-day variation in CBF, and correlate to CBF and oxygen extraction. All patients showed increase in spasm indices with peak index in the second or third week. The index seemed stable in spite of day-to-day fluctuations in CBF. Severe vasospasm were associated with poor clinical condition, reduced CBF (less than 30) and high AVDO2. The same picture could be seen with minor degree of vasospasm, probably, in some cases, due to high intracranial pressure. The results suggest that the spasm index is useful in monitoring patients with subarachnoid haemorrhage, and that severe vasospasm has a negative influence on clinical condition, CBF and oxygen extraction.

Blood Flow Velocity↗