Brachial plexus injuries. Prognosis of postganglionic lesions

One hundred ninety-eight cases of postganglionic brachial plexus injury with no signs of combined damage to preganglionic sites were treated conservatively. Among them, 50 whole, 32 upper and 13 lower type injuries were followed up for at least 2 years and the course of the progression of the individual muscle was observed. In the whole type, 44% showed good functional recovery, although some of them needed reconstructive surgery. Thirty-eight percent recovered usefully only in the muscles innervated by upper roots. Three out of 50 cases did not recover at all. There were no particular differences between the whole and upper types with regard to the recovery rate of the arm muscles. However, the upper type showed better functional recovery than the whole type. If the muscles innervated by upper roots could gain a strength of M1 before 9 months after injury, and muscles innervated by lower roots reached M1 before 12 months, their final results were more than M3. But muscles with a strength of less than M2 at 18 months did not recover to more than M3. The muscular power at 24 months was almost the same as the final results. About half of the postganglionic brachial plexus injuries which did not combine preganglionic lesions showed favorable spontaneous recovery with conservative treatment. At the exploration of the brachial plexus, if the somatosensory evoked potential test is positive, which negates the possibility of root avulsion, and also if there is no definite discontinuity of the postganglionic nerves, it should be treated conservatively.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical experiences with Wilhelm's method of wrist joint denervation]

Wrist joint denervation for treatment of painful arthrosis was carried out in 36 patients in the last five years. 33 Patients could be followed up. Besides subjective reports on pain and maximum stress, strength, mobility and the X-ray of the wrist-joint were also considered in the evaluation of the results. As a whole, a success rate of 84% could be attained. We have not observed disorders of sensitivity or trophic alterations. An increase of symptoms after the second postoperative year was noteworthy.

Characteristics of spinal dorsal horn neurons after partial chronic deafferentation by dorsal root transection

Unilateral transections of 1-3 lumbar dorsal roots were performed in 13 adult cats to investigate the effect of partial deafferentation on dorsal horn neurons. Eleven to 45 days after deafferentation various parameters of spontaneous and evoked activity of 169 neurons were measured and compared to the data of 168 neurons from previous experiments recorded under identical experimental conditions except that these animals had not been deafferented. Eighty-six of the units encountered were located in the segment of transected dorsal root(s) and 82 in the caudally adjacent segment. No significant differences could be observed in the functional properties of these two samples of units. Most parameters measured indicate that either no change at all in responsiveness or signs of decreased excitability occurred in the partially deafferented neurons compared to units recorded in control animals. Discharges evoked by noxious skin heating indicate a linear relationship between discharge frequency and skin temperature. This kind of encoding curve could also be measured during a reversible cold block of the spinal cord at segment L1. The mean encoding curves before and during spinal blockade were not different in deafferented compared to corresponding curves measured in control animals. The only finding that could be interpreted as an indication for increased excitability of partially deafferented neurons was that the mean frequency of spontaneous discharges of a subsample of heat-sensitive neurons was higher in deafferented compared to control animals. Possible mechanisms are discussed.

Interfascicular nerve repair

The technique of nerve repair that results in the greatest percentage of regeneration of axons into their original end organs will result in the greatest functional return and the best result. Of prime importance is the motor-to-motor and sensory-to-sensory axonal orientation. Anatomic and physiologic data, as well as technical expertise, must be utilized for precise nerve approximation. To this end, fascicular repair under high-power magnification is an attempt to achieve the best alignment and coaptation of the neural elements.

Neurorrhaphy of the recurrent laryngeal nerve

The authors have experimentally performed neurorrhaphy and its modifications and nerve grafting with end-to-end anastomosis of the recurrent laryngeal nerve in dogs. Recovery of a neurorrhaphy of the recurrent laryngeal nerve resulted in the bizarre and spasmodic movement of the vocal cords. These effects were recorded by means of electromyography and 16 mm cinematography to demonstrate restoration of nerve muscle function and vocal cord movements. From these results, it was concluded that these single modes were not adequate for restoration of laryngeal function, however, some specific attention is given to a few trophic changes of the affected muscles after a period of ten months postoperative.

Corticotrophin release induced by surgical trauma after transection of various afferent nervous pathways to the hypothalamus

Corticotrophin (ACTH) release induced by surgical trauma under pentobarbitone anaesthesia was studied in rats. The plasma corticosterone level was used as an index of 'rapid' ACTH release.

One hour after surgical trauma the plasma corticosterone level had risen in rats with various cuts around the medial basal hypothalamus except in the group with lateral cuts. After stress no significant difference was found between the plasma levels of the controls and those of the rats with anterior, 'low' superior, 'low' anterosuperior, and 'short' posterior cuts. In contrast, in rats with 'high' superior, 'high' anterosuperior, 'long' posterior and lateral cuts the plasma corticosterone level was lower than in the appropriate sham-operated controls.

It is suggested that the nerve fibres initiating ACTH release after surgical trauma ascend the spinal cord to the medulla and mid-brain whence the pathways pass forward in the region of the dorsal longitudinal fasciculus and/or the median forebrain bundle to the lateral hypothalamic area, and from there to the medial basal hypothalamus.

Neurally mediated and direct effects of acetylstrophanthidin on canine skeletal muscle vascular resistance

The effects of acetylstrophanthidin on the vascular resistance of the isolated canine gracilis muscle were examined in 38 anesthetized mongrel dogs. The neurally mediated effect of intravenous acetylstrophanthidin (0.5 mg) on the vascular resistance of the innervated, separately perfused (constant flow) right gracilis muscle was a transient mean fall of 4.0 ± 0.9 resistance units (RU) ( P < 0.001) at 1 minute followed by a sustained rise to 4 RU ( P < 0.05) above control from 8 to 18 minutes after injection. The sustained increase in resistance was blocked by intra-arterial phenoxybenzamine. The combined direct and neurally mediated effects of intravenous acetylstrophanthidin were directionally similar and greater in magnitude in the innervated, autoperfused (intact circulation) left gracilis. Following denervation of the muscle, however, the initial decrease in vascular resistance was abolished and the prolonged subsequent rise was greatly reduced. Hence the initial fall and most of the subsequent rise in vascular resistance are neurally mediated. There was no consistent change in aortic pressure to explain either of these changes in vascular resistance solely on a reflex basis. Thus, systemically administered acetylstrophanthidin produces skeletal muscle vasoconstriction through both a direct and a neurally mediated effect. The latter is mediated through alphareceptor stimulation and appears to be the predominant mechanism whereby this drug increases muscle vascular resistance.