Minimizing shoulder syndrome with intra-operative spinal accessory nerve monitoring for neck dissection.
(28/43)
The objective of this study was to analyze the safety and results of intra-operative SAN (spinal accessary nerve) monitoring during selective neck dissection, with emphasis on shoulder syndrome. Twenty-five consecutive patients with head and neck cancer were studied. Selective neck dissection was performed by a single clinical fellow under the supervision of the department chief using an intra-operative SAN monitor. Electrophysiological data were recorded after initial identification of the SAN and continued until just before closure. Electromyographic evaluation was carried out to assess SAN function one month postoperatively. Shoulder disability was also evaluated at this time using a questionnaire for shoulder syndrome (shrug, flexion, abduction, winging, and pain). No patients had postoperative shoulder syndrome involving shrug, flexion, abduction, or winging. Twenty-two of the 25 (88%) patients had shoulder pain, but the average pain score was low (2.3 +/- 1.3). No patients had neck recurrence during at least 1 year of follow up. By using nerve monitoring during selective neck dissection, no patient developed significant "shoulder syndrome", with the exception of slight pain. (+info)
The spinal accessory nerve plexus, the trapezius muscle, and shoulder stabilization after radical neck cancer surgery.
(29/43)
A clinical and anatomic study of the spinal accessory, the eleventh cranial nerve, and trapezius muscle function of patients who had radical neck cancer surgery was conducted. This study was done not only to document the indispensibility of the trapezius muscle to shoulder-girdle stability, but also to clarify the role of the eleventh cranial nerve in the variable motor and sensory changes occurring after the loss of this muscle. Seventeen male patients, 49-69 years of age, (average of 60 years of age) undergoing a total of 23 radical neck dissections were examined for upper extremity function, particularly in regard to the trapezius muscle, and for subjective signs of pain. The eleventh nerve, usually regarded as the sole motor innervation to the trapezius, was cut in 17 instances because of tumor involvement. Dissection of four fresh and 30 preserved adult cadavers helped to reconcile the motor and sensory differences in patients who had undergone loss of the eleventh nerve. The dissections and clinical observations corroborate that the trapezius is a key part of a "muscle continuum" that stabilizes the shoulder. Variations in origins and insertions of the trapezius may influence its function in different individuals. As regards the spinal accessory nerve, it is concluded that varying motor and sensory connections form a plexus with the eleventh nerve, accounting, in part, for the variations in motor innervation and function of the trapezius, as well as for a variable spectrum of sensory changes when the eleventh nerve is cut. For this reason, it is suggested that the term "spinal accessory nerve plexus" be used to refer to the eleventh nerve when it is considered in the context of radical neck cancer surgery. (+info)
Localisation of the spinal nucleus of the accessory nerve in the rabbit.
(30/43)
The spinal nucleus of the accessory nerve (SNA) was localised in eight adult rabbits by a retrograde degeneration technique using thionine as a stain for the Nissl substance. The SNA was found to extend from the caudal one fifth of the medulla oblongata to the cranial one fourth of the sixth cervical segment. In the caudal part of the medulla oblongata, the SNA was located in the dorsal part of the detached ventral grey column. In the first cervical segment, the SNA was dorsolateral to the dorsomedial column and dorsal to the ventromedial column of the ventral grey column. In the cranial part of the second cervical segment, the SNA shifted laterally to the lateral margin of the ventral grey column. After this lateral shift, the SNA was located in the lateral part of the ventral grey column of the second, third and fourth cervical segments. In the fifth and cranial one fourth of the sixth cervical segments, the SNA was not a well defined column of cells but was represented by isolated cells scattered in the ventral part of the ventral grey column between the phrenic nucleus and the ventral border of the grey matter. The total number of chromatolysed cells found in the SNA of the right experimental side varied from 2723 to 3210. (+info)
Observations on the innervation of the sternomastoid muscle.
(31/43)
Nine out of fifteen cases having division of the spinal component of the accessory nerve and the upper cervical motor roots as treatment for spasmodic torticollis had residual movements in the sternomastoid of sufficient magnitude to make further surgery necessary before the muscle was effectively paralysed. These observations imply a more complex innervation for the muscle than is to be found in most anatomical texts. (+info)
Some metabolic responses of axotomized neurones to contact between their axons and denervated muscle.
(32/43)
1. The nucleolar and cell body dry mass and nucleic acid content of hypoglossal neurones were measured in adult rats using interference microscopy and ultra-violet absorption microspectrography.2. The left hypoglossal nerve was transplanted into the ipsilateral sternomastoid. Seventy days later the sternomastoid was denervated by dividing the ipsilateral spinal accessory nerve. This was followed by metabolic changes in hypoglossal nerve cells.3. The changes induced in hypoglossal neurones by division of the ipsilateral accessory nerve did not occur if botulinum toxin was injected locally at the same time.4. In other rats the left hypoglossal nerve was anastomosed to the proximal stump of the ipsilateral median nerve simultaneously divided at the level of the wrist. Seventy days later this median nerve was divided in the axilla. This was followed by metabolic changes in hypoglossal nerve cells.5. These results are discussed in relation to the possible roles of reacting Schwann cells, degenerating axoplasm and denervated muscle in maintaining aspects of the metabolic response of nerve cells to injury.6. It is suggested that the synthesis of acetylcholine by an axonal ending, or its release, is dependent upon the presence of an adjacent membrane which can respond to it, and that the metabolic changes measured in the nerve cell body are secondary to this response of the axon terminal. (+info)