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Biomedical subjects

J M Fredrickson

Publications and source records attributed to J M Fredrickson.

At least 37 records · Page 2Linked to original sources
PubMed1991

The latissimus dorsi donor site. Current use in head and neck reconstruction.

Reconstruction of head and neck defects after trauma, tumor extirpation, or disease has improved with the modern development of multiple donor sites. However, the selection of a particular pedicled or free flap should balance the required sophistication of repair with donor site morbidity. The latissimus dorsi donor site is capable of providing a versatile group of tissues; ie, muscle, skin, subcutaneous tissue, bone, nerve, and vascular pedicle. We present a series of 30 latissimus dorsi flaps (20 pedicled and 10 free) used for craniotemporal, craniofacial, midfacial, oral, oropharyngeal, mandibular, and neck skin reconstructions. The flap survival rate was 90%, a result similar to other large series. The indications for using the latissimus dorsi as opposed to other donor sites were large skin defects, cephalad defects, total glossectomy defects, defects requiring free tissue transfer, and defects where other regional donor tissue was unavailable. We also present a novel flap design for total glossectomy reconstruction.

Adolescent↗
PubMed1990

Cervical metastases from unknown primaries: radiotherapeutic management and appearance of subsequent primaries.

Between 1964 and 1986, 72 patients who presented with squamous or undifferentiated metastatic carcinoma to neck nodes, where the primary tumor could not be found by standard clinical procedures, were treated at the Mallinckrodt Institute of Radiology. These cases were managed in the following manner: biopsy and radiotherapy in 46 out of 72 patients, radiotherapy (RT) and a planned neck dissection in 14 out of 72, and neck dissection after failure to achieve a complete response (CR) with RT in 12 out of 72. Minimum follow-up was 2 years. The initial CR rates for stages N1, N2a, N2b, N3a, and N3b were 83%, 93%, 61%, 50%, and 33%, respectively. The long-term neck tumor control for the same stages was 83%, 71%, 67%, 44%, and 50%, respectively. One patient had soft tissue necrosis and two had carotid artery ruptures, one of which left no symptomatic sequelae. Twenty-one out of 72 patients developed subsequent primary tumor. Only one of these patients survived. This incidence was not affected significantly by prophylactic treatment of the mucosal areas except in patients with bilateral neck nodes, undifferentiated or poorly differentiated histologies, and/or posterior cervical node involvement. A multivariate analysis showed that prognosticators of an improved disease-free survival were: a complete clearance of tumor by the end of radiotherapy (p less than 0.0009) and no appearance of a subsequent primary tumor (p = 0.035). The only factor that correlated with an increased loco-regional control was having a complete response by the end of radiotherapy (p less than 0.00009). The recommended management and possible ways of preventing the appearance of subsequent primaries will be discussed.

Adult↗
PubMed1988

Comparison of benefit from vibrotactile aid and cochlear implant for postlinguistically deaf adults.

Four postlinguistically deaf adults were evaluated presurgically with a one- or two-channel vibrotactile aid and postsurgically with a multichannel, multielectrode, intracochlear implant. Although the vibrotactile aid provided awareness of sound and enhanced flow of conversation, benefit to lipreading was small on videotaped tests and speech tracking. Scores on recorded, sound-only speech tests were not significantly above chance except in discrimination of noise from voice. With the cochlear implant, benefit to lipreading was significantly greater than with the vibrotactile aid, and scores on sound-only tests were significantly above chance. Communication was markedly better with the implant than with the vibrotactile aid. In counseling those who get no benefit from a hearing aid, the results of this study provide data on the amount of benefit one- or two-channel vibrotactile aids provide postlinguistically deaf adults who are subsequently implanted.

Adult↗
PubMed1984

Ventilation during laryngoscopy in chronic obstructive lung disease.

Many patients requiring direct examination of the upper airway and gastrointestinal tract under general anesthesia have chronic obstructive lung disease, yet virtually no work has been done to assess the adequacy of their ventilation during laryngoscopy and in the early postoperative period. This study demonstrates that, using the Carden tube, their blood gases are well maintained even when areas outside the endolarynx, such as the upper esophagus, are examined. The Carden tube is shown to be easy to insert and remove as well as permitting a superior view of the larynx. Also, this study pinpoints the period of maximum danger of respiratory failure as occurring postoperatively in the recovery room. This should be independent of the method of ventilation employed at surgery and indicates the need for cocainization of the vocal cords before extubation, as well as careful, early postoperative monitoring. The problems of ventilation during direct examination of the upper airway and gastrointestinal tract are discussed and alternative methods evaluated.

Adult↗
PubMed1983

The irradiated larynx and voice: a perceptual study.

The voices of patients with laryngeal cancer following a specific radiotherapy regimen were subjected to perceptual evaluation. Interval scaling of the severity of perceived dysphonia was completed for the voices of male patients sampled before and 1 year following radiation therapy and for a set of male controls. Eight listeners did this quantitative rating and also specified the predominant quality in each voice. The results indicated that the degree of dysphonia in the pretreatment group was highest. Radiotherapy decreased this dysphonia but not to the point that posttreatment voices were indistinguishable from those of normal subjects. Also, the voice qualities of laryngeal cancer patients shifted toward those of the control group following radiotherapy with over one half of the irradiated patients judged to have rough or normal qualities.

Adult↗
PubMed1981

Efferent vestibular neurons: a study employing retrograde tracer methods in the pigeon (Columba livia).

Efferent neurons innervating the vestibular labyrinth and cochlea of the pigeon have been identified by means of a variety of retrograde tracers: [3H]-adenosine (Ad), horseradish peroxidase (HRP), Evan's Blue (EB) and Bisbenzimide (Bb). Discrete injections into individual cristae ampullares of the semicircular canals, into the macula utriculi, or into several of these end organs resulted in similar patterns of neuronal labelling. Efferent vestibular neurons were always found within a small portion of the nucleus reticularis pontis caudalis (RP), ventrolateral to the abducens nucleus on both sides. No systemic difference in the locations of labelled cells was found following injection into different sensory epithelia. Cell counts following injections into individual cristae did not differ significantly from those following injections into all three cristae. The injections into all cristae in both labyrinths yielded cell counts that were much lower than twice the number of cells labelled by injections into the three cristae on one side only. When HRP was injected into the right lateral canal crista and Ad into the right posterior canal crista, a high proportion of neurons was labelled with both compounds (61% of the HRP-labelled cells and 67% of the Ad-labelled cells). Injections of EB into all three cristae on the right side and Bb into all three cristae on the left side produced a smaller percentage of doubly labelled cells (10% of the EB-labelled cells and 6% of the Bb-labelled cells). It is concluded, therefore, that there is a considerable degree of collateralization within one labyrinth. Fewer collaterals of efferent neurons are directed to both labyrinths. Since each semicircular canal represents head rotation in one direction and one plane, it is unlikely that efferents which contact several different movement sensors can provide sensory motor control that is specific for directions and planes of head movements. Control injections of these tracers into the cochlea yielded labelled cells in a different reticular structure, the nucleus reticularis paragigantocellularis lateralis (Pgc), on both sides, as well as in the RP. It is proposed that the Pgc cells represent cochlear efferents, while the RP neurons are related to the macula lagenae, an otolithic organ of balance in the pigeon.

Animals↗
PubMed1981

Gastric pull-up vs deltopectoral flap for reconstruction of the cervical esophagus.

Reconstruction of the cervical esophagus and pharynx after a total laryngopharyngectomy for patients with advanced hypopharyngeal cancer still remains a problem for surgeons. The results of two procedures, the tubed deltopectoral flap reconstruction and the gastric pull-up operation with pharyngogastric anastomosis, which are used in fulfilling postoperative deglutition requirements, were compared. There were nine patients in the gastric pull-up group and eight patients in the deltopectoral flap group. The groups were reasonably comparable with regard to age, sex, preoperative radiotherapy, and stage of tumor. Three of the patients in the gastric pull-up group were operated on for palliation alone. Average operation-to-swallow time was 12 days for the gastric pull-up groups and 90 days for the deltopectoral flap group. Reconstruction of the gullet with the stomach pull-up operations seems to be superior to the tubed deltopectoral flap. This is especially true if the operation is palliative because the patient is unlikely to survive more than one year after surgery.

Adult↗
PubMed1981

Occult intralabyrinthine schwannoma.

Report of a case of an intralabynrinthine schwannoma discovered unexpectedly during a labyrinthectomy for intractable vertigo, and description of the light and electron microscopic appearances. Although only 18 of these tumors have been previously reported, it is possible that some cases which are categorized as peripheral vertigo of unknown origin, may be due to an occult Schwannoma. All material removed during surgical procedures on the inner ear should therefore be submitted for histopathological examination.

Female↗
PubMed1980

Microvascular surgery.

In situations where existing techniques of reconstruction are inadequate or involve multiple stages, free-flap transfer offers major advantages for the head and neck surgeon. Wider application of free-flap surgery has been inhibited by problems of flap design and graft take. Thrombosis at the microanastomic site, particularly at the venous site, is still a cause of failure. Techniques of anastomosis are of paramount importance. Nakayama ring pin anastomosis is easier to learn, less time-consuming, and shows less early thrombosis that suture techniques. Use of adjunctive pharmacologic agents, such as the tetrahydroimidazo quinazolines, will increase the likelihood of success.

Humans↗
PubMed1978

Vestibulothalamic projections in man--a sixth primary sensory pathway.

1. Responses suggesting activation of the vestibular system, elicited by electrical stimulation of the human thalamus during 22 routine stereotaxic neurosurgical procedures, were examined in a retrospective study to determine the possible existence of vestibulothalamo-cortical projections in man. 2. Such responses were most frequently described as sensations of movement through space and were associated with two distinct vestibulothalamic projections: a) an anterior relay was situated ventral to the medial lemniscus, passing lateral to the red nucleus and dorsal to the subthalamic nucleus prior to terminating in the nucleus ventrointermedius (Vim) (comparable to VPLo in primates); b) a posterior relay associated with the auditory pathway (lateral lemniscus and brachium of the inferior colliculus) projected to the medial geniculate body. 3. The production of sensations of motion in conscious patients by stimulating areas that are similar to those reported constituting vestibulothalamic pathways in cats and primates implies a distinct primary sensory cortical projection for processing information from the vestibular receptors pertaining to the recognition of spatial movements.

Brain Mapping↗
PubMed1978

Vertigo after head injury--a five year follow-up.

Three hundred and twenty-one head injury patients investigated at the Workmen's Compensation Board Hospital and Rehabilitation Centre were studied. The patients were classified into two groups, minor and moderate according to the duration of post-traumatic amnesia. Post-traumatic vertigo was a significant symptom in 34 per cent and 50 per cent of the minor and moderate groups respectively. Based on the findings of full otoneurologic and vestibular examination, objective vestibular disorder was noted in 40 per cent and 65 per cent of the two vertiginous groups respectively. An approach to the interpretation of vestibular and oculomotor abnormalities is outlined in order to assign a peripheral (end organ or nerve), central (brainstem or cerebellar) or undertermined localization. Hearing loss occurred in 20 per cent of the minor and 72 per cent of th e moderate head injury patients tested. A five-year post head injury follow-up was available with respect to recovery of vertigo and work rehabilitation. The results of this follow-up are discussed.

Adolescent↗
PubMed1977

Vestibular responses in the rhesus monkey ventroposterior thalamus. II. Vestibulo-proprioceptive convergence at thalamic neurons.

The vestibular thalamic relay in the Rhesus ventrobasal complex, identified in a previous field potential study (part I, Deecke et al., 1974), has now been investigated with neuronal recordings in the thalamus in order to clarify its functional role. In part I, short latency responses (2.5 msec) were found in the corner between VPL, VPM and VPI nuclei, largely including dorsal portions of the VPI nucleus. Field potentials of somewhat longer latency (4-5 msec) were recorded in VPL and in other thalamic nuclei, including the posterior nuclear group. Neuronal responses were recorded in thalamic nuclei of awake flaxedilized Rhesus monkeys. Cells not responding to vestibular stimulation (round window polarisation of either labyrinth) were ignored. The great majority (80%) of those neurons responding to labyrinth polarisation showed convergence with deep somatic (proprioceptive) input from joints and muscles of vertebral column and limbs. 60% of these bimodal neurons responded to movement of cervical joints. Very few vestibularly responsive cells received cutaneous (6.6%), non-optokinetic visual or auditory (2.6% each) input. Proprioceptive fields tended to be large, frequently involving more than one joint, and could be even bilateral. For a few cells the pattern of vestibulo-proprioceptive convergence could be fitted to a coordinated body position that might occur during normal locomotion. 78% of the cells responded to polarisation of both labyrinths, indicating strong bilateral projection.

Animals↗