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Biomedical subjects

R L Saunders

Publications and source records attributed to R L Saunders.

At least 19 recordsLinked to original sources
PubMed1992

Continuous infusion of intrathecal morphine to control acquired immunodeficiency syndrome-associated bladder pain.

A 36-year-old man with acquired immunodeficiency syndrome had incapacitating dysuria and vesical pain secondary to interstitial cystitis. When medical management and suprapubic urinary diversion failed to control the symptoms the patient was started on subarachnoid morphine sulfate. Bupivacaine was added 1 year later via an implanted Therex M-3000 implantable continuous infusion pump, which has continued successfully for more than 18 months. We believe that subarachnoid narcotics and other analgesic agents, such as clonidine, bupivacaine hydrochloride and baclofen, may prove equally valuable in the treatment of bladder spasm and pain. Furthermore, implanted intrathecal ports and pumps may have less associated risk of infection than the percutaneous vascular access catheters presently used for the continuous delivery of medications in immunosuppressed patients.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Geniculate ganglion: anatomic study with surgical implications.

The geniculate ganglion and adjacent segments of the facial nerve were dissected in 11 human temporal bones to study the extent and distribution of ganglion cells. A histologic basis for the use of geniculate ganglionectomy as the treatment for geniculate neuralgia was sought. In 9 of 11 specimens (81.8%), the ganglion cell bodies appeared to be aggregated at the apex of the genu close to the origin of the greater superficial petrosal nerve. The mean ratio of the width of the ganglion cell cluster to the width of the facial nerve trunk at the level of the genu was 0.4. In two specimens, significant anatomic variation was present. One specimen showed extension of cell bodies into the labyrinthine segment of the facial nerve; another specimen showed a single ganglion cell in the region of the genu. These findings lead us to postulate that geniculate ganglionectomy may be ineffective as the sole treatment for certain cases of geniculate neuralgia, and that nervus intermedius section may also be required to achieve a more complete deafferentation.

Facial Nerve↗
PubMed1991

Neurosurgical complications after intranasal ethmoidectomy.

Intranasal ethmoidectomy is a common otolaryngological procedure. Despite the potential for serious intracranial complications, there is a paucity of reports describing the neurosurgical complications of the procedure. Two patients with intracranial complications of intranasal ethmoidectomy, and the relevant medical literature, are reviewed. The anatomy of the ethmoid air cells and their relation to the intracranial cavity are described. The importance of definitive, emergent repair with attention to the potential for vascular injury is discussed.

Aged↗
PubMed1991

Repair of a cerebrospinal fluid perilymph fistula primarily through the middle ear and secondarily by occluding the cochlear aqueduct.

A 35-year-old man had a 5-year history of fluctuating hearing loss in his only hearing ear. History and diagnostic tests indicated a perilymph fistula, a diagnosis subsequently confirmed by exploration. Primary and secondary repairs temporarily ameliorated symptoms. A spinal fluid to middle ear fluid pathway was identified by radioactive tracer. A patent cochlear aqueduct indicated on computed tomography scan was found and repaired through a posterior cranial fossa approach. Hearing was preserved, remaining relatively stable during the 2-year follow-up period.

Adult↗
PubMed1991

Central corpectomy for cervical spondylotic myelopathy: a consecutive series with long-term follow-up evaluation.

Since 1984, a consecutive series of patients with cervical spondylotic myelopathy has been treated by central corpectomy and strut grafting. This report focuses on 40 cases operated on between 1984 and 1987 and followed from 2 to 5 years. The perioperative complication rate was 47.5%, with a 7.5% incidence of persistent sequelae: severe C-5 radiculopathy in one patient, swallowing dysfunction in one, and hypoglossal nerve palsy in one. No single factor (age, duration of symptoms, or severity of myelopathy) was absolutely predictive of outcome; however, syndromes of short duration had the best likelihood of cure. Similar outcomes were associated, individually, with long duration of symptoms, age over 70 years, and severe myelopathy. After factoring a 5% regression of improvement, the long-term cure rate was 57.5% and the failure rate was 15%. Myelopathy worsening was not documented.

Cervical Vertebrae↗
PubMed1991

Geniculate neuralgia: the surgical management of primary otalgia.

Intractable, unexplained deep-ear pain presents a rare, albeit significant problem in otolaryngological and neurosurgical practice. The authors review their experience with 18 cases of primary otalgia during the past 15 years. A total of 31 surgical procedures were performed. Seventeen patients had sequential rhizotomies and one patient had microvascular decompression alone. Based on the clinical diagnosis, the nerves sectioned were singly or in combination: the nervus intermedius (14 patients), geniculate ganglion (10 patients), ninth nerve (14 patients), 10th nerve (11 patients), tympanic nerve (four patients), and chorda tympani nerve (one patient). Microvascular decompression of the involved nerves was undertaken in nine patients, in whom vascular loops were discovered. Adhesions (six patients), thickened arachnoid (three patients), and benign osteoma (one patient) were other intraoperative abnormalities noted. The overall success of these procedures in providing pain relief was 72.2%, and the mean follow-up period was 3.3 years (range 1 month to 14.5 years). There was no surgical mortality. Expected side effects were: decreased lacrimation, salivation, and taste related to nervus intermedius nerve section, and transient hoarseness and diminished gag related to ninth and 10th nerve section. Four patients developed sequelae consisting of sensorineural hearing loss, vertigo, and transient facial nerve paresis. One patient had a cerebrospinal fluid leak and another developed aseptic meningitis as postoperative complications. Except when primary glossopharyngeal neuralgia is the working diagnosis, a combined posterior cranial fossa-middle cranial fossa approach is recommended for adequate exploration and/or section of the fifth, ninth, and 10th cranial nerves as well as the geniculate ganglion and nervus intermedius.

Adult↗
PubMed1990

Influence of ration level and salinity on circulating thyroid hormones in juvenile Atlantic salmon (Salmo salar).

Following acute exposure to seawater (30 ppt), plasma thyroxine (T4) of Atlantic salmon (Salmo salar) smolts increased 80% in the first 6 hr, declined to initial levels after 24 hr, and remained stable for 18 days thereafter. In nonsmolts, plasma T4 did not rise immediately after exposure to seawater, fell slightly after 2 days, and remained low for 18 days. Plasma triiodothyronine (T3) of smolts and nonsmolts was not affected by acute exposure to seawater. To examine the effect of long-term adaptation to ration and salinity, Atlantic salmon smolts were acclimated to three salinities (0, 10, and 30 ppt) and four ration levels (0, 0.2, 0.8, and 1.6% wet weight per day) for 6 weeks. Plasma T4 increased with increasing ration level (P less than 0.001) but was not significantly affected by salinity (P = 0.4). Plasma T3 also increased with increasing ration (P less than 0.001) and was more strongly correlated with ration level (r = 0.85) and growth rate (r = 0.88) than was plasma T4 (r = 0.73 and 0.75, respectively). At low ration (0 and 0.2% per day), fish in 10 ppt had slightly but significantly lower plasma T3 than fish in 0 ppt. There was no effect of salinity on plasma T3 at the higher rations, nor did plasma T3 levels differ significantly in fish in 0 and 30 ppt at any ration. The results indicate that ration level is a more important influence on circulating levels of plasma thyroid hormones than is salinity.

Animals↗
PubMed1988

Magnetic resonance imaging in the diagnosis and treatment of Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum).

Lhermitte-Duclos disease is a rare disorder characterized by a slowly enlarging mass lesion in the cerebellum. The pathophysiology of the disease is poorly understood, but recent reports have suggested that a clinically significant mass may recur many years after total gross removal of the tumor. Computed tomography and angiography have been relatively insensitive in imaging the tumor either at presentation or during the postoperative period. The authors present three patients with histologically proven Lhermitte-Duclos disease who have undergone magnetic resonance imaging (MRI). In the first case, preoperative T1- and T2-weighted images clearly demonstrated the location and extent of the lesion, which was verified at operation. In the other two cases, only postoperative images were obtained. These demonstrated the extent of residual tumor and indicate a high probability of lesion expansion during periods of 4 and 10 years, respectively. We conclude that MRI is an important tool in both the diagnosis and the treatment of patients with Lhermitte-Duclos disease.

Adult↗
PubMed1988

Use of implantable pumps for central nervous system drug infusions to treat neurological disease.

Increasing knowledge of the neurochemical aspects of central nervous system function raises the possibility of treating neurological disease by the appropriate manipulation of neurotransmitters, neuromodulators, and neurohormones. Clinical application of this knowledge has been inhibited, however, by long-standing problems with drug delivery to the central nervous system (CNS). The availability of implantable drug infusion pumps and stereotactic catheter placement techniques may overcome many of these problems. The problems of drug delivery to the brain and the present and potential uses of implantable drug pumps for neurological disease are discussed. In addition, the relationship between CNS drug infusion and neural tissue transplantation is briefly reviewed.

Brain Neoplasms↗
PubMed1987

External ventricular drainage for initial treatment of neonatal posthemorrhagic hydrocephalus: surgical and neurodevelopmental outcome.

Thirty-seven infants were treated for posthemorrhagic hydrocephalus (PHH) with external ventricular drainage (EVD) in 1977-1985. The mean age at EVD placement was 13 days; the mean duration of drainage was 21 days, and an average of 1.8 drains was used per patient. Complications were apnea (10%), hemorrhage (8%) and ventriculitis (6%). Ten infants died from pulmonary disease unrelated to the surgery. Thirty-two percent of the survivors did not require a permanent shunt. Neurodevelopmental outcome was evaluated at a mean age of 38 months. Eighteen of the twenty-seven survivors (67%) had normal cognitive function, 3 had borderline and 6 (22%) had moderate to profound mental retardation. Nine of the children (33%) had a normal neuromuscular exam. One child had mild, 11 had moderate and 6 had severe cerebral palsy. Four children had serious visual impairment. The worst outcomes were in the children with parenchymal or large intraventricular hemorrhages.

Cerebral Hemorrhage↗
PubMed1986

The effect of temperature on the vitellogenic response in Atlantic salmon post-smolts (Salmo salar).

Effects of low (3 degrees) and high (10 degrees) temperatures on the vitellogenic response to estradiol treatment were analyzed in female and male salmon post-smolts. Vitellogenic response as indicated by levels of circulating vitellogenin, hepatic protein, RNA, and nuclear count depends on the ambient temperature during hormone treatment but not on the previous 1 month acclimation temperature. Thus, the level of vitellogenin in the serum or hepatic RNA did not increase above the levels of the untreated controls in previously warm-acclimated smolts if the fish were exposed to low temperature water during treatment with estradiol. Conversely, cold-acclimated smolts showed increased levels of hepatic RNA and circulating vitellogenin only when transferred to 10 degrees water during treatment. No such response could be elicited if salmon were kept at 3 degrees during estradiol treatment. The negative influence of low ambient temperature on the vitellogenic response could not be eliminated by using higher doses of estradiol. Salmon post-smolts, long-term acclimated to 3 degrees revealed a significant vitellogenic response to estradiol only if the temperature during treatment was increased to 10 degrees. Estradiol treatment at 10 degrees stimulated the growth of liver as determined by the increase in liver somatic index and amounts of total hepatic protein, RNA, and nuclear count. On a per unit liver wet weight basis, however, only RNA increased above the level of the untreated control fish. As the nuclear count per gram of liver is similar in estradiol-treated and untreated groups, estradiol-induced liver growth in the salmon post-smolts may be accounted for by an increase in cell number (hyperplasia) rather than an increase in cell size (hypertrophy).

Animals↗
PubMed1986

Table-fixed retractor system for noncranial surgery. Technical note.

A retractor system based on the principle of table fixation of the retraction device has been fabricated and utilized in a broad range of noncranial procedures. Based on the refinement of self-retaining brain retractor methods, this device allows an atraumatic fixed exposure without the danger of "self-retained devices" impaling soft tissue and the compromises of hand-held retractors.

Neurosurgery↗
PubMed1986

Continuous intrathecal hydromorphone and clonidine for intractable cancer pain.

The use of hydromorphone and clonidine, delivered intrathecally by an implanted infusion pump, is described in a patient with intractable cancer pain. The patient was a 48-year-old woman with uterine cervical cancer-related pain that was poorly responsive to conventional oral narcotics. Hydromorphone was used because of the patient's history of morphine intolerance. When progressive intrathecal hydromorphone dosages were required, intrathecal clonidine (an alpha 2 adrenergic agonist) was infused concomitantly. Intrathecal hydromorphone and clonidine successfully controlled this patient's pain without the necessity to resort to destructive neurosurgery.

Carcinoma↗
PubMed1985

A cranial nail for fetal shunting.

A small number of human fetal hydrocephalics have been treated by ventriculoamniotic shunts of silastic tubing. The Colorado device appears to be the one most commonly used. The original experimental device tested on a primate model resembled a hollow shingle nail. This was designed by Michedja and Hodgen, contained a spring valve, measured approximately 32 X 4 mm and was placed by hysterotomy. An attractive feature of this design was its fixation by impaction in the skull, preventing displacement by fetal activity, a reported disadvantage with the silastic devices. To our knowledge, no one has used this nail-like design and tailored it to transuterine percutaneous placement in a human case.

Adult↗
PubMed1985

Tympanic membrane sensation.

Sensation from the tympanic membrane is generally believed to be mediated via at least four cranial nerves, some authors describing discrete territories for each of these nerves. The lack of critical evidence for independent sensory areas prompted a clinical study of tympanic membrane sensation in 32 patients having known cranial nerve deficits. Tympanic membrane sensation was tested in four quadrants using a 300 mg bristle under a Zeiss operating microscope. The findings were highly suggestive of a predominantly nociceptive system. Any change relative to the opposite tympanum was usually anaesthesia. No complete trigeminal deficit retained perception in all tympanic quadrants. Facial, glossopharyngeal and vagal deficits alone never affected tympanic sensation. These findings support the trigeminal nerve as the principal sensory nerve to the tympanic membrane, supplemented only inconstantly and incompletely by the other cranial nerves.

Adolescent↗