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Biomedical subjects

G A Morrison

Publications and source records attributed to G A Morrison.

At least 19 recordsLinked to original sources
PubMed2006

Laryngeal cancer after topical mitomycin C application.

Mitomycin C is part of the mitomycin group of antibiotics and has found use in medicine in the treatment of various cancers, including those of the head and neck. In recent years, it has gained popularity as a topical treatment to prevent scar formation in the larynx and choanae in paediatric and adult inflammatory processes. Also, this alkylating agent is potentially a potent carcinogen. We report the first case in the world literature of laryngeal carcinoma in a non-smoking adult, which may have been induced by topical mitomycin C application to a glottic web. We discuss the mechanism of action of this drug, and we advise caution on its use for benign laryngeal pathologies.

Administration, Topical↗
PubMed2006

Botulism in a pregnant intravenous drug abuser.

A case of botulism is reported in a heroin-abusing parturient who initially presented with lethargy and slurred speech. The diagnostic difficulty, complications, intensive care and anaesthetic management of this case are discussed, with particular reference to the pregnancy and the effects of both botulism and its empirical treatment on the fetus. A short review is provided of a condition that has seen a marked increase in its incidence since 2000.

Adult↗
PubMed1998

Neonatal stridor in association with herpes simplex infection of the larynx.

Herpes simplex virus (HSV) infection in the neonatal period may be confined to the eyes, skin and upper aerodigestive tract or may be widely disseminated to other organs, with particular recognition of involvement of the central nervous system (CNS) causing herpes encephalitis (Whitley et al., 1980a, b; Andersen, 1987). Primary laryngeal HSV infection is extremely uncommon. We present a case of acute neonatal stridor secondary to such localized disease and discuss its management.

Acyclovir↗
PubMed1997

Acquired subglottic cysts in the low birth weight, pre-term infant.

Although subglottic cysts have previously been reported as a cause of airway obstruction in the neonate, they have previously been considered to be a relatively rare cause. Cystic narrowing of the subglottis has been associated with endotracheal intubation. With improving survival of pre-term infants the incidence of the condition could be expected to rise. Prior to 1996, only 58 cases had been reported in the literature. We believe that the true incidence of the condition has been considerably under-reported. Over a six-month period our unit diagnosed five cases of compressible cysts in the subglottis in low birth weight, pre-term infants. All patients underwent diagnostic microlaryngobronchoscopy and vaporization of the cysts by CO2 laser. Three children required more than one procedure. In all cases a satisfactory airway was achieved. The pathogenesis, diagnosis and treatment of the condition is discussed.

Cysts↗
PubMed1997

Recessive epidermolysis bullosa simplex associated with plectin mutations: infantile respiratory complications in two unrelated cases.

Plectin is a 500 kDa protein involved in cytoskeleton-plasma membrane attachment with a wide tissue distribution including cutaneous and airway epithelia, muscle and neuronal tissue. Recently, mutations in the gene encoding plectin (PLEC1) have been implicated in the pathogenesis of an autosomal recessive variant of epidermolysis bullosa simplex in which cutaneous blistering starting in the neonatal period is associated with muscular dystrophy in later life. In this study, we report two unrelated patients, both of consanguineous parentage, who presented with cutaneous blistering and a hoarse cry from birth. Both experienced inspiratory stridor and respiratory distress, necessitating emergency tracheostomy in one case. Immunoreactivity to monoclonal antibodies against plectin was absent or markedly reduced in skin biopsies from both patients. Electron microscopy revealed a low intraepidermal plane of cleavage and hypoplastic hemidesmosomes with a reduced association with keratin intermediate filaments. Direct sequencing of PLEC1 in each case demonstrated two novel homozygous frameshift deletion mutations, 5069del19 and 5905del2, which both create downstream premature termination codons. Although currently neither patient has symptoms of muscle disease, the identification of mutations in PLEC1 may be predictive for the future development of muscular dystrophy. Recessive epidermolysis bullosa simplex resulting from abnormalities in plectin should be considered in the differential diagnosis blistering, hoarseness and stridor in infancy.

Child, Preschool↗
PubMed1996

Unusual presentations of acoustic tumours.

A series of 238 consecutive patients with acoustic neuromas, operated on in Paris has been studied to identify unusual presentations and varied symptomatology. The most common history was that of a progressive unilateral hearing loss (in 68.1%), with tinnitus (in 49.1%) or disequilibrium (in 49.1%) or both. Sudden hearing loss (in 14.7%) or fluctuating hearing loss (in 6.3%), and a single or repeated episodes of acute vertigo (in 8.8%) were seen less commonly. Headaches occurred as an associated symptom in 10.5%, tinnitus was the sole symptom in 2.8% and other uncommon symptoms included otalgia, facial nerve palsy, facial or ocular pain, altered sensation in the face or eye, or tingling of the tongue. Some 11.3% of patients presented with normal pure tone auditory thresholds and a 100% speech discrimination score and of these patients acoustic reflex thresholds were normal in 53% and brainstem auditory evoked responses were suggestive of the retro-cochlear abnormality in only 76.2%. Amongst the less common presentations, the initial symptoms mimicked such diagnoses as Meniére's disease, benign positional vertigo, vertebro-basilar migraine, vertebro-basilar insufficiency, Bell's palsy and Trigeminal neuralgia. Overall, 20.6% of patients had unusual initial presenting symptoms, 36.5% of the symptoms were unusual and these were found in isolation in 11.8% of patients. An awareness of the spectrum of more subtle symptoms of acoustic tumours may lead to the correct diagnosis at an earlier stage.

Aged↗
PubMed1996

Effect of glycerol on electrochemical composition of endolymph and perilymph in the rat.

Glycerol (2 g/kg body weight), or 0.15 M NaCl for control animals, was administered to rats by i.v. injection. The dose was chosen in order to obtain an osmolarity increase in plasma of about 15 mosm/l 1 h after the glycerol administration, an increase which is similar to that observed in the human glycerol dehydration test. Endolymph and perilymph were sampled from the basal turn of the cochlea; cerebrospinal fluid (CSF) was sampled from cisterna magna. Plasma osmolarity, endocochlear potential, Na and K concentrations in endolymph, perilymph and CSF were determined 1 and 2 h after the glycerol injection. Compared with control animals, glycerol induced an increase in Na and K concentration in perilymph and endolymph, respectively, 1 and 2 h after the glycerol injection. No modification of the endocochlear potential was observed. These results are compatible with an increase in inner ear fluids osmolarity induced by glycerol.

Action Potentials↗
PubMed1994

Through-flow revascularization of the tongue using a radial forearm free flap.

Surgery for invasive squamous cell carcinoma involving the tongue base usually necessitates a total glossectomy because complete tumour resection requires sacrifice of both lingual arteries leaving a non-viable anterior tongue. A case is presented in which both lingual arteries were sacrificed to achieve complete tumour excision and the remaining anterior two-thirds of the tongue were successfully revascularized by through-flow from a radial forearm free flap which was used for pharyngeal reconstruction. This technique offers hope of preservation of the tongue when radical surgery would otherwise lead to its removal.

Aged↗
PubMed1994

Preservation of facial, cochlear, and other nerve functions in acoustic neuroma treatment.

Between March 1966 and September 1992, 1400 acoustic neuromas were treated in Paris, France, by surgical excision. The findings over the last 7 years are presented. The translabyrinthine approach has been used in more than 85% of cases. Where hearing preservation is attempted, the middle fossa approach has been adapted for intracanilicular tumors and the retrosigmoid approach for small tumors extending into the cerebellopontine angle, in which the fundus of the internal meatus is free of tumor. The main goal is to achieve a grade I or II result in facial function within 1 month of surgery. Results improved during 1991 after the introduction of continuous facial nerve monitoring and the use of the Beaver mini-blade for dissection of tumor from nerve. With these techniques, facial function of grade I or II at 1 month improved from 20% to 52% for large tumors (larger than 3 cm), from 42% to 81% for medium tumors (2 to 3 cm). and from 70% to 92% for small tumors (up to and including 2 cm extracanalicular). The facial nerve was at greater risk using the retrosigmoid or middle fossa approaches than by the translabyrinthine route. Since 1985, success in hearing preservation has changed little, with useful hearing being preserved in 38.2% of cases operated on by means of the retrosigmoid route and a 36.4% of cases after the middle fossa approach. In older patients with good hearing and small tumors, observation with periodic MRI scanning is recommended. Despite earlier diagnosis, the number of patients suitable for hearing preservation surgery remains very limited and careful selection is required. Trigeminal nerve signs were present in 20% of cases preoperatively, in 10% postoperatively, and recovered spontaneously. Palsies of the other cranial nerves after surgery were much rarer and were as follows: sixth nerve (abducens), 0.5%; ninth nerve (glossopharyngeal), 1.4%; and tenth nerve (vagus), 0.7%. The importance of preservation of function of the nervus intermedius of Wrisberg is stressed. These results emphasize the advantages of the translabyrinthine approach, offering greater security to the facial nerve and lower morbidity.

Adolescent↗
PubMed1993

Juvenile respiratory papillomatosis: acyclovir reassessed.

Four patients with aggressive respiratory papillomatosis have been treated with oral Acyclovir as adjuvant therapy while continuing to undergo regular endoscopy and laser treatment to the lesions. The duration of Acyclovir administration ranged from 2 weeks to 3 months. Two patients had papillomatosis confined to the larynx and two in addition had disease in the lower respiratory tract. One of the four patients had less aggressive disease during the treatment period. Acyclovir does not appear to significantly influence respiratory papillomatosis. Acyclovir's activity is dependent upon the presence of virally encoded thymidine kinase. This enzyme is not known to be encoded by papilloma viruses. Acyclovir is not recommended in the treatment of juvenile respiratory papillomatosis.

Acyclovir↗
PubMed1993

T-tubes: a retrospective review of 1274 insertions over a 4-year period.

1274 T-tubes were inserted for persistent otitis media with effusion in 661 patients over a 4-year period. The peak ages for insertion were between 4 and 7 years, and by 11 years the condition is uncommon. If a tube has not extruded spontaneously after 30 months it becomes increasingly less likely to do so. Complications were persistent perforations (32.6%), tympanosclerosis (23.6%), repeated otorrhoea or tympanic membrane granulations (21%), and impacted wax (10.9%). Forty-eight percent of patients experienced one or more complication in the study period, and the complication rate increased dramatically in patients whose tubes had remained in situ for longer than 36 months. After this time surgical removal is recommended.

Cerumen↗
PubMed1993

Surgical decannulation of children with tracheostomy.

Over a five-year period during which 99 children underwent successful ward decannulation, 14 other children were deemed unsuitable and underwent surgical decannulation. The technique of surgical decannulation involves excision of the tracheostomy tract with any granuloma and splinting of the anterior tracheal wall by the use of an indwelling nasotracheal tube for 48 hours post-operatively. It is indicated in carefully selected patients whose tracheostomies are complicated by large suprastomal granulomas, anterior tracheal wall collapse or previous anterior rib graft collapse into the airway. Nine of the 14 decannulations were successful. Success is dependent upon accurate prior endoscopic assessment and satisfactory previous reconstruction surgery in cases of subglottic stenosis. The five failures (4.42 per cent of all decannulations) represent some of the most demanding airway problems encountered.

Endoscopy↗
PubMed1993

Ribavirin treatment for juvenile respiratory papillomatosis.

Juvenile respiratory papillomatosis involving the tracheo-bronchial tree imposes a significant management problem and is sometimes life threatening. The mainstay of treatment is repeated vapourization with a CO2 laser. To date, adjunctive medical treatments have been of limited value. A tracheostomized child with extensive laryngo-tracheo-bronchial papillomatosis who has required bronchoscopic lasering at two-weekly intervals for three years was treated with ribavirin, a broad spectrum anti-viral agent. The drug was administered in nebulized form using a small particle aerosol generator (S.P.A.G.) to the lower respiratory tract (6 gm/150 ml over nine hours) on three consecutive nights every two weeks over seven weeks and also administered orally (15 mg/kg/day). Endoscopic assessments were made every two weeks. At 14 days the papillomata were regressing and far less lasering was required. No further lasering was required up to 56 days. One month after stopping the ribavirin, however, a few sessile papillomata in the tracheo-bronchial tree had recurred and were treated with the laser. No adverse reactions were encountered. During the treatment period there was a significant reduction in the frequency of therapeutic endoscopies. This promising response requires further evaluation to define the role of ribavirin in the treatment of juvenile respiratory papillomatosis.

Administration, Oral↗
PubMed1991

Rare presentation of a parapharyngeal schwannoma.

Schwannoma, or neurilemmoma, is included in the differential diagnosis of masses in the parapharyngeal space. Schwannomata do not usually cause acute inflammation, and therefore do not tend to present as emergencies as in this case, in which there was acute respiratory embarrassment.

Airway Obstruction↗
PubMed1991

The value of CT scanning in chronic suppurative otitis media.

High definition CT has been advocated for the evaluation of chronic suppurative otitis media (CSOM) either generally or in selected cases. It is said to be capable of producing the fine detail needed to detect lateral canal fistulae, exposed dura and facial canal dehiscences, and to demonstrate the ossicular chain. At present there is no agreement on either the indications for CT scanning in CSOM or the most appropriate scanning plane. To determine the value of high definition CT in CSOM and to decide a unit policy for its application, 36 cases of CSOM underwent pre-operative CT scanning and their scans were compared with the operative findings. Our results show CT to be highly sensitive to the presence of soft tissue disease and bone erosion, moderately sensitive to the presence of lateral canal fistulae but less sensitive to the presence of small areas of exposed dura, ossicular continuity and facial canal dehiscence. Axial scans were better able to demonstrate the lateral canal but otherwise coronal scans were superior; ideally patients should be scanned in both planes. The principle value of CT in CSOM is its ability to demonstrate disease which is not clinically apparent.

Cholesteatoma↗