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Biomedical subjects

R J Stark

Publications and source records attributed to R J Stark.

At least 19 recordsLinked to original sources
PubMed2000

Intravenous lignocaine infusions for severe chronic daily headache.

OBJECTIVES: To determine the safety and efficacy of intravenous lignocaine infusion in patients with severe chronic daily headache (CDH). DESIGN: Retrospective survey of consecutive patients. PARTICIPANTS: 19 patients, 18 with rebound headache and three with status migrainosus. Two patients had both conditions at different times. SETTING: Neurology unit in a major metropolitan teaching hospital, 1994-1998. MAIN OUTCOME MEASURES: Adverse events; headache resolution; long term efficacy. RESULTS: The 19 patients (16 women) received 27 lignocaine infusions. Seven minor adverse events were noted during four infusions. Twenty-two infusions were given for analgesic rebound headache in 18 patients, with headache resolution in 82% of infusions (17 of the 18 patients responded at least once). Four patients obtained lasting relief, six returned to their regular manageable pattern of migraine (in two of these patients CDH recurred after six months), four were lost to follow-up, and in four there was no long term benefit. Five infusions were given for status migrainosus in three patients, with four of these infusions successfully relieving the headache. CONCLUSIONS: Intravenous lignocaine appears to be useful in the management of severe intractable CDH and status migrainosus.

Adolescent↗
PubMed1993

HTLV-I associated myelopathy in a Seychellois immigrant.

OBJECTIVE: To describe the clinical and laboratory features of human T-lymphotropic virus type I (HTLV-I) associated myelopathy in an immigrant from the Seychelles. CLINICAL FEATURES: A slowly progressive myelopathy has been recently diagnosed in a 64-year-old woman who emigrated to Australia from the Seychelles in 1957. Sphincter disturbance and back pain were the first manifestations, followed by gait disturbance. Neurophysiological investigation supported the clinical diagnosis of a myelopathy and radiological investigations revealed no structural cause. Serum antibodies to HTLV-I were detected by enzyme-linked particle agglutination and the presence of antibodies to individual HTLV-I gene products in the serum was confirmed by western blot. The virus was detected in a culture of the patient's peripheral blood mononuclear cells by antigen capture assay and by sequencing a polymerase chain reaction product amplified from the env gene. INTERVENTION AND OUTCOME: The patient was advised of the nature and prognosis of her illness. Oral corticosteroids were tried without benefit. CONCLUSIONS: The prevalence of HTLV-I infection is low in Australia although it may be endemic in some Aboriginal communities. Most infections are asymptomatic but the chronic neurological disease associated with HTLV-I infection has now been shown to exist in this country. HTLV-I infection should be considered in the aetiology of myelopathy without another obvious cause.

Australia↗
PubMed1992

Thrombolytic therapy in vertebrobasilar occlusion.

Since 1983 at the Alfred Hospital 4 patients with thrombotic or embolic vertebrobasilar occlusions have been treated with intra-arterial streptokinase (SK) infusions for the effects of persisting brainstem ischaemia despite anticoagulation with heparin. In 3 cases there was immediate and dramatic neurological improvement, in all cases associated with arteriographically demonstrated reperfusion of a blocked vessel. Two of these patients suffered further thromboembolic vertebral or basilar artery occlusions (3 days and 2 years later) but recovered fully without further thrombolytic therapy. The other patient was given intra-arterial SK 12 days after an apparently completed brainstem stroke: the therapy failed to cause reperfusion of a vertebral occlusion or produce any clinical improvement. Complications from the therapy were nausea requiring the termination of the SK infusion in one case, easily controlled bleeding from a recent surgical wound, and a clinically insignificant haemorrhagic transformation of cerebellar infarction in a third. The benefits of thrombolytic therapy in vertebrobasilar ischaemia and the dose of streptokinase required are discussed.

Cerebral Angiography↗
PubMed1990

Tonic contraversive ocular tilt reaction due to unilateral meso-diencephalic lesion.

We studied 4 patients with tonic contraversive ocular tilt reactions due to unilateral, paramedian, mesodiencephalic lesions. This is in contrast to the only 2 previously reported patients with ocular tilt reactions due to unilateral mesodiencephalic lesions, each of whom had a paroxysmal ipsiversive ocular tilt reaction. This new finding is considered in the context of previous clinical and experimental data on the various types of ocular tilt reactions that follow stimulation or destruction of the peripheral and central vestibular system. Otolithic inputs to the interstitial nucleus of Cajal from the contralateral vestibular nucleus and motor outputs from the interstitial nucleus of Cajal to cervical and ocular motoneurons could be involved in the ocular tilt reaction. We propose that in patients with unilateral meso-diencephalic lesions, a tonic contraversive ocular tilt reaction could be due to persistently decreased resting activity of ipsilateral interstitial nucleus neurons, whereas a paroxysmal ipsiversive ocular tilt reaction could be due to transiently increased activity of the same interstitial nucleus neurons. Cases of ocular tilt reaction due to unilateral meso-diencephalic lesion point to the existence of a crossed graviceptive pathway between the vestibular nucleus and the contralateral interstitial nucleus of Cajal.

Adult↗
PubMed1989

Intraventricular infusion of Dopamine in Parkinson's disease.

A patient with severe end-stage Parkinson's disease and troublesome fluctuations in motor function was treated with a long-term intraventricular infusion of dopamine. There was modest improvement in speech and mentation and there was smoother control of motor symptoms that was superior to that achieved by conventional oral medications.

Adult↗
PubMed1989

Cerebral deposits of carcinoid tumour.

This report details a most unusual case of cystic cerebral metastasis. The patient developed symptoms due to carcinoid deposits in the brain. The clinical course has been protracted and the primary source of the carcinoid tumour remains unknown.

Brain↗
PubMed1988

Spinal subdural abscess.

Spinal subdural abscess is a rare condition that is clinically similar to spinal epidural abscess. A case of spinal subdural abscess is reported, and the characteristic clinical findings and specific myelographic features in this patient are noted. Urgent myelography and surgery are necessary to prevent the rapid deterioration that often occurs in this condition.

Abscess↗
PubMed1987

Paramedian thalamic and midbrain infarction: the 'mesencephalothalamic syndrome'.

Paramedian infarction in the region of the thalamus and upper midbrain may produce a wide range of neuro-ophthalmological, behavioural and motor abnormalities. The paramedian arteries arise from the first part of the posterior cerebral artery, also known as the basilar communicating artery. The particular arterial topography and its anatomical variation may result in unusual combinations of clinical signs, and infarction may be bilateral in some cases. Diagnosis is often aided by CT scanning and magnetic resonance imaging. Both atherosclerotic occlusion and embolism are thought to be responsible for these particular syndromes. We describe 3 cases that illustrate some of the various clinical features and underlying anatomical vascular arrangements which may be seen in this condition. Thalamic dementia was present in one case with evidence of bilateral thalamic infarction. A complex ophthalmoplegia and hemiparesis were seen in another case, and the third case had a combination of thalamic dementia and ophthalmoplegia.

Adult↗
PubMed1985

Vincristine neurotoxicity in Charcot-Marie-Tooth syndrome.

The case of a patient with Charcot-Marie-Tooth syndrome and diffuse large-cell lymphoma, in whom a severe generalized weakness developed after the intravenous administration of vincristine (2 mg) during combination chemotherapy, is reported. Spontaneous resolution of the severe weakness occurred when teniposide was substituted for vincristine in the chemotherapy regimen.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Peripheral neuropathy with gammopathy responding to plasmapheresis.

Two patients with subacute sensorimotor peripheral neuropathy were found to have benign gammopathies. They both responded to treatment by plasmapheresis. We suggest that a vigorous search for a paraprotein should be made in all undiagnosed patients presenting with peripheral neuropathy, including electrophoresis with isoelectric focusing. Plasmapheresis may be a treatment modality that should be explored in such cases.

Aged↗
PubMed1983

Changes in cytosolic calcium during cholinergic and adrenergic stimulation of the parotid salivary gland.

Ca-selective microelectrodes were used to examine calcium transport during acetylcholine (ACh) and Epinephrine (Ep) stimulation of amylase secretion in the parotid gland. The cytosolic concentration of free ionized Ca2+ ( [Ca]i) determined in unstimulated cells was 0.44 +/- 0.04 microM. By measuring the induced changes in intracellular electrode potentials (ECa, EM) we were able to demonstrate that ACh at 10(-9), 10(-8), 10(-7), 10(-6), and 10(-5) M increased [Ca]i by 0.20 +/- 0.02, 0.61 +/- 0.04, 0.53 +/- 0.02, 0.30 +/- 0.05, and 0.14 +/- 0.03 microM. Similarly, Ep increased [Ca]i by 0.14 +/- 0.01, 0.42 +/- 0.06, 0.31 +/- 0.04, 0.15 +/- 0.03, and 0.05 +/- 0.04, respectively. Removal of extracellular Ca2+ significantly (P less than 0.001) altered the changes in ECa in response to ACh and Ep stimulation, thereby demonstrating that the induced increases in [Ca]i must be due to a transmembrane movement of Ca2+. Enzyme secretion was found to vary with the concentration of the stimulus used. Maximal secretion occurred during stimulation using 10(-7) M and 10(-8) M Ep with a suppression of release at supramaximal concentrations. The dose-response curve for ACh differed in that there were two concentrations of stimulus (2 X 10(-9) and 1 X 10(-6) M ACh) in which the greatest rate of secretion occurred. Concentrations of stimulus which increase [Ca]i between 0.86 +/- 0.06 microM and 0.74 +/- 0.05 appeared to produce optimal amylase secretion, indicating that salivary secretion in the mouse parotid is regulated within a narrow concentration range of cytosolic Ca2+.

Acetylcholine↗
PubMed1983

Primary orthostatic cerebral ischaemia.

four patients with "primary orthostatic cerebral ischaemia" are described. They complained of dizziness, light-headedness or syncope on standing. None had a significant fall in his systemic blood pressure on assuming the erect posture. Each had bruits over the major neck vessels or absent pulses. Angiography showed widespread narrowing or occlusion of the cervical blood vessels which supply the brain. Carotid endarterectomy relieved the patients' symptoms and also reduced the fall in retinal artery pressures on standing noted preoperatively. The clinician who is not aware of the poorly documented syndrome of "primary orthostatic cerebral ischaemia" may fail to recognise that a patient's complaints are due to cerebrovascular disease for they are strikingly different from those of classical transient ischaemic attacks.

Aged↗
PubMed1983

A transcellular route for Na-coupled Cl transport in secreting pancreatic acinar cells.

Ion-selective microelectrodes were employed to determine the electrochemical driving forces involved in the transepithelial transport of Na+ and Cl- during acetylcholine (ACh) stimulation of pancreatic acinar cells. In HCO-3-free Ringer solution, the mean values of intracellular Cl and Na activities (aiCl and aiNa) were 68.9 +/- 1.1 and 8.3 +/- 0.3 mM, respectively. The mean value of aiCl is above the calculated equilibrium value, indicating that Cl entry into the cell is an energy-requiring process. Continuous measurement of intracellular electrode potentials during stimulation of the cells with concentrations of ACh ranging from 10(-7) to 10(-5) M demonstrated the neurotransmitter's influence on transmembrane Na+ and Cl- movement in secreting cells. The mean values of the induced changes in aiCl and aiNa at every concentration of ACh measured were not significantly different (P greater than 0.5), although the mean changes in either aiNa or aiCl determined with every decade change in ACh concentration were significant (P less than 0.05). The transmembrane Na+ electrochemical gradient dissipated with the induced increases in aiCl. These results suggest that, during stimulus-secretion coupling of pancreatic acinar cells, there is a transcellular route for NaCl secretion, and the energy for NaCl entry into the cell may be derived from the Na+ electrochemical gradient that exists across the basolateral epithelial membrane. They also suggest that the ACh-induced changes in ionic permeability of the plasma membrane may be the coupling mechanism by which the simultaneous events enzyme release and electrolyte secretion are controlled in stimulated cells.

Acetylcholine↗
PubMed1982

Ionophore A23187 can mimick the changes in membrane permeability that occur during acetylcholine-stimulation of pancreatic acinar secretion.

Acetylcholine (ACh) released from vagal terminals increases the permeability of the pancreatic acinar membrane to Na+ and Ca2+ ions. In this report, we compare the induced changes in intracellular Na+ and Ca2+ electrode potentials (ENa and ECa) due to ACh-stimulation of acini with those observed during stimulation with the calcium ionophore, A23187, which mimicks the action of ACh on pancreatic secretion. Stimulation with ACh concentrations varying from 10(-8) to 10(-5) M and with A23187 concentrations of 10(-6) and 10(-5) M caused parallel increases in cytosolic Ca2+ and Na+ ([Ca]i, [Na]i). The magnitude of the increases in [Ca]i and [Na]i due to A23187-stimulation further indicate that when presented with a calcium challenge the acinar cells continue to regulate [Ca]i close to physiological levels and suggest that the observed increases in ionized calcium could reflect much larger increases in complexed Ca2+. ACh-stimulation following removal of either extracellular Na+ or Ca2+ ions, eliminated the intracellular increases found when the removed ions is present, but did not affect the increases usually found with the other ion. The independence of the permeability changes to either the presence of Ca2+ or Na+ indicates the ACh-induced currents carried by Na+ and Ca2+ are also independent. The selective translocation of Na+ and Ca2+ during acetylcholine-stimulation in a manner analogous to the changes observed when ionophore A23187 was used as stimulus, indicates the ability of the activated acinar membrane to function as an ionophore.

Acetylcholine↗
PubMed1982

Spinal metastases. A retrospective survey from a general hospital.

One hundred and thirty-one patients presenting to a general hospital with neurological symptoms deriving from spinal metastases were reviewed. The primary site of tumour was the lung in 33 per cent, breast in 28 per cent, other sites in 25 per cent and unknown in 14 per cent. Haematological malignancies were excluded. In 47 per cent of cases the spinal metastasis produced the first evidence of malignant disease. Spinal or radicular pain was the initial complaint in 69 per cent of cases, followed by the appearance of neurological symptoms. Leg weakness usually preceded sphincter disturbance, and was the commonest reason for referral. Spinal cord compression occurred in 106 patients, 10 had compression of conus medullaris or cauda equina and 15 had evidence of radicular compression only. Plain x-rays of the spine were abnormal in 84 per cent of patients, and in 94 per cent of those with carcinoma of the breast. The results of treatment by radiotherapy alone were retrospectively compared with those of surgical decompression (with or without radiotherapy). There was no significant difference between these results for immediate response to treatment or for long-term outcome. The best predictor of outcome was the site of primary tumour. Only 17 per cent of patients with lung cancer responded well to treatment and only 2 per cent were alive one year after treatment; 51 per cent of patients with breast cancer responded well and 36 per cent were alive at one year. Surgical treatment is considered preferable in cases in which the diagnosis of cancer is not proven, when there is a possibility of neural compression by diseased bone rather than soft tumour tissue and when the area has previously been irradiated. These groups accounted for about 60 per cent of our patients. Radiotherapy alone may be preferred if multiple lesions are demonstrated. In other cases a therapeutic decision is required. The availability of neurosurgical and radiotherapeutic facilities will be a factor. There is no clear evidence from our figures or from the literature of a difference between results obtained by radiotherapy alone and those with surgical decompression followed by irradiation. The choice of treatment will depend upon the particular requirements of each individual parent.

Female↗