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Biomedical subjects

C J Mathias

Publications and source records attributed to C J Mathias.

At least 73 records · Page 4Linked to original sources
PubMed1999

Continuous haemodynamic monitoring in an unusual case of swallow induced syncope.

A 69 year old man is described with a 12 year history of intermittent syncope associated with ingesting solid food, mainly after having fasted. He was taking enalapril, propranolol, bendrofluazide (bendroflumethiazide), omeprazole, finasteride, and aspirin. Detailed investigations, including gastrointestinal evaluation, measurement of various gut hormones, and autonomic testing, indicated no abnormality. A liquid meal, performed before fasting, failed to elicit an episode. However, a solid meal after an overnight fast provoked near-syncope. Continuous non-invasive haemodynamic monitoring (with a Portapres II) indicated a short lived rise in blood pressure and heart rate, followed by severe hypotension, a fall in stroke volume and cardiac output, and then bradycardia. This favoured an initial increase in sympathetic activity, followed by vasodepression due to sympathetic withdrawal or activation of humoral vasodilatatory mechanisms, with bradycardia secondary to impaired cardiac filling. Withdrawal of enalapril abolished the episodes. The unusual nature of this case, in which haemodynamic recordings continuously were made during and after swallow syncope, induced soon after food ingestion, is discussed.

Aged↗
PubMed1999

Cardiovascular, autonomic, and plasma catecholamine responses in unilateral and bilateral carotid artery stenosis.

OBJECTIVE: To determine impairment of baroreceptor afferent activity, which may affect cardiovascular autonomic function in patients with unilateral and bilateral carotid artery stenosis. Comparison was made with normal subjects and hypertensive patients. METHODS: A series of cardiovascular autonomic function tests along with plasma noradrenaline (norepinephrine) measurements were performed in 46 patients with carotid artery stenosis (CAS); 23 had unilateral and 23 had bilateral stenosis. Comparison was made with 21 hypertensive patients (with a similar degree of raised blood pressure), and 27 normal subjects. RESULTS: Over a third of patients with unilateral and bilateral CAS had postural hypotension. Heart rate did not rise appropriately in CAS despite the postural fall in blood pressure. Pressor responses in CAS were preserved. Heart rate responses to respiratory stimuli were attenuated. Plasma noradrenaline concentrations rose normally during head up tilt. CONCLUSION: A substantial proportion with CAS had postural hypotension and attenuated heart rate responses. This was not due to sympathetic vasoconstrictor or cardiac parasympathetic failure, thus suggesting impaired afferent baroreceptor activity, probably secondary to involvement of the carotid sinus. Cardiovascular autonomic testing and assessment of postural hypotension and factors enhancing it may be of clinical relevance in such patients, especially as the symptoms of postural hypotension overlap with those due to thromboembolism.

Aged↗
PubMed1999

Postural hypotension: causes, clinical features, investigation, and management.

Postural hypotension may result from various neurogenic and non-neurogenic causes. It may be a key feature of certain disorders, such as the primary chronic autonomic failure syndromes; it can complicate a variety of diseases, such as diabetes mellitus; and its prevalence increases with advancing age. When symptomatic, it may result in loss of consciousness and thus cause injury. Postural hypotension can be suspected from the patient's history and is readily documented in the clinic by measuring lying and standing blood pressure. The diagnosis ideally should be confirmed in the laboratory with additional tests to determine the cause and evaluate the functional deficit, so as to aid treatment. Treatment of the causative disorder is often curative when there are non-neurogenic causes. A combination of nonpharmacological and pharmacological measures is needed in the management of neurogenic postural hypotension.

Age Factors↗
PubMed1998

Consensus statement on the diagnosis of multiple system atrophy.

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate other domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poorly levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.

Autonomic Nervous System Diseases↗
PubMed1998

Differing haemodynamic and catecholamine responses to exercise in three groups with peripheralautonomic dysfunction: insulin-dependent diabetes mellitus, familial amyloid polyneuropathy and pure autonomic failure.

The haemodynamic and catecholamine responses to supine exercise, and the effect on standing blood pressure (BP), were studied in three groups with peripheral autonomic dysfunction; insulin-dependent diabetes mellitus (IDDM), familial amyloid polyneuropathy (FAP) and pure autonomic failure (PAF). Healthy normal subjects were studied as controls. With exercise, BP increased in controls, was unchanged in IDDM and FAP, and fell in PAF. Heart rate (HR) increased more in controls than IDDM, FAP or PAF. Cardiac index (CI) increased less in IDDM than controls, FAP or PAF. Systemic vascular resistance (SVR) fell similarly in controls and IDDM, with a greater fall in FAP and PAF. Plasma noradrenaline increased in controls and IDDM only; plasma adrenaline did not change and plasma dopamine was undetectable in all groups. On standing, BP was unchanged in controls; BP fell pre- and post-exercise in IDDM, FAP and PAF, with a significantly greater fall post-exercise in FAP and PAF. In conclusion, the haemodynamic responses to supine exercise and to standing after exercise differed in the three groups with peripheral autonomic dysfunction. These differences, and also the similarities, between different forms of peripheral autonomic dysfunction, may be of relevance to the clinical assessment and therapy of these patients.

Adult↗
PubMed1998

The sympathetic skin response in peripheral autonomic failure--evaluation in pure failure, pure cholinergic dysautonomia and dopamine-beta-hydroxylase deficiency.

The sympathetic skin response (SSR) detects changes in the electrical potential in the skin in response to physiological and electrical stimuli and, therefore, may indicate the integrity of sympathetic cholinergic neural pathways to sweat glands. This has been evaluated in 21 patients with three forms of peripheral autonomic failure. Of these, 15 had pure autonomic failure (PAF) without additional neurological features; investigations indicated both sympathetic and parasympathetic failure. Four patients had pure cholinergic dysautonomia (PCD), with clinical and laboratory features indicating only cholinergic failure. Two siblings had dopamine-beta-hydroxylase (DBH) deficiency with only sympathetic adrenergic failure. None was on drugs affecting cholinergic function. Ten normal individuals were aged-matched with PAF patients and studied as controls. The SSR was recorded from the palmar hand and plantar foot surfaces, using previously described techniques, in response to physiological (auditory, cough and inspiratory gasp) and electrical stimuli. Nerve conduction studies excluded an associated motor or sensory neuropathy. The SSR was present in all normal individuals, and in both patients with DBH deficiency who had preserved cholinergic and sudomotor function, It was absent in all 15 PAF and all four PCD patients with impaired cholinergic function. Therefore, we conclude that the SSR reflected sympathetic cholinergic function in these three different groups with peripheral autonomic failure.

Adult↗
PubMed1998

Synthesis and evaluation of a monocationic copper(II) radiopharmaceutical derived from N-(2-pyridylmethyl)-N'-(salicylaldimino)-1,3-propanediamine.

The monocationic 67Cu complex of N-(2-pyridylmethyl)-N'-(salicylaldimino)-1,3-propanediamine was obtained in high radiochemical purity by reaction of 67Cu2+ with the ligand in ethanol solution. Although this compound exhibited low heart uptake, the desired myocardial retention was observed over the 30 min time period studied in a rat model. Since the octanol/water partition coefficient of [67Cu]Cu(II)-N-(2-pyridylmethyl)-N'-(salicylaldiminato)-1,3- propanediamine] is lower than a value believed to be the optimal myocardial uptake, it is likely that derivatives of this compound with a higher lipophilicity merit further investigation for use in myocardial imaging with copper radioisotopes.

Animals↗
PubMed1998

A kit formulation for preparation of [(111)In]In-DTPA-folate, a folate-receptor-targeted radiopharmaceutical.

A kit formulation has been developed for convenient, routine compounding of (111)In-labeled In(III)-DTPA-Folate, an investigational radiopharmaceutical for targeting tumor-associated folate receptors. The kit consists of the DTPA-Folate conjugate in sodium citrate solution, from which [(111)In]In-DTPA-Folate can be rapidly and reliably compounded by the addition of aqueous [(111)In]In(III)-chloride.

Carrier Proteins↗
PubMed1998

Hypotensive and regional haemodynamic effects of exercise, fasted and after food, in human sympathetic denervation.

1. In human sympathetic denervation due to primary autonomic failure, food and exercise in combination may produce a cumulative blood pressure lowering effect due to simultaneous splanchnic and skeletal muscle dilatation unopposed by corrective cardiovascular reflexes. We studied 12 patients with autonomic failure during and after 9 min of supine exercise, when fasted and after a liquid meal. Standing blood pressure was also measured before and after exercise. 2. When fasted, blood pressure fell during exercise from 162 +/- 7/92 +/- 4 to 129 +/- 9/70 +/- 5 mmHg (mean arterial pressure by 22 +/- 5%), P < 0.0005. After the meal, blood pressure fell from 159 +/- 8/88 +/- 6 to 129 +/- 6/70 +/- 4 mmHg (mean arterial pressure by 22 +/- 3%), P < 0.0001, and further during exercise to 123 +/- 6/61 +/- 3 mmHg (mean arterial pressure by 9 +/- 3%), P < 0.01. The stroke distance-heart rate product, an index of cardiac output, did not change after the meal. During exercise, changes in the stroke distance-heart rate product were greater when fasted. 3. Resting forearm and calf vascular resistance were higher when fasted. Calf vascular resistance fell further after exercise when fasted. Resting superior mesenteric artery vascular resistance was lower when fed; 0.19 +/- 0.02 compared with 0.32 +/- 0.06, P < 0.05. After exercise, superior mesenteric artery vascular resistance had risen by 82%, to 0.53 +/- 0.12, P < 0.05 (fasted) and by 47%, to 0.29 +/- 0.05, P < 0.05 (fed). 4. On standing, absolute levels of blood pressure were higher when fasted [83 +/- 7/52 +/- 7 compared with 71 +/- 2/41 +/- 3 (fed), each P < 0.05]. Subjects were more symptomatic on standing post-exercise when fed. 5. In human sympathetic denervation, exercise in the fed state lowered blood pressure further than when fasted and worsened symptoms of postural hypotension.

Cardiac Output↗
PubMed1998

Clinical usefulness of magnetic resonance imaging in multiple system atrophy.

OBJECTIVES: To determine the sensitivity, specificity, and positive predictive values of a selection of abnormal findings in the putamen and infratentorial structures on routine magnetic resonance imaging for distinguishing between multiple system atrophy, idiopathic Parkinson's disease, and age matched controls. PATIENTS AND METHODS: Two neuroradiologists blindly and independently rated axial T2 weighted and proton density MRI of 44 patients with multiple system atrophy, 47 patients with idiopathic Parkinson's disease, and 45 controls. High field (1.5 T) scans were available in 16 patients with multiple system atrophy, 15 patients with idiopathic Parkinson's disease, and 16 controls. All other patients had 0.5 T scans. RESULTS: On both 0.5 and 1.5 T scans the following items had high specificity but low sensitivity: putaminal atrophy, a hyperintense putaminal rim, and infratentorial signal change. Finding any infratentorial abnormality gave higher sensitivity but lower specificity. Putaminal isointensity or hypointensity relative to globus pallidus, absolute putaminal hypointensity, and altered size of the olives were not useful discriminators. The overall sensitivity was 73% on 0.5 T and 88% on 1.5 T scans. The specificities of these findings for multiple system atrophy in comparison to idiopathic Parkinson's disease and controls on 0.5 T were 95% and 100% respectively, and on 1.5 T were 93% and 91% respectively. Finding any of the described abnormalities on MRI gave a positive predictive value of 93% on the 0.5 T machine, and 85% on the 1.5 T scanner.

Adult↗
PubMed1998

Chronic cough in the Holmes-Adie syndrome: association in five cases with autonomic dysfunction.

The Holmes-Adie syndrome consists of unilateral or bilateral tonic pupils with near light dissociation and tendon areflexia. It is associated with autonomic disturbances affecting sudomotor and vasomotor function. Five such patients are reported on who also had a troublesome chronic dry cough, which was of unknown aetiology and was resistant to a range of treatments. The cough may be related to involvement of afferent or efferent pathways in the vagus. Chronic cough may be an accompaniment in the Holmes-Adie syndrome, like other forms of autonomic dysfunction.

Adie Syndrome↗
PubMed1998

Neck and other muscle pains in autonomic failure: their association with orthostatic hypotension.

Neck pain in the suboccipital and paracervical region ('coathanger' configuration) is often reported by patients with autonomic failure and orthostatic hypotension. The frequency of this pain, along with pains in the buttock and calf regions, was determined by questionnaire in two major groups with primary chronic autonomic failure--pure autonomic failure (PAF) and multiple system atrophy (MSA). Comparisons were made with Parkinson's disease, cerebellar degeneration and other disorders in which neurological symptoms overlap but in which there was neither autonomic failure nor orthostatic hypotension. Neck pain was present in 93% of patients with PAF, 51% of patients with MSA and 38-47% of the non-autonomic groups. Buttock pain was present in smaller but similar proportions (8-19%) of each group, like calf pain (23-37%). Neck pain in PAF and MSA differed from that in the other groups in being relieved by sitting or lying flat and in being associated with factors that lower blood pressure in these patients. Buttock pain was posturally related in PAF and MSA; for calf pain there was no difference between groups. Neck pain was related to the degree of orthostatic hypotension; in PAF patients, whose postural blood-pressure fall was greater than that in MSA, there was a greater frequency of neck pain.

Adult↗