Neurosarcoidosis-related intracranial haemorrhage: three new cases and a systematic review of the literature.

BACKGROUND AND PURPOSE: Intracranial haemorrhage in neurosarcoidosis (NS-ICH) is rare, poorly understood and the diagnosis of NS may not be immediately apparent. METHODS: The clinical features of three new NS-ICH cases are described including new neuropathological findings and collated with cases from a systematic literature review. CASES: (i) A 41-year-old man with headaches, hypoandrogenism and encephalopathy developed a cerebellar haemorrhage. He had neuropathological confirmation of NS with biopsy-proven angiocentric granulomata and venous disruption. He responded to immunosuppressive therapy. (ii) A 41-year-old man with no history of hypertension was found unconscious. A subsequently fatal pontine haemorrhage was diagnosed. Liver biopsy revealed sarcoid granulomas. (iii) A 36-year-old man with raised intracranial pressure headaches presented with a seizure and a frontal haemorrhage. Hilar lymph node biopsy confirmed sarcoidosis, and he was treated successfully. Systematic review: Twelve other published cases were identified and collated with our cases. Average age was 36 years and M:F = 2.3:1; 46% presented with neurological symptoms and 31% had CNS-isolated disease. Immediate symptoms of ICH were acute/worsening headache or seizures (60%). ICH was supratentorial (62%), infratentorial (31%) or subarachnoid (7%). Forty percent had definite NS, 53% probable NS and 7% possible NS (Zajicek criteria). Antigranulomatous/immunosuppressive therapy regimens varied and 31% died. CONCLUSIONS: This series expands our knowledge of the pathology of NS-ICH, which may be of arterial or venous origin. One-third have isolated NS. Clinicians should consider NS in young-onset ICH because early aggressive antigranulomatous therapy may improve outcome.

An integrative framework for stochastic, size-structured community assembly.

We present a theoretical framework to describe stochastic, size-structured community assembly, and use this framework to make community-level ecological predictions. Our model can be thought of as adding biological realism to Neutral Biodiversity Theory by incorporating size variation and growth dynamics, and allowing demographic rates to depend on the sizes of individuals. We find that the species abundance distribution (SAD) is insensitive to the details of the size structure in our model, demonstrating that the SAD is a poor indicator of size-dependent processes. We also derive the species biomass distribution (SBD) and find that the form of the SBD depends on the underlying size structure. This leads to a prescription for testing multiple, intertwined ecological predictions of the model, and provides evidence that alternatives to the traditional SAD are more closely tied to certain ecological processes. Finally, we describe how our framework may be extended to make predictions for more general types of community structure.

Sensory abnormalities in unaffected relatives in familial adult-onset dystonia.

Somatosensory abnormalities are found in adult-onset primary torsion dystonia (PTD). Therefore we assessed spatial discrimination thresholds (SDT), a measure of spatial acuity, in four multiplex families with adult-onset PTD. In family members aged 20 to 45 years vs controls (mean + 2.5 SD), abnormal SDTs were found in four of five affected with adult-onset PTD and in 12 of 49 unaffected relatives. Sensory abnormalities may be an endophenotype, possibly expressed later as adult-onset PTD.

Continuous measurement of systemic vascular resistance.

We have successfully linked a standard patient monitor system (Hewlett Packard M1166A-A66) with the Baxter Edwards Critical-Care Swan Ganz Intellicath continuous cardiac output catheter and the Vigilance continuous cardiac output monitor system to produce continuous values of systemic vascular resistance. Six cases are presented in which marked changes in indexed systemic vascular resistance were observed as a result of clinical interventions. The continuous derivation of systemic vascular resistance has much potential as a diagnostic and research tool as well as allowing rapid accurate assessment of the response of patients to therapy.

The use of esmolol to attenuate the haemodynamic response when extubating patients following cardiac surgery--a double-blind controlled study.

We have assessed the cardiovascular changes associated with emergence from anaesthesia, reversal of neuromuscular blockade and extubation in a group of 14 patients immediately after coronary artery bypass graft surgery had been completed. Patients were randomly allocated to receive either esmolol 500 micrograms.kg-1 over 1 min followed by 100 micrograms.kg-1.min-1 or placebo starting prior to reversal. Significant hypertension and tachycardia occurred in the placebo group, whilst these changes were prevented by the administration of esmolol.

Upper oesophageal sphincter pressure during inhalational anaesthesia.

Upper oesophageal sphincter pressure was recorded with a Dent sleeve in 30 patients breathing nitrous oxide, oxygen and halothane. Twenty-three patients, after thiopentone induction, received suxamethonium and had their trachea intubated either before (group A, n = 11), or after (group B, n = 11), a study period of inhalational anaesthesia. Group C (n = 8) received an inhalational induction. Mean (SD) sphincter pressure after loss of consciousness was 8 (7) mmHg (group A), 6 (5) mmHg (group B) and 24 (13) mmHg (group C) increasing to 19 (7) mmHg in group A immediately after intubation. With an end-tidal halothane concentration of 1.5%, mean sphincter pressure in group B, 16 (7) mmHg, was significantly lower than in group A, 45 (21) mmHg (p < 0.001) and group C, 27 (14) mmHg (p < 0.05). Halothane had no dose-related effect on sphincter pressure. Insertion of a laryngeal mask in group C (n = 7) had no significant effect on sphincter pressure. Induction and maintenance of anaesthesia with halothane, unlike thiopentone or suxamethonium, maintained a degree of upper oesophageal sphincter tone, although three patients in this study had sphincter pressures of less than 10 mmHg and would therefore have been at risk of regurgitation in the presence of gastro-oesophageal reflux.

Upper oesophageal sphincter pressure and the intravenous induction of anaesthesia.

The upper oesophageal sphincter can prevent regurgitation of oesophageal contents into the pharynx following gastrooesophageal reflux in the awake patient. Upper oesophageal sphincter pressure was recorded with a Dent sleeve after hypnosis with midazolam (n = 7) and also during the rapid intravenous induction of anaesthesia with thiopentone (n = 16) or ketamine (n = 7). Thiopentone decreased mean (SD) sphincter pressure from an awake value of 43 (19) to 9 (7) mmHg (p less than 0.001) and midazolam from 38 (25) to 7 (3) mmHg (p less than 0.02). Mean (SD) sphincter pressures before and after ketamine were not significantly different at 29 (15) and 32 (21) mmHg respectively. After suxamethonium mean (SD) sphincter pressure in all patients (n = 30) was 7 (4) mmHg. Laryngoscopy (n = 30) caused a small increase in mean (SD) sphincter pressure to 13 (10) mmHg (p less than 0.001). Thiopentone caused a rapid fall in upper oesophageal sphincter pressure which usually started before loss of consciousness. These findings have implications for the timing of cricoid pressure application.

Upper oesophageal sphincter pressure and the effect of cricoid pressure.

Upper oesophageal sphincter pressure has been measured in 24 patients with a sleeve device. The median sphincter pressure when awake was 38 mmHg, and when anaesthetized and paralysed was 6 mmHg. After tracheal intubation, cricoid pressure was applied at measured values between 5 and 50 N using a hand-held cricoid yoke while the sphincter pressure was recorded in two head and neck positions: with and without a standard intubating pillow with neck support. A cricoid force of 40 N increased sphincter pressure to above 38 mmHg in all the patients and the use of the pillow did not alter this effect. With the application of cricoid pressure, operating department assistants raised sphincter pressure to above 38 mmHg in only 50% of patients. Laryngoscopy made little difference to the effect of cricoid pressure except in one patient in whom it reduced the sphincter pressure by 27 mmHg.

Milrinone and the pulmonary vascular system.

In a multicentre study of 99 adult patients undergoing cardiac surgery, if post-operative cardiac failure was demonstrated (pulmonary capillary wedge pressure greater than 8 mmHg, cardiac index less than 2.5 litre min-1 m-2), then a bolus dose of milrinone (50 micrograms kg-1) was given, followed by an infusion at one of three rates (0.375, 0.5 or 0.75 microgram kg-1 min-1), and haemodynamic effects were assessed. Mean pulmonary artery pressures fell by 15% initially (P less than 0.001), and this significant reduction was maintained throughout the infusion period and reversed with the withdrawal of milrinone. Mean pulmonary vascular resistance fell progressively throughout the infusion period, the maximum change (30-40%) being evident at the 12 h point (P less than 0.05). Reversal of this effect after terminating the milrinone infusion was less marked than with pulmonary capillary wedge pressure or mean pulmonary artery pressure. A group of 39 of these patients from two centres were retrospectively divided into three groups: 1. Mitral valve replacement with high baseline pulmonary vascular resistance (greater than 200 dyne s cm-5) 2. Coronary revascularization with lower baseline pulmonary vascular resistance (100-200 dyne s cm-5) 3. Coronary revascularization with high baseline pulmonary vascular resistance (greater than 200 dyne s cm-5). There was a significant reduction in pulmonary vascular resistance and increase in cardiac index in all patients. At the 15 min point, there was significant between-group variation, the fall in pulmonary vascular resistance and increase in cardiac index being greater in Group 1 than in Groups 2 or 3. This difference between groups was not maintained during the infusion.