Ten-Year Follow-up on Tumor Growth and Hearing in Patients Observed With an Intracanalicular Vestibular Schwannoma.

BACKGROUND: Reports on the natural history of tumor growth and hearing in patients with a vestibular schwannoma (VS) are almost exclusively short-term data. Long-term data are needed for comparison with results of surgery and radiotherapy. OBJECTIVE: To report the long-term occurrence of tumor growth and hearing loss in 156 patients diagnosed with an intracanalicular VS and managed conservatively. METHODS: In this longitudinal cohort study, diagnostic and follow-up magnetic resonance imaging and audiometry were compared. RESULTS: After a follow-up of 9.5 years, tumor growth had occurred in 37% and growth into the cerebellopontine angle had occurred in 23% of patients. Conservative treatment failed in 15%. The pure tone average had increased from 51- to 72-dB hearing level, and the speech discrimination score (SDS) had decreased from 60% to 34%. The number of patients with good hearing (SDS > 70%) was reduced from 52% to 22%, and the number of patients with American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) class A hearing was reduced from 19% to 3%. Hearing was preserved better in patients with 100% SDS at diagnosis than in patients with even a small loss of SDS. Serviceable hearing was preserved in 34% according to AAO-HNS (class A-B) and in 58% according to the word recognition score (class I-II). Rate of hearing loss was higher in patients with growing tumors. CONCLUSION: Tumor growth occurred in only a minority of patients diagnosed with an intracanalicular VS during 10 years of observation. The risk of hearing loss is small in patients with normal discrimination at diagnosis. Serviceable hearing is preserved spontaneously in 34% according to AAO-HNS and in 58% according to the word recognition score.

[The internal carotid artery as a pulsating protrusion into the pharyngeal wall].

This case report describes an aberrant course of the internal carotid artery (ICA) in a patient presenting with symptoms of globus sensation, mild chronic cough and occasional aspiration. Clinically, a pulsating oro-hypopharyngeal tumour could only be visualized by fiberlaryngoscopy. A CT-scan showed a tortuous ICA protruding into the lateral and posterior pharyngeal wall. This condition may need treatment in itself, and it can lead to co-morbidity and serious surgical complications in undiagnosed patients. Referral to an oto-rhino-laryngologist is highly recommended for diagnostics.

[Pasteurella multocida meningitis secondary to functional endoscopic sinus surgery].

Functional endoscopic sinus surgery (FESS) is a common, surgical procedure in Danish ear-nose-throat departments. Surgery is often performed as an outpatient procedure. Major complications are rare, however, they may develop after the patient has been discharged. This is a case report of Pasteurella multocida meningitis secondary to FESS in a 54-year-old male.

Effect of Prometheus liver assist system on systemic hemodynamics in patients with cirrhosis: a randomized controlled study.

AIM: To evaluate treatment safety and hemodynamic changes during a single 6-h treatment with the Prometheus liver assist system in a randomized, controlled study. METHODS: Twenty-four patients were randomized to either the study group or to one of two control groups: Fractionated Plasma Separation Adsorption and Dialysis, Prometheus system (Study group; n = 8); Molecular Adsorbent Recirculation System (MARS) (Control group 1, n = 8); or hemodialysis (Control group 2; n = 8). All patients included in the study had decompensated cirrhosis at the time of the inclusion into the study. Circulatory changes were monitored with a Swan-Ganz catheter and bilirubin and creatinine were monitored as measures of protein-bound and water-soluble toxins. RESULTS: Systemic hemodynamics did not differ between treatment and control groups apart from an increase in arterial pressure in the MARS group (P = 0.008). No adverse effects were observed in any of the groups. Creatinine levels significantly decreased in the MARS group (P = 0.03) and hemodialysis group (P = 0.04). Platelet count deceased in the Prometheus group (P = 0.04). CONCLUSION: Extra-corporal liver support with Prometheus is proven to be safe in patients with endstage liver disease but does not exert the beneficial effects on arterial pressure as seen in the MARS group.

Cerebral blood flow autoregulation in experimental liver failure.

Patients with acute liver failure (ALF) display impairment of cerebral blood flow (CBF) autoregulation, which may contribute to the development of fatal intracranial hypertension, but the pathophysiological mechanism remains unclear. In this study, we examined whether loss of liver mass causes impairment of CBF autoregulation. Four rat models were chosen, each representing different aspects of ALF: galactosamine (GlN) intoxication represented liver necrosis, 90% hepatectomy (PHx90) represented reduction in liver mass, portacaval anastomosis (PCA) represented shunting of blood/toxins into the systemic circulation thus mimicking intrahepatic shunting in ALF, PCA+NH(3) provided information about the additional effects of hyperammonemia Rats were intubated and sedated with pentobarbital. We measured CBF with laser Doppler, intracranial pressure (ICP) was measured in the fossa posterior and registered with a pressure transducer, brain water was measured using the wet-to-dry method, and cerebral glutamine/glutamate was measured enzymatically. The CBF autoregulatory index in both the GlN and PHx90 groups differed significantly from the control group. Conversely, CBF autoregulation was intact in the PCA and PCA+NH(3) groups despite high arterial ammonia, high cerebral glutamine concentration, and increased CBF and ICP. Increased water content of the brainstem or cerebellum was not associated with defective CBF autoregulation. In conclusion, impairment of CBF autoregulation is not caused by brain edema/high ICP. Nor does portacaval shunting or hyperammonemia impair autoregulation. Rather, massive liver necrosis and reduced liver mass are associated with loss of CBF autoregulation.

Comparison of terlipressin and noradrenalin on cerebral perfusion, intracranial pressure and cerebral extracellular concentrations of lactate and pyruvate in patients with acute liver failure in need of inotropic support.

BACKGROUND/AIMS: Volume expansion and inotropic support with catecholamines are sometimes insufficient to ensure adequate blood pressure and cerebral perfusion in acute liver failure (ALF). The aim of this study was to determine if terlipressin increases cerebral perfusion, cerebral concentration of lactate and intracranial pressure (ICP), and to compare the effect with that of noradrenalin (NA). METHODS: Ten patients (median age 42.5 yr; range 15-66; 5 women) who needed inotropic support and had an ICP and a cerebral microdialysis catheter placed had concomitant recording of cerebral perfusion pressure (CPP), cerebral perfusion (using transcranial Doppler sonography (V(mean))) and ICP. Also cerebral extracellular concentration of lactate ([lactate]ec) and pyruvate ([pyruvate]ec) was collected before and after an increase in the NA infusion rate and/or i.v.-injection of 1mg terlipressin. RESULTS: Both NA and terlipressin increased CPP and V(mean) (p<0.01). Also ICP increased during NA infusion (p<0.01) but not after terlipressin. The cerebral [lactate]ec decreased after terlipressin injection from 2.34 (1.52-8.38) to 1.99 (0.03-4.83)mmol/l (p=0.027) but not during NA infusion (2.83 (1.53-7.11)mmol/l). The [lactate]ec to [pyruvate]ec ratio remained unchanged in both the NA group (20.7 (13.2-40.0)) and terlipressin group (22.2 (10.5-30.0)). CONCLUSIONS: This study shows that terlipressin increases CPP and cerebral perfusion with little influence upon ICP and cerebral [lactate]ec in ALF patients. These findings indicate that terlipressin may be valuable, as an additive treatment to NA infusion to secure brain viability.

Hearing in patients with intracanalicular vestibular schwannomas.

This paper reports data on the spontaneous course of hearing in 156 patients with purely intracanalicular vestibular schwannomas. The mean pure tone average (PTA) was 51 dB HL and the mean speech discrimination score (SDS) 60% at diagnosis. The risk of a significant subsequent hearing loss (>or=10 dB PTA or >or=10% SDS) was 54% during 4.6 years of observation. Patients with normal speech discrimination at diagnosis had a significantly smaller risk of loosing hearing. The hearing loss at diagnosis and during observation was not related to age, gender, diagnostic tumor size, tumor- induced expansion of the internal auditory canal or tumor sublocalization (fundus, central or porus). However, the loss of PTA was smaller in shrinking tumors and the PTA deterioration rate correlated with the volumetric tumor growth rate. After 4.6 years observation, the PTA had increased by 14 dB to 65 dB HL, and the SDS reduced by 17% to 43%. The proportion of patients eligible for hearing preservation treatment as determined by word recognition score class I (70-100% SDS) was reduced to 28% (a 44% reduction), and by AAO-HNS class A to 9% (a 53% reduction).

Sublocalization and volumetric growth pattern of intracanalicular vestibular schwannomas.

OBJECTIVE: None of several previous reports on the growth pattern of vestibular schwannomas (VS) have dealt with the sublocalization and volumetric growth pattern of intracanalicular tumors. This paper reports such data from 196 patients. STUDY DESIGN: All VS patients have been registered prospectively at one center in Denmark since 1975. Data on intracanalicular tumors were drawn from the database, yielding 196 patients with a diagnostic and at least one control magnetic resonance imaging scan. All images were retrieved and the tumor sublocalization, size, and growth rate determined. RESULTS: The majority (50%) of the tumors was located centrally in the internal auditory canal (IAC), whereas 31% were porus-near and 19% fundus-near. Of the 196 tumors, 88 (45%) displayed growth, 20 (10%) shrinkage, and 88 (45%) remained unchanged. Thirty-eight (19%) tumors grew to extrameatal extension. Growth occurred only within 5 years after diagnosis. In the 88 growing tumors, the mean absolute growth rate was 111mm/year and the relative rate 114%/volume/year. The occurrence of IAC expansion at diagnosis was higher for tumors displaying subsequent shrinkage. Growth occurrence and rate, IAC expansion, and progression to extrameatal extension were not related to tumor sublocalization. CONCLUSION: Most intracanalicular VS are located centrally in a nonexpanded IAC at diagnosis. Growth occurs within 5 years after diagnosis in up to 45% of the tumors, although only 19% extend into the cerebellopontine angle. IAC expansion, growth occurrence, and rate are not related to tumor sublocalization. These findings justify primary observation of all purely intracanalicular tumors, unless realistic hearing preservation is intended.

Effects of porta-systemic shunting and ammonia infusion on cerebral blood flow autoregulation in the rat.

BACKGROUND: Portacaval shunting of blood, hyperammonemia, and impaired cerebral blood flow (CBF) autoregulation are assumed to be involved in the development of high intracranial pressure (ICP) in liver failure. In this study, we determined whether CBF autoregulation is impaired by portacaval anastomosis and hyperammonemia. METHODS: Four groups of pentobarbital-sedated and mechanically ventilated rats were investigated after construction of a portacaval anastomosis or following sham operation. Half of the rats received either infusion of ammonia (55 micromol/kg/minute) or saline for 180 minutes. Arterial pressure and ICP was monitored, and lower limit of CBF autoregulation was determined. RESULTS: Lower limit of autoregulation was preserved in all four groups of studied animals; vehicle lower limits were 40 +/- 2.3, 40 +/- 2, 54 +/- 1, and 51 +/- 3 mmHg in sham-operated rats, sham rats receiving ammonia infusion, portacaval anastomosis-vehicle animals, and portacaval anastomosis-hyperammonemia animals, respectively. The lower limit of auto regulation was higher in portacaval anastomosis rats (p = 0.01) compared to the sham- operated rats. Hyperammonemia in portacaval anastomosis rats did not aggravate this. CONCLUSION: Portacaval anastomosis and hyperammonemia does not impair the lower limit of CBF autoregulation. However, shunting of portal blood to the systemic circulation shifts the lower limit of autoregulation to higher blood pressure values, making the brain more sensitive to episodes of arterial hypotension.

Tacrolimus ameliorates cerebral vasodilatation and intracranial hypertension in the rat with portacaval anastomosis and hyperammonemia.

Arterial hyperammonemia and cerebral vasodilatation correlate with cerebral herniation in patients with fulminant hepatic failure (FHF). Tacrolimus is a calcineurin inhibitor that passes the blood-brain barrier and may increase cerebrovascular tone and restrict cerebral ammonia influx. In this study, we determined if tacrolimus prevents cerebral vasodilatation and high intracranial pressure (ICP) in the rat with portacaval anastomosis (PCA) challenged to high arterial ammonia (NH4+) concentration. Seven groups of mechanically ventilated rats, with 6-9 rats in each group, were investigated within 48 hours after construction of a PCA (4 groups) or after sham operation (3 groups). Three groups of the rats received infusion of NH4+ and 4 groups received saline for approximately 180 minutes. Two groups of the PCA rats receiving either NH4+ or saline had an i.v. injection of tacrolimus (0.4 mg/kg) or vehicle before start of NH4+ or saline infusion. Cerebral blood flow (CBF) was monitored by a laser Doppler probe in brain cortex. ICP was monitored by placement of a catheter in the cerebrospinal fluid. CBF and ICP increased in PCA rats receiving NH4+ infusion compared to PCA controls and to all groups of sham-operated animals (P <.05). In the group of PCA rats pre-treated with tacrolimus before receiving ammonia infusion, the increase in ICP was ameliorated compared to the ammonia infused group receiving vehicle (P <.03). Tacrolimus also prevented an increase in CBF in the PCA group receiving NH4+ (P <.05) compared to the control groups. In conclusion, Tacrolimus prevents cerebral vasodilatation and ameliorates intracranial hypertension in PCA rats receiving NH4+ infusion. These findings indicate that tacrolimus could be of clinical value in the prevention of cerebral hyperemia, high ICP, and serious brain damage in patients with FHF.

Cerebral blood flow and metabolism during infusion of norepinephrine and propofol in patients with bacterial meningitis.

BACKGROUND AND PURPOSE: In patients with severe bacterial meningitis, norepinephrine is often infused to increase mean arterial pressure (MAP). This increases cerebral blood flow (CBF), but it is unknown if this increase is caused by impaired cerebral autoregulation or by a cerebral effect of norepinephrine through increased cerebral metabolism. The latter possibility implies a CBF-metabolism coupling. This has not been studied during meningitis. We studied the effect of norepinephrine and propofol on CBF and oxidative metabolism in patients with severe bacterial meningitis. METHODS: In seven patients with pneumococcal meningitis and 7 healthy subjects, norepinephrine was infused intravenously; patients also underwent intravenous propofol infusion. Global CBF was measured by the Kety-Schmidt technique; cerebral oxidative metabolism and net flux of norepinephrine and epinephrine were calculated from measured arterial-to-jugular venous concentration differences (a-vD). RESULTS: During norepinephrine infusion, MAP increased from a median value of 79 (range, 70 to 89) to 99 (98 to 129) mm Hg in patients, and from 87 (72 to 103) to 123 (112 to 132) mm Hg in controls. CBF increased in patients (51 [48 to 60] to 59 [54 to 77] mL/100 g per minute) but remained unchanged in controls. The cerebral metabolic rate of oxygen (CMRO2) decreased in patients and remained unchanged in controls. No cerebral net flux of norepinephrine or epinephrine was found at any time in the 2 groups. During propofol infusion, CMRO2, and the a-vDO2 decreased whereas CBF was unchanged. CONCLUSIONS: In patients with severe bacterial meningitis, norepinephrine increases both MAP and CBF but not CMRO2, indicating impaired autoregulation. Propofol reduces CBF relatively less than cerebral metabolism, suggesting a resetting of the CBF-CMRO(2) relationship.