Cerebral vasoreactivity in children and adolescents with type 1 diabetes mellitus

Bihemispheric Cerebral Oximetry Monitoring's Functionality in Suspected Cerebral Edema Diabetic Ketoacidosis With Therapeutic 3% Hyperosmolar Therapy in a Pediatric Emergency Department

BACKGROUND

Suspected cerebral edema diabetic ketoacidosis (SCEDKA) is more common than perceived with symptoms including altered mentation, headache with vomiting, depressed Glasgow coma scale (GCS), abnormal motor or verbal responses, combativeness, and neurological depression. Suspected cerebral edema diabetic ketoacidosis has been associated with initial diabetic ketoacidosis (DKA) presentation and at start of DKA therapy.Cerebral oximetry (bihemispheric regional cerebral oxygen saturation [rcSO2] and cerebral blood volume index [CBVI]) can detect increased intracranial pressure (ICP)-induced altered bihemispheric cerebral physiology (rcSO2) (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700). In pediatrics, rcSO2 of less than 60% or rcSO2 of greater than 85% reflects increased ICP and cerebral edema (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700). Cerebral oximetry can detect increased ICP-induced altered bihemispheric cerebral physiology (rcSO2, CBVI) and cerebral physiological changes (rcSO2, CBVI changes) during therapeutic mechanical cerebral spinal fluid removal to decrease increased ICP (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700).In the pediatric intensive care units, SCEDKA patients with nonbihemispheric cerebral oximetry showed an initial rcSO2 of greater than 90%. Bihemispheric rcSO2 with CBVI in SCEDKA patients has the potential to detect the abnormal cerebral physiology and disruptive autoregulation while detecting 3% hypertonic saline solution (HTS) effects on the SCEDKA altered cerebral physiology (rcSO2).

PURPOSE

The purposes of this study were to analyze and compare 3% HTS effect on bihemispheric rcSO2 readings, neurological and biochemical parameters in SCEDKA with 3% HTS infusion to non-SCEDKA patients in pediatric emergency department (PED).

METHODS

An observational retrospective comparative analysis study of bihemispheric rcSO2 readings, neurological and biochemical parameters in 2 groups of PED DKA patients were performed: PED DKA patients with SCEDKA +3% HTS infusions versus non-SCEDKA without 3% HTS infusions.

RESULTS

From 2008 to 2013, of the 1899 PED DKA patients, 60 SCEDKA patients received 3% HTS (5 mL/kg via peripheral intravenous) infusion (median age of 5 years [range, 3.7-7 years]), with 42 new DKA insulin dependent diabetes mellitus onset. Suspected cerebral edema diabetic ketoacidosis patients had GCS of 11 (range, 11-12), with consistent SCEDKA signs and symptoms (severe headaches with vomiting, confusion, blurred vision, altered speech, lethargy, and combativeness). Suspected cerebral edema diabetic ketoacidosis patients' initial (0-5 minutes) left rcSO2 readings were 91.4% (range, 88.4%-94.1%) and right was 90.3% (range, 88.6%-94.1%) compared with non-SCEDKA patients' left rcSO2 readings of 73.2% (range, 69.7%-77.8%) and right of 73.2% (range, 67.6%-77%) (P < 0.0001). The rcSO2 monitoring time before 3% HTS infusion was 54.9 minutes (range, 48.3-66.8 minutes) with 3% HTS time effect change: pre-3% HTS (54.9 minutes [range, 48.3-66.8 minutes]). Before 3% HTS infusion, the left rcSO2 readings were 90.0% (range, 89%-95%) and right was 91% (range, 86%-95%). The 30 to 45 minutes post-3% HTS showed that left was 64% (range, 62%-69%) and right was 65.4% (range, 63%-70%) (P < 0.0001). rcSO2 Δ change for post-3% HTS (0-20 minutes) to pre-3% HTS was as follows: left, -26.58 (-29.5 to -23.7) (P < 0.0001); right, -25.2 (-27.7 to -22.6) (P < 0.0001). Post-3% HTS GCS (14,15) and biochemistry compared with pre-3% HTS infusions all improved (P < 0.001).

CONCLUSIONS

In PED SCEDKA patients, the pre-3% HTS bihemispheric rcSO2 readings were greater than 90% and had lower GCS than non-SCEDKA patients. The post-3% HTS infusion rcSO2 readings showed within minutes a substantial reduction compared with non-SCEDKA patients, with no complications. Changes in rcSO2 readings after 3% HTS correlated with improved SCEDKA indicators (improved mental status, headache, and GCS) without any complications. We showed that cerebral oximetry in PED SCEDKA patients has shown an initial bihemispheric of greater than 90% readings signifying abnormal bihemispheric cerebral physiology. We also showed the cerebral oximetry's functionality in detecting 3% HTS therapeutic effects on SCEDKA's abnormal cerebral physiology and the beneficial therapeutic effects of 3% HTS infusion in SCEDKA patients. Using cerebral oximetry in pediatric DKA patients' initial cerebral assessment could have a significant impact in detecting SCEDKA patients. Further SCEDKA research using cerebral oximetry should be considered.

Young Patients With Diabetes Have Decreased Cerebrovascular Reactivity Under Hypercapneic Conditions

OBJECTIVE

Adult diabetic patients have an abnormal cerebrovascular response to hypercapnia, but there are few studies focused on diabetes mellitus type 1 and cerebral blood flow in pediatric or adolescent patients. We hypothesize that young patients with diabetes exhibit a different response to hypercapnia than normal control counterparts.

METHODS

Using transcranial Doppler techniques, we compared young diabetic patients with healthy controls by measuring cerebral blood velocity before and during carbon dioxide challenge.

RESULTS

Subjects with diabetes had decreased cerebral blood velocity reactivity when compared with the control group (P = 0.005).

CONCLUSION

Our results suggest cerebrovascular dysfunction in diabetic patients beginning at an early age. The possibility of long-term implications for cerebrovascular disease demonstrates the need for further studies in the pediatric and adolescent diabetic population to better understand this prevalent condition.

Niaspan enhances vascular remodeling after stroke in type 1 diabetic rats

We investigated the changes and the molecular mechanisms of cerebral vascular damage and tested the therapeutic effects of Niaspan in type-1 streptozotocin induced diabetic (T1DM) rats after stroke. T1DM-rats were subjected to transient middle cerebral artery occlusion (MCAo) and treated without or with Niaspan. Non-streptozotocin rats (WT) were also subjected to MCAo. Functional outcome, blood-brain-barrier (BBB) leakage, brain hemorrhage, immunostaining, and rat brain microvascular endothelial cell (RBEC) culture were performed. Compared to WT-MCAo-rats, T1DM-MCAo-rats did not show an increase lesion volume, but exhibited significantly increased brain hemorrhage, BBB leakage and vascular damage as well as decreased functional outcome after stroke. Niaspan treatment of stroke in T1DM-MCAo-rats significantly attenuated BBB damage, promoted vascular remodeling and improved functional outcome after stroke. T1DM-MCAo-rats exhibited significantly increased Angiopoietin 2 (Ang2) expression, but decreased Ang1 expression in the ischemic brain compared to WT-MCAo-rats. Niaspan treatment attenuated Ang2, but increased Ang1 expression in the ischemic brain in T1DM-MCAo-rats. In vitro data show that the capillary-like tube formation in the WT-RBECs marginally increased compared to T1DM-RBEC. Niaspan and Ang1 treatment significantly increased tube formation compared to non-treatment control. Inhibition of Ang1 attenuated Niacin-induced tube formation in T1DM-RBECs. Niaspan treatment of stroke in T1DM-rats promotes vascular remodeling and improves functional outcome. The Ang1/Ang2 pathway may contribute to Niaspan induced brain plasticity. Niaspan warrants further investigation as a therapeutic agent for the treatment of stroke in diabetics.

Metabolic syndrome and cerebral vasomotor reactivity

BACKGROUND AND PURPOSE

Metabolic syndrome has been proposed as a risk factor for stroke and transient ischaemic attack. One pathophysiological mechanism could be impairment of endothelial function. Thus, we hypothesized that cerebral vasomotor reactivity would be decreased in patients with metabolic syndrome, compared to patients without metabolic syndrome.

METHODS

In this retrospective analysis, 83 consecutive patients (aged 59.19 ± 15.98; 33 women) underwent Doppler examination for carotid artery disease including bi-hemispherical vasomotor reactivity assessment using transcranial Doppler monitoring. Vasomotor reactivity data were analyzed from the hemisphere with no or low-grade carotid stenosis (<40%). Cerebral vasomotor reactivity was calculated as percent increase in mean flow velocity per mmHg pCO(2) during 2 min of 5% CO(2) inhalation delivered by anesthesia mask (normal if ≥ 2%/mmHg). Univariate and multivariable linear regression models were used to determine factors, including metabolic syndrome, that were independently associated with pathologic vasomotor reactivity.

RESULTS

After adjusting for the presence of contralateral carotid stenosis and ipsilateral stroke in the multivariable model, metabolic syndrome was independently associated with lower vasomotor reactivity values (2.27 ± 1.24% vs. 2.68 ± 1.37; ß = -0.258, P = 0.033). In this model, there was no association of cerebral vasomotor reactivity with age, gender, race, cardiac disease, current statin therapy, or small vessel disease.

CONCLUSIONS

Our findings suggest that impaired cerebral vasomotor reactivity may be a mediator of stroke in patients with metabolic syndrome, a syndrome affecting a significant and growing proportion of the population. A prospective longitudinal study is warranted to study the cerebral haemodynamic effect of metabolic syndrome.

Cerebrovascular reactivity, intima-media thickness, and nephropathy presence in patients with type 1 diabetes

OBJECTIVE

Cerebrovascular reactivity impairment was reported as a marker of cerebral microangiopathy in long-term type 1 diabetes. Intima-media complex thickening reflects early stages of macroangiopathy in type 1 diabetes. The analysis of the relationship between these variables and other microangiopathic complications might serve as a beneficial indicator for early prophylaxis in these patients.

RESEARCH DESIGN AND METHODS

Vasomotor reactivity reserve (VMRr) and breath-holding index (BHI) of the middle cerebral artery were measured with transcranial Doppler in 59 patients (median age 32.0 years, range 20-51, 36 females) with type 1 diabetes, without history of cerebrovascular events, and 30 healthy control subjects (median age 31.5 years, range 25-39, 15 females). The relationships between the presence of selected vascular complications of type 1 diabetes and biochemical parameters, intima-media thickness (IMT), and VMRr and BHI in patients were analyzed.

RESULTS

VMRr and BHI were lower in patients with type 1 diabetes when compared with healthy subjects (81.5 vs. 100%, P < 0.01, and 1.6 vs. 2.2, P = 0.04, respectively), whereas IMT was significantly higher in patients then in healthy control subjects (0.36 vs. 0.30 mm, P = 0.001). However, no association of IMT with VMRr was found. We found a significant reduction of VMRr and BHI in patients with diabetic nephropathy.

CONCLUSIONS

The presence of diabetic nephropathy, but not IMT, can be regarded as an indicator of cerebral microangiopathy severity in patients with type 1 diabetes.

Changing cerebral blood flow velocity by transcranial Doppler during head up tilt in patients with diabetes mellitus

OBJECTIVE

Diabetes mellitus is an independent risk factor for poor prognosis in patients with ischemic stroke. It is known that diabetes mellitus directly affects cerebral vasculature as a secondary, long-term complication of cerebral circulation, and causes cerebral blood flow abnormalities. The abnormalities of cerebral autoregulation also poorly affects the prognosis of ischemic stroke. In this study, we aimed to show the cerebral autoregulation with transcranial Doppler (TCD) ultrasound in diabetic patients with autonomic nervous system abnormalities, determined with electrophysiological studies.

MATERIAL AND METHOD

Twenty healthy controls and 39 patients, who had at least 2 years of diabetes mellitus, were evaluated (age ranges: 42-75 years). The patients were divided into two groups according to sympathetic skin response and R--R interval variation studies: (1) patients with autonomic neuropathy; (2) patients without autonomic neuropathy. Blood flow velocities were measured during supine position and after the patients were raised upright position on head up tilt table. Arterial blood pressures and heart rates were also evaluated.

RESULTS

Mean blood flow velocities of diabetic patients with autonomic neuropathy were found more decreased at 90s after the patients were raised upright position.

DISCUSSION

Autonomic neuropathy due to diabetes mellitus affects cerebral autoregulation, and by this way cerebral perfusion loses protection against hemodynamical changes.

Cerebral hyperemia and impaired cerebral autoregulation associated with diabetic ketoacidosis in critically ill children*

OBJECTIVE

Cerebral edema associated with diabetic ketoacidosis is an uncommon but severe complication of insulin-dependent diabetes mellitus with unclear pathophysiology. We sought to determine whether cerebral edema in patients with diabetic ketoacidosis was related to changes in cerebral blood flow, autoregulation, regional cerebral saturation, or S100B.

DESIGN

Prospective case series.

SETTING

Pediatric intensive care unit of a tertiary children's hospital.

PATIENTS

Six patients with diabetic ketoacidosis and altered mental status, requiring computed tomographic scan of the head.

INTERVENTIONS

Study evaluations included: 1) transcranial Doppler evaluations to determine middle cerebral artery flow velocities and cerebral autoregulation, defined by the autoregulatory index, at 6 and 36 hrs; 2) continuous monitoring of regional cerebral oxygenation on the left lateral forehead using near-infrared spectroscopy for the first 24 hrs of admission; 3) serial measurement of S100B as a marker of central nervous system injury; and 4) follow-up head computed tomographic scan.

RESULTS

Serial computed tomographic scans showed that four of six patients had changes in brain volume without overt cerebral edema. Initial scans showed narrowing of the third and lateral ventricles when compared with follow-up. There was no difference in middle cerebral artery flow velocities between admission and recovery at 36 hrs, despite Paco2 increasing during treatment. Cerebral flow was normal to increased, despite hypocapnia. Cerebral autoregulation was impaired in five of six patients at 6 hrs and normalized by 36 hrs. Mean regional cerebral oxygenation was measured in five of six patients and decreased linearly with time. Two patients showed maximal regional cerebral oxygenation before returning to baseline. There were no periods of low regional cerebral oxygenation in any patient at any time. No elevation in S100B was found.

CONCLUSIONS

We found normal to increased cerebral blood flow, elevated regional cerebral oxygenation, impaired autoregulation, and changes in brain volume in clinically ill pediatric patients with diabetic ketoacidosis. We found no evidence of cerebral ischemia. These findings suggest that the pathophysiology of cerebral edema in diabetic ketoacidosis may involve a transient loss of cerebral autoregulation, allowing a paradoxic increase in cerebral blood flow and the development of vasogenic cerebral edema.