Prospective, Longitudinal Study of Clinical Outcome and Morphometric Posterior Fossa Changes after Craniocervical Decompression for Symptomatic Chiari I Malformation.

BACKGROUND AND PURPOSE: The time course of changes in posterior fossa morphology, quality of life, and neurologic function of patients with Chiari I malformation after craniocervical decompression requires further elaboration. To better understand the pace of these changes, we longitudinally studied patients with Chiari I malformation, with or without syringomyelia, before and after the operation for up to 5 years. MATERIALS AND METHODS: Thirty-eight symptomatic adult patients (35 women, 3 men) diagnosed with Chiari I malformation only (n = 15) or Chiari I malformation and syringomyelia (n = 23) and without previous Chiari I malformation surgery were enrolled in a clinical study. Patients underwent outpatient study visits and MR imaging at 7 time points (ie, initial [before the operation], 3 months, 1 year, 2 years, 3 years, 4 years, and 5 years) during 5 years. The surgical procedure for all patients was suboccipital craniectomy, C1 laminectomy, and autologous duraplasty. RESULTS: Morphometric measurements demonstrated an enlargement of the CSF areas posterior to the cerebellar tonsils after the operation, which remained largely stable through the following years. There was a decrease in pain and improved quality of life after the operation, which remained steady during the following years. Reduction in pain and improved quality of life correlated with CSF area morphometrics. CONCLUSIONS: Most changes in MR imaging morphometrics and quality of life measures occurred within the first year after the operation. A 1-year follow-up period after Chiari I malformation surgery is usually sufficient for evaluating surgical efficacy and postoperative MR imaging changes.

Diurnal Range and Intra-patient Variability of ACTH Is Restored With Remission in Cushing's Disease.

CONTEXT: Single ACTH measurements have limited ability to distinguish patients with Cushing's disease (CD) from those in remission or with other conditions. OBJECTIVE: To investigate the changes in ACTH levels before and after transsphenoidal surgery (TSS) to identify trends that could confirm remission from CD and help establish ACTH cutoffs for targeted clinical trials in CD. DESIGN: Retrospective analysis of CD patients who underwent TSS from 2005 to -2019. SETTING: Referral center. PATIENTS: CD patients (n = 253) with ACTH measurements before and after TSS. INTERVENTIONS: TSS for CD. MAIN OUTCOME MEASURES: Remission after TSS. RESULTS: Remission was observed in 223 patients after TSS. Those in remission had higher ACTH variability at AM (P = .02) and PM (P < .001) time points compared to nonremission. The nonremission group had a significantly narrower diurnal range compared to the remission group (P = <.0001). A decrease in plasma ACTH of ≥50% from mean preoperative levels predicted CD remission after TSS, especially when using PM values. The absolute plasma ACTH concentration and ratio of preoperative to postoperative values were significantly associated with nonremission after multivariable logistic regression (adj P < .001 and .001, respectively). CONCLUSIONS: Our findings suggest that ACTH variability is suppressed in CD, and remission from CD is associated with the restoration of this variability. Furthermore, a decrease in plasma ACTH by 50% or more may serve as a predictor of remission post-TSS. These insights could guide clinicians in developing rational outcome measures for interventions targeting CD adenomas.

Cortisol and ACTH Measurements at Extubation From Pituitary Surgery Predicts Hypothalamic-Pituitary-Adrenal Axis Function.

Context: Early prediction of hypothalamic-pituitary-adrenal (HPA) axis function following transsphenoidal surgery (TSS) can improve patient safety and reduce costs. Objective: Systematic measurement of ACTH and cortisol at extubation following anesthesia to predict remission from Cushing's disease (CD) and HPA axis preservation following non-CD surgery. Design: Retrospective analysis of clinical data between August 2015 and May 2022. Setting: Referral center. Patients: Consecutive patients (n = 129) undergoing TSS who had perioperative ACTH and cortisol measurements. Interventions: ACTH and cortisol measurement at extubation. Further serial 6-hourly measurements in CD patients. Main outcome measures: Prediction of future HPA axis status based on ACTH/cortisol at extubation. Results: ACTH and cortisol increased sharply in all patients at extubation. CD patients (n = 101) had lower ACTH values than non-CD patients (110.1 vs 293.1 pg/mL; P < 0.01). In non-CD patients, lower plasma ACTH at extubation predicted the need for eventual corticosteroid replacement (105.8 vs 449.1 pg/mL, P < 0.01). In CD patients, the peak post-extubation cortisol at 6 hours was a robust predictor for nonremission (60.7 vs 219.2 µg/dL, P = 0.03). However, normalized early postoperative value (NEPV; the post-extubation values minus the peak preoperative CRH or desmopressin test values) of cortisol reliably distinguished nonremission earlier, at the time of extubation (-6.1 vs 5.9, P = 0.01), and later. Conclusions: We found that at extubation following TSS, ACTH can predict the need for eventual steroid replacement in non-Cushing's patients. In patients with CD, we found a robust prediction of nonremission with NEPV cortisol at extubation and later.

Neurological Pupil Index as an Indicator of Irreversible Cerebral Edema: A Case Series.

ABSTRACT: BACKGROUND: Assessing the pupillary light reflex is a core component of neurological assessments. Pupil size and reactivity can provide early warning about early neurological decline. Automated infrared pupillometry is noninvasive and easy to use and has greater reliability compared with manual assessments to obtain objective and consistent measurements of pupillary size and reactivity to light. METHODS: This is a case series of 3 patients who had poor baseline clinical neurological examinations. Because it would be more difficult to detect acute neurological deterioration, automated infrared pupillometry and the Neurological Pupil index (NPi) were used in addition to the clinical neurological examination. NPi values < 3.0 prompted further imaging. RESULTS: In each case, abnormal NPi values prompted emergent imaging that confirmed acute cerebral edema and resulted in a change in management and treatment plan. CONCLUSION: The automated infrared pupillometry is a noninvasive monitor that can provide additional objective data in patients with a poor baseline neurological examination in whom it may otherwise be difficult to detect neurological deterioration.

Blood Pressure measurements are site dependent in a cohort of patients with neurological illness.

Blood pressure (BP) management is a crucial part of critical care that directly affects morbidity and mortality. While BP has become a mainstay in patient care, the accuracy and precision of BP measures across commonly used sites (left upper arm, right upper arm, etc.) and methods have not been established. This study begins to fill this gap in literature by testing the null hypothesis that BP measurement does not vary according to site. This is a prospective, non-randomized, cross-sectional study of 80 neurocritical care unit patients. Near simultaneous non-invasive blood pressure (NIBP) readings from 4 different locations (bilateral upper arm, bilateral wrist) and, when available, intra-arterial blood pressure readings (IABP) were included. Pearson correlation coefficients and one-way repeated measures ANOVA were used to observe the systolic, diastolic, and mean arterial pressure (MAP) correlations. The BP measured at the four most common sites (left upper arm, left wrist, right upper arm, right wrist) had adequate correlation coefficients but were statistically significantly different and highly unpredictable. The median inter-site systolic variability was 10 mmHg (IQR 2 to 10 mmHg). The median inter-site MAP variability was 6mmHg with an interquartile range (IQR) of 3 to 9 mmHg. As expected, the values correlated to show that patients with high BP in one site tended to have high BP in another site. However, the unpredictable inter-site variability is concerning within the clinical setting where oftentimes BP measurement site is not standardized but resulting values are nevertheless used for treatment. There is prominent inter-site variability of BP measured across the 4 most common measurement sites. The variability persists across non-invasive (NIBP) and invasive (IABP) methods of assessment.

Objective Pupillometry as an Adjunct to Prediction and Assessment for Oculomotor Nerve Injury and Recovery: Potential for Practical Applications.

BACKGROUND: Pupillary light reflex examinations are intrinsic to any good neurological examination. Consistent evidence has shown that automated pupillometry assessments provide superior accuracy and interrater correlation compared with bedside eye examinations. Pupillary indexes such as the neurological pupil index (NPI) can also provide several hours of warning before the advent of herniation syndromes or third nerve palsy. METHODS: We determined the unique temporal relationship between NPI changes and third nerve palsy occurrence and recovery in an initially neurologically intact hospitalized patient. A 53-year-old woman presented with aneurysmal subarachnoid hemorrhage and headaches. Her aneurysm was treated surgically without complications. After lumbar drainage for hydrocephalus, she developed isolated left third nerve palsy that slowly recovered over the following weeks. Pupilometer data were obtained throughout her hospital stay. RESULTS: A total of 121 pupillary measurement sets were obtained. The NPI had decreased to an abnormal level (<3) 12 hours before she became symptomatic. The NPI also started improving 24 hours before improvement in her clinical examination. The patient did not display signs of neurological dysfunction related to vasospasm during her stay. CONCLUSION: The NPI seems to reliably correlate with third nerve function and appears to possess predictive temporal properties that could allow practitioners to anticipate neurological injury and recovery. These findings could affect the fields of neurosciences, trauma, military medicine, critical care, and ophthalmology.