Faculty Bibliography

OBJECTIVE: Rotator cuff tendon tears are the most common soft tissue injuries in the shoulder joint. Various animal models have been described for this condition, but all current translational animal models have inherent weaknesses in their ability to generate chronically degenerated rotator cuff tendons. The objective of this study was to evaluate a partial infraspinatus tendon transection model as a means of creating a chronically degenerated rotator cuff tendon in an ovine model and compare the injury characteristics of this model to those observed in human patients with severe chronic rotator cuff tendon injuries. STUDY DESIGN/METHODS: The infraspinatus tendons of six sheep were partially detached followed by capping of the detached medial section of the tendon with Gore-Tex. Human tissue samples of the supraspinatus tendon were harvested from patients undergoing primary reverse shoulder arthroplasty and served as positive controls of chronic rotator cuff tendinopathy. RESULTS: Transected sheep tendons were characterized predominantly by an acute reactive and reparative pathological process as compared with the chronic degenerative changes observed in the human tendons. In contrast, the non-transected portion of the ovine tendon showed histological changes, which were more chronic and degenerative in nature when compared with the transected tendon. CONCLUSION/CONCLUSIONS: Overall, histological features of the non-transected portion of ovine tendon were more similar to those observed in the chronic degenerated human tendon.

BACKGROUND:Optical coherence tomography (OCT) studies have demonstrated differences between people with schizophrenia and controls. Many questions remain including the agreement between scanners. The current study seeks to determine inter-device agreement of OCT data in schizophrenia compared to controls and to explore the relations between OCT and visual function measures. METHODS:Participants in this pilot study were 12 individuals with schizophrenia spectrum disorders and 12 age- and sex-matched controls. Spectralis and Cirrus OCT machines were used to obtain retinal nerve fiber layer (RNFL) thickness and macular volume. Cirrus was used to obtain ganglion cell layer + inner plexiform layer (GCL + IPL) thickness. Visual function was assessed with low-contrast visual acuity and the King-Devick test of rapid number naming. RESULTS:There was excellent relative agreement in OCT measurements between the two machines, but poor absolute agreement, for both patients and controls. On both machines, people with schizophrenia showed decreased macular volume but no difference in RNFL thickness compared to controls. No between-group difference in GCL + IPL thickness was found on Cirrus. Controls showed significant associations between King-Devick performance and RNFL thickness and macular volume, and between low-contrast visual acuity and GCL + IPL thickness. Patients did not show significant associations between OCT measurements and visual function. CONCLUSIONS:Good relative agreement suggests that the offset between machines remains constant and should not affect comparisons between groups. Decreased macular volume in individuals with schizophrenia on both machines supports findings of prior studies and provides further evidence that similar results may be found irrespective of OCT device.

BACKGROUND:Verification of complete occlusion or resection of neurovascular lesions is often done with intraoperative angiography. Surgery for spinal vascular lesions such as arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) is typically performed in the prone position making intraoperative angiography difficult. There is no standardized protocol for intraoperative angiography in spinal surgeries performed in the prone position. OBJECTIVE:We describe our experience with using radial artery access for intraoperative angiography in thoracic spinal neurovascular procedures performed with patients in the prone position. METHODS:We reviewed all patients who underwent surgical resection of spinal vascular lesions in the prone position with radial artery vascular access for intraoperative angiography. Patients were treated in a hybrid endovascular operating room. RESULTS:4 patients were treated in the pone position utilizing transradial artery access intraoperative angiography for confirmation of complete resection of the vascular lesions. 2 patients were operated for dural AVFs, one patient had a pial AVF, and one patient had an AVM of the filum terminale. None of the patients faced any procedural complications. CONCLUSION/CONCLUSIONS:Radial artery access for intraoperative angiography in spinal neurovascular procedures in which selective catheterization of a thoracic branch is necessary, is feasible, safe, and practical.

Background and aims: Distinguishing neurogenic orthostatic hypotension (nOH) from other causes of blood pressure (BP) instability is of pivotal importance in clinical practice. Norcliffe-Kaufmann et al. recently showed that when the ratio between the heart rate increase and the systolic BP fall after 3 minutes of passive head-up tilt (HUT) is <0.492, this indicates nOH. Here we aimed at validating this nOH ratio with standard arm-cuff BP measurements upon active standing (AS).
Method(s): We screened all patients who had undergone cardiovascular autonomic function testing at the Innsbruck Medical University between January 2008 and September 2019.
Result(s): We included 51 patients (27 with Parkinson's disease, 22 with multiple system atrophy) diagnosed with orthostatic hypotension either upon AS or HUT. 49 patients showed no BP overshoot after the Valsalva maneuver and were thus classified as having nOH. Out of these, 27 patients showed a systolic BP fall >=20mmHg in both the HUT and the AS and were considered for further analysis. The nOH ratio was <0.492 for 20 patients during HUT and for 19 patients during the AS. The sensitivity of the nOH ratio for neurogenic OH was therefore 74% upon HUT and 70% upon AS. The correlation between the nOH-ratio upon HUT and AS was strong (rho=0.86, p<0.001).
Conclusion(s): A nOH ratio <0.492 evaluated with standard arm-cuff heart rate and BP measurements has a good sensitivity for nOH both upon HUT and AS. This ratio can be therefore used as bedside nOH screening measure, if no tilt-test facilities are available

Children with cleft and craniofacial conditions commonly present with concurrent airway anomalies, which often manifest as sleep disordered breathing. Craniofacial surgeons and members of the multidisciplinary team involved in the care of these patients should appreciate and understand the scope of airway pathology as well as the proper means of airway assessment. This review article details the prevalence and assessment of sleep disordered breathing in patients with craniofacial anomalies, with emphasis on indications, limitations, and interpretation of polysomnography.

BACKGROUND AND PURPOSE/OBJECTIVE:The brain stem is a complex configuration of small nuclei and pathways for motor, sensory, and autonomic control that are essential for life, yet internal brain stem anatomy is difficult to characterize in living subjects. We hypothesized that the 3D fast gray matter acquisition T1 inversion recovery sequence, which uses a short inversion time to suppress signal from white matter, could improve contrast resolution of brain stem pathways and nuclei with 3T MR imaging. MATERIALS AND METHODS/METHODS:-space to reduce motion; total scan time = 58 minutes). One subject returned for an additional 5-average study that was combined with a previous session to create a highest quality atlas for anatomic assignments. A 1-mm isotropic resolution, 12-minute version, proved successful in a patient with a prior infarct. RESULTS:The fast gray matter acquisition T1 inversion recovery sequence generated excellent contrast resolution of small brain stem pathways in all 3 planes for all 10 subjects. Several nuclei could be resolved directly by image contrast alone or indirectly located due to bordering visualized structures (eg, locus coeruleus and pedunculopontine nucleus). CONCLUSIONS:The fast gray matter acquisition T1 inversion recovery sequence has the potential to provide imaging correlates to clinical conditions that affect the brain stem, improve neurosurgical navigation, validate diffusion tractography of the brain stem, and generate a 3D atlas for automatic parcellation of specific brain stem structures.

OBJECTIVE:To assess the proportion of individuals who report dizziness and/or vertigo during the prodromal phase or headache phase of migraine. METHODS:The databases of MEDLINE and EMBASE were searched for studies on dizziness and/or vertigo during the prodromal phase or headache phase of migraine. Pooled relative frequencies were estimated using a random-effects meta-analysis. RESULTS: = 87%). Study quality was rated 5/9 or below for seven studies and 6/9 or above for two studies. CONCLUSION/CONCLUSIONS:We found that there is a scarcity of literature on dizziness and vertigo as prodromal- and headache-associated symptoms in individuals with migraine. Methodological variations confound comparisons of epidemiological patterns, although it appears that dizziness and vertigo are more frequent during the headache phase of migraine, compared with the prodromal phase. Future studies should ensure use of standardized definitions and rigorous methodology to enable accurate measurements of dizziness and vertigo in migraine.

Functional imaging studies have implicated an area in the left lateral fusiform gyrus, known as the visual word form area (VWFA), in pre-lexical orthographic processing. There are very few studies that have examined the functional specificity of this area in patients with discrete lesions limited to this region. Here we describe a rare opportunity to examine the functional specificity of the VWFA in a patient with stereo EEG (sEEG) electrodes implanted for localization of seizures prior to epilepsy surgery. sEEG offers the opportunity to create a transient and highly localized electrophysiological lesion to examine brain behavior correlates during functional mapping. In this case, word reading and writing as well as a variety of non-orthographic language functions (e.g., picture and face naming, auditory naming, and non-word repetition), were tested during electrical stimulation at a series of different electrode contact sites in the ventral temporal region. Pure alexia resulted from stimulation of the lateral fusiform gyrus at coordinates nearly identical to those published for the VWFA in the functional imaging literature.

OBJECTIVE:A meta-analysis of published studies was performed to determine whether the efficacy of antiseizure drugs in adults with primary generalized tonic-clonic seizures (PGTCS) is comparable with that in the pediatric population (2-12 years of age). METHODS:Electronic searches were conducted in EMBASE, Medline, and the Cochrane Central Register of Controlled Trials for clinical trials of PGTCS in adults and children 2-12 years of age. Neurologists used standardized search and study evaluations to select eligible trials. Median percent reduction in seizure frequency from baseline and ≥50% responder rates were used to compare drug efficacy in adults and children. RESULTS:Among 7 adjunctive-therapy PGTCS trials in adults and children (2-12 years of age) that met evaluation criteria, effect sizes were consistent between adults and children for lamotrigine and topiramate. The baseline-subtracted median percent seizure reduction in seizure frequency ranged from 50.0% to 79.7% in children and 57.0% to 64.0% in adults. The ≥50% responder rate was similar between children and adults in a topiramate study (50% in children compared with 58% in adults). CONCLUSIONS:This meta-analysis supports the use of drug response from antiseizure drug clinical trials for PGTCS in adults to predict comparable treatment response in children 2-12 years of age with PGTCS.