Doris Lieba-Samal

The pattern and time course of somatosensory changes in the human UVB sunburn model reveal the presence of peripheral and central sensitization.

Summary Ultraviolet B irradiation induces generalized hyperalgesia to all pain modalities primarily on the basis of multiple mechanisms of peripheral sensitization, but also involves central sensitization (secondary hyperalgesia and dynamic mechanical allodynia). Abstract The ultraviolet B (UVB) sunburn model was characterized with a comprehensive battery of quantitative sensory testing (QST). Primary hyperalgesia in UVB‐irradiated skin and secondary hyperalgesia in adjacent nonirradiated skin were studied in 22 healthy subjects 24 h after irradiation with UVB at 3‐fold minimal erythema dose of a skin area 5 cm in diameter at the thigh and compared to mirror‐image contralateral control areas. The time course of hyperalgesia over 96 h was studied in a subgroup of 12 subjects. Within the sunburn area, cold hyperesthesia (P = .01), profound generalized hyperalgesia to heat (P < .001), cold (P < .05), pinprick and pressure (P < .001), and mild dynamic mechanical allodynia (P < .001) were present. The finding of cold hyperalgesia and cold hyperesthesia is new in this model. The sunburn was surrounded by large areas of pinprick hyperalgesia (mean ± SEM, 218 ± 32 cm2) and a small rim of dynamic mechanical allodynia but no other sensory changes. Although of smaller magnitude, secondary hyperalgesia and dynamic mechanical allodynia adjacent to the UVB‐irradiated area were statistically highly significant. Primary and secondary hyperalgesia developed in parallel within hours, peaked after 24–32 h, and lasted for more than 96 h. These data reveal that the UVB sunburn model activates a broad spectrum of peripheral and central sensitization mechanisms and hence is a useful human surrogate model to be used as a screening tool for target engagement in phases 1 and 2a of drug development.

Characteristics of acute posttraumatic headache following mild head injury

Background: To examine the prevalence and characteristics of acute posttraumatic headache (APTH) attributed to mild head injury within a prospective, observational study design. Methods: We recruited 100 patients with acute mild head injury as defined in the International Classification of Headache Disorders, 2nd Edition (ICHD-2) presenting to the department of trauma surgery at the Medical University of Vienna. Patients underwent a detailed telephone interview between days 7 and 10 and between days 90 and 100 after the injury. Results: The prevalence of APTH was 66%. APTH had occurred within 24 hours after the trauma in 78% and lasted for a median of 3.0 days. Headache was unilateral in 45%. Aggravation by physical activity, nausea and photo-/phonophobia was present in 49%, 42% and 55%, respectively. The prevalence of APTH was related to conditions of chronic pain (excluding headache), pre-existing episodic headache, number of posttraumatic symptoms, anxiety and depression. At follow-up at 90–100 days, posttraumatic headache had abated in all patients. Conclusions: APTH attributed to mild head injury is a common but self-limiting condition frequently showing migrainous features. Participants with chronic pain other than headache, pre-existing headache and affective disorders are at higher risk of developing APTH. None of the patients developed chronic posttraumatic headache.

Migraine and vertigo – a prospective diary study

The objective of the study was to examine migrainous vertigo prospectively by means of a diary. We included 146 patients with at least one migraine attack per month. All patients underwent a semistructured interview, completed questionnaires on depression, anxiety and quality of sleep and kept a diary covering detailed information on headache, vertigo and dizziness over a period of 30 days. A completed diary was returned by 116 patients (79.5%). Based on the diary migrainous vertigo (MV) was diagnosed in 18 patients (15.5%) and non-migrainous vertigo or dizziness (non-MV) in 35 patients (30.2%). MV was present on 65 of 3477 patient days (1.9%) and non-MV on 145 days (4.2%). MV occurred more often on days with headache (P < 0.001). Its median duration was 3 h and it lasted longer on days with headache than on days without headache (P < 0.001). The most prominent specific feature of MV was head motion intolerance. Patients with MV showed anxiety more often (P < 0.001) and tended to have worse quality of sleep and higher depression scores. In conclusion, vertigo and dizziness are frequent symptoms in migraineurs. The 1-month prevalence of MV is 16% and that of non-MV 30% in patients with at least one migraine attack per month. Frequency of MV is higher and duration longer on days with headache. MV is a risk factor for co-morbid anxiety.

Sex Hormones and Primary Headaches Other than Migraine

The relation between sex hormones and migraine has been examined in a series of studies, leading to the definitions of pure menstrual migraine and menstrually-related migraine. The relation between sex hormones and other types of primary headache has been studied less extensively, but there is at least some evidence that hormones in general, and menstruation, pregnancy, or menopause in particular, also impact these disorders. This article reviews the available literature on changes of tension-type headache, cluster headache, other trigeminal autonomic cephalalgias, and hemicrania continua during women’s reproductive periods.

Reliability of assessing lifestyle and trigger factors in patients with migraine--findings from the PAMINA study.

Numerous lifestyle factors are blamed for triggering migraine attacks. The reliability of assessing these factors retrospectively is unknown. Therefore, retrospective and prospective assessments of lifestyle in general and of migraine triggers in particular were compared in patients with migraine.

Neuroimaging of classic neuralgic amyotrophy

Introduction: Neuralgic amyotrophy (NA) often imposes diagnostic problems. Recently, MRI and high‐resolution ultrasound (HRUS) have proven useful in diagnosing peripheral nerve disorders. Methods: We performed a chart and imaging review of patients who were examined using neuroimaging and who were referred because of clinically diagnosed NA between March 1, 2014 and May 1, 2015. Results: Six patients were included. All underwent HRUS, and 5 underwent MRI. Time from onset to evaluation ranged from 2 weeks to 6 months. HRUS showed segmental swelling of all clinically affected nerves/trunks. Atrophy of muscles was detected in those assessed >1 month after onset. MRI showed T2‐weighted hyperintensity in all clinically affected nerves, except for the long thoracic nerve, and denervation edema of muscles. Conclusions: HRUS and MRI are valuable diagnostic tools in NA. This could change the diagnostic approach from one now focused on excluding other disorders to confirming NA through imaging markers. Muscle Nerve 54: 1079–1085, 2016

The course of migraine—a diary study in unselected patients

The course of disease and the predictive value of depression and anxiety in patients with migraine were prospectively examined. We recruited 393 migraineurs through articles in newspapers and performed a follow-up examination 30 months later. At baseline and follow-up, patients underwent a semi-structured interview, filled out the Headache Impact Test (HIT-6), Self-rating Depression Scale (SDS) and Self-rating Anxiety Scale (SAS) and they kept a headache diary for 30 days. One hundred and fifty-one patients (38.6%) were seen at follow-up. The baseline data of patients with and without follow-up were comparable. At follow-up the number of headache days per month had decreased from 9.6 ± 5.8 to 8.1 ± 6.3 (P < 0.001) and the proportion of patients with chronic headache (15.4%) and medication overuse (13%) had remained stable. SDS and SAS scores were associated with a high migraine frequency and high initial SDS scores predicted high migraine frequency at follow-up. This longitudinal study in unselected patients with migraine not excluding subjects with chronic headache, medication overuse, depression or anxiety does not point towards migraine as a progressive disease in the vast majority of patients and confirms the importance of psychiatric comorbidity.

Visualization of the Long Thoracic Nerve using High-Resolution Sonography.

PURPOSE The long thoracic nerve (LTN) innervates the serratus anterior muscle (SA) which plays an important role in shoulder function. Evaluation of the LTN has so far been restricted to clinical assessment and partly electromyography and neurography. Progress of high-resolution ultrasound (HRUS) increasingly enables visualization of small peripheral nerves and their pathologies. We therefore aimed at (a) clarifying the possibility of visualization of the LTN from its origin to the most distal point in the supraclavicular region visible and (b) developing an ultrasound protocol for routine use. We further present two cases of patients with LTN pathology. METHODS The study consisted of two parts: Part 1 included 4 non-enbalmed human bodies in whom the LTN (n = 8) was located and then marked by ink injection. Correct identification was confirmed by anatomical dissection. Part 2 included 20 healthy volunteers whose LTN (n = 40) was assessed independently by two radiologists. Identification of the LTN was defined as consensus in recorded images. RESULTS LTN was clearly visible in all anatomical specimens and volunteers using HRUS and could be followed until the second slip of the serratus anterior muscle from the supraclavicular region. In anatomical specimens, dissection confirmed HRUS findings. For all volunteers, consensus was obtained. The mean nerve diameter was 1.6 mm ± 0.3 (range 1.1 - 2.1 mm) after the formation of the main trunk. DISCUSSION We hereby confirm a reliable possibility of visualization of the LTN in anatomical specimens as well as in volunteers. We encourage HRUS of the LTN to be part of the diagnostic work-up in patients presenting with scapular winging, shoulder weakness or pain of unknown origin.

High-Resolution Ultrasound for Diagnostic Assessment of the Great Auricular Nerve--Normal and First Pathologic Findings.

PURPOSE The great auricular nerve (GAN) is a sensory branch of the superficial cervical plexus. While its blockade is an established procedure, little is known about the ultrasound appearance of pathologic conditions of the GAN itself. We, therefore, aimed to evaluate the possibility of the visualization and diagnostic assessment of the GAN along its entire course by means of high-resolution ultrasound (HRUS). MATERIALS AND METHODS To assess the feasibility of visualization, we performed HRUS with an 18 MHz probe, HRUS-guided, fine-needle ink markings and consecutive dissection in six anatomical specimens. Then, we measured the diameter of the GAN in healthy volunteers and finally performed a retrospective review of patients referred for HRUS examinations because of pain within GAN territory between August 1, 2012 and August 1, 2013. RESULTS The GAN was clearly visible with HRUS from its formation to the final branches, and was marked successfully on both sides in all anatomical specimens (n = 12). The mean average in-vivo was 0.14 cm ± 0.03 (range 0.08-0.2). Seven cases of patients with GAN pathologies of various origins (idiopathic, traumatic, tumorous and iatrogenic) were identified, of which 6 were visible on HRUS and all of which could be confirmed by complete resolution of symptoms after selective HRUS-guided GAN block. CONCLUSION This study confirms the reliable ability to visualize the GAN with HRUS throughout its course, both in anatomical specimens and in vivo. The provided cases show that pathologies of the GAN seem to have a variety of causes and may not be rare. We, therefore, encourage the use of HRUS in patients with unclear pain in the auricular, periauricular and posterior-lateral head.

High-Resolution Axonal Bundle (Fascicle) Assessment and Triple-Echo Steady-State T2 Mapping of the Median Nerve at 7 T: Preliminary Experience.

ObjectivesThe aims of this preliminary study were to determine the number of axonal bundles (fascicles) in the median nerve,1 using a high-resolution, proton density (PD)–turbo spin echo (TSE) fat suppression sequence, and to determine normative T2 values, measured by triple-echo steady state, of the median nerve in healthy volunteers and in patients with idiopathic carpal tunnel syndrome (CTS), at 7 T.2 Materials and MethodsThis prospective study was approved by the local ethics committee and conducted between March 2014 and January 2015. All study participants gave written informed consent. Six healthy volunteers (30 ± 12 years) and 5 patients with CTS (44 ± 16 years) were included. Measurements were performed on both wrists in all volunteers and on the affected wrist in patients (3 right, 2 left). Based on 5-point scales, 2 readers assessed image quality (1, very poor; 5, very good) and the presence of artifacts that might have a possible influence on fascicle determination (1, severe artifacts; 5, no artifacts) and counted the number of fascicles independently on the PD-TSE sequences. Furthermore, T2 values by region of interest analysis were assessed. Student t tests, a hierarchic linear model, and intraclass correlation coefficients (ICCs) were used for statistical analysis. ResultsProton density-TSE image quality and artifacts revealed a median of 5 in healthy volunteers and 4 in patients with CTS for both readers. Fascicle count of the median nerve ranged from 13 to 23 in all subjects, with an ICC of 0.87 (95% confidence interval [CI], 0.67–0.95). T2 values were significantly higher (P = 0.023) in patients (24.27 ± 0.97 milliseconds [95% CI, 22.19–26.38]) compared with healthy volunteers (21.01 ± 0.65 milliseconds [95% CI, 19.61–22.41]). The ICC for all T2 values was 0.97 (95% CI, 0.96–0.98). ConclusionsThis study shows the possibility of fascicle determination of the median nerve in healthy volunteers and patients with CTS (although probably less accurately) with high-resolution 7 T magnetic resonance imaging, as well as significantly higher T2 values in patients with CTS, which seems to be associated with pathophysiological nerve changes.