Background and purpose Trigeminal neuralgia (TN) is an extremely painful condition which can be difficult to diagnose and treat. In Europe, TN patients are managed by many different specialities. Therefore, there is a great need for comprehensive European guidelines for the management of TN. The European Academy of Neurology asked an expert panel to develop recommendations for a series of questions that are essential for daily clinical management of patients with TN. Methods A systematic review of the literature was performed and recommendations was developed based on GRADE, where feasible; if not, a good practice statement was given. Results The use of the most recent classification system is recommended, which diagnoses TN as primary TN, either classical or idiopathic depending on the degree of neurovascular contact, or as secondary TN caused by pathology other than neurovascular contact. Magnetic resonance imaging (MRI), using a combination of three high‐resolution sequences, should be performed as part of the work‐up in TN patients, because no clinical characteristics can exclude secondary TN. If MRI is not possible, trigeminal reflexes can be used. Neurovascular contact plays an important role in primary TN, but demonstration of a neurovascular contact should not be used to confirm the diagnosis of TN. Rather, it may help to decide if and when a patient should be referred for microvascular decompression. In acute exacerbations of pain, intravenous infusion of fosphenytoin or lidocaine can be used. For long‐term treatment, carbamazepine or oxcarbazepine are recommended as drugs of first choice. Lamotrigine, gabapentin, botulinum toxin type A, pregabalin, baclofen and phenytoin may be used either alone or as add‐on therapy. It is recommended that patients should be offered surgery if pain is not sufficiently controlled medically or if medical treatment is poorly tolerated. Microvascular decompression is recommended as first‐line surgery in patients with classical TN. No recommendation can be given for choice between any neuroablative treatments or between them and microvascular decompression in patients with idiopathic TN. Neuroablative treatments should be the preferred choice if MRI does not demonstrate any neurovascular contact. Treatment for patients with secondary TN should in general follow the same principles as for primary TN. In addition to medical and surgical management, it is recommended that patients are offered psychological and nursing support. Conclusions Compared with previous TN guidelines, there are important changes regarding diagnosis and imaging. These allow better characterization of patients and help in decision making regarding the planning of medical and surgical management. Recommendations on pharmacological and surgical management have been updated. There is a great need for future research on all aspects of TN, including pathophysiology and management.

AMP-activated protein kinase (AMPK) β1 or β2 subunits are required for assembling of AMPK heterotrimers and are important for regulating enzyme activity and cellular localization. In skeletal muscle, α2β2γ3-containing heterotrimers predominate. However, compensatory up-regulation and redundancy of AMPK subunits in wholebody AMPK α2, β2, and γ3 null mice has made it difficult to determine the physiological importance of AMPK in regulating muscle metabolism, because these models have normal mitochondrial content, contraction-stimulated glucose uptake, and insulin sensitivity. In the current study, we generated mice lacking both AMPK β1 and β2 isoforms in skeletal muscle (β1β2M-KO). β1β2M-KO mice are physically inactive and have a drastically impaired capacity for treadmill running that is associated with reductions in skeletal muscle mitochondrial content but not a fiber-type switch. Interestingly, young β1β2M-KO mice fed a control chow diet are not obese or insulin resistant but do have impaired contraction-stimulated glucose uptake. These data demonstrate an obligatory role for skeletal muscle AMPK in maintaining mitochondrial capacity and contraction-stimulated glucose uptake, findings that were not apparent in mice with single mutations or deletions in muscle α, β, or γ subunits.is an evolutionarily conserved stress-sensing kinase that controls energy metabolism and appetite by responding to nutrients and hormones (1). The regulation of AMPK activity depends on AMP and ADP regulated phosphorylation of the α catalytic subunit at T172 by the upstream kinases LKB1 and Ca 2+ /CaM-dependent protein kinase kinase (CaMKKβ; refs. 2 and 3). AMPK exists as a heterotrimer, consisting of an α catalytic subunit (α1, α2), a scaffolding β subunit (β1, β2) and a nucleotide-binding γ subunit (γ1, γ2, γ3) (1). The C-terminal of the β subunit contains a highly conserved α and γ subunit-binding sequence (SBS) that is required for the formation of a stable, active AMPK αβγ complex (4). We recently reported on the physiological effects of germline deletion of β1 (5) and β2 (6) isoforms in mice. We showed that β1 null mice have reduced AMPK α-subunit expression and activity in liver, adipose tissue and the hypothalamus (5). In contrast, AMPK β2 null mice have reduced AMPK activity in skeletal muscle, are aminoimidazole carboxamide ribonucleotide (AICAR) insensitive and have reduced exercise tolerance despite a greater than 50% increase in muscle β1 protein expression (6). The phenotype of β2 null mice was similar to that of mice lacking α2 (7) or γ3 (8) subunits or muscle-specific overexpression of an α2 kinase dead (KD) mutation (9, 10).During exercise, AMPK is activated in an intensity-dependent manner (for review, see ref. 11). Mice with reduced AMPK in muscle are exercise intolerant, an effect shown not to be due to cardiac impairments in AMPK (12-14). However, the cause for this reduction in exercise capacity remains largely unknown, because mitochondrial content and glucose uptake are not altered (6,7,10,12,(15)(16)(17) or onl...

Introduction Trigeminal neuralgia (TN) is characterized by touch-evoked unilateral brief shock-like paroxysmal pain in one or more divisions of the trigeminal nerve. In addition to the paroxysmal pain, some patients also have continuous pain. TN is divided into classical TN (CTN) and secondary TN (STN). Etiology and pathophysiology Demyelination of primary sensory trigeminal afferents in the root entry zone is the predominant pathophysiological mechanism. Most likely, demyelination paves the way for generation of ectopic impulses and ephaptic crosstalk. In a significant proportion of the patients, the demyelination is caused by a neurovascular conflict with morphological changes such as compression of the trigeminal root. However, there are also other unknown etiological factors, as only half of the CTN patients have morphological changes. STN is caused by multiple sclerosis or a space-occupying lesion affecting the trigeminal nerve. Differential diagnosis and treatment Important differential diagnoses include trigeminal autonomic cephalalgias, posttraumatic or postherpetic pain and other facial pains. First line treatment is prophylactic medication with sodium channel blockers, and second line treatment is neurosurgical intervention. Future perspectives Future studies should focus on genetics, unexplored etiological factors, sensory function, the neurosurgical outcome and complications, combination and neuromodulation treatment as well as development of new drugs with better tolerability.

Oral administration of therapeutic peptides is hindered by poor absorption across the gastrointestinal barrier and extensive degradation by proteolytic enzymes. Here, we investigated the absorption of orally delivered semaglutide, a glucagon-like peptide-1 analog, coformulated with the absorption enhancer sodium N-[8-(2-hydroxybenzoyl) aminocaprylate] (SNAC) in a tablet. In contrast to intestinal absorption usually seen with small molecules, clinical and preclinical dog studies revealed that absorption of semaglutide takes place in the stomach, is confined to an area in close proximity to the tablet surface, and requires coformulation with SNAC. SNAC protects against enzymatic degradation via local buffering actions and only transiently enhances absorption. The mechanism of absorption is shown to be compound specific, transcellular, and without any evidence of effect on tight junctions. These data have implications for understanding how highly efficacious and specific therapeutic peptides could be transformed from injectable to tablet-based oral therapies.

Objective.-To prospectively describe the clinical characteristics of classical trigeminal neuralgia (TN) in a standardized manner.Background.-TN is a rare disease and most clinicians only see a few patients. There is a lack of prospective systematic studies of the clinical characteristics of TN. We hypothesized that contrary to current thinking, some TN patients suffer from sensory abnormalities at neurological examination.Methods.-Clinical characteristics such as demographics, pain characteristics, and comorbidities were systematically and prospectively collected from consecutive TN patients in a tertiary referral center in a cross-sectional study.Results.-A total of 158 patients were included. Average age of onset was 52.9 years. TN was more prevalent in women (95; 60%) than in men (63; 40%), P = .011, and more often located on the right (89; 56%) than on the left side (64; 41%), P = .043. It affected solely the second and/or third trigeminal branch in 109 (69%) while the first branch alone was affected in only 7 (4%). Notably, 78 (49%) had concomitant persistent pain in addition to paroxysmal stabbing pain. Autonomic symptoms were present in 48 (31%). Patients who had not undergone surgery for TN had sensory abnormalities in 35 (29%).Conclusions.-This, the first study in a series of papers focusing on the clinical, radiological, and etiological aspects of TN, revealed that the symptomatology of TN includes a high percentage of concomitant persistent pain, autonomic symptoms, and sensory abnormalities. These findings offer new insights to the prevailing clinical impression of the clinical characteristics in TN.

In skeletal muscle, the actin cytoskeleton-regulating GTPase, Rac1, is necessary for insulin-dependent GLUT4 translocation. Muscle contraction increases glucose transport and represents an alternative signaling pathway to insulin. Whether Rac1 is activated by muscle contraction and regulates contraction-induced glucose uptake is unknown. Therefore, we studied the effects of in vivo exercise and ex vivo muscle contractions on Rac1 signaling and its regulatory role in glucose uptake in mice and humans. Muscle Rac1-GTP binding was increased after exercise in mice (∼60–100%) and humans (∼40%), and this activation was AMP-activated protein kinase independent. Rac1 inhibition reduced contraction-stimulated glucose uptake in mouse muscle by 55% in soleus and by 20–58% in extensor digitorum longus (EDL; P < 0.01). In agreement, the contraction-stimulated increment in glucose uptake was decreased by 27% (P = 0.1) and 40% (P < 0.05) in soleus and EDL muscles, respectively, of muscle-specific inducible Rac1 knockout mice. Furthermore, depolymerization of the actin cytoskeleton decreased contraction-stimulated glucose uptake by 100% and 62% (P < 0.01) in soleus and EDL muscles, respectively. These are the first data to show that Rac1 is activated during muscle contraction in murine and human skeletal muscle and suggest that Rac1 and possibly the actin cytoskeleton are novel regulators of contraction-stimulated glucose uptake.

No abstract

Neurovascular contact is considered a frequent cause of classical trigeminal neuralgia and microvascular decompression with transposition of a blood vessel is preferred over other surgical options in medically refractory patients with classical trigeminal neuralgia. However, the prevalence of neurovascular contact has not been investigated in a representative cohort of patients with classical trigeminal neuralgia based in a neurological setting and using high-quality neuroimaging and blinded evaluation. We aimed to investigate whether presence and degree of neurovascular contact are correlated to pain side in classical trigeminal neuralgia. Consecutive classical trigeminal neuralgia patients with unilateral symptoms were referred to 3.0 T magnetic resonance imaging and included in a cross-sectional study. Magnetic resonance imaging scans were evaluated blindly and graded according to presence and degree of neurovascular contact. Severe neurovascular contact was defined as displacement or atrophy of the trigeminal nerve. A total of 135 patients with classical trigeminal neuralgia were included. Average age of disease onset was 53.0 years (95% confidence interval mean 40.5-55.5) and current age was 60.1 years (95% % confidence interval mean 57.5-62.7). Eighty-two (61%, 95% confidence interval 52-69%) patients were female. Neurovascular contact was prevalent both on the symptomatic and asymptomatic side [89% versus 78%, P = 0.014, odds ratio = 2.4 (1.2-4.8), P = 0.017], while severe neurovascular contact was highly prevalent on the symptomatic compared to the asymptomatic side [53% versus 13%, P < 0.001, odds ratio = 11.6 (4.7-28.9), P < 0.001]. Severe neurovascular contact was caused by arteries in 98%. We conclude that neurovascular contact causing displacement or atrophy of the trigeminal nerve is highly associated with the symptomatic side in classical trigeminal neuralgia as opposed to neurovascular contact in general. Our findings demonstrate that severe neurovascular contact is involved in the aetiology of classical trigeminal neuralgia and that it is caused by arteries located in the root entry zone.