Botulinum toxin (BT), a first-line treatment for focal dystonias in adults, has gained USA Food and Drug Administration approval for pediatric upper and lower extremity spasticity and sialorrhea, ...though its use in children younger than 2 years old is still considered off-label treatment for all pathologies. Dosing, treatment strategies and outcome measures lack international consensus, and they are often extrapolated from adult or spasticity guidelines. This review aims to evaluate the best available evidence on the efficacy and safety of BT therapy in pediatric dystonia (age under 21 years old), isolated or associated with other medical conditions. A comprehensive search in PubMed, Scopus and Web of Science was conducted, including only articles in English. Although no randomized controlled trials are still present, 12 articles were included with an overall of 57 patients. All the papers demonstrate that BT can improve motor function, decrease pain and ameliorate quality of life, with minimal adverse effects in pediatric patients affected by pure or mixed dystonic motor disorders. Despite the low level of evidence, our review shows that BT could be an efficacious treatment for these pediatric patients. The frequent generalized involvement, together with the heterogeneous nature of childhood dystonic forms, sometimes intermingled with spasticity, prompts further multicenter clinical trials or prospective studies with a higher level of evidence to shed light on the efficacy and safety profile of BT in pediatric dystonia.
Camptocormia is a disabling complication of Parkinson's disease (PD), but its pathophysiology is poorly elucidated. Depending on the fulcrum of forward trunk flexion, two subtypes have been defined, ...upper (UCC) and lower camptocormia, the former being much more frequent. The aim of the study was to explore possible pathophysiological mechanisms of PD-related UCC.
Ten PD patients with UCC (UCC-PD) and ten PD patients without camptocormia (NoUCC-PD) underwent simultaneous electromyography (EMG) of thoracic paraspinal (TPS), obliquus externus abdominis (OEA), rectus abdominis (RA), and iliopsoas (IP) muscles during relaxed standing (both groups) and trunk realignment (UCC-PD group). Quantitative EMG and magnetic resonance imaging (MRI) of TPS muscles were also performed.
UCC-PD patients showed hyperactivity of TPS and OEA muscles in quiet stance. During voluntary trunk extension, hyperactivity of OEA muscles persisted, thus revealing a co-contraction of flexor and extensor trunk muscles. Motor unit potentials (MUP) of TPS muscles showed shorter duration (p = 0.005) and lower amplitude (p = 0.004) in UCC-PD than in NoUCC-PD patients. MRI did not detect significant between-group differences in the cross-sectional area and fat fraction of TPS muscles, although the latter was higher in the UCC-PD than in the NoUCC-PD group at all thoracic levels.
Our findings suggest that hyperactivity of OEA might sustain UCC in PD. Concurrent mild myopathic changes in TPS muscles in PD with UCC may be secondary to muscle disuse but nevertheless may contribute to abnormal trunk posture.
•Co-contraction of antagonistic trunk muscles exists in upper camptocormia.•Obliquus externus muscles play a crucial role in upper camptocormia.•Thoracic paraspinal muscles show subtle myopathic EMG changes in upper camptocormia.•Central and peripheral patomechanisms contribute to PD-related upper camptocormia.
Several observations would suggest that dystonic pain is not simply muscular in origin. While ascending nociceptive pathways are normal in cervical dystonia, it is unknown whether descending ...inhibitory pain pathways are also normal.
We applied a conditioned pain modulation protocol and concomitantly recorded laser evoked potentials in patients with cervical dystonia (n = 15), blepharospasm (n = 15) and healthy volunteers (n = 15).
During the application of a heterotopic noxious conditioning stimulation, patients with cervical dystonia, but not with blepharospasm, lacked the physiological reduction of the perceived intensity of a painful test stimulus as well as of the related evoked potential. This was observed in cervical dystonia patients regardless of the presence of clinical pain.
Our results suggest that pain in CD is not simply muscular in origin but it also possibly reflects a dysfunction of the descending pain inhibitory control, thus providing a novel venue to explore the pathophysiology of pain in CD.
•Several lines of clinical evidence suggest that pain in cervical dystonia is not merely driven by excessive muscular contractions•We tested the function of inhibitory descending pain pathways in cervical dystonia, bepharospasm and healthy volunteers through a conditioned pain paradigm•During the application of a conditioning stimulus, patients with cervical dystonia lacked both the physiological reduction of perception of pain and of the nocicpetive evoked potentials to laser stimuli as compared to patients with blepharospasm and healthy subjects•Abnormal inhibitory descending pain pathway might predispose patients with cervical dystonia to develop clinical pain
Introduction
Intraoperative neurophysiologic monitoring (IOM) is nowadays extensively used to minimize neurological morbidity in tethered cord surgery. Our goal is to describe and discuss the ...standard IOM techniques used during these surgical procedures and to summarize our clinical experience using a multimodal IOM approach.
Material and methods
Neurophysiological mapping of the conus-cauda is performed through direct stimulation of these structures and bilateral recording from segmental target muscles. While mapping identifies ambiguous neural structures, their functional integrity during surgery can be assessed by monitoring techniques only, such as somatosensory evoked potentials (SEPs), transcranial motor-evoked potentials (MEPs) from the limb muscles and anal sphincters, and the bulbocavernosus reflex (BCR).
Results
Between 2002 and 2012, we performed 48 surgical procedures in 47 patients with a tethered cord secondary to a variety of spinal dysraphisms. The monitorability rate was 84 % for SEPs, 97 % for limb muscle MEPs, 74 % for the anal sphincter MEPs, and 59 % for the BCR. In all patients but one, SEP, MEP, and BCR remained stable during surgery. Postoperatively, two out of 47 patients presented a significant—though transient—neurological worsening. In six patients, an unexpected muscle response was evoked by stimulating tissue macroscopically considered as not functional.
Conclusions
Mapping techniques allow identifying and sparing functional neural tissue and vice versa to cut nonfunctional structures that may contribute to cord tethering. Monitoring techniques, MEP and BCR in particular, improve the reliability of intraoperative neurophysiology, though these may require a higher degree of neuromonitoring expertise. IOM minimizes neurological morbidity in tethered cord surgery.
Pisa Syndrome is clinically defined as the sustained lateral bending of the trunk worsened by a prolonged sitting position or by walking. Pisa syndrome, also termed lateral trunk flexion (LTF), has ...been rarely reported in patients affected by Parkinson’s disease (PD) and, therefore, the pathophysiology has been poorly investigated. In some cases, the hyperactivity of paravertebral muscles contralateral to the leaning side has been interpreted as a sign of dystonia; however, it is well known that paravertebral muscles flex the trunk ipsilaterally. We systematically explored the pattern of muscular activation underlying the lateral flexion of trunk in 10 PD patients (mean disease duration: 9.2 ± 3.0 years) presenting LTF for 3.6 ± 2.1 years. EMG performed during stance and during left and right lateral trunk flexion showed a continuous ipsilateral muscular hyperactivity in three patients, while in the remaining ones there was no ipsilateral activity during standing and a tonic contraction of paravertebral muscles contralateral to the leaning side. In conclusion, this EMG study investigating the synergies of paravertebral muscles during dynamic conditions detected two different patterns with a typical dystonic activation in only a minority of cases. Possible pathophysiologic mechanisms and treatment approaches are discussed.
Awake surgery requires coordinated teamwork and communication between the surgeon and the anesthesiologist, as he monitors the patient, the neuroradiologist as he interprets the images for ...intraoperative confirmation, and the neuropsychologist and neurophysiologist as they evaluate in real-time the patient's responses to commands and questions. To improve comparison across published studies on clinical assessment and operative settings in awake surgery, we reviewed the literature, focusing on methodological differences and aims. In complex, interdisciplinary medical care, such differences can affect the outcome and the cost-benefit ratio of the treatment. Standardization of intraoperative mapping and related controversies will be discussed in Part II.
Neurophysiological testing of the pelvic floor is recognized as an essential tool to identify pathophysiological mechanisms of pelvic floor disorders, support clinical diagnosis, and aid in ...therapeutic decisions. Nevertheless, the diagnostic value of these tests in specific neurological diseases of the pelvic floor is not completely clarified. Seeking to fill this gap, the members of the Neurophysiology of the Pelvic Floor Study Group of the Italian Clinical Neurophysiology Society performed a systematic review of the literature to gather available evidence for and against the utility of neurophysiological tests. Our findings confirm the utility of some tests in specific clinical conditions e.g. concentric needle electromyography, evaluation of sacral reflexes and of pudendal somatosensory evoked potentials (pSEPs) in cauda equina and conus medullaris lesions, and evaluation of pSEPs and perineal sympathetic skin response in spinal cord lesions, and support their use in clinical practice. Other tests, particularly those not currently supported by high-level evidence, when employed in individual patients, should be evaluated in the overall clinical context, or otherwise used for research purposes.
Introduction:
Near‐infrared spectroscopy (NIRS) is a non‐invasive technique used to measure tissue oxygenation. In this study we describe oxyneurography (ONG), a novel application of the NIRS ...technique in non‐invasive surface measurement of oxygenation in ulnar nerve.
Methods:
NIRS sensors were applied directly over the ulnar epicondylar groove to measure the ulnar nerve ONG index, a ratio of oxygenated over total hemoglobin content. Ulnar motor conduction studies were obtained in all subjects.
Results:
The ONG index and ulnar motor conduction had a positive linear association. Ulnar motor conduction could be linearly predicted by the ONG index. The ONG index showed a sensitivity of 1.0 and a specificity of 0.852 for the presence of an ulnar neuropathy symptom. During limb ischemia, the ONG index gradually decreased.
Conclusions:
Oxyneurography can lead to the early detection of a compromise in a nerve's oxygenation status leading to neuropathy. Muscle Nerve 45:75–80, 2012
Delta-9-tetrahydrocannabinol (THC)/cannabidiol (CBD) (nabiximols or Sativex
) is an oromucosal spray formulation containing THC and CBD at an approximately 1:1 fixed ratio. Its administration for the ...treatment of pain in patients with multiple sclerosis (MS) has been established. MS patients generally complain of different kinds of pain, including spasticity-related and neuropathic pain. In this study, we compared and evaluated pain modulation and thermal/pain threshold of MS patients before and after THC/CBD administration.
19 MS patients underwent clinical examination, numerical rating scale (NRS), quantitative sensory testing (QST), and laser-evoked potentials (LEPs) before and after 1 month of therapy. Psychophysiological and neurophysiological data were compared to sex- and age-matched controls.
Patients reported a significant reduction in pain. We found statistically significant differences in LEP parameters between patients and controls but no significant change in LEP measures after THC/CBD therapy. Cold and heat detection thresholds were altered in patients but did not change after THC/CBD therapy. There was a significant increase in cold pain threshold by hand stimulation and a significant reduction in abnormal cold perception thresholds.
Our results indicate that Sativex
therapy provides pain relief in MS patients and suggest that it might modulate peripheral cold-sensitive TRP channels.
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