Peter L. Silbert

SHORT TERM VITAMIN E SUPPLEMENTATION HAS NO EFFECT ON PLATELET FUNCTION, PLASMA PHOSPHOLIPASE A2 AND LYSO‐PAF IN MALE VOLUNTEERS

1. Based largely upon in vitro studies, vitamin E has been reported to inhibit phospholipase A2 activity, to alter phospholipid metabolism and reduce platelet aggregation.

An open label pilot investigation of the efficacy of Botulinum toxin type A [Dysport] injection in the rehabilitation of chronic anterior knee pain

Purpose. To examine the effect of intramuscular injection of botulinum toxin type A [Dysport®] to reduce relative overactivity of the vastus lateralis [VL] muscle, in conjunction with re-training of vastus medialis [VM] muscle as an adjunct to rehabilitation for chronic anterior knee pain. Method. Eight females with chronic (>6 months) history of anterior knee pain, who had failed conservative management, were studied in this open label pilot study. Intramuscular Dysport® injection [300 – 500 units] to the distal third of VL muscle was followed by a 12-week customized home exercise programme to improve recruitment of VM muscle and functional knee control. VL and VM muscle cross sectional area from a standardized spiral CT sequence, isometric quadriceps strength (dynamometry), timed stair task, self-reported pain and disability were assessed. Results. Subjects reported reduced knee pain and brace dependency and increased participation in sporting and daily living activities. Isometric quadriceps muscle strength was maintained or improved despite significant atrophy, evident on CT, of the distal component of VL in the treated limb. Time taken to ascend and descend a flight of stairs improved in all subjects. Subjective and objective improvements were maintained at 24-week follow-up. Conclusions. These pilot data provide preliminary support for the role of Dysport® as an adjunct to non-surgical management of individuals with chronic anterior knee pain. Larger double blind, randomized, placebo-injection controlled studies of this novel approach to improving patellofemoral mechanics are needed to establish the efficacy of this intervention.

Evidence for an excitatory GABAA response in human motor cortex in idiopathic generalised epilepsy

PURPOSE Impaired GABAergic inhibition has been implicated in the pathophysiology of epilepsy. The possibility of a paradoxical excitatory effect of GABA in epilepsy has been suggested, but has not been investigated in vivo. We investigated pre- and post-synaptic GABAergic mechanisms in patients with idiopathic generalised epilepsy (IGE). METHOD In 10 patients and 12 control subjects we explored short- and long-interval intracortical inhibition (SICI, LICI; post-synaptic GABAA and GABAB-mediated respectively) and long-interval intracortical facilitation (LICF; pre-synaptic disinhibition) using transcranial magnetic stimulation. RESULTS While post-synaptic GABAB-mediated inhibition was unchanged in IGE (p=0.09), LICF was reduced compared to controls (controls: 141±17% of baseline; untreated patients: 107±12%, p=0.2; treated patients: 79±10%, p=0.003). GABAA-mediated inhibition was reduced in untreated patients (response amplitude 56±4% of baseline vs. 26±6% in controls, p=0.004) and normalised with treatment (37±12%, p=0.5 vs. controls). When measured during LICI, GABAA-mediated inhibition became excitatory in untreated IGE (response amplitude 120±10% of baseline, p=0.017), but not in treated patients. CONCLUSION Pre- and post-synaptic GABA-mediated inhibitory mechanisms are altered in IGE. The findings lend in vivo support to evidence from experimental models and in vitro studies of human epileptic brain tissue that GABA may have a paradoxical excitatory role in ictogenesis.

Vertebral artery dissection as a cause of cervical radiculopathy.

The acute onset of neck pain and arm weakness is most commonly due to cervical radiculopathy or inflammatory brachial plexopathy. Rarely, extracranial vertebral artery dissection may cause radiculopathy in the absence of brainstem ischemia. We describe a case of vertebral artery dissection presenting as cervical radiculopathy in a previously healthy 43-year-old woman who presented with proximal left arm weakness and neck pain aggravated by movement. Cervical magnetic resonance imaging (MRI) and angiography revealed dissection of the left vertebral artery with an intramural hematoma compressing the left C5 and C6 nerve roots. Antiplatelet treatment was commenced, and full power returned after 2 months. Recognition of vertebral artery dissection on cervical MRI as a possible cause of cervical radiculopathy is important to avoid interventions within the intervertebral foramen such as surgery or nerve root sleeve injection. Treatment with antithrombotic agents is important to prevent secondary ischemic events.

Botulinum toxin injection to facilitate rehabilitation of muscle imbalance syndromes in sports medicine

Intramuscular injection of Botulinum toxin to produce reduction of focal muscle overactivity, and localized muscle spasm, has been utilized therapeutically for almost two decades. Muscle overactivity in neurologically normal muscle, where an imbalance exists between a relatively overactive muscle and its less active synergist or antagonist, can inhibit control of the antagonist producing a functional muscle imbalance. This brief review provides an overview of the role of muscle imbalance in sports-related pain and dysfunction, and outlines the potential for intramuscular injection of Botulinum toxin to be used as an adjunct to specific muscle re-education and functional rehabilitation in this patient group. A comprehensive understanding of normal movement and the requirements of the sporting activity are essential to allow accurate diagnosis of abnormal motor patterns and to re-educate more appropriate movement strategies. Therapeutic management of co-impairments may include stretching of tight soft tissues, specific re-education aimed at isolation of the non-dominant weak muscles and improvement in their activation, ‘unlearning’ of faulty motor patterns, and eventual progression onto functional exercises to anticipate gradual return to sporting activity. Intramuscular injection of Botulinum toxin, in carefully selected cases, provides short term reduction of focal muscle overactivity, and may facilitate activation of relatively ‘inhibited’ muscles and assist the restoration of more appropriate motor patterns.

Postprocedural inflammatory inferior alveolar neuropathy: an important differential diagnosis

Lingual or inferior alveolar nerve (IAN) injury after dental procedures may result from direct trauma or local anesthetic agent and presents with immediate onset of typically nonprogressive symptoms, including pain and sensory changes. We report a case of delayed-onset pain and progressive sensory symptoms after IAN block for amalgam restoration. A 54-year-old man presented with progressive right-sided facial pain 48 hours after IAN block for amalgam restoration, followed 1 week later by hypoesthesia and allodynia in IAN distribution. The presentation is more consistent with inflammatory neuropathy, as is well recognized in brachial plexopathy. Imaging was used to exclude local and central causes, following which the clinical diagnosis was made. Inflammatory neuropathies may be distinguished from iatrogenic causes on the basis of delayed symptom onset, early severe pain, and progressive sensory symptoms. Awareness of this condition is important, because early steroid therapy followed by medications for neuropathic pain may provide benefit.

Prolonged vastus lateralis denervation after botulinum toxin type A injection.

Intramuscular injection of botulinum toxin (BoNT) produces reversible blockade of neuromuscular transmission. In animal experimental models, recovery begins within four weeks and is usually complete by twelve weeks. We present evidence of prolonged denervation following BoNT injection of the vastus lateralis (VL) muscle to correct quadriceps muscle imbalance in patients with chronic anterior knee pain. Needle electromyography data were obtained from 10 subjects who had received a single BoNT treatment 5 to 19 months earlier as part of a clinical trial. Insertional and spontaneous activity, recruitment, and motor unit action potentials were examined. Clear differences between the injected and non‐injected VL muscles, which correlated with the time since injection, were identified in all subjects. All 10 subjects studied with needle EMG showed evidence of persisting denervation in the BoNT‐A injected VL muscle beyond the period of neuromotor recovery expected from animal experimental studies.

Parsonage–Turner Syndrome in a major burns patient☆

The patient concerned was a 36-year-old right-handed male who suffered 35% total body surface area burns (10% full thickness) post-self-immolation, affecting his face, anterior neck and torso, bilateral arms and left leg. He had no significant past medical history apart from depression and there was no history of alcohol dependence. He was admitted for a total of 42 days and spent 13 days in the intensive care unit, intubated and ventilated for 12 of these. On admission, he was significantly hypothermic and acidotic. Escharotomies of bilateral forearms and left thigh were performed within 21/ 2 h of admission (Fig. 1). Debridement and skin grafting was carried out on day 8 and day 26. His clinical course was complicated early by episodes of sepsis requiring inotropic support, coagulopathy, neutropaenia, acute respiratory distress syndrome and electrolyte disturbances. Once stable on the ward he made progressive recovery until discharge on day 42. One month after discharge, he re-presented with a history of acute pain and weakness in his right shoulder without obvious provocation. He described waking at 2 a.m. with a sharp pain in his shoulder but was able to move it normally. With simple analgesia he went back to sleep to wake 6 h later pain free but with weakness of his right shoulder. On examination, he had weakness of right shoulder abduction, and external rotation with power grade 0–1/5 (Fig. 2). He had

The Role of Botulinum Toxin Type A in the Clinical Management of Refractory Anterior Knee Pain

Anterior knee pain is a highly prevalent condition affecting largely young to middle aged adults. Symptoms can recur in more than two thirds of cases, often resulting in activity limitation and reduced participation in employment and recreational pursuits. Persistent anterior knee pain is difficult to treat and many individuals eventually consider a surgical intervention. Evidence for long term benefit of most conservative treatments or surgical approaches is currently lacking. Injection of Botulinum toxin type A to the distal region of vastus lateralis muscle causes a short term functional “denervation” which moderates the influence of vastus lateralis muscle on the knee extensor mechanism and increases the relative contribution of the vastus medialis muscle. Initial data suggest that, compared with other interventions for anterior knee pain, Botulinum toxin type A injection, in combination with an active exercise programme, can lead to sustained relief of symptoms, reduced health care utilisation and increased activity participation. The procedure is less invasive than surgical intervention, relatively easy to perform, and is time- and cost-effective. Further studies, including larger randomized placebo-controlled trials, are required to confirm the effectiveness of Botulinum toxin type A injection for anterior knee pain and to elaborate the possible mechanisms underpinning pain and symptom relief.

Enduring efficacy of Botulinum toxin type A injection for refractory anterior knee pain

Purpose: To examine long-term outcomes of Botulinum toxin type A (BoNT-A) injection to vastus lateralis (VL) for refractory anterior knee pain (AKP). Methods: Two cohorts (private clinic referrals and previous research participants) injected with BoNT-A for AKP by one neurologist were surveyed retrospectively. Primary outcomes were self-reported benefit, duration of symptom relief, and knee surgery post-injection. Secondary outcomes were changes in utilization of medication/physiotherapy treatment, AKP symptoms and activity limitation. Results: Overall, average symptom duration was 76 months (SD 98). Responses were available from 46 of 53 private patients. Thirty-eight reported benefit from injection, which was ongoing in 29. Average benefit was 25 months (SD 21). Nine individuals reported symptom recurrence after an average of 14 months (SD 21). Ten had knee surgery post-injection; six of whom had not benefitted from BoNT-A injection. Nineteen of 23 previous research participants were contactable. Initially, all responded favorably to injection. Symptomatic benefit, with an average duration of 44 months (SD 20), persisted in 15. Two subjects proceeded to surgical intervention. Conclusions: A single BoNT-A treatment to VL led initially to improved function and relief of knee-related symptoms in 57 of 65 individuals. Improvements were sustained at follow-up, with an average benefit of 34 months (SD 25) post-injection, in 44 of 57 cases. Implications for Rehabilitation Persistent anterior knee pain (AKP) can be difficult to treat and many individuals seek surgical intervention, often with variable results. Injection of Botulinum toxin type A (BoNT-A) to Vastus Lateralis muscle offers an effective alternative treatment for individuals with refractory AKP associated with patella mal-tracking related to quadriceps muscle imbalance. BoNT-A injection can provide sustained benefit, is less invasive than surgical intervention, is relatively easy to perform, and is very time- and cost-effective.