Botulinum Toxin Type A in Dental Medicine.

Botulinum toxins (BoNTs) are a product of the bacteria Clostridium botulinum. By entering nerve endings, they cleave and inactivate SNARE proteins, which are essential for neurotransmitter release. Prevention of acetylcholine release at the neuromuscular junction causes long-lasting and potentially fatal flaccid paralysis-a major feature of botulism. However, an intramuscular injection of minute amounts of BoNTs, primarily type A (BoNT-A), has useful long-lasting muscle relaxation effects on spastic motor disorders. This characteristic of BoNT-A is widely used in neurology and cosmetics. Over the last few decades, it has been demonstrated that the functions of BoNT-A are not limited to muscle-relaxing or autonomic cholinergic effects but that it can act as an analgesic agent as well. More recently, it was revealed that this antinociceptive effect starts after entering the sensory nerve endings, where these agents are axonally transported to the central nervous system, suggesting that at least part of their analgesic effect might be of central origin. Because of its antinociceptive effect, BoNT-A is currently approved for treatment of chronic migraine; nonetheless, case reports and preclinical and clinical experiments indicating its benefit in numerous potential painful conditions have increased. In the field of dentistry, the US Food and Drug Administration approved BoNT-A for the treatment of sialorrhea only. Legal status of the use of BoNT-A in other countries is less known. However, there are controlled clinical trials suggesting its efficacy in other conditions, such as bruxism, temporomandibular disorders, and trigeminal neuropathic pain. Thereby, using criteria of the American Academy of Neurology, we critically reviewed the uses of BoNTs in oral medicine and found it effective for trigeminal neuralgia (category A) and probably effective in temporomandibular disorders and bruxism.

Assessment: Botulinum neurotoxin in the treatment of autonomic disorders and pain (an evidence-based review): report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.

OBJECTIVE: To perform an evidence-based review of the safety and efficacy of botulinum neurotoxin (BoNT) in the treatment of autonomic and urologic disorders and low back and head pain. METHODS: A literature search was performed including MEDLINE and Current Contents for therapeutic articles relevant to BoNT and the selected indications. Authors reviewed, abstracted, and classified articles based on the quality of the study (Class I-IV). Conclusions and recommendations were developed based on the highest level of evidence and put into current clinical context. RESULTS: The highest quality literature available for the respective indications was as follows: axillary hyperhidrosis (two Class I studies); palmar hyperhidrosis (two Class II studies); drooling (four Class II studies); gustatory sweating (five Class III studies); neurogenic detrusor overactivity (two Class I studies); sphincter detrusor dyssynergia in spinal cord injury (two Class II studies); chronic low back pain (one Class II study); episodic migraine (two Class I and two Class II studies); chronic daily headache (four Class II studies); and chronic tension-type headache (two Class I studies). RECOMMENDATIONS: Botulinum neurotoxin (BoNT) should be offered as a treatment option for the treatment of axillary hyperhidrosis and detrusor overactivity (Level A), should be considered for palmar hyperhidrosis, drooling, and detrusor sphincter dyssynergia after spinal cord injury (Level B), and may be considered for gustatory sweating and low back pain (Level C). BoNT is probably ineffective in episodic migraine and chronic tension-type headache (Level B). There is presently no consistent or strong evidence to permit drawing conclusions on the efficacy of BoNT in chronic daily headache (mainly transformed migraine) (Level U). While clinicians' practice may suggest stronger recommendations in some of these indications, evidence-based conclusions are limited by the availability of data.

Evidence based medicine in the use of botulinum toxin for back pain.

Two randomized, prospective studies, one double blind and one open label, longterm evaluated efficacy and safety of Botulinum toxin A (Allergan-Inc) in 31 and 75 patients with chronic low back pain. Both studies used a novel technique imploying 5 level (L1 to L5) injections (40-50 units/level) of BoNT-A into erector spinae muscles. Significant (p < 0.05) improvement of pain intensity, frequency and activities of daily living was noted in 60% and 53% of the patients, respectively. The second study also depicted safety with repeated injections over 14 months of follow up. Botulinum toxin-A should be considered for treatment of low back pain when other modes of treatment fail to improve pain.

Modafinil for treatment of fatigue in post-polio syndrome: a randomized controlled trial.

OBJECTIVE: To determine if modafinil can improve fatigue in patients with post-polio syndrome. METHODS: We used a randomized, placebo-controlled crossover trial. Intervention with modafinil (400 mg/day) and placebo occurred over 6-week periods. Primary endpoint (fatigue) was assessed using the Fatigue Severity Scale as the main outcome measure. Other measures included the Visual Analog Scale for Fatigue and the Fatigue Impact Scale. Secondary endpoint (health-related quality of life) was assessed using the 36-Item Short-Form. Analysis of variance for repeated measures was applied to assess treatment, period, and carryover effects. RESULTS: Thirty-six patients were randomized, 33 of whom (mean age: 61 years) completed required interventions. Treatment with modafinil was safe and well-tolerated. After adjusting for periods and order effects, no difference was observed between treatments. CONCLUSION: Based on the utilized measures of outcome modafinil was not superior to placebo in alleviating fatigue or improving quality of life in the studied post-polio syndrome population.

Language dominance in partial epilepsy patients identified with an fMRI reading task.

BACKGROUND: fMRI language tasks readily identify frontal language areas; temporal activation has been less consistent. No studies have compared clinical visual judgment to quantitative region of interest (ROI) analysis. OBJECTIVE: To identify temporal language areas in patients with partial epilepsy using a reading paradigm with clinical and ROI interpretation. METHODS: Thirty patients with temporal lobe epilepsy, aged 8 to 56 years, had 1.5-T fMRI. Patients silently named an object described by a sentence compared to a visual control. Data were analyzed with ROI analysis from t-maps. Regional asymmetry indices (AI) were calculated ([L-R]/[L+R]) and language dominance defined as >0.20. t-Maps were visually rated by three readers at three t thresholds. Twenty-one patients had intracarotid amobarbital test (IAT). RESULTS: The fMRI reading task provided evidence of language lateralization in 27 of 30 patients with ROI analysis. Twenty-five were left dominant, two right, one bilateral, and two were nondiagnostic; IAT and fMRI agreed in most patients, three had partial agreement, none overtly disagreed. Interrater agreement ranged between 0.77 to 0.82 (Cramer V; p < 0.0001); agreement between visual and ROI reading with IAT was 0.71 to 0.77 (Cramer V; p < 0.0001). Viewing data at lower thresholds added interpretation to 12 patients on visual analysis and 8 with ROI analysis. CONCLUSIONS: An fMRI reading paradigm can identify language dominance in frontal and temporal areas. Clinical visual interpretation is comparable to quantitative ROI analysis.

Botulinum toxin A and chronic low back pain: a randomized, double-blind study.

OBJECTIVES: To investigate the efficacy of botulinum toxin A in chronic low back pain and associated disabilities. METHODS: Thirty-one consecutive patients with chronic low back pain who met the inclusion criteria were studied: 15 received 200 units of botulinum toxin type A, 40 units/site at five lumbar paravertebral levels on the side of maximum discomfort, and 16 received normal saline. Each patient's baseline level of pain and degree of disability was documented using the visual analogue scale (VAS) and the Oswestry Low Back Pain Questionnaire (OLBPQ). The authors reevaluated the patients at 3 and 8 weeks (visual analogue scale) and at 8 weeks (OLBPQ). RESULTS: At 3 weeks, 11 of 15 patients who received botulinum toxin (73.3%) had >50% pain relief vs four of 16 (25%) in the saline group (p = 0.012). At 8 weeks, nine of 15 (60%) in the botulinum toxin group and two of 16 (12.5%) in the saline group had relief (p = 0.009). Repeat OLBPQ at 8 weeks showed improvement in 10 of 15 (66.7%) in the botulinum toxin group vs three of 16 (18.8%) in the saline group (p = 0.011). No patient experienced side effects. CONCLUSION: Paravertebral administration of botulinum toxin A in patients with chronic low back pain relieved pain and improved function at 3 and 8 weeks after treatment.

Bilateral painful hand-moving fingers: electrophysiological assessment of the central nervous system oscillator.

We describe a 35-year-old woman who presented with the syndrome of painful hand-moving fingers on the right side. Eight months later, she developed similar finger movements and hand discomfort on the left side. She had a history of hand trauma and recurrent shoulder dislocation on the right side. Kinesiologic electromyography suggested a common central oscillator for finger movements in both hands. Electrophysiological assessment of spinal alpha motor neuron excitability, reciprocal inhibition, and Renshaw cell inhibition failed to show any abnormalities. Somatosensory evoked potential test showed marked attenuation of N20 potential recorded from the left somatosensory cortex; paired transcortical magnetic stimulation of the left motor cortex suggested failure of cortical facilitation. The data suggest that the central oscillator responsible for finger movements is located above the spinal cord level in this patient.

Electroencephalogram of asymptomatic adult subjects.

OBJECTIVES: The objective of this study is to investigate the incidence of epileptiform activity, focal or generalized slowing, patterns of uncertain significance and the effects of hyperventilation, photic stimulation and sleep on the electroencephalogram of asymptomatic adult subjects. METHODS: The studied group consisted of 100 male subjects with a mean age of 34 years (range 18-45 years). Each subject was screened closely for personal or family history of seizures, HIV, head trauma and drug abuse. Half of the subjects had a magnetic resonance imaging scan (MRI). RESULTS: In no subject resting or activated EEG showed any epileptiform activity or excessive slowing (focal or generalized). One subject demonstrated an H-response, one disclosed an alpha asymmetry of more than 50% and one showed slow alpha variant. Fourteen and 6 positive burst (12%) and small sharp spikes (11%) were the two most common patterns of uncertain significance. CONCLUSION: In a carefully screened population of young and middle age adults, the incidence of epileptiform activity, photoparoxysmal response or excessive slowing is less than 1%.

Painful tonic/dystonic spasms in Sjogren's syndrome.

Three patients with Sjogren's syndrome are presented in whom frequent tonic/dystonic spasms of the limbs developed during the course of the illness. These patients' clinical findings suggested spinal cord involvement, a localization that was confirmed by magnetic resonance imaging in two patients. In one patient the painful movements responded to treatment with phenytoin and in one other to baclofen. Sjogren's syndrome should be considered in the differential diagnosis of conditions that produce tonic/dystonic limb spasms.

Painful legs and moving toes associates with tarsal tunnel syndrome and accessory soleus muscle.

Painful legs, moving toes is a rare syndrome characterized by leg pain and uncontrolled toe movements. We present a 35-year-old man with a 1-year history of unilateral knee, calf, and medial ankle pain with spontaneous movements of second through fifth toes. Electrodiagnostic studies showed an absent lateral plantar nerve response consistent with a tarsal tunnel entrapment neuropathy. Cine magnetic resonance imaging revealed a large accessory soleus muscle compressing the flexor hallucis longus in the tarsal tunnel of the affected extremity. Lidocaine block of the tibial nerve at the popliteal fossa did not stop these movements, but blockade of the medial and lateral plantar nerves distal to the medial malleolus stopped them temporarily. Treatment with foot orthotics and cessation of running activity decreased the symptoms. We conclude that painful leg and moving toes in this patient resulted from a compression neuropathy at the tarsal tunnel possibly caused by a large adjacent accessory soleus muscle.

Botulinum toxin A for spasticity, muscle spasms, and rigidity.

We studied the effects of botulinum toxin A in 12 patients with spasticity and in eight patients with rigidity. The study design was a double-blind, placebo-controlled crossover trial with botulinum toxin A versus saline. Using the Ashworth Scale for spasticity and the Unified Parkinson's Disease Rating Scale for rigidity, we gave the patients a tone grade before and 2 weeks after treatment. Improvement in tone by two grades or more was considered clinically significant. In the spasticity group, botulinum toxin A reduced the tone of all patients significantly, improved functionality and nursing care in eight of 12 patients, and alleviated painful spasms in five of five patients. In the rigidity group, muscle tone was decreased in seven of eight patients, functionality improved in four of seven, and joint and muscle pain decreased in four of five. We conclude that botulinum toxin A is effective against the disabling effects of spasticity and rigidity. The treatment was well tolerated.

Concurrent cerebral venous sinus thrombosis and myeloradiculopathy in Sjögren's syndrome.

A 41-year-old woman complained of severe headaches and developed quadriparesis and neurogenic bladder. Evaluation disclosed the presence of Sjögren's syndrome complicated by myeloradiculopathy with MRI evidence of cervical cord involvement. Concurrent cerebral venous sinus thrombosis was also noted. Treatment with steroids and warfarin led to clinical improvement and resolution of MRI findings.

Effectiveness of botulinum toxin type A against painful limb myoclonus of spinal cord origin.

Botulinum toxin is now an established treatment for blepharospasm, hemifacial spasm, spasmodic torticollis, and spastic dysphonia. We report the effectiveness of botulinum toxin against painful limb myoclonus of spinal cord origin. The patient, a 16-year-old girl with a pulmonary vascular anomaly, Scimitar syndrome, suffered from an acute spinal cord infarct at age 11. She was left with paralysis of the right leg and bladder dysfunction. Four years after the original insult, she developed "painful cramping" and involuntary movements of the left thigh, which were unresponsive to a wide range of therapeutic trials. The movements were continuous, rhythmic, and confined to the left quadriceps muscles. Electromyographic examination revealed continuous myoclonic discharges. Treatment with botulinum toxin in the left quadriceps muscles resulted in complete cessation of pain and marked reduction in amplitude of the movements, both clinically and electromyographically. This observation indicates the efficacy of botulinum toxin in the treatment of painful spinal myoclonus.

Botulinum toxin-A improves the rigidity of progressive supranuclear palsy.

Botulinum toxin-A (botox) can improve spasticity and decrease painful spasms in the affected limbs of patients with multiple sclerosis. We report significant improvement of muscle rigidity in the upper limbs after focal administration of botulinum toxin A to 2 patients with progressive supranuclear palsy.

Significant improvement of stiff-person syndrome after paraspinal injection of botulinum toxin A.

Following several months of low back pain, a 36-year-old man developed progressive stiffness of the abdominal, low back, and thigh muscles. On examination, these muscles demonstrated marked hypertonia consistent with the clinical diagnosis of stiff-person syndrome. The patient demonstrated increased lumbar lordosis and had focal hyperhidrosis at different sites. Electromyography showed continuous activity of the paraspinal and thigh muscles, and serum and cerebrospinal fluid antibodies to glutamic acid decarboxylase (GAD) were markedly elevated. Diazepam and Lioresal offered partial pain relief. Paraspinal muscle administration of botulinum toxin A reduced the tone of paraspinal and thigh muscles significantly and resulted in marked improvement of ambulation and cessation of pain.