[Botulinum toxin treatment in children]

Botulinum toxin type A treatments in children were started nearly 20 years ago. The first and still most common indication is spastic equinus gait in cerebral palsy, but other indications have emerged, such as idiopathic toe-walking, peri- and post-operative pain, drooling and idiopathic congenital torticollis. The official indication for botulinum toxin treatment is spastic equinus gait in children over 2 years of age. Botulinum toxin is known as the most potent toxin. However, it has proved to be safe and well tolerated among paediatric patients. Adverse events are infrequent, mostly bruising and limited, temporary muscle weakness. With higher doses the risk for generalized adverse events increases.

Frequency-velocity mismatch: a fundamental abnormality in parkinsonian gait

Gait dysfunction and falling are major sources of disability for patients with advanced Parkinson's disease (PD). It is presently thought that the fundamental defect is an inability to generate normal stride length. Our data suggest, however, that the basic problem in PD gait is an impaired ability to match step frequency to walking velocity. In this study, foot movements of PD and normal subjects were monitored with an OPTOTRAK motion-detection system while they walked on a treadmill at different velocities. PD subjects were also paced with auditory stimuli at different frequencies. PD gait was characterized by step frequencies that were faster and stride lengths that were shorter than those of normal controls. At low walking velocities, PD stepping had a reduced or absent terminal toe lift, which truncated swing phases, producing shortened steps. Auditory pacing was not able to normalize step frequency at these lower velocities. Peak forward toe velocities increased with walking velocity and PD subjects could initiate appropriate foot dynamics during initial phases of the swing. They could not control the foot appropriately in terminal phases, however. Increased treadmill velocity, which matched the natural PD step frequency, generated a second toe lift, normalizing step size. Levodopa increased the bandwidth of step frequencies, but was not as effective as increases in walking velocity in normalizing gait. We postulate that the inability to control step frequency and adjust swing phase dynamics to slower walking velocities are major causes for the gait impairment in PD.

Striatal inhibition of PKA prevents levodopa-induced behavioural and molecular changes in the hemiparkinsonian rat

l-3,4-dihydroxyphenylalanine methyl ester hydrochloride (l-DOPA) is the gold standard for symptomatic treatment of Parkinson's disease (PD), but long-term therapy is associated with the emergence of abnormal involuntary movements (AIMS) known as l-DOPA-induced dyskinesias (LID). The molecular changes underlying LID are not completely understood. Using the 6-hydroxydopamine-lesioned rat model of PD, we showed that l-DOPA elicits profound alterations in the activity of three LID molecular markers, namely DeltaFosB, dopamine, cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) and extracellular signal-regulated kinases 1 and 2 (ERK1/2), as well as in phosphorylation levels of the cytoskeletal-associated protein tau. These modifications are triggered by protein kinase A (PKA) activation and intermittent stimulation of dopamine receptors as they are totally prevented by intrastriatal injections of Rp-cAMPS, a PKA inhibitor, or by continuous administration of l-DOPA via subcutaneous mini-pump. Importantly, Rp-cAMPS does not modulate the positive effect of l-DOPA on locomotor deficits and significantly attenuates the emergence of AIMS in 6-hydroxydopamine hydrobromide-lesioned rats. Even if decreased PKA signalling in the striatum may represent a clinical challenge, these data provide novel evidence that PKA activation, through modification of striatal signalling and alterations of cytoskeletal constituents, plays a key role in the manifestation of LID.

[Pharmacological hypotheses and therapeutic strategies for gait disorders in Parkinson's disease]

Gait disorders form part of the axial symptoms observed in Parkinson's disease (PD) and also represent a major source of therapeutic failure in the later stages of PD, with the appearance of freezing of gait (FOG) and falls. Double-blind clinical trials and, above all, clinical experience have demonstrated that l-DOPA is effective in reducing FOG. Dopaminergic agonists appear to be less effective than l-DOPA and lack formal proof of their efficacy. The enzyme inhibitors provide modest benefits, which need to be confirmed. Hence, these symptoms appear to be partially doparesistant and justify investigation of other major neurotransmission systems. Of the various drugs with partial noradrenergic activity, methylphenidate may improve FOG and attention disorders. Memantine has shown some value in improving motor symptoms and gait in fluctuating parkinsonian patients - possibly by reducing the effect of glutamatergic hyperactivation of the subthalamic nucleus on the pedunculopontine nucleus (PPN). The PPN's dense cholinergic innervation also suggests that cholinesterase inhibitors may be of use, although any benefits must be set against a potential aggravation of rest tremor. The many interactions between the serotoninergic and dopaminergic systems require the implementation of clinical studies on the complex motor impact of serotoninergic treatments, which may aggravate the parkinsonian syndrome while improving gait (as is the case with paroxetine and ritanserin). This review seeks to develop the various pathophysiological hypotheses prompted by the results of fundamental studies and pilot clinical trials, with a view to justifying the implementation of confirmatory, double-blind, placebo-controlled therapeutic trials.

[Effects of piracetam therapy in a case of Lance-Adams syndrome]

We report a 17-year-old female patient with Lance-Adams syndrome caused by anoxic encephalopathy during a severe attack of bronchial asthma. She had difficulty in writing because of action myoclonus in her arms. She also exhibited freezing gait and was unable to walk without cane. Although her gait disturbance resembled those seen in patients with parkinsonism secondary to anoxic encephalopathy, surface electromyography revealed that it was caused by action myoclonus in her legs. The presence of giant somatosensory evoked potentials and enhanced cortical reflexes in response to the electrical stimulation to her posterior tibial nerves supported our diagnosis. A combined therapy with valproate sodium, clonazepam and piracetam (15 g/day) was not effective. However, her freezing gait remarkably improved and she was able to walk without help, after the treatment with sufficient dose of piracetam (21 g/day). Cortical hyperexcitability as revealed by electrophysiological examination also improved. We concluded that the combined therapy with antiepileptic drugs and piracetam was effective in the treatment for action myoclonus. However, because the effects seemed dose-related, the dosage of piracetam needed to be increased until the optimum effects were obtained.

Locomotion and muscle mass measures in a murine model of collagen-induced arthritis

BACKGROUND

Rheumatoid arthritis (RA) is characterized by chronic poly-arthritis, synovial hyperplasia, erosive synovitis, progressive cartilage and bone destruction accompanied by a loss of body cell mass. This loss of cell mass, known as rheumatoid cachexia, predominates in the skeletal muscle and can in part be explained by a decreased physical activity. The murine collagen induced arthritis (CIA) model has been proven to be a useful model in RA research since it shares many immunological and pathological features with human RA. The present study explored the interactions between arthritis development, locomotion and muscle mass in the CIA model.

METHODS

CIA was induced in male DBA/1 mice. Locomotion was registered at different time points by a camera and evaluated by a computerized tracing system. Arthritis severity was detected by the traditionally used semi-quantitative clinical scores. The muscle mass of the hind-legs was detected at the end of the study by weighing. A methotrexate (MTX) intervention group was included to study the applicability of the locomotion and muscle mass for testing effectiveness of interventions in more detail.

RESULTS

There is a strong correlation between clinical arthritis and locomotion. The correlations between muscle mass and locomotion or clinical arthritis were less pronounced. MTX intervention resulted in an improvement of disease severity accompanied by an increase in locomotion and muscle mass.

CONCLUSION

The present data demonstrate that registration of locomotion followed by a computerized evaluation of the movements is a simple non invasive quantitative method to define disease severity and evaluate effectiveness of therapeutic agents in the CIA model.

[Rehabilitation of gait disorders in patients with Parkinson's disease and vascular parkinsonism]

Thirty patients with Parkinson's disease (PD) and 30--with vascular parkinsonism (VP) have been studied. A soft-hardware-controlled complex "Dorozhka" elaborated previously by the authors was used to assess objectively the step length. The coefficient of step length variability (CSLV) which normal value is about 1 has been calculated. A method of tempo-rhythmic correction of gait including the synchronization of step with the rate of individually tailored exogenic sound stimulation has been applied. The dose of antiparkinsonian drugs was not changed during the rehabilitation. The decrease of mean step length and CSLV in patients with PD and VP was found. There were differential-diagnostic differences between individual gait profiles of PD and VP patients: patients with PD had the relatively even decrease of the length of all steps and in patients with VP the initiation of gait with the following increase of step length was affected. The significant increase of step length and CSLV (p<0.01), improvement on GABS and PDQ-39 scales were observed during and after the tempo-rhythmic correction of gait. The improvement of gait was correlated mostly with the increase of CSLV (two-fold in PD and 3-fold in VP). Therefore, the assessment of step variability allows to objectively differentiate the gait in patients with PD and VP and the method of tempo-rhythmic correction of gait with sound stimulation allows to improve significantly parameters of gait and patient's quality of life without changing the dose of antiparkinsonian drugs.

alpha-Phenyl-n-tert-butyl-nitrone attenuates lipopolysaccharide-induced brain injury and improves neurological reflexes and early sensorimotor behavioral performance in juvenile rats

Our previous study showed that treatment with alpha-phenyl-n-tert-butyl-nitrone (PBN) after exposure to lipopolysaccharide (LPS) reduced LPS-induced white matter injury in the neonatal rat brain. The object of the current study was to further examine whether PBN has long-lasting protective effects and ameliorates LPS-induced neurological dysfunction. Intracerebral (i.c.) injection of LPS (1 mg/kg) was performed in postnatal day (P) 5 Sprague Dawley rat pups and PBN (100 mg/kg) or saline was administered intraperitoneally 5 min after LPS injection. The control rats were injected (i.c.) with sterile saline. Neurobehavioral tests were carried out from P3 to P21, and brain injury was examined after these tests. LPS exposure resulted in severe brain damage, including enlargement of ventricles bilaterally, loss of mature oligodendrocytes, impaired myelination as indicated by the decrease in myelin basic protein immunostaining, and alterations in dendritic processes in the cortical gray matter of the parietal cortex. Electron microscopic examination showed that LPS exposure caused impaired myelination as indicated by the disintegrated myelin sheaths in the juvenile rat brain. LPS administration also significantly affected neurobehavioral functions such as performance in righting reflex, wire hanging maneuver, cliff avoidance, negative geotaxis, vibrissa-elicited forelimb-placing test, beam walking, and gait test. Treatment with PBN, a free radical scavenger and antioxidant, provided protection against LPS-induced brain injury and associated neurological dysfunction in juvenile rats, suggesting that antioxidation might be an effective approach for therapeutic treatment of neonatal brain injury induced by infection/inflammation.

Fluctuating functions related to quality of life in advanced Parkinson disease: effects of duodenal levodopa infusion

OBJECTIVE

To assess fluctuations in quality of life (QoL) and motor performance in patients with advanced Parkinson disease (PD) treated with continuous daytime duodenal levodopa/carbidopa infusion or conventional therapy.

METHODS

Of 18 patients completing a 6-week trial (DIREQT), 12 were followed for up to 6 months and assessed using electronic diaries and the PD Questionnaire-39 (PDQ-39).

RESULTS

During the trial and follow-up, major diurnal fluctuations were observed, especially for hyperkinesia, 'off' time, ability to walk and depression. Duodenal infusion was associated with significantly more favourable outcomes compared with conventional treatment for satisfaction with overall functioning, 'off' time and ability to walk, with improved outcomes with PDQ-39.

CONCLUSIONS

Relative to conventional treatment, infusion therapy may stabilize and significantly improve motor function and patient's QoL. The potential for daily fluctuation in PD symptoms means single measures of treatment effectiveness can result in bias in effect estimates and hence repeated measures are recommended.

Aceruloplasminaemia with progressive atrophy without brain iron overload: treatment with oral chelation

BACKGROUND

Hereditary aceruloplasminaemia is a disorder of iron metabolism that is characterised by iron accumulation in the brain and other visceral organs. In previously reported cases, individuals with the disorder were noted to have evidence of iron accumulation in the brain. Oral chelating agents have not been used in neurological diseases of iron metabolism.

METHODS

A 54-year-old woman who presented with ataxia, lower extremity spasticity and chorea was evaluated for evidence of the source of neurological dysfunction.

RESULTS

Blood studies revealed no detectable ceruloplasmin. Marked iron overload was defined by a liver biopsy, which showed a variegated pattern consistent with a primary cause of iron overload. Review of MRI scans showed progressive brain atrophy without visible iron accumulation occurring over a 5-year period. The history suggested that neurodegeneration was coincident with aggressive oral iron replacement. Oral chelation improved many symptoms.

CONCLUSIONS

Our findings in this patient suggest that disorders of iron transport such as aceruloplasminaemia can be a cause of neurological symptoms such as chorea and cognitive decline, as well as progressive neurodegeneration in the absence of visible iron on MRI scans. We found that oral iron chelation was effective at improving symptoms.

[Preliminary trial of botulinum toxin A therapy for lower extremity spasticity in children with cerebral palsy]

Eleven children with gait disturbance due to cerebral palsy (mean age, 5.6 years, ranging from 2.4 to 11.5) were treated with Botulinum toxin A (BTA, BOTOX, Allergan) for improvement of spasticity and walking difficulty. BTA was injected into the gastrocnemius, adductors, and hamstring muscles with an initial total dose up to 8 units/kg or 100 units. Spasticity and gait disturbance were significantly improved in all patients 4 weeks after the treatment. Their parents also reported that BTA was helpful for brace tolerance and assistance of caregivers. No side effects including worsening of gait or signs of systemic adverse effects were observed. Management of leg spasticity with BTA is thought to be useful and safe, and approval for this use in Japan is recommended.

A case of levodopa-responsive camptocormia associated with advanced Parkinson's disease

BACKGROUND

A 48-year-old man with a 9-year history of Parkinson's disease who had previously shown a good response to levodopa presented for evaluation of increasingly disabling motor fluctuations and marked camptocormia.

INVESTIGATIONS

Video-recorded neurological examinations when in 'off' and 'on' states, brain MRI scan.

DIAGNOSIS

Advanced Parkinson's disease complicated by levodopa-responsive camptocormia.

MANAGEMENT

Adjustment of dopaminergic therapy (carbidopa-levodopa and entacapone) to minimize motor fluctuations and camptocormia.

Pyridoxine and pyridostigmine treatment in vincristine-induced neuropathy

Vincristine is a commonly used antineoplastic drug and frequently causes neurotoxicity. Here the authors report a 4-year-old boy with acute lymphoblastic leukemia in whom vincristine-induced peripheral and cranial neuropathy developed during remission induction therapy. The patient seemed to benefit from pyridoxine and pyridostigmine therapy greatly and this therapy is recommended in patients with severe vincristine-induced neuropathy.

Stereotypic circling behavior in mice with vestibular dysfunction: asymmetrical effects of intrastriatal microinjection of a dopamine agonist

Bronx Waltzer (bv) mouse, which has been used as a model of hearing and vestibular dysfunction, shows remarkable repetitive circling behavior. This study investigated whether the behavior is caused by the asymmetry of striatal function by observing the behavior of the bv mice following microinjection of dopamine D1 agonist, A68930 into the striatum ipsilaterally and contralaterally to the preferred direction of rotation separately. High dose of the drug induced opposite effects on ipsilateral rotations by the side of injections with statistical significance (p = .0026). These results suggested that the stereotypic circling behavior involves striatum and is based on striatal asymmetry.

Effects of caffeine on the freezing of gait in Parkinson's disease

Caffeine is a nonselective competitive blockade of adenosine A1 and A2A receptors. In this report, we studied the efficacy of 100 mg of caffeine per day on the freezing of gait (FOG) for patients with Parkinson's disease. Different subtypes of FOG showed different therapeutic responses to caffeine. Caffeine improved "total akinesia" type of FOG, but had no effect on "trembling in place." Tolerance developed to the beneficial effect of caffeine on FOG within a few months, but a 2-week caffeine withdrawal period could restore the effect of caffeine.

Use of a dynamic foot pressure index to monitor the effects of treatment for equinus gait in children with cerebral palsy

The purpose of this study is to introduce and describe a newly developed index using foot pressure analysis to quantify the degree of equinus gait in children with cerebral palsy before and after injection with botulinum toxin. Data were captured preinjection and 12 weeks postinjection. Ten children aged 2(1/2) to 6(1/2) years took part (5 boys and 5 girls). Three of them had a diagnosis of spastic diplegia and 7 of congenital hemiplegia. In total, 13 limbs were analyzed. After orientation and segmentation of raw pedobarographic data, we determined a dynamic foot pressure index graded 0 to 100 that quantified the relative degree of heel and forefoot contact during stance. These data were correlated (Pearson correlation) with clinical measurements of dorsiflexion at the ankle (on a slow and fast stretch) and video observation (using the Observational Gait Scale). Pedobarograph data were strongly correlated with both the Observational Gait Scale scores (R = 0.79, P < 0.005) and clinical measurements of dorsiflexion on a fast stretch, which is reflective of spasticity (R = 0.70, P < 0.005). We demonstrated the index's sensitivity in detecting changes in spasticity and good correlation with video observations seems to indicate this technique's potential validity. When manipulated and segmented appropriately, and with the development of a simple ordinal index, we found that foot pressure data provided a useful tool in tracking changes in patients with spastic equinus.

Improvement of gait by chronic, high doses of methylphenidate in patients with advanced Parkinson's disease

BACKGROUND

Therapeutic management of gait disorders in patients with advanced Parkinson's disease (PD) can sometimes be disappointing, since dopaminergic drug treatments and subthalamic nucleus (STN) stimulation are more effective for limb-related parkinsonian signs than for gait disorders. Gait disorders could also be partly related to norepinephrine system impairment, and the pharmacological modulation of both dopamine and norepinephrine pathways could potentially improve the symptomatology.

AIM

To assess the clinical value of chronic, high doses of methylphenidate (MPD) in patients with PD having gait disorders, despite their use of optimal dopaminergic doses and STN stimulation parameters.

METHODS

Efficacy was blindly assessed on video for 17 patients in the absence of L-dopa and again after acute administration of the drug, both before and after a 3-month course of MPD, using a Stand-Walk-Sit (SWS) Test, the Tinetti Scale, the Unified Parkinson's Disease Rating Scale (UPDRS) part III score and the Dyskinesia Rating Scale.

RESULTS

An improvement was observed in the number of steps and time in the SWS Test, the number of freezing episodes, the Tinetti Scale score and the UPDRS part III score in the absence of L-dopa after 3 months of taking MPD. The L-dopa-induced improvement in these various scores was also stronger after the 3-month course of MPD than before. The Epworth Sleepiness Scale score fell dramatically in all patients. No significant induction of adverse effects was found.

INTERPRETATION

Chronic, high doses of MPD improved gait and motor symptoms in the absence of L-dopa and increased the intensity of response of these symptoms to L-dopa in a population with advanced PD.

Gait patterns of a patient with myoclonus of a lower limb, when OFF and ON treatment with antiepileptic drugs

We describe kinematics, kinetics and electromyographic patterns of a patient with spinal myoclonus of the left lower limb, during walking. Gait analysis was performed when the patient was OFF and ON his treatment with antiepileptic drugs. When OFF, we mainly observed clonic bursts and out-of-phase activations of m. tibialis anterior and m. rectus femoris, with increased hip flexion, reduction of knee flexion during swing and excessive ankle dorsal flexion. Furthermore, large oscillations of knee moment of force and power during stance phase were also observed. These abnormal patterns markedly recovered when ON drugs.

Effects of the novel 5-HT(6) receptor antagonist RO4368554 in rat models for cognition and sensorimotor gating

Serotonin(6) (5-HT(6)) receptors are almost exclusively located in the central nervous system. High expression in the hippocampus, nucleus accumbens and striatum is consistent with a potential role in cognition and psychosis. The availability of potent, selective and brain-penetrating 5-HT(6) antagonists such as RO4368554 allows further characterization of the role of the 5-HT(6) receptor in these processes. Herein, we tested RO4368554 in several cognition tasks, as well as sensorimotor gating tests. Using scopolamine-impaired and unimpaired adult male rats, RO4368554 was given in novel object discrimination, social recognition, social discrimination, Morris water maze, passive avoidance and autoshaping procedures. RO4368554 reversed the effects of scopolamine in novel object discrimination (active doses in mg/kg, i.p., 3, 10), social recognition (3, 10), social discrimination (1, 3, 10) and passive avoidance (10, 30 i.p. and 100 p.o.) tasks. In unimpaired rats, RO4368554 enhanced object discrimination (3, 10; 4-h forgetting interval) and autoshaping learning (3), but was inactive in a water maze task (doses tested: 1-10 mg/kg, i.p.). In tests sensitive to antipsychotics, RO4368554 did not reverse sensorimotor gating deficits induced by the psychostimulants dizocilpine and amphetamine (doses tested: 1-30 mg/kg, i.p.) or neonatal lesion of the ventral hippocampus (1-10 mg/kg, i.p.). In conclusion, RO4368554 enhanced learning and memory processes in unimpaired and scopolamine-impaired rats, supporting the notion that the cognitive enhancing effects of 5-HT(6) receptor antagonists involve modulation of cholinergic neurotransmission.

Effects of desensitized nicotinic receptors on rotational behavior in a 6-hydroxydopamine model of Parkinson's disease

The purpose of this study was to investigate the effects of desensitized nicotinic acetylcholine receptors (nAChRs) on rotational behavior in the unilateral 6-hydroxydopamine (6-OHDA) model of Parkinson's disease (PD). When rats were treated with different doses of nicotine, nAChRs were observed in activated, subacute desensitized, acute desensitized, and chronic desensitized states. The rotational behavior of the hemiparkinsonian rats was determined when nAChRs were in the activated or different desensitized states. The results showed that hemiparkinsonian rats exhibited no significant changes in apomorphine-induced rotation when brain nAChRs were in an activated state. However, hemiparkinsonian rats displayed a significant reduction in apomorphine-induced rotational behavior when brain nAChRs were in subacute, acute, or chronic desensitized states induced by repeated administration of nicotine. When nAChRs were blocked by the nAChR antagonist mecamylamine, the behavior of the hemiparkinsonian rats worsened. These results suggest that desensitized nAChRs can lead to behavioral improvement in the 6-OHDA rat model of PD.