Co-registration of stereotactic MRI and isofieldlines during deep brain stimulation

OBJECT

The parameter adjustment process during deep brain stimulation (DBS) for dystonia remains time consuming and based on clinical observation alone. The aim was to correlate the electric field with the GPi anatomy to be able to study the stimulated volume.

METHODS

We developed a computer-assisted method (model) for visualizing electric field in reference to the stereotactic space. Electric field values were correlated with the GPi anatomy (stereotactic Magnetic Resonance Imaging) in one reference patient.

RESULTS

Using this methodology it becomes possible to correlate the electric field distributions for patient specific parameters with the anatomical information. The application to one patient showed that the 0.1V/mm isofieldline fits best with the lateral GPi borders at the level of the stimulated contacts.

CONCLUSIONS

The electric field is a crucial parameter as it is assumed to be responsible for triggering action potentials. Electric field visualisation allows the calculation of the stimulated volume for a given isoline. Its application to our whole patient population might help in determining a threshold for obtaining a therapeutic effect, to date unknown, and consequently in optimizing the parameter setting in each patient.

The effect of deep brain stimulation on quality of life in movement disorders

Deep brain stimulation (DBS) is a viable treatment alternative for patients with Parkinson's disease (PD), essential tremor (ET), dystonia, and cerebellar outflow tremors. When poorly controlled, these disorders have detrimental effects on the patient's health related quality of life (HRQoL). Instruments that measure HRQoL are useful tools to assess burden of disease and the impact of therapeutic interventions on activities of daily living, employment, and other functions. We systematically and critically reviewed the literature on the effects of DBS on HRQoL in PD, ET, dystonia, and cerebellar outflow tremor related to multiple sclerosis.

Motor training as treatment in focal hand dystonia

Focal hand dystonia may arise as a result of aberrant plasticity from excessive repetitive use. Improvement might be possible with appropriate motor training. Focusing on trying to decrease abnormal overflow of movement to fingers not involved in a task, we developed a motor training program for individualized finger movements. Ten patients with writer's cramp participated in the motor training program. Evaluation was done with the Fahn dystonia scale, kinematic analysis of handwriting, transcranial magnetic stimulation (TMS), and electroencephalography (EEG). Clinical improvement of dystonia was significant using the Fahn dystonia scale, and 6 patients reported an improvement in writing. The handwriting analysis showed a trend for improvement after training in simple exercises. There were no changes in cortical excitability measured by TMS and EEG. Whereas this method of motor training for 4 weeks led to mild subjective improvement and some improvement in handwriting, it is not sufficient to reverse motor cortex abnormalities measured by TMS and EEG.

Pallidal stimulation improves pantothenate kinase-associated neurodegeneration

Pantothenate kinase-associated neurodegeneration (PKAN) causes a progressive generalized dystonia which remains pharmacologically intractable. We performed bilateral internal globus pallidus stimulation in six patients with genetically confirmed PKAN who obtained a major and long-lasting improvement of their painful spasms, dystonia, and functional autonomy. This study shows the benefits of pallidal DBS for the dystonia of PKAN patients.

[Primary generalized dystonia and deep brain stimulation: a randomized, placebo-controlled, double-blind, multicentre study]

Dystonia describes a group of movement disorders characterized by involuntary muscle contractions which cause twisting involuntary movements and/or abnormal postures. Primary generalized dystonia often begins in childhood and over a number of years leads to a serious and debilitating illness. The effects of medication and physiotherapy are often disappointing. In the Netherlands a randomized, placebo-controlled and double-blind study has been started to examine the effects and risks of long-term deep brain stimulation in patients with primary generalized dystonia.

Nurses' role in management and treatment of dystonia

Dystonia is a neurological movement disorder characterised by sustained muscle contractions, producing twisting and repetitive movements or abnormal posture. It is often accompanied by chronic pain. Specialist nurses now treat and support many patients.

A writing device improves writing in primary writing tremor

Primary writing tremor (PWT) is task-specific and interferes with handwriting. Several reports have shown a beneficial response of this disorder to stereotactic functional neurosurgery. Significant improvement with a writing device was demonstrated with blind rating of handwriting and spiral drawing samples collected before and during its use in nine patients with PWT, suggesting that this therapeutic modality should be tried before considering chronic pharmacotherapy or functional neurosurgery.

Tonic dystonia: an uncommon complication of reflex sympathetic dystrophy syndrome. A review of five cases

Tonic dystonia is an underrecognized complication of reflex sympathetic dystrophy syndrome (RSDS) characterized by an increase in muscle tone at the site of injury. Case-reports.- We describe five cases of tonic dystonia complicating RSDS of the lower extremity. There were four women and one man, with a mean age of 52 years. In addition to the typical features of RSDS, the patients had fixed equinovarus of the foot with hyperextension or hyperflexion of the great toe. In two patients, examination after spinal anesthesia showed that the deformity was reducible. Spontaneous resolution of the dystonia occurred in one patient. Another patient failed to experience meaningful improvement after a motor block followed by botulinic toxin injections. In two patients, the same treatment was followed by a slight improvement. Treatment options are still being evaluated in the last patient. Discussion.- Tonic dystonia is an underrecognized complication of RSDS that often develops after a minor injury yet causes prolonged pain and disability. Spread of the dystonia to other sites is not infrequent. The underlying mechanisms remain unclear but may involve dysfunction of the central or peripheral nervous system or psychogenic factors. Suggested treatments include motor block, intrathecal baclofen, sympathetic block, and sympathectomy. However, none of these treatments has been proved effective. Conclusion.- The five cases described here provide useful information on RSDS-associated tonic dystonia, a condition that runs a protracted course and remains difficult to manage.

[Kinematic evaluation of dystonic syndromes in patients treated with deep brain stimulation]

INTRODUCTION

Quantification of motor functions of patients with dystonic syndromes treated by chronic high frequency stimulation of the internal globulus pallidus is a challenge.

OBJECTIVE

Through a series of clinical examples this paper shows that kinematic analysis of movements in dystonic syndromes treated by deep brain stimulation (DBS) is a complement to clinical evaluation. In addition, it provides valuable information for early detection of improvement or impairment of movements associated with modifications of stimulation parameters.

METHOD

Thirteen dystonic patients and eleven reference subjects completed three tests (i.e., rest: lying supine; posture: standing with arms held in front (at shoulder height); and alternative movements: bimanual finger-to-nose test). These tests were recorded with an electromagnetic system quantifying movement kinematics (position) in three-dimensional space.

RESULTS

From the recorded data, several indices were developed and provided a quantitative evaluation of movements during each test. In addition, a clinical evaluation (BMFDRS) was also completed. No correlation between clinical and kinematic evaluations was found.

CONCLUSION

It is shown that kinematic analysis is a useful complement of clinical evaluation and can assist clinicians in monitoring the evolution of movements in dystonic patients treated by DBS in a simple, reliable and valid fashion.

[Clinical analysis of musicians' focal hand dystonia. Review of 86 cases]

INTRODUCTION

Focal hand dystonia in musicians due to its rareness and specificity. It has been insufficiently described thus remaining a largely unknown condition.

OBJECTIVE

To describe the clinical characteristics of musician's focal dystonia.

METHODS AND RESULTS

We analyzed 658 musicians' cases seen during the past 4 years in a medical center for performing artists. Of the musicians treated, 86 (13 %) suffered from focal dystonia, 42 % were guitarists, 21% pianists and 6% violinists. Men were more affected than women (7:1). Sufferers reported longer practice times (4.8 hours per day) and were older (33.6 years). In comparison, other pathologies were seen when musicians were younger (26.5 years) and played no more than 3.5 hours per day.

CONCLUSIONS

Focal dystonia in musicians appear to be the consequence of a long history of intense and repetitive manual work while playing music added to other factors, as for example, gender.

Long-term high-frequency bilateral pallidal stimulation for neuroleptic-induced tardive dystonia

✓ The authors report the results of long-term bilateral high-frequency pallidal stimulation in two patients affected by neuroleptic-induced dystonia.

The first patient, a 33-year-old man, experienced a dystonic posture of the trunk, with involvement of the neck and upper and lower limbs after 11 years of treatment with neuroleptic drugs. The second patient, a 30-year-old man, presented with a torsion dystonia, spasmodic torticollis, and involuntary movements of the upper limbs, which appeared after 4 years of neuroleptic treatment. Both of these dystonias worsened even after the neuroleptic treatment had been discontinued, and neither patient responded to clozapine or benzodiazepine therapy. The time lapse between the first appearance of dystonia and surgery was, respectively, 5 and 3 years. In each case bilateral stereotactic implantation of electrodes within the globus pallidus internus (GPI) was performed while the patient was in a state of general anesthesia. The electrodes were placed at the following anterior commissure—posterior commissure line—related coordinates: 20 mm lateral to the midline, 6 mm below the intercommissural plane, and 3 mm anterior to the midcommissural point. Electrical stimulation (130 Hz, 1 V, 90 µsec) was begun on the 1st postoperative day. In both patients, a genetic analysis positively ruled out a mutation in the DYT1 gene, and magnetic resonance imaging yielded normal findings in both cases.

Extrapyramidal symptoms and dystonia disappeared almost completely and dramatically in both patients just a few days after high-frequency bilateral pallidal stimulation commenced. Both patients regained autonomy and neuroleptic treatment was reinitiated. The follow-up period for both cases was 1 year. Long-term bilateral high-frequency stimulation of GPI resulted in a dramatic and long-lasting improvement of neuroleptic-induced tardive dystonia.

Bilateral deep-brain stimulation of the globus pallidus in primary generalized dystonia

BACKGROUND

Severe forms of dystonia respond poorly to medical treatment. Deep-brain stimulation is a reversible neurosurgical procedure that has been used for the treatment of dystonia, but assessment of its efficacy has been limited to open studies.

METHODS

We performed a prospective, controlled, multicenter study assessing the efficacy and safety of bilateral pallidal stimulation in 22 patients with primary generalized dystonia. The severity of dystonia was evaluated before surgery and 3, 6, and 12 months postoperatively during neurostimulation, with the use of the movement and disability subscores of the Burke-Fahn-Marsden Dystonia Scale (range, 0 to 120 and 0 to 30, respectively, with higher scores indicating greater impairment). Movement scores were assessed by a review of videotaped sessions performed by an observer who was unaware of treatment status. At three months, patients underwent a double-blind evaluation in the presence and absence of neurostimulation. We also assessed the patients' quality of life, cognition, and mood at baseline and 12 months.

RESULTS

The dystonia movement score improved from a mean (+/-SD) of 46.3+/-21.3 before surgery to 21.0+/-14.1 at 12 months (P<0.001). The disability score improved from 11.6+/-5.5 before surgery to 6.5+/-4.9 at 12 months (P<0.001). General health and physical functioning were significantly improved at month 12; there were no significant changes in measures of mood and cognition. At the three-month evaluation, dystonia movement scores were significantly better with neurostimulation than without neurostimulation (24.6+/-17.7 vs. 34.6+/-12.3, P<0.001). There were five adverse events (in three patients); all resolved without permanent sequelae.

CONCLUSIONS

These findings support the efficacy and safety of the use of bilateral stimulation of the internal globus pallidus in selected patients with primary generalized dystonia.

Deep brain stimulation for generalised dystonia and spasmodic torticollis

Dystonia appears distinct from the other tremulous disorders in that improvement following deep brain stimulation frequently appears in a delayed and progressive manner. The rate of this improvement and the point at which no further progress can be expected are presently unknown. The establishment of these parameters is important in the provision of accurate and relevant prognostic information to these patients, their carers, and their treating physicians. We studied 12 consecutive patients with generalised dystonia (n=6) and spasmodic torticollis (n=6) who underwent bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) and were followed up for a minimum of 2 years postoperatively. Standard rating scales were used to quantify their neurological improvement. Both groups experienced a statistically significant improvement in their rating scores at both one and two years following surgery. At 2 years follow-up, the spasmodic torticollis group exhibited a 59% improvement in their total Toronto Western Spasmodic Torticoilis Rating Scale (TWSTRS) rating score and the generalised dystonia group attained a 46% improvement in their overall Burke, Fahn and Marsden Dystonia Rating Scale (BFMDRS) evaluation. Ninety-five percent of the final improvement was attained by 6.4 months in the generalised dystonia group and by 6.6 months in those with spasmodic torticollis. There was no significant improvement after one year postoperatively. These findings add further support to GPi DBS as an effective treatment for generalised dystonia and spasmodic torticollis, and furnish important information as to the expected rate of improvement and the point at which no further gains can be reasonably anticipated.

Stimulation of the globus pallidus internus for childhood-onset dystonia

We report the results of deep brain stimulation (DBS) of the globus pallidus internus (GPi) in 12 patients with childhood-onset generalized dystonia refractory to medication, including 3 patients with status dystonicus. There were 8 patients who had DYT1-negative primary dystonia, 1 had DYT1-positive dystonia, and 3 had symptomatic dystonia. Stimulation was effective in all but 1 patient. Dystonic postures and movements of the axis and limbs responded to DBS to a greater extent than oromandibular dystonia and fixed dystonic postures. These findings provide further evidence that pallidal stimulation is an effective treatment for intractable childhood-onset dystonia, including status dystonicus, and together with previous findings, suggest that it should be considered the treatment of choice for these conditions.

[Effect of acupuncture treatment for a patient with severe axial dystonia appearing during treatment for schizophrenia]

We performed acupuncture treatment on first consultation for a female 28-year-old patient with severe axial dystonia, causing involuntary movement and abnormal posture of the neck and body, which had developed during treatment for schizophrenia. Involuntary movement involving elevation of the right shoulder began to occur in October X-1. Drugs were prescribed by her doctor, but her involuntary movement worsened and spread to the whole body. Thereafter, she began receiving acupuncture treatment at the out patient clinic for dystonia at the Kansai Medical College Hospital in July X. Involuntary movements of her neck involved repeated left lateral bending or a rigidly straight posture while sitting and standing. Her neck also showed a left lateral bend and right rotation. Her body showed a left lateral bend and right shoulder elevation. The neck problems in this case were induced by a hypertonicity of the left sternocleidomastoid (SCM), which caused the left lateral bending and right rotation of the neck. Problems in her body involved left lateral bending due to hypotonicity of the left abdominal muscle and hypotonicity of the left back muscles, which were unable to control the left lateral bending of the body. The right shoulder elevation was caused by a hypertonicity of the right trapezius and this was another of her problems. Acupuncture treatments were given using a penetrating needle method. The treatment points were left LI4 to decrease the hypertonicity of the left SCM, left ST41 to increase the hypotonicity of the left abdominal muscles, right BL60 to increase the hypotonicity of the right back muscles and right TE5 to decrease the hypertonicity of the right trapezius. At the initial stage of acupuncture treatment, the patient was not able to attend the hospital regularly enough to obtain sufficient improvement by acupuncture. In December X+1, she started to receive acupuncture treatment weekly, and the posture of the neck and body improved. In May X+3, her neck and body postures remained erect while sitting and she did not show involuntary movement. For problems of dystonia, we perform acupuncture treatment, using meridian and acupressure points selected based on the oriental medicine system, and we achieved improvement of symptoms in this case. The patient also achieved improved stability with regard to the symptoms of schizophrenia. It is suggested that acupuncture treatment has had a positive effect on tardive dystonia including axial dystonia.

Stimulation du cortex moteur, Parkinson et dystonie : que nous enseigne la stimulation magnétique transcrânienne? revue de la littérature

INTRODUCTION

Over the last few years, deep brain stimulation techniques, with targets such as the subthalamic nucleus or the pallidum, have bee found to be beneficial in the treatment of Parkinson's disease and dystonia. Conversely, therapeutic strategies of cortical stimulation have not yet been validated in these diseases, although they are known to be associated with various cortical dysfunctions. Transcranial magnetic stimulation (TMS) is a valuable tool for non-invasive study of the role played by the motor cortex in the pathophysiology of movement disorders, in particular by assessing various cortical excitability determinants using single or paired pulse paradigms. In addition, repetitive TMS (rTMS) trains can be used to study the effects of transient activity changes of a targeted cortical area.

BACKGROUND

Studies with TMS revealed significant motor cortex excitability changes, particularly regarding intracortical inhibitory pathways, both in Parkinson's disease and in dystonia, and these changes can be distinguished owing to the resting state or to the phases of movement preparation or execution. However, more specific correlation between electrophysiological features and clinical symptoms remains to be established. In addition, the stimulation of various cortical targets by rTMS protocols applied at low or high frequencies have induced some clear clinical effects.

PERSPECTIVES

The TMS effects are and will remain applied in movement disorders to better understand the role played by the motor cortex, to assess various types of treatment and appraise the therapeutic potential of cortical stimulation.

CONCLUSION

TMS provides evidence for motor cortex dysfunction in Parkinson's disease or dystonia. Moreover, rTMS results have opened new perspectives for therapeutic strategies of implanted cortical stimulation. By these both aspects, TMS techniques show their usefulness in the assessment of movement disorders.

Clinical features of adult GM1gangliosidosis: Report of three Indian patients and review of 40 cases

Deficiency of enzyme acid beta-galactosidase causes GM1 gangliosidosis. Patients with adult GM1 gangliosidosis typically present with generalized dystonia. We describe clinical, bone marrow, and radiological features of adult GM1 gangliosidosis to help improve its recognition. We report 3 Indian patients and review of reports between 1981 and October 2002. The disease frequently is reported in the Japanese literature (75%). Patients are normal at birth and have normal early motor and mental development. Onset is within the first decade with abnormal gait, or worsening of speech is an initial symptom. Dystonia occurs in 97% of patients. Facial dystonia described as "facial grimacing" observed in approximately 90% could be an important clinical clue. Dysarthria/anarthria (97%) is frequent, and eye movements are normal. Bone marrow examination may show Gaucher-like foam cells (39%). Magnetic resonance imaging (MRI) frequently (90.9%) shows bilateral symmetrical putamenal hyperintensities on T2-weighted and proton density images. Diagnosis is confirmed by demonstrating deficiency of beta-galactosidase. Adult (Type 3) GM1 Gangliosidosis commonly presents with generalized dystonia with prominent facial dystonia, severe speech disturbances, and normal eye movements. Bone marrow frequently shows Gaucher-like foam cells. MRI shows typical lesions in the putamen. Deficiency of beta-galactosidase in fibroblasts confirms the diagnosis.