Stereotaxic thalamotomy for treatment of posttraumatic movement disorders

Unilateral deep brain stimulation (DBS) of nucleus ventralis intermedius thalami (Vim) for the treatment of post-traumatic tremor in children: a multicentre experience

PURPOSE

Deep brain stimulation (DBS) of nucleus ventralis intermedius thalami (Vim) is a validated technique for the treatment of essential tremor (ET) in adults. Conversely, its use for post traumatic tremor (PTT) and in paediatric patients is still debated. We evaluated the efficacy of Vim-DBS for lesional tremor in three paediatric patients with drug-resistant post-traumatic unilateral tremor.

METHODS

We retrospectively collected data regarding three patients with unilateral tremor due to severe head injury, with no MRI evidence of basal ganglia lesions. The three patients underwent stereotactic frame-based robot-assisted DBS of Vim contralateral to the tremor side.

RESULTS

Mean follow-up was 48 months (range: 36-60 months). Tremor was reduced in all patients with a better control of voluntary movements and improvement of functional status (mean FIM scale improvement + 7 points). No surgical complications occurred.

CONCLUSION

Unilateral contralateral DBS of Vim could be efficacious in post-traumatic tremor, even in paediatric patients and should be offered in PTT drug-resistant patients.

Disorders of Movement due to Acquired and Traumatic Brain Injury

Purpose of Review

Both traumatic and acquired brain injury can result in diffuse multifocal injury affecting both the pyramidal and extrapyramidal tracts. Thus, these patients may exhibit signs of both upper motor neuron syndrome and movement disorder simultaneously which can further complicate diagnosis and management. We will be discussing movement disorders following acquired and traumatic brain injury.

Recent Findings

Multiple functions including speech, swallowing, posture, mobility, and activities of daily living can all be affected. Medical treatment and rehabilitation-based therapy can be especially challenging due to accompanying cognitive deficits and severity of the disorder which can involve multiple limbs in addition to muscles of the face and axial skeleton. Tremor and dystonia are the most reported movement disorders following traumatic brain injury. Dystonia and myoclonus are well documented following hypoxic ischemic brain injuries. Electrophysiological studies such as dynamic surface poly-electromyography can assist with identifying phenomenology, especially differentiating between jerk-like phenomenon and help guide further work up and management. Management with medications remains challenging due to potential adverse effects. Surgical interventions including stereotactic surgery, deep brain stimulation, and intrathecal baclofen pumps have been reported, but most of the evidence supporting them has been limited to primarily case reports except for post-traumatic tremor.

Summary

Brain injury can lead to motor disorders, movement disorders, visual (processing) deficits, and vestibular deficits which often coexist with cognitive deficits making it challenging to treat and rehabilitate these patients. Unfortunately, the evidence regarding the medical management and rehabilitation of brain injury patients with movement disorders is sparse and leaves much to be desired.

Speech and language adverse effects after thalamotomy and deep brain stimulation in patients with movement disorders: A meta-analysis

BACKGROUND

The thalamus has been a surgical target for the treatment of various movement disorders. Commonly used therapeutic modalities include ablative and nonablative procedures. A major clinical side effect of thalamic surgery is the appearance of speech problems.

OBJECTIVE

This review summarizes the data on the development of speech problems after thalamic surgery.

METHODS

A systematic review and meta-analysis was performed using nine databases, including Medline, Web of Science, and Cochrane Library. We also checked for articles by searching citing and cited articles. We retrieved studies between 1960 and September 2014.

RESULTS

Of a total of 2,320 patients, 19.8% (confidence interval: 14.8-25.9) had speech difficulty after thalamotomy. Speech difficulty occurred in 15% (confidence interval: 9.8-22.2) of those treated with a unilaterally and 40.6% (confidence interval: 29.5-52.8) of those treated bilaterally. Speech impairment was noticed 2- to 3-fold more commonly after left-sided procedures (40.7% vs. 15.2%). Of the 572 patients that underwent DBS, 19.4% (confidence interval: 13.1-27.8) experienced speech difficulty. Subgroup analysis revealed that this complication occurs in 10.2% (confidence interval: 7.4-13.9) of patients treated unilaterally and 34.6% (confidence interval: 21.6-50.4) treated bilaterally. After thalamotomy, the risk was higher in Parkinson's patients compared to patients with essential tremor: 19.8% versus 4.5% in the unilateral group and 42.5% versus 13.9% in the bilateral group. After DBS, this rate was higher in essential tremor patients.

CONCLUSION

Both lesioning and stimulation thalamic surgery produce adverse effects on speech. Left-sided and bilateral procedures are approximately 3-fold more likely to cause speech difficulty. This effect was higher after thalamotomy compared to DBS. In the thalamotomy group, the risk was higher in Parkinson's patients, whereas in the DBS group it was higher in patients with essential tremor. Understanding the pathophysiology of speech disturbance after thalamic procedures is a priority. © 2017 International Parkinson and Movement Disorder Society.

Post-Traumatic Tremor and Thalamic Deep Brain Stimulation: Evidence for Use of Diffusion Tensor Imaging

BACKGROUND

Deep brain stimulation (DBS) is a well-established treatment to reduce tremor, notably in Parkinson disease. DBS may also be effective in post-traumatic tremor, one of the most common movement disorders caused by head injury. However, the cohorts of patients often have multiple lesions that may impact the outcome depending on which fiber tracts are affected.

CASE DESCRIPTION

A 20-year-old man presented after road traffic accident with severe closed head injury and polytrauma. Computed tomography scan showed left frontal and basal ganglia hemorrhagic contusions and intraventricular hemorrhage. A disabling tremor evolved in step with motor recovery. Despite high-intensity signals in the intended thalamic target, a visual analysis of the preoperative diffusion tensor imaging revealed preservation of connectivity of the intended target, ventralis oralis posterior thalamic nucleus (VOP). This was confirmed by the postoperative tractography study presented here. DBS of the VOP/zona incerta was performed. Six months postimplant, marked improvement of action (postural, kinetic, and intention) tremor was achieved.

CONCLUSIONS

We demonstrated a strong connectivity between the VOP and the superior frontal gyrus containing the premotor cortex and other central brain areas responsible for movement control. In spite of an existing lesion in the target, the preservation of these tracts may be relevant to the improvement of the patient's symptoms by DBS.

Movement disorders secondary to craniocerebral trauma

Over the past few decades it has been recognized that traumatic brain injury may result in various movement disorders. In survivors of severe head injury, post-traumatic movement disorders were reported in about 20%, and they persisted in about 10% of patients. The most frequent persisting movement disorder in this population is kinetic cerebellar outflow tremor in about 9%, followed by dystonia in about 4%. While tremor is associated most frequently with cerebellar or mesencephalic lesions, patients with dystonia frequently have basal ganglia or thalamic lesions. Moderate or mild traumatic brain injury only rarely causes persistent post-traumatic movement disorders. It appears that the frequency of post-traumatic movement disorders overall has been declining which most likely is secondary to improved treatment of brain injury. In patients with disabling post-traumatic movement disorders which are refractory to medical treatment, stereotactic neurosurgery can provide long-lasting benefit. While in the past the primary option for severe kinetic tremor was thalamotomy and for dystonia thalamotomy or pallidotomy, today deep brain stimulation has become the preferred treatment. Parkinsonism is a rare consequence of single head injury, but repeated head injury such as seen in boxing can result in chronic encephalopathy with parkinsonian features. While there is still controversy whether or not head injury is a risk factor for the development of Parkinson's disease, recent studies indicate that genetic susceptibility might be relevant.

Rescue GPi-DBS for a Stroke-associated Hemiballism in a Patient with STN-DBS

Background

Hemiballism/hemichorea commonly occurs as a result of a lesion in the subthalamic region.

Case Report

A 38-year-old male with Parkinson’s disease developed intractable hemiballism in his left extremities due to a small lesion that was located adjacent to the right deep brain stimulation (DBS) lead, 10 months after bilateral subthalamic nucleus (STN)-DBS placement. He underwent a right globus pallidus internus (GPi)-DBS lead implantation. GPi-DBS satisfactorily addressed his hemiballism.

Discussion

This case offered a unique look at basal ganglia physiology in human hemiballism. GPi-DBS is a reasonable therapeutic option for the treatment of medication refractory hemiballism in the setting of Parkinson’s disease.

Posttraumatic hemiballism with focal discrete hemorrhage in contralateral subthalamic nucleus

Although head trauma has occasionally been described as a cause of hemiballism, relevant traumatic lesion involving subthalamic nucleus (STN) has rarely been reported. We report a 49-year-old man with focal and discrete traumatic STN hemorrhage, which presented as transient contralateral hemiballism. Although such discrete STN lesion is not infrequently found in patients with post-stroke hemiballism, it has not been reported in posttraumatic hemiballism.

Thalamic deep brain stimulation for posttraumatic action tremor

We report a case of thalamic deep brain stimulation (DBS) for treatment of posttraumatic tremor. An 18-year-old right-handed man developed a disabling and medically refractory action tremor in the right upper extremity 9 months after sustaining diffuse axonal injury in a motor vehicle collision. DBS of the left ventral intermediate nucleus of the thalamus (Vim) suppressed the tremor without complication and should be considered as an option for the management of intractable posttraumatic tremor.

Treatment of hemiballismus with stereotactic pallidotomy

Hemiballismus is a relatively rare movement disorder that is characterized by uncontrolled, random, large-amplitude movements of the limbs. It is usually caused by a vascular lesion that involves the contralateral subthalamic nucleus (STN) (also known as the nucleus hypothalamicus or corpus luysi) and its afferent and efferent pathways.

The authors present a case of medically intractable hemiballismus in a 70-year-old woman who was successfully treated with stereotactic posteroventral pallidotomy. In agreement with the data reported earlier by other groups, the microrecording performed during the pallidotomy showed a decreased rate of firing of the pallidal neurons, supporting the theory of impaired excitatory input from the STN to the internal part of the globus pallidus.

Stereotactic pallidotomy may be the procedure of choice in the treatment of medically intractable hemiballismus. Intraoperative microrecording significantly improves the precision of the stereotactic targeting and should be considered a standard part of the pallidotomy protocol.

Movement Disorders After Head Injury

Head injury can cause extrapyramidal movement disorders such as tremors, parkinsonism, dystonia, chorea, myoclonus, and tics. Pure adventitious movements are rare, but combinations with paresis, spasticity, apraxia, or ataxia occur in approximately 20% of cases of severe head injury, in many cases appearing or evolving in the months following the injury. Tremors may improve in time but many of the other syndromes tend to persist. Reversible causes such as medications or metabolic derangements are occasionally identifiable. Some of these adventitious movements can be improved using neuroactive drugs, botulinum toxin injections, or stereotactic brain surgery.

Tremor in children

Tremor in childhood, beginning in the neonatal period, is more common than generally appreciated. Although some tremor disorders in children (eg, essential tremor) also affect adults, others (eg, shuddering, jitteriness, spasmus nutans, and vitamin B12-deficiency tremor) are seen exclusively in children. This review covers the etiology, clinical features, and treatment of the major tremor syndromes in children, and when appropriate, makes comparisons with similar disorders in adults.

Head injury and posttraumatic movement disorders

WE REVIEW THE phenomenology, pathophysiology, pathological anatomy, and therapy of posttraumatic movement disorders with special emphasis on neurosurgical treatment options. We also explore possible links between craniocerebral trauma and parkinsonism. The cause-effect relationship between head injury and subsequent movement disorder is not fully appreciated. This may be related partially to the delayed appearance of the movement disorder. Movement disorders after severe head injury have been reported in 13 to 66% of patients. Although movement disorders after mild or moderate head injury are frequently transient and, in general, do not result in additional disability, kinetic tremors and dystonia may be a source of marked disability in survivors of severe head injury. Functional stereotactic surgery provides long-term symptomatic and functional benefits in the majority of patients. Thalamic radiofrequency lesioning, although beneficial in some patients, frequently is associated with side effects such as increased dysarthria or gait disturbance, particularly in patients with kinetic tremor secondary to diffuse axonal injury. Deep brain stimulation is used increasingly as an option in such patients. It remains unclear whether pallidal or thalamic targets are more beneficial for treatment of posttraumatic dystonia. Trauma to the central nervous system is an important causative factor in a variety of movement disorders. The mediation of the effects of trauma and the pathophysiology of the development of posttraumatic movement disorders require further study. Functional stereotactic surgery should be considered in patients with disabling movement disorders refractory to medical treatment.

Thalamic surgery and tremor

The results of thalamotomy for the various kinds of tremor are described. The nomenclature of the ventrolateral thalamic nuclei is discussed. Long-term thalamic stimulation seems a promising addition to or alternative for the thalamotomy, but this has still to be proven by a prospective trial that includes a cost-effectiveness analysis.

Evolution of neuroablative surgery for involuntary movement disorders: an historical review

Surgical therapy of involuntary movement disorders has evolved during the past century from gross destructive ablations of the central nervous system to refined, accurate, discrete lesioning of sites deep within the brain. The understanding of neuroanatomic and physiological systems improved tremendously through experimentation in animals and empirical observations of surgery in humans. A continuum of accumulated knowledge has been achieved through ablation or lesioning of virtually all aspects of the central and peripheral nervous system predicated on previous successes or failures. This compilation of surgical history of involuntary movement disorders has provided present neurosurgeons with the foundations on which they base their therapeutic measures and will direct future endeavors within this field.

Acquired childhood dysarthria: review of its clinical presentation

The adult classification of dysarthria correlating with the pathophysiology of the motor systems is usually applied to classify acquired childhood dysarthria. However, the validity of this adult model for children has not been studied systematically. All studies pertaining to analysis of speech features in acquired childhood dysarthria published since 1980 were reviewed. Studies were classified on the basis of neuroradiologic evidence of lesion site and associated motor disorder. This review demonstrates that knowledge of acquired childhood dysarthria is based on a limited number of single case studies, most of which pertain to dysarthria occurring after resection of cerebellar tumor. Definite similarities to adult dysarthria were not evident. Some similarity to acquired childhood dysarthria due to basal ganglia lesions was detected. We conclude that acquired childhood dysarthria requires its own classification.

Functional stereotactic surgery for hemiballism

The symptomatic and functional outcomes of a series of 14 patients with disabling and medically refractory hemiballism who were treated with functional stereotactic surgery are reported. Seven (50%) of the 14 patients had concomitant hemichorea. To relieve the hyperkinesia, the 14 patients underwent a total of 15 stereotactic operations (one patient had a second stereotactic procedure). Combined lesions in the contralateral zona incerta and the base of the ventrolateral (oroventral) thalamus were applied in 13 instances. The zona incerta was reached by means of a movable chord electrode to obviate the need for repeated puncture. In two instances the medial pallidum was used as the stereotactic target. Hemiballism was abolished or considerably improved in 13 (93%) of 14 patients in the immediate postoperative phase. Residual dyskinesia was evaluated using the hemiballism/hemichorea outcome rating scale. Long-term follow-up review was available for 13 of the 14 patients (mean follow-up period 11 years). Persistent improvement in the hemiballism was found in 12 of these 13 patients: seven patients (54%) were free of any hyperkinesia and five patients (39%) had minor residual and predominantly hemichoreic hyperkinesia. One of the 13 patients presented with a probable psychogenic movement disorder at long-term follow-up examination. Persistent morbidity, most likely related to the operative intervention, was detected in three of the 13 patients; this included mild hemiparesis and dystonia. Functional disability was assessed using the Huntington's Disease Activities of Daily Living scale. The patients' preoperative mean value of 83% of maximum disability was reduced to a mean of 30% observed at long-term follow-up review (p < 0.001). The residual disability exhibited in most older patients was associated with cardiovascular disease. The authors compare their findings with the results of 44 cases reported previously. The authors contend that functional stereotactic surgery should be considered in patients with persistent, medically refractory hemiballism.

Hemiballismus following closed head injury

Movement disorders are relatively rare after closed head injury (CHI), but when present they can go unrecognized if clinicians are not aware of their occurrence. We are presenting a case of hemiballismus which was not recognized over 3 years and was labelled as malingering or as psychosomatic. The symptoms have responded significantly to pharmacological interventions. The SPECT scan of the brain showed the lesions in the subthalamic areas while MRI, CT scans of brain and EEGs were reported normal. It is concluded that one should be aware of the existence of movement disorders after mild to moderate CHI, and that SPECT scan of the brain should be considered if a patient is symptomatic and other neuroimaging studies prove 'normal'.

The treatment of posttraumatic tremor by stereotactic surgery. Symptomatic and functional outcome in a series of 35 patients

The authors report the long-term results of stereotactic surgery for severe posttraumatic appendicular tremor in 35 patients. The tremors developed after severe head trauma in 33 patients (94%) and after mild to moderate head trauma in two (6%). In all but one, the tremor was most evident during activity. The amplitude of the kinetic tremor was greater than 5 cm in 33 patients (94%) and greater than 12 cm in 19 patients (54%). All were severely incapacitated in their daily living activities due to the tremors. The 35 patients underwent 42 stereotactic operations; five patients were reoperated on the same side and two were treated with a bilateral staged procedure. The contralateral zona incerta was the stereotactic target in 12 patients and was targeted in combination with the base of the ventrolateral (oroventral) thalamus in 23 patients. Long-term postoperative follow-up review was obtained in 32 patients (mean follow-up period 10.5 years). Persistent improvement of tremor was noted in 88%. The tremor was absent or markedly reduced in 65%. Functional disability was assessed and quantified with a modified form of an established rating scale for patients with tremor; it was reduced from a mean value of 57% of maximum disability to 37% over the long term (p < 0.001). Follow-up lesion assessment was obtained in 18 patients by multiplanar magnetic resonance imaging and at autopsy in one patient whose death was unrelated to surgery. As in previous studies, the frequency of persistent side effects was relatively high (38%). These consisted mainly of aggravation of preoperative symptoms. The results are compared to those of a total of 55 patients reported from 1960 to 1992. The occurrence of dystonia and dystonic postures is discussed. Stereotactic surgery is a powerful tool to alleviate posttraumatic tremor and to improve functional disability. However, as there is considerable risk of persistent morbidity in patients after severe head trauma, the operation should be restricted to selected cases with disabling tremor.

The use of thalamotomy in the treatment of levodopa-induced dyskinesia

Peak dose dyskinesia is a major problem in the treatment of parkinsonian patients with levodopa and yet this remains the best pharmacological agent for treating the condition. The hypothesis which this research set out to test was that thalamotomy in the area of the thalamus which receives the input from the medial segment of the globus pallidus would decrease or prevent the dyskinesia. A well established primate model of parkinsonism was used. Eight monkeys (Macaca fascicularis) were rendered parkinsonian with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Regular dosing with levodopa or apomorphine reliably resulted in peak dose dyskinesia. Thalamotomy was carried out using a radiofrequency electrode. To ensure that the appropriate area of the thalamus was targeted, that is the area receiving the pallidal input, an anatomical tracing study was carried out. The anterograde anatomical tracer horseradish peroxidase, covalently bound to wheatgerm agglutinin, was injected into the medial segment of the globus pallidus bilaterally in three monkeys. The target site for thalamotomy was accurately worked out from the tracings obtained. Chorea was usually abolished and always reduced by a thalamotomy in the pallidal terminal territory. This result was obtained after 10 thalamotomies: 4 animals receiving bilateral lesions, with an interval between operations, and 2 animals undergoing unilateral surgery. Lesions in three control sites were carried out and had no permanent effect on chorea. The effect of lesions in other areas was also assessed. Dystonia was not relieved by any thalamic lesion. Thalamotomy is a long established procedure used to help parkinsonian tremor. Appropriately placed thalamotomy should be considered for the relief of disabling peak dose dyskinesia, which is predominantly choreic, in parkinsonian patients on otherwise successful levodopa therapy.

Symptomatic and functional outcome of stereotactic ventralis lateralis thalamotomy for intention tremor

In the past, intention tremor has responded well to selected neuroablative procedures; however, objective symptomatic and functional outcomes of ventralis lateralis (VL) thalamotomy specifically for intention tremor in the post-computerized tomography era has rarely been reported. This series explored the symptomatic and functional impact of VL thalamotomy on 14 patients presenting at the Mayo Clinic with severe, refractory intention tremor due to multiple sclerosis (five patients), trauma (four patients), or stroke (five patients). General neurological examinations, psychometric evaluations, speech pathology assessments, and neuroradiological scans were performed. Pre- and postoperative disability were graded according to a modified form of an established rating scale for tremor. All patients received VL radiofrequency thalamotomies utilizing neurophysiological recording and stimulation control. Contralateral targeted upper-extremity tremor remained symptomatically absent or markedly reduced in 81.8% of cases (mean follow-up period 23.4 months). The median disability score was reduced by 12 points (0.02 less than p less than 0.05). Persistent surgical morbidity was limited to two patients with mild, nondisabling dysarthrias. One elderly patient died of pulmonary complications 2 weeks postoperatively. There were no reported surgically induced exacerbations in multiple sclerosis; however, some of these patients exhibited difficulties with electrophysiological localization. These results compare favorably with those reported in the literature and confirm that stereotactic VL thalamotomy for debilitating intention tremor carries a low surgical risk and can be an effective treatment option for properly selected patients.

Stereotactic ventrolateralis thalamotomy for medically refractory tremor in post-levodopa era Parkinson's disease patients

Thirty-six patients with Parkinson's disease and medically refractory tremor underwent stereotactic ventrolateralis thalamotomy at the Mayo Clinic between 1984 and 1989. All patients had been or were being treated with carbidopa/levodopa but with unsatisfactory tremor control. Modern stereotactic techniques, including microelectrode recording, were used to treat 36 patients, of whom 31 (86%) had complete abolition of tremor and three patients (5%) had significant improvement. Tremor recurred in two patients within 3 months of surgery; however, the remaining patients suffered no recurrence of tremor during follow-up periods ranging from 14 to 68 months (mean 33 months). Persistent complications (arm dyspraxia, dysarthria, dysphasia, or abulia) were noted in five patients but were a source of disability in only two. It is concluded that thalamotomy in carefully selected patients is a beneficial operation for the control of medically refractory parkinsonian resting tremor.

Post-traumatic intention tremor--clinical features and CT findings

Eight patients with post-traumatic intention tremor were reported. Intention tremor developed in the young as a late complication of severe head injury (Glasgow Coma Scale was below 8 in all cases) and impaired their functional outcome. This state was treatable with medication or by stereotactic thalamotomy. Neurologically, all the patients lapsed into coma immediately after the injury and many patients manifested clinical signs of a midbrain lesion in the chronic stage. The characteristic CT (computed tomography) findings in the acute stage were a high density area in the midbrain, accompanied by diffuse cerebral swelling or intraventricular hemorrhage, and in the chronic stage, brain atrophy or ventricular enlargement were the most prominent CT findings. These characteristics, indicating diffuse brain damage in addition to midbrain injury, may suggest the presence of shearing injury. The midbrain damage is consistent with the classical hypothesis that the damage to the Dentate-Rubro-thalamic system accounts for the occurrence of intention tremor. Furthermore, the presence of diffuse brain damage suggests that a more widespread brain injury may participate in its development.