Thalamic stimulation for midbrain tremor after partial hemangioma resection

Deep brain stimulation in posterior subthalamic area for Holmes tremor: Case reports with review of the literature

Background

Holmes tremor (HT) is a refractory tremor associated with cortico-basal ganglia loops and cerebellothalamic tract abnormalities. Various drug treatments have been attempted; however, no treatment method has yet been established. Historically, thalamic deep brain stimulation (DBS) has been performed in medically refractory cases. Recently, the posterior subthalamic area (PSA) has been used for HT. Here, we report cases of HT and review the effectiveness and safety of PSA-DBS for HT.

Cases

We conducted a retrospective chart review of two patients with HT who underwent PSA-DBS. Improvement in tremors was observed 1 year after surgery without apparent complications.

Literature review

We identified 12 patients who underwent PSA-DBS for HT, including our cases. In six patients, PSA was targeted alone; for the rest, the ventralis intermediate nucleus (Vim) of the thalamus and PSA were simultaneously targeted. The Fahn-Tolosa-Marin Tremor Rating Scale improvement rates were 56.8% (range, 33.9-82.1%; n = 6) and 77.8% (range, 42.6-100%; n = 5) for the PSA-DBS and PSA+Vim-DBS, respectively.

Conclusion

Reasonable improvements in HT were observed after PSA-DBS. PSA might be an appropriate target for improving the symptoms of HT. Long-term observations, accumulation of cases, and randomized studies are required in future.

Holmes tremor: a delayed complication after resection of brainstem cavernomas

OBJECTIVE

In this paper, the authors aimed to illustrate how Holmes tremor (HT) can occur as a delayed complication after brainstem cavernoma resection despite strict adherence to the safe entry zones (SEZs).

METHODS

After operating on 2 patients with brainstem cavernoma at the Great Metropolitan Hospital Niguarda in Milan and noticing a similar pathological pattern postoperatively, the authors asked 10 different neurosurgery centers around the world to identify similar cases, and a total of 20 were gathered from among 1274 cases of brainstem cavernomas. They evaluated the tremor, cavernoma location, surgical approach, and SEZ for every case. For the 2 cases at their center, they also performed electromyographic and accelerometric recordings of the tremor and evaluated the post-operative tractographic representation of the neuronal pathways involved in the tremorigenesis. After gathering data on all 1274 brainstem cavernomas, they performed a statistical analysis to determine if the location of the cavernoma is a potential predicting factor for the onset of HT.

RESULTS

From the analysis of all 20 cases with HT, it emerged that this highly debilitating tremor can occur as a delayed complication in patients whose postoperative clinical course has been excellent and in whom surgical access has strictly adhered to the SEZs. Three of the patients were subsequently effectively treated with deep brain stimulation (DBS), which resulted in complete or almost complete tremor regression. From the statistical analysis of all 1274 brainstem cavernomas, it was determined that a cavernoma location in the midbrain was significantly associated with the onset of HT (p < 0.0005).

CONCLUSIONS

Despite strict adherence to SEZs, the use of intraoperative neurophysiological monitoring, and the immediate success of a resective surgery, HT, a severe neurological disorder, can occur as a delayed complication after resection of brainstem cavernomas. A cavernoma location in the midbrain is a significant predictive factor for the onset of HT. Further anatomical and neurophysiological studies will be necessary to find clues to prevent this complication.

Deep brain stimulation in uncommon tremor disorders: indications, targets, and programming

BACKGROUND

In uncommon tremor disorders, clinical efficacy and optimal anatomical targets for deep brain stimulation (DBS) remain inadequately studied and insufficiently quantified.

METHODS

We performed a systematic review of PubMed.gov and ClinicalTrials.gov. Relevant articles were identified using the following keywords: "tremor", "Holmes tremor", "orthostatic tremor", "multiple sclerosis", "multiple sclerosis tremor", "neuropathy", "neuropathic tremor", "fragile X-associated tremor/ataxia syndrome", and "fragile X."

RESULTS

We identified a total of 263 cases treated with DBS for uncommon tremor disorders. Of these, 44 had Holmes tremor (HT), 18 orthostatic tremor (OT), 177 multiple sclerosis (MS)-associated tremor, 14 neuropathy-associated tremor, and 10 fragile X-associated tremor/ataxia syndrome (FXTAS). DBS resulted in favorable, albeit partial, clinical improvements in HT cases receiving Vim-DBS alone or in combination with additional targets. A sustained improvement was reported in OT cases treated with bilateral Vim-DBS, while the two cases treated with unilateral Vim-DBS demonstrated only a transient effect. MS-associated tremor responded to dual-target Vim-/VO-DBS, but the inability to account for the progression of MS-associated disability impeded the assessment of its long-term clinical efficacy. Neuropathy-associated tremor substantially improved with Vim-DBS. In FXTAS patients, while Vim-DBS was effective in improving tremor, equivocal results were observed in those with ataxia.

CONCLUSIONS

DBS of select targets may represent an effective therapeutic strategy for uncommon tremor disorders, although the level of evidence is currently in its incipient form and based on single cases or limited case series. An international registry is, therefore, warranted to clarify selection criteria, long-term results, and optimal surgical targets.

Deep brain stimulation for stroke: Current uses and future directions

BACKGROUND

Survivors of stroke often experience significant disability and impaired quality of life related to ongoing maladaptive responses and persistent neurologic deficits. Novel therapeutic options are urgently needed to augment current approaches. One way to promote recovery and ameliorate symptoms may be to electrically stimulate the surviving brain. Various forms of brain stimulation have been investigated for use in stroke, including deep brain stimulation (DBS).

OBJECTIVE/METHODS

We conducted a comprehensive literature review in order to 1) review the use of DBS to treat post-stroke maladaptive responses including pain, dystonia, dyskinesias, and tremor and 2) assess the use and potential utility of DBS for enhancing plasticity and recovery from post-stroke neurologic deficits.

RESULTS/CONCLUSIONS

A large variety of brain structures have been targeted in post-stroke patients, including motor thalamus, sensory thalamus, basal ganglia nuclei, internal capsule, and periventricular/periaqueductal grey. Overall, the reviewed clinical literature suggests a role for DBS in the management of several post-stroke maladaptive responses. More limited evidence was identified regarding DBS for post-stroke motor deficits, although existing work tentatively suggests DBS-particularly DBS targeting the posterior limb of the internal capsule-may improve paresis in certain circumstances. Substantial future work is required both to establish optimal targets and parameters for treatment of maladapative responses and to further investigate the effectiveness of DBS for post-stroke paresis.

Clinical Outcome and Characterization of Local Field Potentials in Holmes Tremor Treated with Pallidal Deep Brain Stimulation

BACKGROUND

Holmes tremor (HT) is an irregular, low-frequency rest tremor associated with prominent action and postural tremors. Currently, the most effective stereotactic target and neurophysiologic characterization of HT, specifically local field potentials (LFPs) are uncertain. We present the outcome, intraoperative neurophysiologic analysis with characterization of LFPs in a patient managed with left globus pallidus interna deep brain stimulation (Gpi DBS).

CASE REPORT

A 24-year-old male underwent left Gpi DBS for medically refractory HT. LFPs demonstrated highest powers in the delta range in Gpi. At the 6-month follow-up, a 90% reduction in tremor was observed.

DISCUSSION

Pallidal DBS should be considered as an alternative target for management of refractory HT. LFP demonstrated neuronal activity associated with higher power in the delta region, similarly seen in patients with generalized dystonia.

Deep brain stimulation for the treatment of uncommon tremor syndromes

Introduction: Deep brain stimulation (DBS) has become a standard therapy for the treatment of select cases of medication refractory essential tremor and Parkinson’s disease however the effectiveness and long-term outcomes of DBS in other uncommon and complex tremor syndromes has not been well established. Traditionally, the ventralis intermedius nucleus (VIM) of the thalamus has been considered the main target for medically intractable tremors; however alternative brain regions and improvements in stereotactic techniques and hardware may soon change the horizon for treatment of complex tremors.

Areas covered: In this article, we conducted a PubMed search using different combinations between the terms ‘Uncommon tremors’, ‘Dystonic tremor’, ‘Holmes tremor’ ‘Midbrain tremor’, ‘Rubral tremor’, ‘Cerebellar tremor’, ‘outflow tremor’, ‘Multiple Sclerosis tremor’, ‘Post-traumatic tremor’, ‘Neuropathic tremor’, and ‘Deep Brain Stimulation/DBS’. Additionally, we examined and summarized the current state of evolving interventions for treatment of complex tremor syndromes.

Expertcommentary: Recently reported interventions for rare tremors include stimulation of the posterior subthalamic area, globus pallidus internus, ventralis oralis anterior/posterior thalamic subnuclei, and the use of dual lead stimulation in one or more of these targets. Treatment should be individualized and dictated by tremor phenomenology and associated clinical features.

Pallidal stimulation for Holmes tremor: clinical outcomes and single-unit recordings in 4 cases

OBJECT

Holmes tremor (HT) is characterized by irregular, low-frequency (< 4.5 Hz) tremor occurring at rest, with posture, and with certain actions, often affecting proximal muscles. Previous reports have tended to highlight the use of thalamic deep brain stimulation (DBS) in cases of medication-refractory HT. In this study, the authors report the clinical outcome and analysis of single-unit recordings in patients with medication-refractory HT treated with globus pallidus internus (GPi) DBS.

METHODS

The authors retrospectively reviewed the medical charts of 4 patients treated with pallidal DBS for medication-refractory HT at the University of California, San Francisco, and San Francisco Veterans Affairs Medical Center. Clinical outcomes were measured at baseline and after surgery using an abbreviated motor-severity Fahn-Tolosa-Marin (FTM) tremor rating scale. Intraoperative microelectrode recordings were performed with patients in the awake state. The neurophysiological characteristics identified in HT were then also compared with characteristics previously described in Parkinson's disease (PD) studied at the authors' institution.

RESULTS

The mean percentage improvement in tremor motor severity was 78.87% (range 59.9%–94.4%) as measured using the FTM tremor rating scale, with an average length of follow-up of 33.75 months (range 18–52 months). Twenty-eight GPi neurons were recorded intraoperatively in the resting state and 13 of these were also recorded during contralateral voluntary arm movement. The mean firing rate at rest in HT was 56.2 ± 28.5 Hz, and 63.5 ± 19.4 Hz with action, much lower than the GPi recordings in PD. GPi unit oscillations of 2–8 Hz were prominent in both patients with HT and those with PD, but in HT, unlike PD, these oscillations were not suppressed by voluntary movement.

CONCLUSIONS

The efficacy of GPi DBS exceeded that reported in prior studies of ventrolateral thalamus DBS and suggest GPi may be a better target for treating HT. These clinical and neurophysiological findings help illuminate evolving models of HT and highlight the importance of cerebellar–basal ganglia interactions.

Neuropsychological deficits associated with destruction of the right nigrostriatal pathway

Hemiparkinsonism secondary to a vascular mesencephalic lesion is infrequent; these patients offer an exceptional opportunity to study neuropsychological alterations attributable to unilateral dopaminergic denervation, shedding light on the pathophysiology of cognitive disorders in early-stage idiopathic Parkinson's disease (PD). From the investigation of our case, we conclude that destruction of the right nigrostriatal pathway is accompanied by deficits in executive functioning and verbal/visual memory similar to those observed in many patients with early-stage idiopathic PD. The more complex neuropsychological dysfunction developed by other PD patients must therefore be related to the additional involvement of other brain structures.

Deep brain stimulation for Holmes' tremor related to a thalamic abscess

BACKGROUND

Medical treatment is usually ineffective for Holmes' tremor, and surgery is the treatment of choice for many patients. Here we report the case of a 14-year-old girl who developed Holmes' tremor related to a thalamic abscess and was successfully treated with thalamic deep brain stimulation.

CASE REPORT

The patient presented with left hemiparesis and headache and was hospitalized. Investigation revealed a thalamic abscess in the left cerebral hemisphere. The abscess was drained via stereotactic surgery and a course of antibiotic treatment was completed. Four months after treatment, the patient developed Holmes' tremor in her left upper extremity. When attempts at medical treatment with levodopa, clonazepam, and trihexyphenidyl all failed, an implant was placed and deep brain stimulation of the ventral intermediate nucleus of the thalamus was initiated. During 2.5 years of follow-up, her tremor diminished by 90%.

CONCLUSION

This case demonstrates that medically resistant Holmes' tremor related to a thalamic lesion can be successfully treated with thalamic deep brain stimulation.

Impact of surgical treatment on tremor due to posterior fossa tumors

Object

The object of this study was to investigate the impact of surgical treatment on tremor caused by posterior fossa tumors.

Methods

The authors performed a retrospective evaluation of 6 cases involving patients with tremors due to posterior fossa tumors. Patients who had been treated with neuroleptic medication or had a family history of movement disorders were excluded. All patients had postural or kinetic tremors. Tremor was mainly unilateral. The study group included 5 women and 1 man. Mean age at surgery was 59 years. Five patients underwent total or subtotal tumor resection, and 1 patient underwent stereotactic biopsy only. The histological diagnosis was epidermoid tumor in 2 patients, metastasis in 2 others, and vestibular schwannoma and low-grade glioma in 1 each.

Results

Two patients had no improvement of tremor, postoperatively. In both of these patients the tumor (low-grade glioma in 1, metastasis in the other) involved the dentate nucleus directly. In the other patients, a compressive effect on the dentate nucleus or the dentatothalamic pathways was present without invasion of the cerebellar structures, and immediate or gradual amelioration of the tremor was observed postoperatively.

Conclusions

The prognosis of tremor due to posterior fossa tumors appears to depend mainly on the involvement of tremor-generating structures. The prognosis appears to be favorable in those patients with compression of these substrates, whereas primary invasion by tumor has a poor prognosis. Caution must be used in generalizing the findings of this study because of the small number of cases in the series.

Ventral intermediate thalamic stimulation in complex tremor syndromes

BACKGROUND/AIMS

We report on deep brain stimulation (DBS) in the ventral intermediate part of the thalamus in 4 patients with complex tremor syndromes, 2 classified as Holmes tremor (HT) and 2 as thalamic tremor (TT).

RESULTS

Three out of 4 patients showed intraoperative improvement and underwent DBS implantation. One patient with TT without intraoperative improvement was not provided with an implant. A sustained beneficial effect was present after a follow-up ranging from 20 months to 7 years, although there was partial persistence of the intentional tremor and of proximal myoclonic-dystonic movements. The mean global clinical impression score was 2. In 1 HT patient the benefit persisted after battery failure.

CONCLUSION

The study confirms that ventral intermediate thalamic DBS can provide long-term efficacy for HT and TT. While the patients experienced considerable and lasting functional improvement, the effect was incomplete and not all elements of their complex movement disorders were equally suppressed.

Lessons learned in deep brain stimulation for movement and neuropsychiatric disorders

The introduction of deep brain stimulation (DBS) as a treatment for medication-refractory essential tremor in the late 1980s revealed, for the first time, that "chronically" implanted brain hardware had the potential to modulate neurologic function with surprisingly low morbidity. Over time, the therapeutic promise of DBS has become evident in Parkinson's disease and dystonia. In some experienced centers, complex tremor disorders, such as posttraumatic Holmes tremor and the tremor of multiple sclerosis, are being increasingly targeted. More recently, other indications, including obsessive-compulsive disorder, Tourette's syndrome, major depression, and chronic pain, have been proposed. As the field has expanded, our knowledge about potential cognitive side effects of DBS has also expanded. This article reviews the current knowledge regarding the impact of stimulation of the subthalamic nucleus, globus pallidus internus, and ventralis intermedius nucleus of the thalamus on symptoms in essential tremor, Parkinson's disease, and dystonia. Also discussed are the emerging targets, what is known about the cognitive sequelae of DBS, and what has been learned about the complications and therapeutic failures.

Dual electrode thalamic deep brain stimulation for the treatment of posttraumatic and multiple sclerosis tremor

OBJECTIVE

To report the results of ventralis intermedius nucleus/ventralis oralis posterior nucleus (VIM) plus ventralis oralis anterior (VOA)/ventralis oralis posterior (VOP) thalamic deep brain stimulation (DBS) for the treatment of posttraumatic and multiple sclerosis tremor.

OBJECTIVE

The treatment of posttraumatic tremor and multiple sclerosis tremor, by either medication or surgery, has proven difficult. Lesions and DBS have had mixed and somewhat disappointing results. Previously, we reported the use of two DBS electrodes (one at the VIM/VOP border and one at the VOA/VOP border) as effective for the treatment of posttraumatic tremor in a single patient. In this study, we report the results of this technique on four patients.

METHODS

Four patients with either posttraumatic tremor (n = 3) or multiple sclerosis tremor (n = 1) underwent placement of two DBS electrodes (one at the VIM/VOP border and one at the VOA/VOP border). Patients underwent preoperative testing and testing at a minimum of 6 months after implantation in four conditions: On VIM DBS/On VOA/VOP DBS; On VIM DBS/Off VOA VOP DBS (5 h DBS washout); Off VIM DBS/Off VOA/VOP DBS (12 h overnight washout); and Off VIM DBS/On VOA/VOP DBS (5 h DBS washout).

RESULTS

Each of the patients showed improvements in all four conditions when compared with the baseline. All of the improvements were maintained with chronic DBS, without tremor rebound. An analysis was performed to determine whether each condition was associated with symptom reduction (percentage change). The percentage reduction was significant for each condition and measure, despite the small number of participants. For the total tremor rating scale score, the Off VIM/Off VOA/VOP condition yielded less symptom reduction than the On VIM condition or the On VOA/VOP condition. The On VIM and On VOA/VOP conditions did not differ significantly from each other in terms of contralateral upper extremity symptoms or total clinical score. Activation of both the VIM and VOA/VOP electrodes was associated with the greatest symptom reduction.

CONCLUSION

Tremors, such as those examined in this study, that are refractory to medications and have a poor response to VIM DBS monotherapy, may respond favorably to VIM plus VOA/VOP DBS. Two electrodes may be better than one for the treatment of certain disorders; however, more study will be required to confirm this hypothesis.

Ventralis intermedius plus ventralis oralis anterior and posterior deep brain stimulation for posttraumatic Holmes tremor: two leads may be better than one: technical note

OBJECTIVE AND IMPORTANCE

To describe the effects of ventralis oralis anterior (VOA) and posterior (VOP), as well as ventralis intermedius (VIM), deep brain stimulation (two ipsilateral thalamic leads implanted) on posttraumatic Holmes tremor. Results of both thalamic lesioning and thalamic deep brain stimulation for Holmes tremor and tremors due to posttraumatic lesions in the region of the midbrain have been disappointing. In 2001, the use of two electrodes implanted in parallel for severe essential tremor was reported. We propose the use of a similar technique for posttraumatic Holmes tremor. One rationalization for the placement of two leads was to affect both the cerebellar receiving area (VIM) and the pallidal receiving area (VOA/VOP). A second rationalization was that the placement of a second electrode may affect somatotopy, and may, therefore, be beneficial for the treatment of more difficult to control tremor subtypes.

CLINICAL PRESENTATION

A 24-year-old man with intractable posttraumatic Holmes tremor presented for consideration of a surgical intervention.

INTERVENTION

A high-resolution, volumetric magnetic resonance imaging scan was obtained 1 day before the procedure. Microelectrode recording was used in addition to stereotactic computed tomography, image fusion, and stereotactic targeting to map the locations of the VIM, VOP, and VOA nuclei of the thalamus. A deep brain stimulation electrode was then implanted on the border between the left VIM and VOP thalamic nuclei, and a second ipsilateral deep brain stimulation lead was placed on the VOA and VOP border, 2 mm anterior to the first. Fourteen videotaped tremor rating scales were evaluated by two blinded reviewers.

CONCLUSION

The patient experienced tremor rebound with VIM-VOP monotherapy. However, when the second lead (VOA/VOP) was activated, he experienced sustained improvement in tremor and tremor disability at a 12-month follow-up examination. This case elucidates a potential new approach for the treatment of patients with posttraumatic Holmes tremor. Additional study and longer follow-up periods will be needed to further evaluate this promising therapy.

Deep brain stimulation of the nucleus ventralis intermedius for Holmes (rubral) tremor and associated dystonia caused by upper brainstem lesions

✓Holmes tremor is caused by structural lesions in the perirubral area of the midbrain. Patients often present with associated symptoms such as dystonia and paresis, which are usually refractory to medical therapy. Here, the authors describe two patients in whom both tremor and associated dystonia improved markedly following unilateral stimulation of the thalamic nucleus ventralis intermedius.

Deep brain stimulation of the nucleus ventralis intermedius for Holmes (rubral) tremor and associated dystonia caused by upper brainstem lesions. Report of two cases

Holmes tremor is caused by structural lesions in the perirubral area of the midbrain. Patients often present with associated symptoms such as dystonia and paresis, which are usually refractory to medical therapy. Here, the authors describe two patients in whom both tremor and associated dystonia improved markedly following unilateral stimulation of the thalamic nucleus ventralis intermedius.

Thalamic deep brain stimulation for disabling tremor after excision of a midbrain cavernous angioma. Case report

Thalamic deep brain stimulation (DBS) has been demonstrated to be effective for the treatment of parkinsonian or essential tremor. To date, however, few data exist to support the application of this method to treat midbrain tremor. A 24-year-old right-handed man underwent radiosurgery and subsequent resection of a recurrently hemorrhaging cavernous angioma located in the left side of the midbrain. The surgery exacerbated severe choreoathetotic resting and action tremors of his right extremities and trunk. The patient underwent placement of a deep brain stimulator into the left ventral intermediate nucleus of the thalamus (Vim). Postoperatively, decreased truncal ataxia and right-sided choreoathetotic tremor were demonstrated, with a 57% increase in dexterity as measured by task testing. The authors demonstrate that DBS can be an effective treatment modality for disabling tremor after resection of a midbrain cavernous angioma.