Holmes' tremor following midbrain Toxoplasma abscess: clinical features and treatment of a case

Presynaptic Hemiparkinsonism Following Cerebral Toxoplasmosis: Case Report and Literature Review

Background

Cerebral toxoplasmosis (CTx) is a central nervous system opportunistic infection with variable neurological manifestations. Although tropism of Toxoplasma gondii for the basal ganglia is well known, movement disorders (MDs) represent only a small percentage of CTx-related neurological complications. CTx-associated MDs are usually hyperkinetic, whereas parkinsonism associated with evidence of presynaptic dopaminergic deficit has never been described.

Case

We report a human immunodeficiency virus-positive patient who developed a complex MD featuring unilateral tremor combined with parkinsonism and dystonia following an acute episode of disseminated CTx. Her dopamine transporter scan (DaTscan) documented contralateral presynaptic dopaminergic deficit. Levodopa initiation improved both tremor and parkinsonism after ineffective trials of several other medications over the years.

Literature Review

A total of 64 patients presenting with CTx-related MDs have been described. The most common MD was chorea (44%), followed by ataxia (20%), parkinsonism (16%), tremor (14%), dystonia (14%), myoclonus (3%), and akathisia (2%). DaTscan was performed only in 1 case, of Holmes tremor, that demonstrated reduced presynaptic dopaminergic uptake. Positive response to dopaminergic treatment was reported in 3 cases of Holmes tremor and 2 cases of parkinsonism.

Conclusions

Presynaptic dopaminergic deficit may occur in CTx-related tremor combined with parkinsonism. Its identification should prompt initiation of levodopa, thus avoiding unnecessary trials of other drugs.

Using Preimplanted Deep Brain Stimulation Electrodes for Rescue Thalamotomy in a Case of Holmes Tremor: A Case Report and Review of the Literature

BACKGROUND

Chronic stimulation of the thalamus is a surgical option in the management of intractable Holmes tremor. Patients with deep brain stimulation (DBS) can encounter infection as a postoperative complication, necessitating explantation of the hardware. Some studies have reported on the technique and the resulting efficacy of therapeutic lesioning through implanted DBS leads before their explantation.

CASE DESCRIPTION

We report the case of a patient with Holmes tremor who had stable control of symptoms with DBS of the nucleus ventralis intermedius of the thalamus (VIM) but developed localized infection over the extension at the neck, followed by gradual loss of a therapeutic effect as the neurostimulator reached the end of its service life. Three courses of systemic antibiotic therapy failed to control the infection. After careful consideration, we decided to make a rescue lesion through the implanted lead in the right VIM before explanting the complete DBS hardware. The tremor was well controlled after the rescue lesion procedure, and the effect was sustained during a 2-year follow-up period.

CONCLUSION

This case and the previously discussed ones from the literature demonstrate that making a rescue lesion through the DBS lead can be the last plausible option in cases where the DBS system has to be explanted because of an infection and reimplantation is a remote possibility.

Is nigrostriatal dopaminergic deficit necessary for Holmes tremor to develop? The DaTSCAN and IBZM SPECT study

Holmes’s tremor (HT) is assumed to be the result of coexistence of nigrostriatal dopaminergic system impairment and the lesion of cerebello-thalamic pathways. It was suggested that dopaminergic deficiency is responsible for rest tremor, and lack of compensatory cerebellar function leads to spill of tremor into voluntary movements. Cases of HT with and without abnormalities of the presynaptic part of dopaminergic nigrostriatal were published and these findings raised the question of possibility of the postsynaptic lesion. Three patients with HT diagnosed according to criteria of Consensus Statement on Tremor were studied. In all of them SPECT imaging with ligands of presynaptic (I 123-FP CIT—DaTSCAN) and postsynaptic (I 123-iodobenzamide—IBZM) nigrostriatal dopaminergic neurons was performed. Indices of uptake in caudate and putamen normalized to nonspecific uptake in occipital cortex and indices of asymmetry for each whole striatum as well as for putamen and caudate separately were calculated. SPECT studies did not reveal asymmetry of DaTSCAN and IBZM binding in striatum in all studied subjects. The current clinical diagnostic criteria of HT are presumably insufficiently specific and when using them we identify patients both with and without the involvement of dopaminergic system. These two groups may represent tremor disorders of similar phenomenology but of different pathomechanism.

Holmes tremor: Clinical description, lesion localization, and treatment in a series of 29 cases

OBJECTIVE

To describe the clinical features, etiology, findings from neuroimaging, and treatment results in a series of 29 patients with Holmes tremor (HT).

METHODS

A retrospective study was performed based on review of medical records and videos of patients with HT diagnosis.

RESULTS

A total of 16 women and 13 men were included. The mean age at the moment of CNS insult was 33.9 ± 20.1 years (range 8-76 years). The most common causes were vascular (48.3%), ischemic, or hemorrhagic. Traumatic brain injury only represented 17.24%; other causes represented 34.5%. The median latency from lesion to tremor onset was 2 months (range 7 days-228 months). The most common symptoms/signs associated with HT were hemiparesis (62%), ataxia (51.7%), hypoesthesia (27.58%), dystonia (24.1%), cranial nerve involvement (24.1%), and dysarthria (24.1%). Other symptoms/signs were vertical gaze disorders (6.8%), bradykinesia/rigidity (6.8%), myoclonus (3.4%), and seizures (3.4%). Most of the patients had lesions involving more than one area. MRI showed lesions in thalamus or midbrain or cerebellum in 82.7% of the patients. Levodopa treatment was effective in 13 out of 24 treated patients (54.16%) and in 3 patients unilateral thalamotomy provided excellent results.

CONCLUSIONS

The most common causes of HT in our series were vascular lesions. The most common lesion topography was mesencephalic, thalamic, or both. Treatment with levodopa and thalamic stereotactic lesional surgery seems to be effective.

Holmes tremor: Clinical description, lesion localization, and treatment in a series of 29 cases

OBJECTIVE

To describe the clinical features, etiology, findings from neuroimaging, and treatment results in a series of 29 patients with Holmes tremor (HT).

METHODS

A retrospective study was performed based on review of medical records and videos of patients with HT diagnosis.

RESULTS

A total of 16 women and 13 men were included. The mean age at the moment of CNS insult was 33.9 ± 20.1 years (range 8-76 years). The most common causes were vascular (48.3%), ischemic, or hemorrhagic. Traumatic brain injury only represented 17.24%; other causes represented 34.5%. The median latency from lesion to tremor onset was 2 months (range 7 days-228 months). The most common symptoms/signs associated with HT were hemiparesis (62%), ataxia (51.7%), hypoesthesia (27.58%), dystonia (24.1%), cranial nerve involvement (24.1%), and dysarthria (24.1%). Other symptoms/signs were vertical gaze disorders (6.8%), bradykinesia/rigidity (6.8%), myoclonus (3.4%), and seizures (3.4%). Most of the patients had lesions involving more than one area. MRI showed lesions in thalamus or midbrain or cerebellum in 82.7% of the patients. Levodopa treatment was effective in 13 out of 24 treated patients (54.16%) and in 3 patients unilateral thalamotomy provided excellent results.

CONCLUSIONS

The most common causes of HT in our series were vascular lesions. The most common lesion topography was mesencephalic, thalamic, or both. Treatment with levodopa and thalamic stereotactic lesional surgery seems to be effective.

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.

Multitarget, dual-electrode deep brain stimulation of the thalamus and subthalamic area for treatment of Holmes' tremor

Object

Holmes' tremor (HT) is generally considered to be a symptomatic tremor associated with lesions of the cerebellum, midbrain, or thalamus. Deep brain stimulation (DBS) therapy for essential tremor and parkinsonian tremor has proved quite successful. In contrast, surgical treatment outcomes for HT have often been disappointing. The use of 2 ipsilateral DBS electrodes implanted in parallel within the thalamus for severe essential tremor has been reported. Since dual-lead stimulation within a single target can cover a wider area than single-lead stimulation, it produces greater effects. On the other hand, DBS of the subthalamic area (SA) was recently reported to be effective for refractory tremor.

Methods

The authors implanted 2 DBS electrodes (one at the nucleus ventralis oralis/nucleus ventralis intermedius and the other at the SA) in 4 patients with HT. For more than 2 years after implantation, each patient's tremor was evaluated using a tremor rating scale under the following 4 conditions of stimulation: “on” for both thalamus and SA DBS; “off” for both thalamus and SA DBS; “on” for thalamus and “off” for SA DBS; and “on” for SA and “off” for thalamus DBS.

Results

The tremor in all patients was improved for more than 2 years (mean 25.8 ± 3.5 months). Stimulation with 2 electrodes exerted greater effect on the tremor than did 1-electrode stimulation. Interestingly, in all patients progressive effects were observed, and in one patient treated with DBS for 1 year, tremor did not appear even while stimulation was temporarily switched off, suggesting irreversible improvement effects.

The presence of both resting and intentional/action tremor implies combined destruction of the pallidothalamic and cerebellothalamic pathways in HT. A larger stimulation area may thus be required for HT patients. Multitarget, dual-lead stimulation permits coverage of the wide area needed to suppress the tremor without adverse effects of stimulation. Some reorganization of the neural network may be involved in the development of HT because the tremor appears several months after the primary insult. The mechanism underlying the absence of tremor while stimulation was temporarily off remains unclear, but the DBS may have normalized the abnormal neural network.

Conclusions

The authors successfully treated patients with severe HT by using dual-electrode DBS over a long period. Such DBS may offer an effective and safe treatment modality for intractable HT.

Midbrain tremor: a tremor resistant to treatment

Midbrain tremor is a resting, postural, action and intentional tremor of the upper extremity. Partial response to pharmacological agents makes the treatment of this tremor difficult. We report, herein, three cases of patients with midbrain tremors involving their midbrain and thalamic area in ischemic and hemorrhagic strokes. In the first case, the patient presented with a midbrain tremor of the right upper extremity involving left midbrain and thalamic area. After MRI examination, he was placed on benztropine, amantadine, pramipexole and eventually levodopa for treatment, all of which were unsuccessful in improving his tremor. In the second case, the patient presented with a midbrain tremor of the right upper extremity after an hemorrhagic stroke. After viewing CT and MRI scans, the patient was placed on amantadine, pramipexole and eventually levodopa, all of which made no contributions to his tremor. The patient in the third case presented with a blunt trauma to the head which led to the development of a midbrain tremor of his left arm. CT and MRI scans showed abnormalities in the right side of the midbrain and pons. He was initially started on amantadine, with no improvement of his tremor. However, he was eventually placed on trihexyphenidyl which contributed to a 70% improvement in his tremor. In the event of midbrain tremor, treatment should be assessed on a case by case basis, and all options should be considered after a risk-benefit assessment.

Is there a relationship between Toxoplasma gondii infection and idiopathic Parkinson's disease?

Idiopathic Parkinson's disease defines a group of Parkinson's disease (PD) of which the aetiology is unknown but an underlying brain disease is suspected. We selected patients of this subgroup of PD and investigated the seropositivity rate for anti-Toxoplasma IgG antibody by Sabin-Feldman dye test (SFDT). By measuring seropositivity in PD patients, we searched for a probable relationship between Toxoplasma gondii infection and idiopathic PD incidence. Fifty patients diagnosed with idiopathic PD and 50 healthy volunteers were included in the study. Blood samples were taken from all 100 participants and anti-T. gondii antibody titres were investigated using SFDT. Anti-T. gondii antibodies were detected at a titre of >or=1/16 in 25 of the 50 patients (50%) and in 20 of the control group (40%). No higher antibody titre was found in the control group. In conclusion, despite the emerging literature on a possible relationship between T. gondii infection and neurological disease, and the high anti-T. gondii seropositivity found in our PD patients, we did not detect any statistically significant association between T. gondii and idiopathic PD.

Cerebral toxoplasmosis in Acquired Immunodeficiency Syndrome (AIDS) patients also provides unifying pathophysiologic hypotheses for Holmes tremor

Background

Holmes tremor is a rare symptomatic movement disorder. Currently suggested pathophysiological mechanisms of the disease are mostly derived from stroke cases. Although rare, cerebral toxoplasmosis may strengthen the pathophysiologic mechanism of disease.

Case presentation

A case of Holmes tremor secondary to cerebral toxoplasmosis in an AIDS patient is presented. A relevant literature search was performed, using pubmed and several entries for Holmes tremor as labelled in the literature. The unifying feature of our case and those of the literature is the involvement of either the cerebello-thalamo-cortical and/or the dentato-rubro-olivary pathways. The abscess or the extension of surrounding edema beyond these two circuits may account for the superimposed dysfunction of the nigrostriatal system in some but not all cases. The short delay observed in our observation and the dramatic response to treatment may indirectly support the secondary neuronal degeneration theory in the mechanism of Holmes tremor.

Conclusion

Cases of cerebral toxoplasmosis in AIDS patients also provide arguments for the role of the thalamo-cortical and/or the dentato-rubro-olivary pathways dysfunction in the pathogenesis of Holmes tremor. Involvement of the nigro-striatal pathway may not be crucial in the development of this syndrome. Our case also brings additional indirect arguments for the role of secondary neuronal degeneration in the mechanism of Holmes tremor.

Unilateral rubral tremor following treatment with risperidone

Rubral tremor is a rare movement disorder that occurs typically with midbrain damage. The main features of this tremor are its low frequency, irregular rhythm, presence at rest, and acceleration during posture and active movement. Antipsychotic agent-induced tremors are usually bilateral parkinsonian tremors. We found no previous reports of unilateral rubral tremor in the literature. A 23-year-old man had unilateral rubral tremors as a result of a midbrain lesion plus risperidone exposure for treatment of manic symptoms. After we stopped the use of risperidone, the tremor became less apparent and then disappeared. This case highlights the importance of being aware of this rare complication in susceptible patients receiving risperidone treatment.

Electrophysiological evaluation of tremors secondary to space occupying lesions and trauma: correlation with nature and sites of lesions

BACKGROUND

Electrophysiological evaluation of tremor secondary to intracranial space occupying lesions (SOL) and cranial trauma may provide information regarding pathophysiology of tremors.

OBJECTIVES

To compare the electrophysiological characteristics of tremor secondary to SOL and trauma and to correlate tremor characteristics with sites of lesion, and types of SOL.

METHODS

Multi-channel tremor recording and MRI were performed in 18 patients with predominantly tremor secondary to SOL (F: M = 5:6; age +/- SD: 26.6 +/- 15.0 years) and following trauma (7 men; age: 27.3 +/- 11.0 years).

RESULTS

In both groups, there was a wide range in the frequency of tremor (2.5-7.5 Hz in the SOL group and 2-7.5 Hz in the post-trauma group) and a strong inverse correlation of the frequency with the duration of EMG bursts (SOL group: r = 0.8, p = 0.004; post-trauma group: r = 0.9, p = 0.02). While all the patients with SOL had regular EMG bursts (synchronous - 54.6%, alternating - 27.3%, mixed - 18.2%), 85.7% of post-trauma patients had irregular EMG bursts (synchronous - 42.9%, alternating - 14.3%, mixed - 42.9%). In SOL group, those with predominantly intrinsic destructive lesions of brainstem, thalamus, or basal ganglia (n = 7) had a statistically significant lower mean frequency of tremor than those (n = 4) with either extrinsic or intrinsic compressive lesions (3.5 +/- 0.9 Hz vs 6.7 +/- 0.6 Hz; p = 0.0001). In the post-trauma group, the patients with additional lesions in thalamus or striatum, apart from white and grey matter lesions had lower mean tremor frequency (3.7 +/- 1.0 Hz vs 6.1 +/- 1.5 Hz; p = 0.05).

CONCLUSIONS

The electrophysiological characteristics of tremor secondary to SOL and trauma differ and correlate with the nature and sites of lesions. This information, which need to be validated in larger cohort of patients, may be useful in understanding the pathogenesis of tremor.

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.

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.