Hyperhidrosis caused by deep brain stimulation in the posterior subthalamic area

Novel targets in deep brain stimulation for movement disorders

The neurosurgical treatment of movement disorders, primarily via deep brain stimulation (DBS), is a rapidly expanding and evolving field. Although conventional targets including the subthalamic nucleus (STN) and internal segment of the globus pallidus (GPi) for Parkinson's disease and ventral intermediate nucleus of the thalams (VIM) for tremor provide substantial benefit in terms of both motor symptoms and quality of life, other targets for DBS have been explored in an effort to maximize clinical benefit and also avoid undesired adverse effects associated with stimulation. These novel targets primarily include the rostral zona incerta (rZI), caudal zona incerta (cZI)/posterior subthalamic area (PSA), prelemniscal radiation (Raprl), pedunculopontine nucleus (PPN), substantia nigra pars reticulata (SNr), centromedian/parafascicular (CM/PF) nucleus of the thalamus, nucleus basalis of Meynert (NBM), dentato-rubro-thalamic tract (DRTT), dentate nucleus of the cerebellum, external segment of the globus pallidus (GPe), and ventral oralis (VO) complex of the thalamus. However, reports of outcomes utilizing these targets are scattered and disparate. In order to provide a comprehensive resource for researchers and clinicians alike, we have summarized the existing literature surrounding these novel targets, including rationale for their use, neurosurgical techniques where relevant, outcomes and adverse effects of stimulation, and future directions for research.

Case Report: Deep Cerebellar Stimulation for Tremor and Dystonia

Background: The cerebellum plays an important role in the pathogenesis and pathophysiology of movement disorders, including tremor and dystonia. To date, there have been few reports on deep cerebellar stimulation.

Case Report: The patient was a 35-year-old previously healthy man with no history of movement disorders. He developed a tremor and stiffness in his left hand at the age of 27 years, which was diagnosed as a dystonic tremor. We performed right thalamotomy, which resulted in a complete resolution of the tremor; however, the dystonia persisted. Subsequently, the patient developed left foot dystonia with inversion and a newly developed tremor in the right hand and foot. The patient underwent left ventralis intermedius (VIM) deep brain stimulation (VIM-DBS) and left pallidothalamic tract DBS (PTT-DBS). Left VIM-DBS completely resolved the right hand and foot tremor, and PTT-DBS significantly improved the left hand and foot dystonia. Three months postoperatively, the patient developed an infection and wound disruption at the surgical site. We performed palliative surgery for deep cerebellar stimulation via the posterior cranial region, which was not infected. The surgery was performed under general anesthesia with the patient lying in the prone position. Eight contact DBS electrodes were used. The placement of electrodes extended from the superior cerebellar peduncle to the dentate nucleus. Both the right hand and foot tremor improved with right cerebellar stimulation. Further, both the left hand and foot dystonia improved with left cerebellar stimulation. Right and left cerebellar stimulation led to no improvement in the left hand and foot dystonia and right hand and foot tremor, respectively. Stimulation-induced complications observed in the patient included dizziness, dysphagia, and dysarthria. After the surgery, the patient developed hypersalivation and hyperhidrosis in the left side of the body, both of which did not improve with adjustments of stimulation parameters. At the 6-month follow-up, the tremor and dystonia had almost completely resolved.

Conclusion: Deep cerebellar stimulation deserves consideration as a potential treatment for tremor and dystonia.

Zona incerta as a therapeutic target in Parkinson's disease

The zona incerta has recently become an important target for deep-brain stimulation (DBS) in Parkinson's disease (PD). The present review summarizes clinical, animal and anatomical data which have indicated an important role of this structure in PD, and discusses potential mechanisms involved in therapeutic effects of DBS. Animal studies have suggested initially some role of neurons as well as GABAergic and glutamatergic receptors of the zona incerta in locomotion and generation of PD signs. Anatomical data have indicated that thanks to its multiple interconnections with the basal ganglia, thalamus, cerebral cortex, brainstem, spinal cord and cerebellum, the zona incerta is an important link in a neuronal chain transmitting impulses involved in PD pathology. Finally, clinical studies have shown that DBS of this structure alleviates parkinsonian bradykinesia, muscle rigidity and tremor. DBS of caudal zona incerta seemed to be the most effective therapeutic intervention, especially with regard to reduction of PD tremor as well as other forms of tremor.

Analysis of Contact Position for Subthalamic Nucleus Deep Brain Stimulation-Induced Hyperhidrosis

Objectives

To analyze the hyperhidrosis neural network structure induced by subthalamic nucleus (STN) - deep brain stimulation (DBS).

Materials and Methods

Patients with Parkinson's disease treated with STN-DBS in Changhai Hospital between July 1, 2015, and December 1, 2016, were analyzed retrospectively. Using records of side effects of the intraoperative macrostimulation test, patients with skin sweats were selected as the sweating group. Based on the number of cases in the sweating group, the same number of patients was randomly selected from other STN-DBS patients without sweating to form the control group. The study standardized electrode position with Lead-DBS software to Montreal Neurological Institute (MNI) standard stereotactic space to compare the differences in three-dimensional coordinates of activated contacts between groups.

Results

Of 355 patients, 11 patients had sweats during intraoperative macrostimulation tests. There was no significant difference in the preoperative baseline information and the postoperative UPDRS-III improvement rate (Med-off, IPG-on) between groups. Contacts inducing sweat were more medial (X-axis) (11.02 ± 0.69 mm vs 11.98 ± 0.84 mm, P=0.00057) and more upward (Z-axis) (−7.15 ± 1.06 mm VS −7.98 ± 1.21 mm, P=0.032) than those of the control group. The straight-line distance between the center of the sweat contact and the nearest voxel of the red nucleus was closer than that of the control group (2.72 ± 0.65 mm VS 3.76 ± 0.85 mm, P=0.00012).

Conclusions

STN-DBS-induced sweat indicated that the contact was at superior medial of STN.