Adult ; Deep Brain Stimulation ; Essential Tremor ; physiopathology ; therapy ; Female ; Humans ; Male ; Middle Aged ; Subthalamic Nucleus ; physiology

AIMTo observe the effect of cortical spreading depression (CSD) on the spontaneous firing activities of neurons of subthalamic nucleus (STN) in normal and model rat of Parkinson's disease (PD).

METHODSExtracellular recording was used to research the neuronal electric activities in subthalamic neurons. The changes of the discharge rates of subthalamic neurons were observed in control and PD rats after intracortical microinjection of KCl solution.

RESULTSThe discharge rates of subthalamic neurons in control and PD rats were (9.78 +/- 0.71) Hz and (23.81 +/- 1.08) Hz, respectively. The discharge rate of PD rats was increased significantly when compared with those of the control rats and the percentage of neurons discharging in bursts was obviously higher than those of control rats (P < 0.01). After a long latent period secondary to intracortical injection of KCl solution, the discharge rates in both group of subthalamic neurons were decreased apparently, then recovered slowly.

CONCLUSIONThe discharge rate and bursting pattern are increased in PD rats and these abnormal activities can be improved by cortical depression. This result indicates that the changes in cortical excitability may be one of the factors increasing the activity of STN in PD.

Animals ; Cortical Spreading Depression ; physiology ; Male ; Neurons ; Parkinson Disease ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Subthalamic Nucleus ; physiology

OBJECTIVETo observe the modulatory effect of subthalamic nucleus (STN) on activity of motor cortex during exhausting exercise.

METHODSElectrocorticogram (ECoG) and local field potentials (LFPs) recording techniques were applied simultaneously to observe the dynamic changes of oscillations in sensorimotor area and STN of rat during exhausting exercise.

RESULTSRats ran well initiatively with treadmill at the beginning of the exercise, about 45 min (45 +/- 11.5) later, movement capacity reduced. Corresponding electrical property showed that STN activity increased significantly while activity of cortex decreased significantly. Subsequently rats continued exercise with minor external stimulation utill exhaustion. Activity of ECoG reached the minimum under exhausting stations (P < 0.01), while the activity of LFPs changed insignificantly (P > 0.05).

CONCLUSIONDuring the exhausting exercise, the cortex activity was extensively depressed with the development of fatigue, while the activity of STN increased significantly at the early stage of fatigue, STN took part in the modulation of central fatigue through negative induction. And the increase of STN activity may be one of the key measures accounting for protective inhibition.

Animals ; Cerebral Cortex ; physiology ; Electrophysiological Phenomena ; physiology ; Male ; Neurons ; physiology ; Physical Conditioning, Animal ; physiology ; Physical Exertion ; physiology ; Rats ; Rats, Wistar ; Subthalamic Nucleus ; physiology

Aged ; Computed Tomography Angiography ; Deep Brain Stimulation ; adverse effects ; Female ; Hematoma, Subdural, Intracranial ; diagnosis ; etiology ; surgery ; Humans ; Subthalamic Nucleus ; physiology

BACKGROUNDDystonia is one of the most challenging movement disorders to treat. Medications and surgeries are the two methods to control dystonic symptoms. For patients with dystonia in whom symptoms are inadequately controlled with pharmacologic measures, the use of deep brain stimulation (DBS) can improve symptoms and enhance functional capacity. The best candidate for DBS is believed to be primary generalized dystonia, especially the DYT-1 type. Here, we report 9 cases of secondary dystonia to explore the feasibility, indications and complications of DBS in the treatment of secondary dystonia.

METHODSFrom July 2003 to June 2006, nine patients with secondary dystonia underwent surgery at Beijing Tiantan Hospital. Among them, 2 were diagnosed as having tardive dystonia, 1 had posttraumatic dystonia, 3 had a history of perinatal anoxia, 1 had neonatal pathologic jaundice, and 2 had no exact contributory history; MRI showed bilateral lentiform nuclei degeneration in one patient. Six patients underwent bilateral subthalamic nucleus (STN)-DBS, two underwent unilateral STN-DBS, the other underwent left STN and right globus pallidus internus (GPi)-DBS.

RESULTSWith intraoperative microelectrode recording, the targeted nucleus was accurately localized. Tentative stimulation could decrease muscle tension to the same extent, but twisting was not obviously improved. Follow-up for 3 months to 3 years showed satisfactory results in 3 patients with tardive dystonia and posttraumatic dystonia and that Burke-Fahn-Marsden Dystonia Scale (BFMS) decreased by more than 90%. The improvement of symptoms was progressive along with time. The other 6 patients had slight to moderate improvement. None of them had severe surgery-related complications. One had lead fracture 16 months after surgery and the lead was then evacuated.

CONCLUSIONSDBS could be an ideal treatment for patients with tardive and posttraumatic dystonia. For patients with perinatal anoxia and diffuse impairment in the basal ganglia, DBS seemed not to be a good choice. STN could be an ideal target. Intraoperative microelectrode recording and mild amelioration of muscle tension are indicators of correct target location. No severe complications occurred.

Adolescent ; Adult ; Deep Brain Stimulation ; adverse effects ; Dystonia ; therapy ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Subthalamic Nucleus ; physiology

BACKGROUNDThe major neuropathological symptoms of Parkinson's disease (PD) consist of a loss of pigmented dopaminergic neurons in the substantia nigra and the presence of Lewy bodies. This study was to investigate the effects of bilateral subthalamic nucleus (STN) stimulation on resting-state cerebral glucose metabolism in advanced PD, and investigate the mechanism of deep brain stimulation (DBS).

METHODSSeven consecutive advanced PD patients (4 men and 3 women, mean age 64 +/- 4 years, mean H-Y disability rating 4.4 +/- 0.65) receiving bilateral STN DBS underwent 18F-fluorodeoxyglucose (18F-FDG)/positron-emission tomography (PET) examinations at rest both preoperatively and one month postoperatively, with STN stimulation still on. The unified PD rating scale was used to evaluate the clinical state under each condition. Statistical parametric mapping (SPM) was used to investigate the regional cerebral metabolic rates of glucose (rCMRGlu) during STN stimulation, and to compare these values to rCMRGlu preoperation.

RESULTSSTN stimulation clearly improved clinical symptoms in all patients. A significant increase in rCMRGlu was found in the bilateral lentiform nucleus, brainstem (midbrain and pons), bilateral premotor area (BA6), parietal-occipital cortex, and anterior cingulated cortex, and a marked decrease in rCMRGlu was noted in the left limbic lobe and bilateral inferior frontal cortex (P < 0.05).

CONCLUSIONBilateral STN stimulation may activate the projection axon from the STN, improving clinical symptoms in advanced PD patients by improving both ascending and descending pathways from the basal ganglia and increasing the metabolism of higher-order motor control in the frontal cortex.

Brain ; metabolism ; Electric Stimulation ; Female ; Glucose ; metabolism ; Humans ; Male ; Middle Aged ; Parkinson Disease ; metabolism ; Subthalamic Nucleus ; physiology

Adult ; Deep Brain Stimulation ; Dystonia ; etiology ; therapy ; Female ; Globus Pallidus ; physiology ; Humans ; Receptors, Dopamine D1 ; physiology ; Subthalamic Nucleus ; physiology ; Ventral Thalamic Nuclei ; physiology

The relationship between neuronal activity in subthalamic nucleus (STN) and parkinsonian symptoms was investigated. Thirty-five patients with idiopathic Parkinson's disease (PD) received stereotactic surgical treatment. Microelectrode recording in STN and electromyography (EMG) on the limb contralateral to the surgical side were employed intraoperatively. Single unit firings discriminated from multiple neuronal discharges were recorded, and the correlation between neuronal activity and limb EMG was analyzed. The results showed that there were distinguished characteristics of neuronal discharges in STN and its surrounding areas. Of 346 STN neurons recorded from 36 microrecording trajectories in 35 patients, three patterns of neuronal activities were identified: irregular bursting pattern with a mean frequency of 43.0+/-11.2 Hz (56%, n=244); tonic firing pattern with a mean firing frequency of 41.0+/-12.0 Hz (15%, n=66); and regular bursting pattern with a mean frequency of 47.0+/-11.7 Hz (29%, n=126). The rhythm of regular bursting with the frequency ranging from 3.8 to 6.0 Hz was highly correlated with the frequency of limb tremor measured by EMG (r(2)=0.66, P<0.01). These cells were therefore called tremor-related neurons or tremor cells. In particular, 80% tremor cells were located in the medio-superior part of STN. In conclusion, our results suggest that microelectrode recording is a critical technique for electrophysiological localization of the target in treating PD. The tremor-related neuronal activity and movement-related neuronal activity recorded from STN are responsible for the clinical parkinsonian symptoms, suggesting that STN plays an important role in the pathophysiology of PD.
Action Potentials ; Aged ; Electromyography ; Female ; Humans ; Male ; Microelectrodes ; Middle Aged ; Neurons ; physiology ; Parkinson Disease ; physiopathology ; surgery ; Stereotaxic Techniques ; Subthalamic Nucleus ; physiopathology

AIMTo observe the change of STR neuronal firing rates with high frequency stimulation of subthalamic nucleus in PD rats.

METHODSA model of Parkinson's disease was induced by unilateral administration of 6-hydroxydopamine into right substantia nigra in rats. After the high-frequency stimulation to STN, the spontaneous firing rates of STR on normal and PD rats were recorded by using extracellular recordings.

RESULTSStimulation caused a direct excited effect of STR neurons in normal rats whereas a excited and inhibited effect in PD rats. The inhibited effect was correlated with the stimulation period (r = 0.94).

CONCLUSIONStimulation to STN may inhibit the spontaneous firing rates of STR neurons in PD rats. These results also give some clues that high-frequency stimulation to STN may be a effective therapy to the clinical treatment of Parkinson's disease.

Action Potentials ; Animals ; Corpus Striatum ; physiopathology ; Disease Models, Animal ; Electric Stimulation Therapy ; Male ; Neurons ; physiology ; Parkinson Disease ; physiopathology ; therapy ; Rats ; Rats, Sprague-Dawley ; Subthalamic Nucleus

In vivo extracellular recordings were made in the subthalamic nucleus (STN) of intact control rats and rats with 5,7-dihydroxytryptamine (5,7-DHT) -produced lesion of dorsal raphe nucleus (DRN). The results showed that the firing rate of STN neurons in control rats and DRN-lesioned rats were (6.93+/-6.55) Hz and (11.27+/-9.31) Hz, respectively, and the firing rate of DRN-lesioned rats significantly increased when compared to the control rats (P<0.01). In control rats, 13% of STN neurons discharged regularly, 46% irregularly and 41% in bursts. In DRN-lesioned rats, 9% of STN neurons discharged regularly, 14% irregularly and 77% in bursts, the percentage of STN neurons firing in bursts was obviously higher than that of the control rats (P<0.01). In addition, the mean interspike interval coefficient of variation of STN neurons in control rats and DRN-lesioned rats were (0.05+/-0.04) and (0.11+/-0.09), respectively. The mean interspike interval coefficient of variation of DRN-lesioned rats was significantly higher than that of the control rats (P<0.001). These results show that the firing rate and the bursting pattern rate of neurons in STN of DRN-lesioned rats increase significantly, suggesting that DRN inhibits the neuronal activity of the subthalamic neurons in the intact rat.
5,7-Dihydroxytryptamine ; pharmacology ; Adrenergic Agents ; pharmacology ; Animals ; Electrophysiological Phenomena ; Male ; Neurons ; physiology ; Random Allocation ; Raphe Nuclei ; drug effects ; pathology ; Rats ; Rats, Sprague-Dawley ; Subthalamic Nucleus ; physiopathology