15 research outputs found
GuÃas clÃnicas para la cirugÃa de la epilepsia y de los trastornos del movimiento
The guidelines for the surgical treatment of the movement disorders and epilepsy have been performed by the functional and stereotactic group of the Spanish Society of Neurosugery (SENEC). The guidelines are recomendations in terms of indication for surgery including timing and methods. The format are supported by prospective studies based in scientific evidence and the expert opinion of the group
Dianas quirúrgicas en el tratamiento de enfermedades psiquiátricas. Desde el movimiento a las emociones
Deep brain stimulation (DBS) for psychiatric
disorders refractory to conventional treatments are
currently been performed based in the knowledgment
obtained in the motor disorder surgery and mainly in
Parkinson´s disease. Depression, obsessive-compulsive
disorder (OCD) and Tourette syndrome, all of them are
cortico-striato-thalamo-cortical pathological process
involved in the limbic loop of the basal ganglia.
This review describes the different targets in these
pathological neuro-psychiatric disorders. For OCD
there are currently two targets, ventral striatum (VS)
Accumbens nucleus (Nacc) and the subthalamic nucleus
(STN). In refractory depression the subgenual area (25
Brodmann area) and VS/Nacc. For Tourette syndrome
the ventralis oralis internus and centromedianum/
parafascicularis of the thalamus (Voi and CM/Pf) and
the internal part of the globus pallidus (GPi). Currently
there are no specific surgical target for each pathological
disorder because clinical results reported are
very similar after stimulation surgery. In other point,
a selected surgical target also may improve different
pathologies
Revisión crÃtica de la estimulación subtalámica en la enfermedad de Parkinson
The authors critically review subthalamic nucleus (STN) stimulation for Parkinson's disease (PD) at long follow-up (3-5 years). Subthalamic stimulation induce a significant improvement during the "off" medication in the assessment motor score UPDRS (Unified Parkinson Disease Rating Scale) 3-5 years after surgery. Results show that the benefits obtained in tremor, rigidity, bradykinesia, dyskinesias induced by medication and levodopa reduction are significantly maintained during long term. The improvement in other clinical signs as gait and postural stability at long follow-up are not maintained comparing with the benefits obtained one year after surgery. A high percentage of patients show a cognitive disturbance during the follow-up period that may be correlated with the disease progression. The conclusion is that bilateral STN stimulation is an effective treatment for PD patients at long term but it should be considered earlier in the course of P
Clinical features, pathophysiology, and treatment of levodopa-induced dyskinesias in Parkinson's disease
Dyskinetic disorders are characterized by excess of motor activity that may interfere with normal movement control. In patients with Parkinson's disease, the chronic levodopa treatment induces dyskinetic movements known as levodopa-induced dyskinesias (LID). This paper analyzed the pathophysiology, clinical manifestations, pharmacological treatments, and surgical procedures to treat hyperkinetic disorders. Surgery is currently the only treatment available for Parkinson's disease that may improve both parkinsonian motor syndrome and LID. However, this paper shows the different mechanisms involved are not well understood
Involvement of the subthalamic nucleus in impulse control disorders associated with Parkinson’s disease
Behavioural abnormalities such as impulse control disorders may develop when patients with Parkinson’s disease receive
dopaminergic therapy, although they can be controlled by deep brain stimulation of the subthalamic nucleus. We have recorded
local field potentials in the subthalamic nucleus of 28 patients with surgically implanted subthalamic electrodes. According to
the predominant clinical features of each patient, their Parkinson’s disease was associated with impulse control disorders
(n = 10), dyskinesias (n = 9) or no dopaminergic mediated motor or behavioural complications (n = 9). Recordings were obtained
during the OFF and ON dopaminergic states and the power spectrum of the subthalamic activity as well as the subthalamocortical
coherence were analysed using Fourier transform-based techniques. The position of each electrode contact was determined
in the postoperative magnetic resonance image to define the topography of the oscillatory activity recorded in each
patient. In the OFF state, the three groups of patients had similar oscillatory activity. By contrast, in the ON state, the patients
with impulse control disorders displayed theta-alpha (4–10 Hz) activity (mean peak: 6.71 Hz) that was generated 2–8mm below
the intercommissural line. Similarly, the patients with dyskinesia showed theta-alpha activity that peaked at a higher frequency
(mean: 8.38 Hz) and was generated 0–2mm below the intercommissural line. No such activity was detected in patients that
displayed no dopaminergic side effects. Cortico-subthalamic coherence was more frequent in the impulsive patients in the
4–7.5 Hz range in scalp electrodes placed on the frontal regions anterior to the primary motor cortex, while in patients with
dyskinesia it was in the 7.5–10 Hz range in the leads overlying the primary motor and supplementary motor area. Thus,
dopaminergic side effects in Parkinson’s disease are associated with oscillatory activity in the theta-alpha band, but at different
frequencies and with different topography for the motor (dyskinesias) and behavioural (abnormal impulsivity) manifestations.
These findings suggest that the activity recorded in parkinsonian patients with impulse control disorders stems from the
associative-limbic area (ventral subthalamic area), which is coherent with premotor frontal cortical activity. Conversely, in
patients with L-dopa-induced dyskinesias such activity is recorded in the motor area (dorsal subthalamic area) and it is coherent
with cortical motor activity. Consequently, the subthalamic nucleus appears to be implicated in the motor and behavioural
complications associated with dopaminergic drugs in Parkinson’s disease, specifically engaging different anatomo-functional
territories
Slow oscillatory activity and levodopa-induced dyskinesias in Parkinson’s disease
The pathophysiology of levodopa-induced dyskinesias (LID) in Parkinson’s disease is not well understood.
We have recorded local field potentials (LFP) from macroelectrodes implanted in the subthalamic nucleus
(STN) of 14 patients with Parkinson’s disease following surgical treatment with deep brain stimulation. Patients
were studied in the ‘Off’ medication state and in the ‘On’ motor state after administration of levodopa–
carbidopa (po) or apomorphine (sc) that elicited dyskinesias in 11 patients. The logarithm of the power
spectrum of the LFP in selected frequency bands (4–10, 11–30 and 60–80 Hz) was compared between the
‘Off’ and ‘On’ medication states. A peak in the 11–30 Hz band was recorded in the ‘Off’ medication state
and reduced by 45.2% (P < 0.001) in the ‘On’ state. The ‘On’ was also associated with an increment of 77. 6%
(P < 0.001) in the 4–10 Hz band in all patients who showed dyskinesias and of 17.8% (P < 0.001) in the 60–80 Hz
band in the majority of patients. When dyskinesias were only present in one limb (n = 2), the 4–10 Hz peak was
only recorded in the contralateralSTN. These findings suggest that the 4–10 Hz oscillation is associated with the
expression of LID in Parkinson’s disease
Effects of dexmedetomidine on subthalamic local field potentials in parkinson's disease
Background: Dexmedetomidine is frequently used for sedation during deep brain stimulator implantation in patients with Parkinson's disease, but its effect on subthalamic nucleus activity is not well known. The aim of this study was to quantify the effect of increasing doses of dexmedetomidine in this population.
Methods: Controlled clinical trial assessing changes in subthalamic activity with increasing doses of dexmedetomidine (from 0.2 to 0.6 μg kg-1 h-1) in a non-operating theatre setting. We recorded local field potentials in 12 patients with Parkinson's disease with bilateral deep brain stimulators (24 nuclei) and compared basal activity in the nuclei of each patient and activity recorded with different doses. Plasma levels of dexmedetomidine were obtained and correlated with the dose administered.
Results: With dexmedetomidine infusion, patients became clinically sedated, and at higher doses (0.5-0.6 μg kg-1 h-1) a significant decrease in the characteristic Parkinsonian subthalamic activity was observed (P<0.05 in beta activity). All subjects awoke to external stimulus over a median of 1 (range: 0-9) min, showing full restoration of subthalamic activity. Dexmedetomidine dose administered and plasma levels showed a positive correlation (repeated measures correlation coefficient=0.504; P<0.001).
Conclusions: Patients needing some degree of sedation throughout subthalamic deep brain stimulator implantation for Parkinson's disease can probably receive dexmedetomidine up to 0.6 μg kg-1 h-1 without significant alteration of their characteristic subthalamic activity. If patients achieve a 'sedated' state, subthalamic activity decreases, but they can be easily awakened with a non-pharmacological external stimulus and recover baseline subthalamic activity patterns in less than 10 min
Radioterapia estereotáctica
La radioterapia con técnica estereotáctica es una
modalidad de radioterapia externa que utiliza un sistema de coordenadas tridimensionales independientes del
paciente para la localización precisa de la lesión. También se caracteriza porque los haces de irradiación son
altamente conformados, precisos y convergentes sobre
la lesión que hacen posible la administración de dosis
muy altas de radioterapia sin incrementar la irradiación
de los órganos o estructuras sanas adyacentes. Cuando
el procedimiento se realiza en una sesión de tratamiento se denomina radiocirugÃa y si se administra en varias
sesiones se denomina radioterapia estereotáctica. Se
precisa de sistemas de fijación e inmovilización del paciente especiales (guÃas o marcos estereotácticos) y dispositivos de radioterapia capaces de generar haces muy
conformados (acelerador lineal, gammaknife, cyberknife,
tomoterapia, ciclotrones). La radioterapia estereotáctica
moderna utiliza marcas radioopacas intratumorales o
sistemas de imágenes de TAC incluidos en el dispositivo de irradiación, que permiten una precisa localización
de las lesiones móviles en cada sesión de tratamiento.
Además, los avances tecnológicos hacen posible coordinar los movimientos de la lesión en la respiración con la
unidad de radioterapia (gaiting y tracking) de forma que
pueden estrecharse al máximo los márgenes y por lo tanto excluir un mayor volumen de tejido sano
La radiocirugÃa está indicada principalmente en lesiones cerebrales benignas o malignas menores de 3-4
centÃmetros (malformaciones arteriovenosas, neurinomas, meningiomas, metástasis cerebrales) y la radioterapia estereotáctica se administra fundamentalmente
en tumores de localización extracraneal que requieran
una alta conformación y precisión como cáncer precoz
de pulmón inoperable y metástasis hepáticas.Stereotactic radiotherapy is an external radiation
modality that uses a system of three dimensional references independent of the patient to achive a precise
location of the lesion. Stereotactic radiotherapy generate highly conformal, precisely focused radiation
beams to administer very high doses of radiation without increasing the radiation to healthy surrounding
organs or structures. When the procedure is carried
out in one treatment session the procedure is termed
radiosurgery, and when the treatment is administered
in several fractions, the radiation modality is termed
stereotactic radiotherapy. Special systems of patient
immobilization (guides or stereotactic frames) are required together with radiotherapy devices capable of
generating conformal beams (lineal accelerator, gammaknife, cyberknife, tomotherapy, cyclotrons). Modern
stereotactic radiotherapy techniques employ intratumoural radio-opaque fiducials or CT image systems
included in the irradiation device, which make possible
a precise location of mobile lesions in each treatment
session. Besides, technological advances permit breathing synchronized radiation (gating and tracking) for
maximum tightening of margins and excluding a greater
volume of healthy tissue.
Radiosurgery is mainly indicated in benign or malign cerebral lesions less than 3-4 centimetres (arteriovenous malformations, neurinomas, meningiomas,
cerebral metastases) and stereotactic radiotherapy is
basically administered in tumours of extracraneal location that require high conformation and precision, such
as inoperable early lung cancer and liver metastasis
Short and long term outcome of bilateral pallidal stimulation in chorea-acanthocytosis
BACKGROUND:
Chorea-acanthocytosis (ChAc) is a neuroacanthocytosis syndrome presenting with severe movement disorders poorly responsive to drug therapy. Case reports suggest that bilateral deep brain stimulation (DBS) of the ventro-postero-lateral internal globus pallidus (GPi) may benefit these patients. To explore this issue, the present multicentre (n=12) retrospective study collected the short and long term outcome of 15 patients who underwent DBS.
METHODS:
Data were collected in a standardized way 2-6 months preoperatively, 1-5 months (early) and 6 months or more (late) after surgery at the last follow-up visit (mean follow-up: 29.5 months).
RESULTS:
Motor severity, assessed by the Unified Huntington's Disease Rating Scale-Motor Score, UHDRS-MS), was significantly reduced at both early and late post-surgery time points (mean improvement 54.3% and 44.1%, respectively). Functional capacity (UHDRS-Functional Capacity Score) was also significantly improved at both post-surgery time points (mean 75.5% and 73.3%, respectively), whereas incapacity (UHDRS-Independence Score) improvement reached significance at early post-surgery only (mean 37.3%). Long term significant improvement of motor symptom severity (≥ 20 % from baseline) was observed in 61.5 % of the patients. Chorea and dystonia improved, whereas effects on dysarthria and swallowing were variable. Parkinsonism did not improve. Linear regression analysis showed that preoperative motor severity predicted motor improvement at both post-surgery time points. The most serious adverse event was device infection and cerebral abscess, and one patient died suddenly of unclear cause, 4 years after surgery.
CONCLUSION:
This study shows that bilateral DBS of the GPi effectively reduces the severity of drug-resistant hyperkinetic movement disorders such as present in ChAc
Clinical features, pathophysiology, and treatment of levodopa-induced dyskinesias in Parkinson's disease
Dyskinetic disorders are characterized by excess of motor activity that may interfere with normal movement control. In patients with Parkinson's disease, the chronic levodopa treatment induces dyskinetic movements known as levodopa-induced dyskinesias (LID). This paper analyzed the pathophysiology, clinical manifestations, pharmacological treatments, and surgical procedures to treat hyperkinetic disorders. Surgery is currently the only treatment available for Parkinson's disease that may improve both parkinsonian motor syndrome and LID. However, this paper shows the different mechanisms involved are not well understood