Functional disconnection of the dentate nucleus in essential tremor.

Despite previous functional MRI studies on alterations within the cerebello-thalamo-cortical circuit in patients with essential tremor (ET), the specific role of disconnection of the dentate nucleus (DN), the main output cerebellar pathway, still needs clarification. In this study, we evaluated DN functional connectivity (FC) changes and their relationship with motor and non-motor symptoms in ET. We studied 25 ET patients and 26 healthy controls. Tremor severity was assessed using the Fahn-Tolosa-Marin tremor rating scale (FTM-TRS) and tremor amplitude and frequency were evaluated using kinematic techniques. Cognitive profile was assessed by montreal cognitive assessment (MoCA) and frontal assessment battery (FAB). All participants underwent a 3 T MRI protocol including resting-state blood oxygenation level dependent and diffusion tensor sequences. We used a seed-based approach to investigate DN FC and to explore the diffusion properties of cerebellar peduncles. There was significantly decreased DN FC with cortical, subcortical, and cerebellar areas in ET patients compared with healthy controls. Correlation analysis showed that: (1) the DN FC with the supplementary motor area, pre and postcentral gyri, and prefrontal cortex negatively correlated with FTM-TRS score and disease duration; (2) DN FC changes in the thalamus and caudate negatively correlated with peak tremor frequency, changes in the cerebellum positively correlated with tremor amplitude, and changes in the bilateral thalamus negatively correlated with tremor amplitude, and (3) DN FC with the associative prefrontal and parietal cortices, basal ganglia, and thalamus positively correlated with the MoCA score. Diffusion abnormalities were found in the three cerebellar peduncles, which did not correlate with clinical scores.

Comparison of tractography-assisted to atlas-based targeting for deep brain stimulation in essential tremor.

BACKGROUND: Direct targeting of the dentato-rubro-thalamic tract is efficacious in DBS for tremor suppression. OBJECTIVES: We sought to compare outcomes and optimal stimulation parameters for tremor control using the technique of directly targeting the dentato-rubro-thalamic tract to those who underwent indirect targeting of the ventral intermediate nucleus thalamus. METHODS: Twenty consecutive essential tremor patients obtained preoperative diffusion MRIs, where the dentato-rubro-thalamic tract was individually drawn and used to directly target the ventral intermediate nucleus of the thalamus during surgery. These patients were compared to an earlier cohort of 20 consecutive patients who underwent surgery using atlas-based coordinates. Baseline and 1-year postsurgery tremor amplitude using The Essential Tremor Rating Assessment Scale was recorded, as were the parameters needed for successful tremor control. RESULTS: The indirectly targeted group had greater baseline and postop tremor severity relative to those directly targeted (baseline, 2.9 vs. 2.6; P = 0.02; postop, 1.1 vs. 0.8; P = 0.03). Mean voltage, pulse width, and frequency for optimal tremor control in the directly targeted group (38 electrodes) = 2.8 V, 80 µs, 153 Hz; the parameters for the indirectly targeted group (38 electrodes) = 2.9 V, 86 µs, 179 Hz (significantly greater, P < 0.001). Both groups had significant improvement in arm tremor amplitude from baseline (P < 0.001) without sustained side effects. CONCLUSION: Direct targeting of the dentato-rubro-thalamic tract provides excellent tremor control, comparable to indirectly targeting the ventral intermediate nucleus of the thalamus. Use of lower stimulation parameters, especially frequency, to control tremor in the directly targeted group suggests that it is a more efficient targeting methodology, which may minimize battery depletion. © 2018 International Parkinson and Movement Disorder Society.

Functional disconnection of thalamic and cerebellar dentate nucleus networks in progressive supranuclear palsy and corticobasal syndrome.

AIM: To assess functional rearrangement following neurodegeneration in the thalamus and dentate nucleus in patients with progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS). METHODS: We recruited 19 patients with PSP, 11 with CBS and 14 healthy subjects. All the subjects underwent resting-state (rs) fMRI using a 3T system. Whole brain functional connectivity of the thalamus and dentate nucleus were calculated by means of a seed-based approach with FEAT script in FSL toolbox. Thalamic volume was calculated by means of FIRST, and the dentate area by means of Jim software. RESULTS: Both thalamic volume and dentate area were significantly smaller in PSP and CBS patients than in healthy subjects. No significant difference emerged in thalamic volume between PSP and CBS patients, whereas dentate area was significantly smaller in PSP than in CBS. Thalamic functional connectivity was significantly reduced in both patient groups in various cortical, subcortical and cerebellar areas. By contrast, changes in dentate nucleus functional connectivity differed in PSP and CBS: it decreased in subcortical and prefrontal cortical areas in PSP, but increased asymmetrically in the frontal cortex in CBS. CONCLUSIONS: Evaluating the dentate nucleus size and its functional connectivity may help to differentiate patients with PSP from those with CBS.

Cerebellar Fastigial Nucleus Electrical Stimulation Alleviates Depressive-Like Behaviors in Post-Stroke Depression Rat Model and Potential Mechanisms.

OBJECTIVE: To identify the molecular mechanism of post-stroke depression (PSD), and observe the therapeutic effects of cerebellar fastigial nucleus electrical stimulation (FNS) on the behaviors and regional cerebral blood flow (rCBF) in a PSD rat model. METHODS: Healthy SD rats were randomly divided into four groups (sham, stroke, post-stroke depress and FNS group). Sham group (n = 6) underwent sham operation. The other three groups (n = 6*3) underwent MCAO. Rats were examined twice a week in open filed test. Moreover, neuroprotective effect on cerebellar Purkinje cells and expression of cytokines in hippocampal tissue were examined. RESULTS: The PSD group showed a significant weight loss, decreased consumption of sucrose water, reduced rearing and locomotor activities. The FNS significantly alleviates the body weight loss and sucrose preference, locomotor and rearing activities. The bilateral rCBF was also restored after FNS treatment. Moreover, FNS improved the neuroprotection via suppressing apoptosis of cerebellar Purkinje cells. And the inflammatory cytokines mRNA level in hippocampus was significantly decreased. CONCLUSION: FNS treatment alleviates depressive-like behaviors and rCBF in PSD rats model, which could be attributed to its ability to protect cerebellar Purkinje cells and decrease the mRNA level of inflammatory cytokines.

Depiction of dentatorubrothalamic tract fibers in patients with Parkinson's disease and multiple sclerosis in deep brain stimulation.

BACKGROUND: We wanted to depict fibers of the dentatorubrothalamic tract in patients with Parkinson's disease and multiple sclerosis in order to use this knowledge for clinical routine and to show its relation to the corticospinal tract for deep brain stimulation. Fibers of these white matter tracts were depicted between February 2014 and February 2015 in nine patients of all ages. There were seven men and two women. The mean age was 60 years. We used a 3DT1 sequence for the navigation. Additional scanning time was less than 9 min. Both tracts were portrayed in all patients. RESULTS: We were able to successfully portray these white matter tracts in all patients. We visualized the medial and lateral parts of the corticospinal tract by using a region of interest which covered the whole motor cortex. Furthermore we segmented the motor cortex. The fibers ran from this area of the brain through the internal capsule and they could be followed until their entry in the brainstem. The dentatorubrothalamic tract was smaller than the corticospinal tract. It was situated medio-posteriorly of the corticospinal tract. After decussation to the contralateral red nucleus it was localised next to the midline when it entered the motor cortex. From the thalamus on, it proceeds medially and posteriorly of the corticospinal tract further to the motor cortex. Depiction of the whole tract is essential for the differentiation of the dentatorubrothalamic tract with the corticospinal tract. CONCLUSIONS: The depiction of the dentatorubrothalamic tract might be useful for neurosurgeons when deep brain stimulation is planned. Knowing its relation to other white matter tracts can help physicians like neurosurgeons or neurologists avoid side effects and deal with patients with DBS. The position of the electrode might be crucial for a satisfactory outcome.

Injury of the dentato-rubro-thalamic tract in a patient with mild traumatic brain injury.

BACKGROUND: Several studies using diffusion tensor tractography (DTT) have demonstrated injury of the dentato-rubro-thalamic tract (DRTT) in various brain pathologies. However, no study on traumatic brain injury (TBI) has been reported. This case study attempted to demonstrate injury of the DRTT in a patient with mild TBI, using DTT. CASE DESCRIPTION: A 41-year-old female patient suffered from head trauma resulting from flexion-hyperextension injury by being hit from behind by a running car while stopped at an intersection. The patient lost consciousness and experienced post-traumatic amnesia for ∼1minute from the time of the car-accident. The patient's Glasgow Coma Scale score was 15. No specific lesion was observed on brain MRI. At 2 weeks after onset, the patient began to show resting and intentional tremor (more severe in the right upper and lower extremities) and ataxic gait. Her symptoms had been aggravated with the passage of time. On 1-month DTT, the left DRTT, which originated from the left dentate nucleus of the cerebellum, was thinner than the right DRTT. CONCLUSIONS: This study demonstrated injury of the DRTT in a patient with tremor and ataxia following mild TBI, using DTT. It is believed that analysis of the DRTT using DTT would be useful in elucidating the cause of post-traumatic abnormal movements.

Cerebellar output controls generalized spike-and-wave discharge occurrence.

OBJECTIVE: Disrupting thalamocortical activity patterns has proven to be a promising approach to stop generalized spike-and-wave discharges (GSWDs) characteristic of absence seizures. Here, we investigated to what extent modulation of neuronal firing in cerebellar nuclei (CN), which are anatomically in an advantageous position to disrupt cortical oscillations through their innervation of a wide variety of thalamic nuclei, is effective in controlling absence seizures. METHODS: Two unrelated mouse models of generalized absence seizures were used: the natural mutant tottering, which is characterized by a missense mutation in Cacna1a, and inbred C3H/HeOuJ. While simultaneously recording single CN neuron activity and electrocorticogram in awake animals, we investigated to what extent pharmacologically increased or decreased CN neuron activity could modulate GSWD occurrence as well as short-lasting, on-demand CN stimulation could disrupt epileptic seizures. RESULTS: We found that a subset of CN neurons show phase-locked oscillatory firing during GSWDs and that manipulating this activity modulates GSWD occurrence. Inhibiting CN neuron action potential firing by local application of the γ-aminobutyric acid type A (GABA-A) agonist muscimol increased GSWD occurrence up to 37-fold, whereas increasing the frequency and regularity of CN neuron firing with the use of GABA-A antagonist gabazine decimated its occurrence. A single short-lasting (30-300 milliseconds) optogenetic stimulation of CN neuron activity abruptly stopped GSWDs, even when applied unilaterally. Using a closed-loop system, GSWDs were detected and stopped within 500 milliseconds. INTERPRETATION: CN neurons are potent modulators of pathological oscillations in thalamocortical network activity during absence seizures, and their potential therapeutic benefit for controlling other types of generalized epilepsies should be evaluated.

Anodal transcranial direct current stimulation (tDCS) decreases the amplitudes of long-latency stretch reflexes in cerebellar ataxia.

Recent studies suggest that the neuromodulation of the cerebellum using transcranial direct current stimulation (tDCS) could represent a new therapeutic strategy for the management of cerebellar disorders. Anodal tDCS of the cerebellum increases the excitability of the cerebellar cortex. We tested the effects of anodal tDCS applied over the cerebellum in ataxic patients. We studied (a) stretch reflexes (SR) in upper limb (SLSR: short-latency stretch reflexes; LLSR: long-latency stretch reflexes), (b) a coordination functional task in upper limbs based on mechanical counters (MCT: mechanical counter test), and (c) computerized posturography. tDCS did not change the amplitude of SLSR, but reduced significantly the amplitudes of LLSR. tDCS did not improve the MCT scores and did not modify posture. We suggest that anodal tDCS of the cerebellum reduces the amplitudes of LLSR by increasing the inhibitory effect exerted by the cerebellar cortex upon cerebellar nuclei. The absence of effect upon upper limb coordination and posture suggests that the cerebello-cerebral networks subserving these functions are less responsive to anodal tDCS of the cerebellum. Anodal tDCS of the cerebellum represents a novel experimental tool to investigate the effects of the cerebellar cortex on the modulation of the amplitudes of LLSR.

Influence of fastigial nucleus stimulation on heart rate variability of surgically induced myocardial infarction rats: fastigial nucleus stimulation and autonomous nerve activity.

Electrical stimulation of the rostal cerebellar fastigial nucleus (FNS) has been proved to have neuroprotective effects, but it is not known whether FNS also has a cardioprotective effect. One hundred Sprague-Dawley rats were randomly allocated into four groups, including a sham-operation group (Sham group), rats whose coronary arteries were ligated but the FNs were sham stimulated (AMI group), rats in which both coronary arteries were ligated and FNs were stimulated (FNS group), and rats whose fastigial nuclei were lesioned 5 days before ligation, then their coronary arteries were ligated and FNs were stimulated (FNL group). Heart rate variability parameters were monitored 6 h, 24 h, 7 days and 21 days after ligation, and mortality rates, hemodynamic parameters and infarction sizes were compared after 21 days. FNS improved the survival of rats, and this may be due to the increased vagal and decreased sympathetic tone. FN stimulation does not affect infarction size and hemodynamic parameters. FN stimulation may have a protective effect on surgically induced myocardial infarction rats.

Electro-stimulation of cerebellar fastigial nucleus (FNS) improves axonal regeneration.

This study focused on the effect of electro-stimulation of fastigial nucleus on the expression of NgR and on axonal regeneration after focal cerebral ischemia-reperfusion in rats. Cerebral ischemia and reperfusion was induced by nylon monofilament. Ninety-six male SD rats were randomly divided into sham group and ischemic insult groups at 12 hours, 24 hours, and 1 to 3 weeks after cerebral ischemia-reperfusion. Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the changes of NgR mRNA expression. Immunohistochemistry was used to detect the expression of NgR protein and the state of axonal regeneration. Fastigial nucleus stimulation was applied at 2 hours after ischemia for one hour. The results demonstrated that NgR mRNA and protein in the infarcted cortex and hippocampus were significantly increased (p<0.01). The axons were grossly damaged at 24 h after cerebral ischemia-reperfusion when compared to the sham group. Fastigial nucleus stimulation decreased NgR mRNA and protein levels in the infarcted cortex and hippocampus (p<0.01) and improved axonal growth at 24 hours and 2 weeks after ischemia-reperfusion (p<0.05). These results suggest that electrostimulation of fastigial nucleus might provide a new strategy to promote CNS axonal regeneration.

Atypical involvement of frontostriatal systems during sensorimotor control in autism.

Autism is a neurodevelopmental disorder involving dysmaturation of widely distributed brain systems. Accordingly, behaviors that depend on distributed systems, such as higher level cognition and sensorimotor control, are compromised in the disorder. The current study investigated alterations in neural systems underlying sensorimotor disturbances in autism. An fMRI investigation was conducted using saccadic and pursuit eye movement paradigms with 13 high functioning individuals with autism and 14 age- and IQ-matched typically developing individuals. Individuals with autism had reduced activation in cortical eye fields and cerebellar hemispheres during both eye movement tasks. When executing visually guided saccades, individuals with autism had greater activation bilaterally in a frontostriatal circuit including dorsolateral prefrontal cortex, caudate nucleus, medial thalamus, anterior and posterior cingulate cortex, and right dentate nucleus. The increased activation in prefrontal-striatal-thalamocortical circuitry during visually guided saccades indicates that systems typically dedicated to cognitive control may need to compensate for disturbances in lower-level sensorimotor systems. Reduced activation throughout visual sensorimotor systems may contribute to saccadic and pursuit disturbances that have been reported in autism. These findings document that neurodevelopmental disturbances in autism affect widely distributed brain systems beyond those mediating language and social cognition.

Gray matter injury associated with periventricular leukomalacia in the premature infant.

Neuroimaging studies indicate reduced volumes of certain gray matter regions in survivors of prematurity with periventricular leukomalacia (PVL). We hypothesized that subacute and/or chronic gray matter lesions are increased in incidence and severity in PVL cases compared to non-PVL cases at autopsy. Forty-one cases of premature infants were divided based on cerebral white matter histology: PVL (n = 17) with cerebral white matter gliosis and focal periventricular necrosis; diffuse white matter gliosis (DWMG) (n = 17) without necrosis; and "Negative" group (n = 7) with no abnormalities. Neuronal loss was found almost exclusively in PVL, with significantly increased incidence and severity in the thalamus (38%), globus pallidus (33%), and cerebellar dentate nucleus (29%) compared to DWMG cases. The incidence of gliosis was significantly increased in PVL compared to DWMG cases in the deep gray nuclei (thalamus/basal ganglia; 50-60% of PVL cases), and basis pontis (100% of PVL cases). Thalamic and basal ganglionic lesions occur almost exclusively in infants with PVL. Gray matter lesions occur in a third or more of PVL cases suggesting that white matter injury generally does not occur in isolation, and that the term "perinatal panencephalopathy" may better describe the scope of the neuropathology.

Electrophysiological effects and clinical results of direct brain stimulation for intractable epilepsy.

OBJECTIVE: Epilepsy can be considered as a result of the imbalance of the excitatory and inhibitory processes. Therefore, the artificial enhancement of the activity of brain inhibitory mechanisms might lead to a beneficial therapeutic effect for intractable epilepsy patients. MATERIAL AND METHODS: Studies of the inhibitory effects of electrical stimulation of the head of the caudate nucleus (HCN), cerebellar dentate nucleus (CDN), thalamic centromedian nucleus (CM), and neocortical and temporal lobe mesiobasal epileptic foci were performed on 150 patients with implanted intracerebral electrodes. Chronic brain stimulation with implanted neurostimulators was performed on 54 patients. Sixteen were followed up to 1.5 years (mean 1.2 years). RESULTS: The study demonstrated that 4-8 Hz HCN and 50-100 Hz CDN stimulation suppressed the subclinical epileptic discharges and reduced the frequency of generalized, complex partial, and secondary generalized seizures. CM stimulation (20-130 Hz) desynchronized the EEG and suppressed partial motor seizures. Direct subthreshold 1-3 Hz stimulation of the epileptic focus may suppress rhythmic afterdischarges (ADs). Seizures were eliminated for 26 of 54 patients (48%), worthwhile improvement was achieved for 23 of 54 patients (43%), and no improvement was observed in 5 of 54 patients (9%). CONCLUSION: The artificial increase of the activity of brain inhibitory system may suppress the activity of epileptic foci, and, in long run, stabilize this epileptic foci activity at a lower, perhaps normal, level. Therapeutic direct brain stimulation, therefore, might serve as a useful tool in the treatment of intractable and multifocal epilepsy, and might be combined with ablative surgical methods.

Thalamic stimulation for parkinsonian tremor: correlation between regional cerebral blood flow and physiological tremor characteristics.

We used (15)O-labeled water (H(2)(15)O) positron emission tomography (PET) to study eight Parkinson's disease (PD) patients with unilateral ventral intermediate (Vim) thalamic nucleus deep brain stimulation (DBS) for severe tremor. Triaxial accelerometry (TRIAX) was used during imaging to obtain on-line measures of tremor characteristics. Regional cerebral blood flow (rCBF) scans together with TRIAX recordings were collected in three stimulation conditions (OFF, MID, and ON, corresponding, respectively, to 0%, 50%, and 100% reductions in mean accelerometry signal). Statistical Parametric Mapping (SPM99) revealed significant rCBF reductions during stimulation in the ipsilateral sensorimotor cortex (SMC) and the contralateral cerebellum, as well as concurrent increases in the ipsilateral ventral thalamus (P < 0.05, corrected). Covariate analysis of rCBF with physiological tremor characteristics revealed that tremor acceleration correlated positively with changes in the SMC and supplementary motor cortex ipsilaterally (P < 0.05, uncorrected), and negatively with changes in the ipsilateral cuneus (P < 0.05, corrected). After removing tremor acceleration effects, changes in tremor frequency correlated negatively with changes in the contralateral dentate nucleus and pons (P < 0.05, uncorrected). Our results suggest that Vim DBS for PD tremor modulates the activity of cerebello-thalamo-cortical pathways. Specific tremor characteristics relate to activity in different nodes of this system.

[The effect of fastigial nucleus electrical stimulation on the therapeutic window of opportunity for intervention of focal cerebral ischemia].

OBJECTIVE: To investigate the effect of cerebellar fastigial nucleus (FN) electrical stimulation on the therapeutic window of opportunity for intervention of focal cerebral ischemia. METHODS: Thirty-five healthy male Wistar rats were divided into focal cerebral ischemia/reperfusion group (I/R group, undergoing ischemia by embolism of middle cerebral artery for 3, 6 or 8 hours and then undergoing reperfusion for 24 hours, thus subdivided into I/R 3 hours, 6 hours, and 8 hours subgroups of 5 rats), focal cerebral ischemia/reperfusion plus FN electrical stimulation group (I/R-FN group, n = 15, undergoing FN electrical stimulation followed by focal cerebral ischemia/reperfusion as in the I/R group), and sham operation group (n = 5). Twenty-four hours after the reperfusion or sham operation, the rats were killed. The brain slices underwent Nissl's staining. Two slices of each rat were examined to observe the neuronal number and morphology, and the status or Nissl's staining, and make a scoring of the affected somatosensory cortex. RESULTS: The survival rates of neurons of the I/R 3, 6 and 8 hours subgroups 3.2% +/- 11.3%, 2.6% +/- 4.5% and 3.8% +/- 3.2% respectively without a significant difference between any 2 subgroups (all P > 0.05). The scores of these 3 subgroups all reached the highest grade (4.0 +/- 0.0). The neuron survival rate of the I/R FN 3 hours subgroup was 64.2% +/- 11.3%, significantly higher than those or other I/R subgroup at the same time point (all P < 0.01), however, the neurons being obviously shrunken. The score of the I/R FN 3 hours subgroup 2.1 +/- 0.2, significantly lower than that of the I/R 3 hours subgroup (P < 0.01). The neuron survival rate of the I/R FN 6 hours subgroup was 32.8% +/- 6.5%, significantly higher than that of the I/R 6 hours subgroup (P < 0.05), however, the neurons being shrunken and irregular in shape. The score of the I/R FM subgroup was 3.0 +/- 0.0, significantly lower than that of the I/R 6 hours subgroup (P < 0.05). The I/R FN 8 hours subgroup showed a neuron survival rate of 4.1% +/- 3.5%, not significantly different from that of the I/R 9 hours subgroup (P > 0.05), and the same score as that of the I/R 8 hours subgroup. The sham operation group showed a survival rate of neurons of 96.9% +/- 17.3% and a score of 0.00 +/- 0.00. CONCLUSION: FN electrical stimulation prolongs the therapeutic window of opportunity for intervention of focal cerebral ischemia. The complete recovery of survived neurons may need further interventions.

Cerebellar mutism associated with a midbrain cavernous malformation. Case report and review of the literature.

The authors report a case of cerebellar mutism arising from a hemorrhagic midbrain cavernous malformation in a 14-year-old boy. No cerebellar lesion was identified; however, edema of the dorsal midbrain was noted on postoperative magnetic resonance images. Dysarthric speech spontaneously returned and then completely resolved to normal speech. This case provides further evidence for the theory that involvement of the dentatothalamic tracts, and not a cerebellar lesion per se, is the underlying cause of "cerebellar" mutism.

[Functional neurosurgery of cerebral palsy]. / La neurochirurgie fonctionnelle de l'infirmité motrice d'origine cérébrale.

In 1983, approximately 40 000 patients in France and 5 760 patients in Switzerland suffered from cerebral palsy, representing more than 0.1% of their respective populations. The functional disability of these patients is particularly impressive and emphasizes the medical, social and economic importance of this problem. The term cerebral palsy is restricted to non-progressive disorders of motor function, already observed at an early age and due to cerebral lesions. These motor disorders can be of paretic, dystonic and dyskinetic nature. Their epidemiology, classification, etiology, pathology, early diagnosis and evolution are extensively reviewed by Th. Deonna. The difficulty in evaluation of treatment is the absence of a generally accepted rating scale. G. Broggi has proposed one on the basis of a large experience which could serve in the future for more objective evaluation. This monograph is devoted to the functional neurosurgical treatment of cerebral palsy. Physiotherapy and rehabilitation are part of the basic treatment of cerebral palsy, and must be continued after any neurosurgical treatment. Various conservative methods of treatment and their neurophysiological rationale are mentioned by P. Claverie. Some technical devices which improve the neurological deficits and facilitate rehabilitation are presented. Radiculotomies and neurotomies are probably the oldest neurosurgical operations for the treatment of spasticity. The neurophysiological and neuroanatomical basis of this therapeutic approach are treated in the review of the material from the neurosurgical department of Montpellier. Sixty cases were collected and the results analysed according to the type of operation (posterior radiculotomy, anterior radiculotomy, mixed) performed. Stereotactic thalamotomies and subthalamotomies are believed to be the best neurosurgical method to treat the tremor and improve other dyskinesias and hyperkinesias. The technique and a personal review of 49 cases of cerebral palsy are presented. The long-term follow-up in this study demonstrates that this type of operation markedly improves the functional disability of patients with moderate hyperkinesias, moderately improves patients severely affected, but also demonstrates that possible side effects cannot be ignored. Review of the literature indicates the difficulty in interpretation of results due to a lack of objective evaluation. Nevertheless, stereotactic thalamotomy can still be recommended when tremor and rigidity are the most prominent symptoms. Stereotactic dentatotomies in the treatment of spasticity were very popular 20 years ago, but have been largely forgotten for nearly a decade.(ABSTRACT TRUNCATED AT 400 WORDS)

[The cerebral lesions in Wilson's disease on computer tomography]. / Zerebrale Läsionen bei Morbus Wilson im Computertomogramm.

M. Wilson is often being mistaken as such for several years and kept for psychosis or another extrapyramidal disease. When the disease causes neuro-psychiatric symptoms a certain part of cases shows typical lesions in CT mainly affecting the Nucleus lentiformis and frontal cortex. From our own material two cases of M. Wilson are shown and compared with two other cases with identical patterns of lesions following toxic and hypoxic brain damage.

Focal cerebellar hyperthermia: effects on cerebral paroxysmal afterdischarges.

Small area hyperthermia is used to selectively increase cerebellar activity, and, as shown by electroencephalographic tracings of sensorimotor area, focal cerebellar hyperthermia with temperatures limited between 39.5 degrees and 41 degrees C effectively reduces the duration of electrically induced afterdischarges. Additional observations on paroxysms induced in the caudate nucleus which involve the sensorimotor area indicate that these also show shortened durations during focal cerebellar hyperthermia. A comparison of effects on these two forebrain structures is given and some similarities are noted between these results and those reported from previous studies in which electrical stimuli were applied directly to the cerebellar cortex.