Pallidal deep brain stimulation for patients with myoclonus-dystonia without SGCE mutations

BACKGROUND

Pallidal deep brain stimulation (GPi-DBS) is effective for treating myoclonus and dystonia caused by SGCE mutations (DYT-SGCE, DYT11). However, it is unknown whether GPi-DBS is effective for the treatment of myoclonus-dystonia which is not associated with the SGCE gene mutations. In this study, we investigated the efficacy of GPi-DBS in treating myoclonus-dystonia in SGCE mutation-negative cases.

METHODS

Three patients with myoclonus-dystonia without SGCE mutations who underwent GPi-DBS were evaluated preoperatively and 6 months postoperatively using the Unified Myoclonus Rating Scale (UMRS) and Fahn-Marsden Dystonia Rating Scale (FMDRS) for myoclonus and dystonia, respectively. In two of the three patients, myoclonus was more evident during action. Myoclonus was predominant at rest in the other patient, and he was unaware of his dystonia symptoms. The results were compared with those of the four DYT-SGCE cases.

RESULTS

The mean UMRS score in patients with myoclonus-dystonia without SGCE mutations improved from 61.7 to 33.7 pre- and postoperatively, respectively, and the mean FMDRS score improved from 7.2 to 4.5. However, the degree of improvement in myoclonus-dystonia in patients without SGCE mutations was inferior to that in patients with DYT-SGCE (the UMRS score improved by 45% and 69%, respectively).

CONCLUSIONS

GPi-DBS is effective for treating myoclonus-dystonia in patients with and without SGCE mutations. GPi-DBS should be considered as a treatment option for myoclonus-dystonia without SGCE mutations.

Visual fixation suppression of caloric nystagmus in progressive supranuclear palsy - A comparison with Parkinson's disease

BACKGROUND

Impairment of visual fixation suppression (VS) in progressive supranuclear palsy (PSP) is not well documented.

OBJECTIVE

To evaluate the usefulness of impaired VS of caloric nystagmus as an index for differential diagnosis between PSP and Parkinson's disease (PD), which is often difficult, especially in the early stage.

METHODS

Subjects comprised 26 PSP patients and 26 PD patients clinically diagnosed at Tokyo Metropolitan Neurological Hospital. We retrospectively investigated VS of caloric nystagmus, horizontal pursuit, saccades, and horizontal optokinetic nystagmus recorded on direct-current-electronystagmography, and neuroradiological findings.

RESULTS

The median of the average VS% was 0% and 50.0% in PSP and PD patients, respectively. In PSP, VS was impaired even in the early stage of disease. We found a significant correlation between VS and velocity of saccades or maximum slow phase velocity of optokinetic nystagmus only in PSP patients. PSP patients with atrophy of the subthalamic nucleus or with decreased blood flow in the frontal lobe showed significantly more severe impairment of VS.

CONCLUSIONS

VS may be a useful biomarker to differentiate patients with PSP from those with PD. Cerebellar networks that connect with the cerebral cortex and basal ganglia may contribute to impaired VS of caloric nystagmus in PSP.

Is Generalized and Segmental Dystonia Accompanied by Impairments in the Dopaminergic System?

Background: The pathogenesis of dystonia is remarkably diverse. Some types of dystonia, such as DYT5 (DYT-GCH1) and tardive dystonia, are related to dysfunction of the dopaminergic system. Furthermore, on pathological examination, cell loss in the substantia nigra (SN) of patients with dystonia has been reported, suggesting that impaired dopamine production may be involved in DYT5 and in other types of dystonia.

Objectives: To investigate functional dopaminergic impairments, we compared patients with dystonia and those with Parkinson's disease (PD) with normal controls using neuromelanin-sensitive magnetic resonance imaging (NM-MRI) and dopamine transporter single photon emission computed tomography (DAT SPECT).

Methods: A total of 18, 18, and 27 patients with generalized or segmental dystonia, patients with PD, and healthy controls, respectively, were examined using NM-MRI. The mean area corresponding to NM in the SN (NM-SN) was blindly quantified. DAT SPECT was performed on 17 and eight patients with dystonia and PD, respectively. The imaging data of DAT SPECT were harmonized with the Japanese database using striatum phantom calibration. These imaging data were compared between patients with dystonia or PD and controls from the Japanese database in 256 healthy volunteers using the calibrated specific binding ratio (cSBR). The symptoms of dystonia were evaluated using the Fahn–Marsden Dystonia Rating Scale (FMDRS), and the correlation between the results of imaging data and FMDRS was examined.

Results: The mean areas corresponding to NM in the SN (NM-SN) were 31 ± 4.2, 28 ± 3.8, and 43 ± 3.8 pixels in patients with dystonia, PD, and in healthy controls, respectively. The mean cSBRs were 5 ± 0.2, 2.8 ± 0.2, 9.2 (predictive) in patients with dystonia, PD, and in healthy controls, respectively. The NM-SN area (r = −0.49, p < 0.05) and the cSBR (r = −0.54, p < 0.05) were inversely correlated with the FMDRS. There was no significant difference between the dystonia and PD groups regarding NM-SN (p = 0.28). In contrast, the cSBR was lower in patients with PD than in those with dystonia (p < 0.5 × 10⁻⁶).

Conclusions: Impairments of the dopaminergic system may be involved in developing generalized and segmental dystonia. SN abnormalities in patients with dystonia were supposed to be different from degeneration in PD.

Variants in saposin D domain of prosaposin gene linked to Parkinson's disease

Recently, the genetic variability in lysosomal storage disorders has been implicated in the pathogenesis of Parkinson's disease. Here, we found that variants in prosaposin (PSAP), a rare causative gene of various types of lysosomal storage disorders, are linked to Parkinson's disease. Genetic mutation screening revealed three pathogenic mutations in the saposin D domain of PSAP from three families with autosomal dominant Parkinson's disease. Whole-exome sequencing revealed no other variants in previously identified Parkinson's disease-causing or lysosomal storage disorder-causing genes. A case-control association study found two variants in the intronic regions of the PSAP saposin D domain (rs4747203 and rs885828) in sporadic Parkinson's disease had significantly higher allele frequencies in a combined cohort of Japan and Taiwan. We found the abnormal accumulation of autophagic vacuoles, impaired autophagic flux, altered intracellular localization of prosaposin, and an aggregation of α-synuclein in patient-derived skin fibroblasts or induced pluripotent stem cell-derived dopaminergic neurons. In mice, a Psap saposin D mutation caused progressive motor decline and dopaminergic neurodegeneration. Our data provide novel genetic evidence for the involvement of the PSAP saposin D domain in Parkinson's disease.

PLA2G6 variants associated with the number of affected alleles in Parkinson's disease in Japan

This study aimed to evaluate genotype-phenotype correlations of Parkinson's disease (PD) patients with phospholipase A2 group V (PLA2G6) variants. We analyzed the DNA of 798 patients with PD, including 78 PD patients reported previously, and 336 in-house controls. We screened the exons and exon-intron boundaries of PLA2G6 using the Ion Torrent system and Sanger method. We identified 21 patients with 18 rare variants, such that 1, 9, and 11 patients were homozygous, heterozygous, and compound heterozygous, respectively, with respect to PLA2G6 variants. The allele frequency was approximately equal between patients with familial PD and those with sporadic PD. The PLA2G6 variants detected frequently were identified in the early-onset sporadic PD group. Patients who were homozygous for a variant showed more severe symptoms than those who were heterozygous for the variant. The most common variant was p.R635Q in our cohort, which was considered a risk variant for PD. Thus, the variants of PLA2G6 may play a role in familial PD and early-onset sporadic PD.

Resting-State Pallidal-Cortical Oscillatory Couplings in Patients With Predominant Phasic and Tonic Dystonia

Pallidal deep brain stimulation (DBS) improves the symptoms of dystonia. The improvement processes of dystonic movements (phasic symptoms) and tonic symptoms differ. Phasic symptoms improve rapidly after starting DBS treatment, but tonic symptoms improve gradually. This difference implies distinct neuronal mechanisms for phasic and tonic symptoms in the underlying cortico-basal ganglia neuronal network. Phasic symptoms are related to the pallido-thalamo-cortical pathway. The pathway related to tonic symptoms has been assumed to be different from that for phasic symptoms. In the present study, local field potentials of the globus pallidus internus (GPi) and globus pallidus externus (GPe) and electroencephalograms from the motor cortex (MCx) were recorded in 19 dystonia patients to analyze the differences between the two types of symptoms. The 19 patients were divided into two groups, 10 with predominant phasic symptoms (phasic patients) and 9 with predominant tonic symptoms (tonic patients). To investigate the distinct features of oscillations and functional couplings across the GPi, GPe, and MCx by clinical phenotype, power and coherence were calculated over the delta (2-4 Hz), theta (5-7 Hz), alpha (8-13 Hz), and beta (14-35 Hz) frequencies. In phasic patients, the alpha spectral peaks emerged in the GPi oscillatory activities, and alpha GPi coherence with the GPe and MCx was higher than in tonic patients. On the other hand, delta GPi oscillatory activities were prominent, and delta GPi-GPe coherence was significantly higher in tonic than in phasic patients. However, there was no significant delta coherence between the GPi/GPe and MCx in tonic patients. These results suggest that different pathophysiological cortico-pallidal oscillations are related to tonic and phasic symptoms.

Phenotype variability and allelic heterogeneity in KMT2B-Associated disease

BACKGROUND

Mutations in Lysine-Specific Histone Methyltransferase 2B gene (KMT2B) have been reported to be associated with complex early-onset dystonia. Almost all reported KMT2B mutations occurred de novo in the paternal germline or in the early development of the patient. We describe clinico-genetic features on four Japanese patients with novel de novo mutations and demonstrate the phenotypic spectrum of KMT2B mutations.

METHODS

We performed genetic studies, including trio-based whole exome sequencing (WES), in a cohort of Japanese patients with a seemingly sporadic early-onset generalized combined dystonia. Potential effects by the identified nucleotide variations were evaluated biologically. Genotype-phenotype correlations were also investigated.

RESULTS

Four patients had de novo heterozygous mutations in KMT2B, c.309delG, c.1656dupC, c.3325_3326insC, and c.5636delG. Biological analysis of KMT2B mRNA levels showed a reduced expression of mutant transcript frame. All patients presented with motor milestone delay, microcephaly, mild psychomotor impairment, childhood-onset generalized dystonia and superimposed choreoathetosis or myoclonus. One patient cannot stand due to axial hypotonia associated with cerebellar dysfunction. Three patients had bilateral globus pallidal deep brain stimulation (DBS) with excellent or partial response.

CONCLUSIONS

We further demonstrate the allelic heterogeneity and phenotypic variations of KMT2B-associated disease. Haploinsufficiency is one of molecular pathomechanisms underlying the disease. Cardinal clinical features include combined dystonia accompanying mild psychomotor disability. Cerebellum would be affected in KMT2B-associated disease.

Frequency-Specific Synchronization in the Bilateral Subthalamic Nuclei Depending on Voluntary Muscle Contraction and Relaxation in Patients with Parkinson's Disease

The volitional control of muscle contraction and relaxation is a fundamental component of human motor activity, but how the processing of the subcortical networks, including the subthalamic nucleus (STN), is involved in voluntary muscle contraction (VMC) and voluntary muscle relaxation (VMR) remains unclear. In this study, local field potentials (LFPs) of bilateral STNs were recorded in patients with Parkinson’s disease (PD) while performing externally paced VMC and VMR tasks of the unilateral wrist extensor muscle. The VMC- or VMR-related oscillatory activities and their functional couplings were investigated over the theta (4–7 Hz), alpha (8–13 Hz), beta (14–35 Hz), and gamma (40–100 Hz) frequency bands. Alpha and beta desynchronizations were observed in bilateral STNs at the onset of both VMC and VMR tasks. On the other hand, theta and gamma synchronizations were prominent in bilateral STNs specifically at the onset of the VMC task. In particular, just after VMC, theta functional coupling between the bilateral STNs increased, and the theta phase became coupled to the gamma amplitude within the contralateral STN in a phase-amplitude cross-frequency coupled manner. On the other hand, the prominent beta-gamma cross-frequency couplings observed in the bilateral STNs at rest were reduced by the VMC and VMR tasks. These results suggest that STNs are bilaterally involved in the different performances of muscle contraction and relaxation through the theta-gamma and beta-gamma networks between bilateral STNs in patients with PD.

Clinical and genetic investigation of 17 Japanese patients with hyperekplexia

AIM

The aim of the study was to determine clinical and genetic characteristics of Japanese patients with hyperekplexia.

METHOD

Clinical courses, responses to antiepileptic drugs, outcomes, and genetic testing were investigated in 17 Japanese patients (nine males, eight females, median age 1y, range birth-45y) with hyperekplexia.

RESULTS

In all patients, muscle stiffness and startle responses appeared soon after birth. Only seven patients were diagnosed with hyperekplexia before 1 year of age. Seven patients had been misdiagnosed with other disorders such as epilepsy and adult-onset anxiety neurosis. Umbilical/inguinal hernias were seen in 10 patients. Life-threatening events were noted in four patients. Clonazepam was the most effective drug. Muscle stiffness completely disappeared in 12 patients before 5 years of age, whereas startle responses resolved in only three patients. Mutations in the GLRA1 and GLRB genes were identified in 16 patients and one patient respectively. In 14 patients, the mutation showed autosomal dominant inheritance; in the other three, inheritance was autosomal recessive. p.R271Q of GLRA1 was the most frequent mutation, found in 10 patients. Novel mutations, p.A272P and p.A384P of GLRA1, were detected. Clinical severity and outcome varied even in the same family.

INTERPRETATION

Early correct diagnosis is essential for prevention of accidental injuries and to provide appropriate treatments for hyperekplexia. Clonazepam is effective, although the time taken for startle responses to resolve varied.

Official Japanese Version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale: validation against the original English version

BACKGROUND

The Movement Disorder Society (MDS)-sponsored revision of the Unified Parkinson's Disease (PD) Rating Scale (UPDRS) (MDS-UPDRS) has been developed and is now available in English. Part of the overall program includes the establishment of official non-English translations of the MDS-UPDRS. We present the process for completing the official Japanese translation of the MDS-UPDRS with clinimetric testing results.

METHODS

In this trial, the MDS-UPDRS was translated into Japanese, underwent cognitive pre-testing, and the translation was modified after taking the results into account. The final translation was approved as Official Working Draft of the MDS-UPDRS Japanese version and tested in 365 native-Japanese-speaking patients with PD. Confirmatory analyses were used to determine whether the factor structure for the English-language MDS-UPDRS could be confirmed in data collected using the Official Working Draft of the Japanese translation. As a secondary analysis, we used exploratory factor analyses to examine the underlying factor structure without the constraint of a pre-specified factor organization.

RESULTS

Confirmatory factor analysis revealed that Comparative Fit Index for all Parts of the MDS-UPDRS exceeded the minimal standard of 0.90 relative to the English version and therefore Japanese translation met the pre-specified criterion to be designated called an OFFICIAL MDS TRANSLATION. Secondary analyses revealed some differences between the English-language MDS-UPDRS and the Japanese translation, however, these differences were considered to be within an acceptable range.

CONCLUSIONS

The Japanese version of the MDS-UPDRS met the criterion as an Official MDS Translation and is now available for use (www.movementdisorders.org).

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.

Primary progressive apraxia of speech (AOS) in a patient with Pick's disease with Pick bodies: a neuropsychological and anatomical study and review of literatures

A 56-year-old right-handed man suffered from progressive apraxia of speech (AOS), characterized by agrammatism and buccofacial apraxia. He also became mute at the later stages of the disease progression. At autopsy, the left precentral gyrus, pars opercularis, and hippocampus showed severe atrophy. Pick bodies and Pick cells were observed. In this report, we also review previous case reports of AOS. Pick's disease is among the most commonly associated of the major diseases. Brain lesions associated with AOS may be found in regions such as the precentral gyrus and the pars opercularis in the left hemisphere.

Novel pathogenic mutations and copy number variations in the VPS13A gene in patients with chorea-acanthocytosis

Chorea-acanthocytosis (ChAc) is a rare autosomal recessive neurodegenerative disorder caused by loss of function mutations in the vacuolar protein sorting 13 homolog A (VPS13A) gene that encodes chorein. It is characterized by adult-onset chorea, peripheral acanthocytes, and neuropsychiatric symptoms. In the present study, we performed a comprehensive mutation screen, including sequencing and copy number variation (CNV) analysis, of the VPS13A gene in ChAc patients. All 73 exons and flanking regions of VPS13A were sequenced in 35 patients diagnosed with ChAc. To detect CNVs, we also performed real-time quantitative PCR and long-range PCR analyses for the VPS13A gene on patients in whom only a single heterozygous mutation was detected. We identified 36 pathogenic mutations, 20 of which were previously unreported, including two novel CNVs. In addition, we investigated the expression of chorein in 16 patients by Western blotting of erythrocyte ghosts. This demonstrated the complete absence of chorein in patients with pathogenic mutations. This comprehensive screen provides an accurate and useful method for the molecular diagnosis of ChAc.

Spinal segmental myoclonus during postural maintenance in a patient with cervical spondylosis: a case report

Spinal segmental myoclonus is defined as a rare involuntary movement characterized by myoclonic jerks of spinal origin. We describe the case of a 62-year-old woman who developed spinal segmental myoclonus 4 months after undergoing cervical laminoplasty for ossification of the posterior longitudinal ligament. Myoclonic jerks were observed in the upper trapezius innervated by C3-4, which corresponded to the level of myelomalacia. These jerks were elicited and aggravated in the sitting and standing positions but were completely suppressed in the supine position. The myoclonus was refractory to medication but improved with the use of a soft neck brace.

Effects of STN stimulation on the initiation and inhibition of saccade in Parkinson disease

OBJECTIVES

The basal ganglia (BG) play an important role in controlling saccades. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is widely used as a treatment of Parkinson disease (PD) by altering the function of the BG. Nevertheless, the effects of STN DBS on saccade performance are not fully clarified in a systematic manner. In this study, we examined the effects of bilateral STN DBS on both the initiation and inhibition of saccades in PD.

METHODS

Thirty-two patients with PD performed 4 oculomotor tasks. Two tasks (visually guided saccades and gap saccades) were reflexive and 2 (memory-guided saccades [MGS] and antisaccades) were volitional. While taking their regular doses of antiparkinsonian drugs, patients performed these tasks under 2 conditions: during DBS (DBS-on condition) and without DBS (DBS-off condition). Fifty-one age-matched subjects served as controls.

RESULTS

In the DBS-on condition, parameters of saccade initiation were improved in all tasks, with shorter latencies and increased amplitudes, except for MGS latency. STN DBS improved the ability to suppress unwanted saccades to the cue stimulus in the MGS task. However, it did not suppress prosaccades during the antisaccade task.

CONCLUSIONS

These results suggest that deep brain stimulation (DBS) of the subthalamic nucleus (STN) affects the neural pathway common to both reflexive and volitional saccades, possibly by acting on the STN-substantia nigra pars reticulata-superior colliculi pathway. STN DBS may set the functional level of the superior colliculi appropriate for both saccade initiation and inhibition through this pathway. These findings provide novel insights into the pathophysiology of Parkinson disease and may yield better treatment strategies.

[Effects of piracetam therapy in a case of Lance-Adams syndrome]

We report a 17-year-old female patient with Lance-Adams syndrome caused by anoxic encephalopathy during a severe attack of bronchial asthma. She had difficulty in writing because of action myoclonus in her arms. She also exhibited freezing gait and was unable to walk without cane. Although her gait disturbance resembled those seen in patients with parkinsonism secondary to anoxic encephalopathy, surface electromyography revealed that it was caused by action myoclonus in her legs. The presence of giant somatosensory evoked potentials and enhanced cortical reflexes in response to the electrical stimulation to her posterior tibial nerves supported our diagnosis. A combined therapy with valproate sodium, clonazepam and piracetam (15 g/day) was not effective. However, her freezing gait remarkably improved and she was able to walk without help, after the treatment with sufficient dose of piracetam (21 g/day). Cortical hyperexcitability as revealed by electrophysiological examination also improved. We concluded that the combined therapy with antiepileptic drugs and piracetam was effective in the treatment for action myoclonus. However, because the effects seemed dose-related, the dosage of piracetam needed to be increased until the optimum effects were obtained.

[Deep brain stimulation for Parkinson's disease and dystonia]

Deep brain stimulation (DBS) has proved highly effective in the treatment for Parkinson's disease and dystonia. Presently, many types of dopamine agonists, monoamine oxidase B (MAOB) inhibitors, catechol-O-methyltransferase (COMT) inhibitor or other antiparkinsonian drugs are being developed. However, it is still very difficult to medically treat motor complications associated with levodopa therapy. Surgical intervention using DBS was possible to stimulate the subthalamic nucleus as the treatment of Parkinson's disease. Stimulation of the subthalamic nucleus improves the cardinal parkinsonian symptoms and motor complication associated with levodopa treatment. DBS is a reversible treatment and the original status could be observed by turning off the stimulation. This procedure enables the observation of clinical outcomes or brain mechanisms under both the conditions of turned on and turned off stimulations. On the other hand, dystonia is heterogeneous and refractory and hence, it has been difficult to medically treat it. Since there was no effective treatment available for patients with generalized dystonia, these patients became disabled. However, recently, bilateral pallidal DBS has been shown to markedly improve the conditions of patients with generalized dystonia, and it has proven to be a reliable treatment. There are two characteristic clinical effects of pallidal DBS on dystonia. It improves primary hereditary generalized dystonia, particularly DYT 1, more prominently than secondary dystonia and its beneficial effects are observed over a period of time course. The beneficial effects of pallidal DBS in patients with dystonia are not immediate but progress over weeks to months. The brain mechanism underlying the improvement of pallidal DBS in dystonia has been unclear. Many studies on DBS in Parkinson's disease and dystonia have been carried out to elucidate the clinical outcomes and/or the underlying neurophysiological mechanisms. In this review, the clinical outcomes of DBS for Parkinson's disease and dystonia will be focused on.

Mutation analysis of the PINK1 gene in 391 patients with Parkinson disease

OBJECTIVES

To determine the frequency, distribution, and clinical features of Parkinson disease (PD) with PINK1 mutations.

DESIGN

Retrospective clinical and genetic review.

SETTING

University hospital.

PATIENTS

We performed extensive mutation analyses of PINK1 in 414 PD patients negative for parkin mutations (mean [SD] age at onset, 42.8 [14.3] years), including 391 unrelated patients (190 patients with sporadic PD and 201 probands of patients with familial PD) from 13 countries.

RESULTS

We found 10 patients with PD from 9 families with PINK1 mutations and identified 7 novel mutations (2 homozygous mutations [p.D297MfsX22 and p.W437R] and 5 single heterozygous mutations [p.A78V, p.P196QfsX25, p.M342V, p.W437R, and p.N542S]). No compound heterozygous mutations were found. The frequency of homozygous mutations was 4.26% (2 of 47) in families with autosomal recessive PD and 0.53% (1 of 190) in patients with sporadic PD. The frequency of heterozygous mutations was 1.89% (2 of 106) in families with potential autosomal dominant PD and 1.05% (2 of 190) in patients with sporadic PD. The mean (SD) age at onset in patients with single heterozygous mutations (53.6 [11.1] years; range, 39-69 years) was higher than that in patients with homozygous mutations (34.0 [20.3] years; range, 10-55 years). Myocardial iodine-123 metaiodobenzylguanidine uptake was low in patients with heterozygous mutations but not in those with homozygous mutations.

CONCLUSIONS

Our results suggest that homozygous PINK1 mutations tend to be diagnosed as the early-onset autosomal recessive form of PD. Single heterozygous mutations may contribute to the development of sporadic PD and also could be an additional genetic predisposition for developing familial PD. The reduced myocardial iodine-123 metaiodobenzylguanidine uptake observed in patients with single heterozygous PINK1 mutations is similar to that seen in patients with sporadic PD.

Lateral flexion in Parkinson's disease and Pisa syndrome

Various types of abnormal posture are observed in Parkinson's disease (PD). Lateral flexion is very common and frequent among them. The clinical characteristics of lateral flexion in PD vary and are classified into two types, the chronic and subchronic types. The chronic type of lateral flexion in PD appears subclinically and worsens, which is related to the laterality of parkinsonian symptoms and the progression of the disease. The subchronic type of lateral flexion in PD develops subacutely and worsens rapidly in several months. An atypical and rare type of tonic truncal dystonia, Pisa syndrome, may be induced following the intake of neuroleptics. The clinical features of the subchronic type of lateral flexion in PD are similar to those of Pisa syndrome. Differences between lateral flexion in PD and Pisa syndrome are described.

Plasma levels of DJ-1 as a possible marker for progression of sporadic Parkinson's disease

DJ-1 is a multifunctional protein whose loss of function by gene mutations may play a causative role for familial Parkinson's disease (PD). A recent study has shown that the expression of this molecule is upregulated in both brains and cerebrospinal fluids (CSF) in various neurological disorders, including sporadic PD, Alzheimer's disease (AD) and stroke, raising a possibility that DJ-1 could be a potential biomarker for these diseases. In this context, the main objective of the present study was to determine if DJ-1 was increased in the plasma of PD patients. For this purpose, blood plasma samples collected from sporadic PD patients, dementia with Lewy bodies (DLB) and healthy age-matched controls were analyzed by immunoblotting and enzyme-linked immunosorbent assay. The results showed that the plasma DJ-1 levels in PD (n=104) were higher than those in control (n=80) (p<0.05). Moreover, the plasma DJ-1 levels in the advanced stage of PD (n=52, Yahr III-IV) were higher than those in the early stage of PD (n=52, Yahr I-II) (p<0.05), demonstrating that the plasma DJ-1 was correlated with the disease severity in PD. Plasma DJ-1 levels were also significantly higher in DLB (n=30) compared with both controls and early stage of PD (p<0.01). Taken together, these results suggest that the plasma DJ-1 could be a useful biomarker for the evaluation of the disease severity in PD and possibly in other Lewy body diseases.

[Unilateral subthalamic stimulation for early-stage Parkinson's disease]

According to evidenced-based criteria, surgical treatment with subthalamic stimulation is indicated for advanced Parkinson's disease with severe motor complications. Currently, the treatment is indicated for patients in whom medical treatment has failed even if the patient is still in an early stage. This study investigated the efficacy and safety of unilateral subthalamic stimulation for patients with early-stage Parkinson's disease. We evaluated the Unified Parkinson's Disease Rating Scale (UPDRS) and the Schwab England ADL score before and 6 months after this treatment in 6 patients with early-stage Parkinson's disease demonstrating predominantly unilateral parkinsonian symptoms. We implanted a stimulation electrode (model 3387 or 3389) unilaterally on the side showing dominate symptoms, using both MRI and electrophysiological guidance. Six months after the beginning of stimulation, the UPDRS motor score without medication was improved by 64% and the Schwab England ADL score was improved by 23%. There were no adverse events except for asymptomatic intra-ventricular hemorrhage in one patient. Unilateral subthalamic stimulation is a useful treatment for patients with early-stage Parkinson's disease showing predominantly unilateral parkinsonian symptoms. However, long-term results of subthalamic stimulation for early-stage patients remain unclear.

[Stereotactic operation for Parkinson's disease]

The aim of stereotactic operation for Parkinson's disease is to improve or keep daily activity or quality of life by ablation or improvement of some parkinsonian symptoms. All of parkinsonian symptoms are not improved by stereotactic operation and classify roughly into three categories. The symptoms which are definitely improved are tremor, rigidity, L-dopa-induced dyskinesia, bradykinesia (secondary bradykinesia caused by rigidity) and wearing off phenomenon. Freezing gait, postural instability or postural abnormality is improved in some patients, but not always. Disturbance of speech or swallowing, L-dopa non-responsive akinesia, psychiatric symptoms or autonomic disturbances are not expected to be improved. Before stereotactic operation symptoms which cause disabilities of patients should be carefully examined. Aim of stereotactic operation should make clear and not ambiguous.

Hemorrhagic complication of stereotactic surgery in patients with movement disorders

OBJECT

Small, asymptomatic hemorrhages are easier to detect during stereotactic surgery when magnetic resonance (MR) imaging is used for targeting rather than when traditional approaches, such as ventriculography, are performed with contrast material. In the present study the authors examined the actual incidence of intraoperative hemorrhages in patients with movement disorders who had undergone MR imaging-targeted surgery, microelectrode recording (MER)-guided implantation of deep brain stimulation (DBS) electrodes, or radiofrequency-induced coagulation surgery performed.

METHODS

Ninety-six consecutive patients underwent a total of 116 stereotactic operations for movement disorders (57 operations for radiofrequency-induced coagulation and 59 for DBS electrode implantation) between January 1998 and November 2002. The authors investigated the correlation between hemorrhages and other factors including the location of the hemorrhage and the type of surgery performed. Postoperative computerized tomography scans demonstrated the occurrence of intraoperative hemorrhages at 12 locations during 11 procedures (9.5% of all procedures). Nine hemorrhages occurred during 57 coagulation operations (15.8%). Within this group, the frequency of hemorrhages was highest during thalamotomy (five [21.7%] of 23 procedures) and lower during pallidotomy (four [11.8%] of 34 procedures). In contrast, only two intraventricular hemorrhages developed during 59 operations in which DBS electrodes were implanted (3.4%). In no case was hemorrhage detected in the main DBS target, that is, the subthalamic nucleus.

CONCLUSIONS

When small, asymptomatic hemorrhages were included in the estimation, the actual rate of hemorrhage was higher than that previously reported. Judging from the incidence of hemorrhage during coagulation and DBS surgeries, the authors suggest that the heat induced by coagulation may play a larger role than microelectrode penetration in the development of hemorrhage.

[Comparison and examination of stereotactic surgical complications in movement disorders]

The purpose of the present study was to determine exactly the incidence of surgical complications in patients for whom MRI-targeted, microelectrode recording (MER)-guided implantation of deep brain stimulation (DBS) or radiofrequency (RF)-coagulation surgery was performed. Between January, 1998 and September, 2002, a total of 110 stereotactic surgeries for movement disorders (57 RF-coagulations and 53 implantations of DBS) were performed. We investigated the type and number of complications for each of the following surgical targets; globus pallidus, thalamus, and subthalamic nucleus (STN). Twenty-four neurological complications in 22 patients and 16 radiological/instrumental complications in 16 patients were verified among the 110 surgeries. Among the neurological complications, hemiparesis and mental disturbances were observed at a high rate, while intraoperative hemorrhage frequently occurred among the radiological/instrumental complications. The rate of neurological and radiological/instrumental complications for each of the stereotactic targets; the globus pallidus, thalamus, and STN-targeted surgeries, was 32.4%, 16.7%, 18.8% and 16.2%, 20.0%, 12.5%, respectively. The reason for the high rate of intraoperative hemorrhage may be associated with technical problems resulting from the penetration of vessels by needles, as well as the destruction of small vessels due to heat ablation. As for the mental disturbances, visual hallucinations (VH) occurred a high rate, especially during STN-DBS. Peduncular damage and/or L-dopa toxicity due to STN-DBS may have been associated with VH, so the STN-DBS may therefore be thought to change the threshold of stimulus-induced hallucinations. We also found that the procedures for DBS surgery, especially in younger patients, have a lower risk of complication, while, on the other hand, coagulation surgery for elderly patients is accompanied by of high risks, from the standpoint of surgical complications.

[Long-term treatment of Parkinson's disease patients with selegiline hydrochloride (FPF 1100): outcome of 5-year treatment]

We herein report on the outcome of 5 year-treatment of Parkinson's disease patients with selegiline hydrochloride. The subjects participated in this study were 10 patients whose treatment had been maintained consecutively by administration of this agent even after completion of the Phase II trial (all cases under adjunct therapy with L-DOPA/DCI). The daily dose of selegiline hydrochloride was 6.6 +/- 2.5 mg in average at the end and/or termination of the study. As for L-DOPA, its daily dose decreased from 410 +/- 160 mg to 365 +/- 133 mg at the 6th month, but the dose reduction level after 9 months was not determinable due to an increase in dropouts. Regarding alteration in the scores for individual symptoms, improvement in wearing-off symptom was pronounced during the treatment period of 3 to 51 months. The Global Improvement Rate and Usefulness Rate remained stable during the period of 18 to 30 months treatment although these rates declined after 36 months probably because of exacerbation in disease conditions. This study may assure tolerability of selegiline hydrochloride in a long-term treatment of Parkinson's disease patients.

[Variance in effects of subthalamic nucleus stimulation]

Chronic stimulation of subthalamus nucleus (STN) is effective in treating severe motor fluctuation and levodopa induced dyskinesia as well as parkinsonian motor symptoms. The improvement of peak-dose/diphasic dyskinesias of STN stimulation is considered to be due to the decrease in the daily dosage of antiparkinsonian drugs. However one report pointed out that STN stimulation improved directly levodopa induced dyskinesia. Moreover the timing of the improvement for levodopa induced dyskinesia is not yet obvious. In the present study, we have assessed variance in the latency of improvement of levodopa induced dyskinesia due to STN stimulation. In addition, we would clarify an issue which cite of STN stimulation improved parkinsonian symptoms and motor complication (motor dyskinesias and motor fluctuation). We have studied seven patients diagnosed with advanced idiopathic Parkinson's disease with motor fluctuations and levodopa induced dyskinesias. Before and after the implantation of stimulating electrode, patients were assessed by the Unified Parkinson's Disease Rating Scale and % 'OFF' motor state. The dosage of the antiparkinsonian medication was not modified for one month prior to implantation. Following implantation, dosage of the medication and strength of stimulation was adjusted, if necessary. Symptoms of motor fluctuation and dyskinesia improved in all patients six month after surgery. The mean off-time duration and dyskinesia disability improved compared with presurgical conditions. However, the time course of the improvement of dyskinesias was not the same among patients. Contralateral limb dyskinesias in three patients improved immediately after the stimulation without modification of medication. In contrast, the stimulation worsened contralateral limb dyskinesias in other three patients immediately following the surgery. In two of the three patients, dyskinesias gradually improved within one month after surgery without reducing the dosage of medication. Dyskinesias of the other patient improved following a reduction in the dosage of medication one month after the surgery. Improvement of parkinsonian symptoms of the patients with longer latency of stimulation effect for dyskinesias was better than that of the patients with shorter latency. Stimulation cite of the former group appeared to locate more central than that of the latter group. Latency and strength of the effects of STN stimulation are variable.

Relationship between lesion location and the outcome of pallidotomy for Parkinson's disease

The relationships between lesion location and clinical outcome following posteroventral pallidotomy for Parkinson's disease were studied. Forty-four patients were operated forty-six times and studied with neurological and psychological examinations before and after pallidotomy. Lesion location was confirmed using films with a coagulation electrode which were X-rayed during the operation. Changes of intelligence were observed in the patients with anteromedial lesions. Wearing-off phenomenon in four patients and dopa-induced dyskinesia in three patients were not improved following pallidotomy in twenty patients with severe wearing-off and dyskinesia. Lesions in the patients with no improvement of wearing off were located more lateral and those in the patients with sustained severe dyskinesia were located more dorsal in the internal part of the globus pallidus. It may be concluded that clinical outcome is related to lesion location.

[Pharmacological treatment of parkinsonian tremor]

Tremor is the most common initial symptom and one of the cardinal features of Parkinson's disease. Mild tremor causes only minimal disability, but severe tremor causes more significant disability and distress for the patient than rigidity and/or bradykinesia. Anticholinergic agents, levodopa/DCI and dopamine agonists are most common and beneficial in parkinsonian tremor, but efficacies of these medications are variable among patients. Rigidity and bradykinesia are more responsive to levodopa/DCI therapy than tremor. Clozapine is an atypical neuroleptic agent, not on the market in Japan, and has been reported to decrease or ameliorate parkinsonian tremor through the studies of open label and double blind crossover as a new drug for parkinsonian tremor.

[A case of chorea-acanthocytosis successfully treated with posteroventral pallidotomy]

We described a 41-year-old man with chorea-acanthocytosis, who presented severe choreoathetosis in all the limbs, neck, face and tongue. Especially, the oral area was affected most strikingly. He had difficulty in eating, because he pushed foods out of the mouth with the tongue. He received left posteroventral pallidotomy (PVP). His involuntary movements became much less enough for the patient to eat with a spoon in a sitting position by himself. Six months after the first operation, although involuntary movement on the right hand remained reduced, choreoballistic movement appeared on the left side. He received PVP on the right side. The choreoballistic movement was remarkably improved after the right PVP. No neurological aggravation has been found for 7 months after the second PVP. Bilateral PVP was fully effective as for the improvement of the activity of daily life. The output from the internal globus pallidus (GPi) is well-known to be inhibitory. Therefore, it is understandable that the coagulation of GPi results in improvement of hypokinesia and rigidity in patients with Parkinson's disease. However, some clinical reports, including ours, have described the significant reduction of hyperkinetic choreoballistic movement after PVP. The exact mechanism of these surgical effects has not been elucidated yet, and further clinical and basic studies are needed to answer this question.

[A long-term clinical effect of selegiline hydrochloride on Parkinson's disease]

A long-term follow-up evaluation on the clinical usefulness of selegiline hydrochloride (selegiline) was performed in 13 patients with Parkinson's disease. All patients, except one case, subjected to the study were symptomatically improved by combination therapy of selegiline with L-DOPA in the preceding short-term evaluation. One patient continued the therapy after an evaluation of no symptomatic improvement in the short-term study, because this patient strongly requested continuation of medication, expecting to stop the progression of the disease. The average daily dose of selegiline at the last evaluation was 7.0 +/- 2.8 mg. The average daily dose of L-DOPA at each evaluation point in the patients who continued the therapy for 12 months remained low compared to that prior to the therapy (before: 450 +/- 138 mg, at the 12th month: 383 +/- 98 mg). In the analysis of individual parkinsonian symptoms, the improvement in the mean score for most of the symptoms, especially the wearing-off phenomenon and frozen gait, persisted for the entire period of study. Global improvement rates (moderately improved) at the 6th and 12th month, and the last evaluation were 60.0%, 50.0% and 50.0%, respectively. Among 10 patients, therapy was discontinued only in one case due to hallucination. Although the global improvement rate declined in the course of the therapy, selegiline seems to be useful for improving L-DOPA responsive symptoms in long-term therapy for Parkinson's disease.

[A 65-year-old man with Parkinsonism, gaze palsy, and dementia]

We report a 65-year-old man with parkinsonism, supranuclear gaze palsy, and dementia. The patient was well until 58 years of the age (1984) when he noted an onset of tremor in his right hand. He visited our neurology service two years after the onset; neurologic examination at that time revealed moderate restriction in down ward gaze, horizontal gaze nystagmus in left and right gaze, stooped posture with loss of arm swing when he walked, slight rigidity in the neck and the right upper and lower extremities, and resting tremor in his right hand and foot; mentation was intact. He was treated with 600 mg of levodopa with carbidopa; his tremor partially improved. He received left Vim thalamotomy on March 14 of 1987. His tremor disappeared after the thalamotomy. Post-operative course was complicated by transient clouding of consciousness due to subdural hematoma which developed after the surgery. Six months after the surgery, he noted increase in the unsteadiness of gait; he also experienced urinary incontinence once in a while, and he became mentally dull. In November of 1988, he had episodes of stiffening of his body. Although his spontaneous speech was very much reduced, he repeatedly hummed a same tune; no one could make him stop humming. In June of 1989, he was totally unable to move his eyes in the vertical direction. He was hospitalized to another hospital in May of 1990 where he died six month after admission because of pneumonia. The clinical course of this patient was characterized by the onset with parkinsonian resting tremor, and supranuclear gaze palsy and dementia in the later course. The patient was discussed in a neurological CPC and the chief discussant arrived at the conclusion that the patient had an overlap syndrome of progressive supranuclear palsy (PSP) and diffuse Lewy body disease. Majority of the participants thought that the patient had progressive supranuclear palsy, but many of them had an impression that parkinsonian tremor responding to levodopa as the initial symptom for PSP is rather unusual. Postmortem examination revealed severe loss of neurons in the substantia nigra, the globus pallidus, and the subthalamic nucleus with reactive gliosis; formy spheroids were seen in the substantia nigra, however, no Lewy bodies or neurofibrillary tangles were observed. Moderate neuronal loss was also seen in the dentate nucleus of the cerebellum. In addition, the precentral gyrus showed moderate neuronal loss, astrocytosis, and spongy change in the second layer; ballooned neurons were seen in the third and the fifth layers. Histologic characteristics were consistent with the pathologic diagnosis of corticobasal degeneration.

[A long-term clinical effect of selegiline hydrochloride on Parkinson's disease]

A long-term follow-up evaluation on the clinical usefulness of selegiline hydrochloride (selegiline) was performed in 13 patients with Parkinson's disease. All patients, except one case, subjected to the study were symptomatically improved by combination therapy of selegiline with L-DOPA in the preceding short-term evaluation. One patient continued the therapy after an evaluation of no symptomatic improvement in the short-term study, because this patient strongly requested continuation of medication, expecting to stop the progression of the disease. The average daily dose of selegiline at the last evaluation was 6.9 +/- 2.5 mg. The average daily dose of L-DOPA at each evaluation point in the patients who continued the therapy for 12 months remained low compared to that prior to the therapy (before: 450 +/- 117 mg, at the 12th month: 389 +/- 89 mg). In the analysis of individual parkinsonian symptoms, the improvement in the mean score for most of the symptoms, especially the wearing-off phenomenon and frozen gait, persisted for the entire period of study. Global improvement rates (moderately improved) at the 6th and 12th month, and the last evaluation were 61.5%, 44.4% and 46.2%, respectively. Among 13 patients, therapy was discontinued only in one case due to hallucination. Although the global improvement rate declined in the course of the therapy, selegiline seems to be useful for improving L-DOPA responsive symptoms in long-term therapy for Parkinson's disease.

[A 75-year-old man with parkinsonism and delirium]

We report a 75-year-old man with a ten-year history of parkinsonism, who developed acute delirium. He was well until 65 years of age, when there was an onset of tremor in his left hand. He had been treated with levodopa and trihexyphenidyl with marked improvement. He was doing well until July of 1991 at his age of 75-year-old, when he noted backache; he was found to have a compression fracture of the third lumbar spine. He had to use a wheel-chair most of the time since then. In December 1991, he started to have visual hallucinations and difficulty in swallowing. On December 25 of that year, he developed fever and delirium, and was admitted to our hospital on December 30. On admission, general physical examination was unremarkable except for low grade fever (37.3 degrees C). Neurologic examination revealed an alert but chronically ill patient. Apparently he had visual hallucinations. He was disoriented to all spheres; he could respond only to simple questions. Apparently he was demented. Cranial nerves were intact except for mumbling speech disturbance and masked face. He was unable to stand or walk. He had flexion contracture in his both knee joints. He had paratonic rigidity in all his limbs and marked bradykinesia. Once in a while, myoclonic jerks were seen in both upper and lower extremities. Deep reflexes were diminished bilaterally, and the plantar reflex was not elicited on either side. On laboratory examination, BUN was increased to 72 mg/dl, creatinine to 3.0 mg/dl, and WBC 16,000/microliter. Cranial CT scans were unremarkable.(ABSTRACT TRUNCATED AT 250 WORDS)

[A 66-year-old man with backache and progressive difficulty of gait]

We report a 66-year-old man with progressive spinal paraplegia. He was well until June of 1991 when he had an onset of backache and right chest pain. On August 25, he lost sensation to void and he became unable to urinate. On the same day, he noted weakness in his legs which became progressively worse, and he was admitted to our hospital. Past medical history included diabetes mellitus which was found 3 years previously. He had upper gastrointestinal series 2 months before, which revealed a normal study. On admission, he was alert and general physical examination was unremarkable. Neurological examination revealed a mentally sound man with normal higher cerebral functions. Cranial nerves were also intact. He was unable to walk. No muscle atrophy was noted, but he had moderate to marked (2/5) weakness in both legs. No ataxia was noted in the upper extremities. Jaw jerk was normal, however, deep reflexes in the upper extremities were decreased, and absent in the lower extremities Babinski sign was present bilaterally. All sensory modalities were diminished below the Th 6 dermatome. No meningeal sign was present. Emergency myelography was performed on the day of admission, which revealed complete block from the Th4 to Th8 segments. CSF taken at that time was xanthochromic, positive Queckenstedt test containing 1,133 mg/dl of protein, 54 mg/dl of sugar and 1/3 microliters of lymphocyte. On August 31, laminectomy was performed from Th5 to Th7. The spinal bones in this area was very fragile and hemorrhagic. A soft yellowish vascular-rich tissue was surrounding the spinal cord in the epidural space. Despite surgery his weakness in legs worsened, and he became paraplegic by September 10th. He became somnolent with disorientation to time. In the subsequent course, he developed metabolic acidosis on September 26. On September 28, he became anuric and hypotensive. He expired later on that day.(ABSTRACT TRUNCATED AT 400 WORDS)

Total biopterin levels in the ventricular CSF of patients with Parkinson's disease: a comparison between akineto-rigid and tremor types

Total L-erythro-biopterin (T-BP) levels in the ventricular cerebrospinal fluid (CSF) were measured in 43 patients with Parkinson's disease (PD) and 12 age-matched neurological controls. In 5 of the PD patients and 1 control, lumbar CSF T-BP values were also measured. The mean ventricular CSF T-BP level in the PD patients, 15.6 +/- 0.5 pmol/ml (mean +/- SE), was significantly lower than that in the controls (21.3 +/- 1.4 pmol/ml, P less than 0.0001). The mean T-BP concentration in the ventricular CSF was 1.9 times higher than that in the lumbar CSF (P less than 0.0005), indicating a rostrocaudal gradient for the T-BP value in the CSF. When the PD patients were classified according to their predominant clinical features into 24 akineto-rigid (A-R) type and 19 tremor (T) type, there was a significant negative correlation between the T-BP levels and duration of illness only for the A-R type patients (rho = -0.605, P less than 0.005). No such significant correlation was found in the T type patients. These results may indicate a difference of pathophysiological changes in the brain between the 2 types of PD.

[Analysis of L-threo-3, 4-dihydroxyphenylserine effect on motor and psychological symptoms in Parkinson's disease]

Improvement of motor and psychological symptoms by L-DOPS (L-threo-3,4-dihydroxyphenylserine) in totally 20 cases with Parkinson's disease (PD), including 5 cases of juvenile or early onset parkinsonism (JP) and one case of pure akinesia was analysed. Improvement was obtained in about two thirds of the cases on symptoms of freezing in gait, difficulty of postural control, depressive mood and bradyphrenia. Severity of freezing in gait and that of the depressive mood were graded in five stage (from 0 to 4) scale and the improvement was evaluated by A (three stage improvement), B (two stage improvement), C (one stage improvement) and D (no change or worsened). Improvement of psychological symptoms was seen parallel to that of motor symptoms. It seems important that marked effect on both motor and psychological symptoms was obtained mostly in PD cases but not in the cases of JP. In MMPI test, depressive score (D) and hypochondriac score (Hs) were normalized in PD cases but not changed in JP, indicating differences in psychological traits between two groups. It was suggested that JP is a condition of mainly DA deficiency in nigro striatum but PD presents wider spectrum of symptoms covering both DA and NE deficiency. Importance of the role of aging of the brain in each individual patient is discussed and interpreted in relation to the difference of clinical pictures.

Loss of reaction time specificity for movement direction in Parkinson's disease

Electromyographic (EMG) reaction times (RTs) of the right biceps brachii muscle and its integrated EMG (iEMG) from the onset until 50 msec after the start of activities for elbow flexion and forearm supination in the condition with or without warning signal were examined in seven patients with Parkinson's disease and seven age- and sex-matched normal subjects. In the control group RT of forearm supination with warning tended to be faster than that of elbow flexion and the reverse occurred without warning, and iEMG of forearm supination were significantly small compared to those of elbow flexion in each condition. In the Parkinson group both RT and iEMG of elbow flexion were nearly the same as that of forearm supination regardless the presence or absence of warning signal, indicating the loss of RT and iEMG specificity for the two direction of movement in Parkinson's disease.

[Lateral coordinate of the thalamic Vim neurons in the cases with dilated third ventricle]

Precise radiographical measurement of the third ventricle in the first and essential procedure in stereotaxic surgery in order to determine the target point. This is done while referring to an available standard brain atlas such as Schaltenbrand & Bailey. However there have been no criteria established for determining the deviation of the coordinates of the thalamic nuclei, especially in their lateral coordinates when the third ventricle is highly dilated. Therefore, in 109 cases encountered recently (81 parkinsonism, 11 essential tremor, 10 cerebral palsy, 3 thalamic pain, 1 Benedikt's syndrome, 1 torticollis, 1 oral dyskinesia, 1 striato-nigral degeneration), we studied the correlation between the width of the third ventricle and the lateral coordinate of the thalamic point where kinesthetic neurons or tremor-synchronously discharging neurons were detected. These neurons were especially related to the arm. According to the width of the third ventricle, we classified the cases into three types: 18 cases with large ventricles (more than 10 mm), 37 cases with medium-sized ventricles (4-10 mm) and 16 cases with small ventricles (less than 4 mm). By plotting the lateral coordinate of the thalamic point where kinesthetic neuron of the upper extremity was recorded in reference to the radiogram of anteroposterior view, we found that the lateral coordinates of large ventricular cases generally tended to show more lateral displacement than cases where the ventricles were narrower. Their mean lateral coordinate was 16.9 mm from midline in contrast ot 14.0 mm in cases with small ventricular width. There was a linear correlation between the width of the third ventricle and the lateral coordinate of the kinesthetic neuron of the Vim nucleus.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term follow-up study of nucleus ventralis intermedius and ventrolateralis thalamotomy using a microelectrode technique in parkinsonism

Long-term observation over 3-8 postoperative years of cases of Parkinson disease operated by stereotactic thalamotomy using a microelectrode recording technique is reported. The procedure is specifically useful in the following four groups: (1) tremor-dominant cases, (2) hemiparkinsonism, (3) cases with marked asymmetry in motor symptoms and (4) juvenile parkinsonism presenting levodopa-induced dyskinesia.