Cost-utility analysis of Parkinson's disease

Many expensive treatments have been developed for Parkinson's disease (PD), and a good cost-utility analysis is required. Quality-adjusted life-years (QALY) allows comparison of the cost-utility of different medical conditions. If a treatment strategy gives a patient an extra but unhealthy year, the QALY he obtained will be less than one. When a therapeutic strategy is more effective, but causes higher costs, it is mandatory to calculate the incremental cost-effectiveness ratio (ICER). In keeping with guidance from the UK National Institute for Health and Clinical Excellence (NICE), a therapy that deliver QALYs of £20,000 or less are likely to be approved. The threshold used by NICE for the maximum it is prepared to pay for a QALY, which lies between £20,000 and £30,000, will be reviewed case by case. Subthalamic deep brain stimulation (STN-DBS) is an effective therapy, which can improve the quality of life in PD patients immediately, but has not been approved by the Bureau of National Health Insurance here. It has been estimated that the ICER/QALY in STN-DBS patients was of 34,389C= , which is within appropriate limits to consider STNDBS as an efficient therapy. We expect that we can have a decision-making mechanism similar to that of NICE that, according to the ICER of each medical condition, medical resource can be redistributed openly and justly.

Val-9Ala and Ile+58Thr polymorphism of MnSOD in Parkinson's disease

OBJECTIVES

To investigate the polymorphism distribution of Val-9Ala and Ile+58Thr of the Mn-superoxide dismutase (Mn-SOD) gene among subjects with Parkinson's disease (PD) by analyses of genders and clinical severity.

DESIGN AND METHODS

We examined the DNA genotypes of Val-9Ala and Ile+58Thr from 295 PD subjects and 111 controls by nucleotide sequencing and BsaWI restriction.

RESULTS

Ala/Ala homozygosity was found in four PD subjects but not in the controls. All of the genotypes at codon +58 among the examined samples were Ile/Ile homozygotes. Although higher carrier rate of Ala allele among PD subjects than the controls, there were no differences by analyses of the genders and clinical severity.

CONCLUSION

The higher Ala-allele carrier rate among PD subjects may suggest a possible higher amount of mitochondrial Mn-SOD rendering higher intracellular stress in PD. In this study the polymorphisms at codons -9 and+58 did not give informative association evidences with PD.

Octarepeat changes of prion protein in Parkinson's disease

Polymorphism in prion protein (PrP) is related to different phenotypes of spongiform encephalopathies and some mental illnesses. The octarepeat region of PrP, encompassing the codon 51 through 91, is related to cellular anti-oxidation function and may play a role in genetic contribution of PrP polymorphism to neurodegeneration, such as Parkinson's disease (PD). We analyzed the genomic patterns of PrP gene from 528 subjects and found a predominance of Met/Met variant at codon 129 of PD subjects without significant difference (97.3%, and 96.5% in controls). But among PD subjects there were one with heterozygosity of silent nucleotide substitution (NS) on octarepeats (R1-2-3g-3-4/R1-2-2-3-4) and three with heterozygosity of single copy deletion (CD) on octarepeats (R1-2-3-4/R1-2-2-3-4). Consistent genomic DNA and cDNA sequences were found in a PD subject without any octarepeat changes and the one with NS, but R1-2-3g-3-4/R1-2-2-3-4 of cDNA pattern occurred in the one with genomic CD. This is the first report of the polymorphic PrP octarepeat change among those with parkinsonism. We proposed a hypothesis about an initial secondary hairpin structure of the template strand followed by the transcript "shift backward" due to the high homology of the sequences between R2 and R3 motifs while synthesizing RNA. This phenomenon may be a key step of neurodegeneration resulting from PrP polymorphism and require further studies.

Polymorphism distribution of prion protein codon 117, 129 and 171 in Taiwan

Prion diseases compass transmissible spongiform neurodegenerative diseases from various causes, including the genetic and infectious ones. We investigated the prevalence of codon 117, 129 and 171 polymorphism in prion protein (PrP) in Taiwanese, mainly for the sake of the informative absence of this genetic distribution. Our subjects were 419 aged ones of Han ethic origin. We evaluated the PrP gene (PRNP) polymorphism by restriction fragment length polymorphism, after amplification of their genomic DNAs by polymerase chain reactions with specific primers, digested by restriction enzyme PvuII (for codon 117), NspI (for codon 129), and BbvI (for codon 171), respectively, and confirmed by nucleotide sequencing. All of the subjects were homozygotes at codon 117 (Ala/Ala, gca/gca) and 171 (Asn/Asn, aac/aac). There were no valine homozygotes (Val/Val) in our 419 subjects, and nine subjects (2.1%) showed methionine-valine heterozygosity (Mal/Val, atg/gtg). The methionine homozygotes (Met/Met) comprised the major population (97.9%), and the prevalence of distribution is different to that seen in Caucasians. The almost 100% conservation of the domain from codon 117 to 171 implies the warranty of PrP in cellular functions. The high prevalence of Met/Met alleles in Taiwan did not imply an increased risk of CJD, and the genetic susceptibility of CJD by codon 129 of PrP may be still elusive for the infectivity.

Mentalis muscle responses to median nerve stimulation

Electrical stimulation may produce excitation or inhibition of the motor neurons, as represented the blink reflex and masseter silent period in response to trigeminal nerve stimulation. Clinically, a light touch on the palm may evoke a mentalis muscle response (MMR), i.e. a palmomental reflex. In this study, we attempted to characterize the MMR to median nerve stimulation. Electrical stimulation was applied at the median nerve with recordings at the mentalis muscles. An inhibition study was done with continuous stimuli during muscle contraction (I1 and I2 of MMRaverage). Excitation was done with a single shot during muscle relaxation (MMRsingle) or by continuous stimuli during muscle contraction (E1 and E2 of MMRaverage). The characteristic differences between MMRaverage and MMRsingle were as follows: earlier onset latencies of MMRaverage (MMRaverage < 45 ms; MMRsingle > 60 ms), and a lower amplitude of MMRaverage (MMRaverage < 50 microV; MMRsingle > 150 microV). The receptive field of MMRsingle was widespread over the body surface and that of MMRaverage was limited to the trigeminal, median and index digital nerves. Series of stimuli usually significantly decreased the amplitude of MMRsingle, as a phenomenon of habituation. On the other hand, it was difficult to evoke the earlier response (i.e. MMRaverage) without continuous stimuli and an average technique. MMRaverage had the components of both excitation (E) and inhibition (I); for example, E1-I1-E2-I2 or I1-E2-I2. E2 was the most consistent component. In patients with dorsal column dysfunction, median nerve stimulation could successfully elicit MMRsingle, but not MMRaverage. Contrarily, in patients with pain sensory loss, it was more difficult to reproduce MMRsingle than MMRaverage. It seemed that MMRaverage and MMRsingle did not have equivalents across the different modalities of stimulation.

An accurate electrocardiographic algorithm for differentiation of tremor-induced pseudo-ventricular tachycardia and true ventricular tachycardia

Tremor-induced electrocardiographic artifacts could be misdiagnosed as ventricular tachycardia (VT). However, there has been no electrocardiographic algorithm effectively differentiating pseudo-VT. In this study, we used 3 electrocardiographic "signs": "Sinus" sign, "Spike" sign, and "Notch" sign, and created an electrocardiographic algorithm. The algorithm was prospectively tested in 98 electrocardiographs (37 tremor-induced pseudo-VT and 61 true VT) Thirty-six out of 37 (97.3%) tremor-induced pseudo-VTs could be accurately diagnosed. In conclusion, this is the first study to systemically analyze the tremor-induced pseudo-VT. Our new electrocardiographic algorithm provides a useful tool for a rapid and accurate diagnosis.

The SCA17 phenotype can include features of MSA-C, PSP and cognitive impairment

Spinocerebellar ataxia (SCA) 17 is a dominant neurodegenerative disorder characterized by ataxia, cognitive decline, dystonia, and parkinsonism. The disease is caused by unstable cytosine-adenine-guanine (CAG) trinucleotide expansion mutation coding for polyglutamine tracts in the TATA box-binding protein (TBP), a general transcription initiation factor. Herein, we report a SCA17 case with a phenotype not previously reported, which consisted of progressive ataxia, autonomic dysfunction, parkinsonism, supranuclear palsy and cognitive impairment. Cerebrospinal fluid study and 18F-dopa PET scanning demonstrated dopamine deficiency and nigrostrital degeneration. This case expands the current phenotype associated with SCA17. SCA17 should be considered in the differential diagnosis of cases resembling multiple system atrophy, especially those with atypical features.

Effect of Transcranial Magnetic Stimulation on Bimanual Movements

Transcranial magnetic stimulation (TMS) of the motor cortex can interrupt voluntary contralateral rhythmic limb movements. Using the method of “resetting index” (RI), our study investigated the TMS effect on different types of bimanual movements. Six normal subjects participated. For unimanual movement, each subject tapped either the right or left index finger at a comfortable rate. For bimanual movement, index fingers of both hands tapped in the same (in-phase) direction or in the opposite (antiphase) direction. TMS was applied to each hemisphere separately at various intensities from 0.5 to 1.5 times motor threshold (MT). TMS interruption of rhythm was quantified by RI. For the unimanual movements, TMS disrupted both contralateral and ipsilateral rhythmic hand movements, although the effect was much less in the ipsilateral hand. For the bimanual in-phase task, TMS could simultaneously reset the rhythmic movements of both hands, but the effect on the contralateral hand was less and the effect on the ipsilateral hand was more compared with the unimanual tasks. Similar effects were seen from right and left hemisphere stimulation. TMS had little effect on the bimanual antiphase task. The equal effect of right and left hemisphere stimulation indicates that neither motor cortex is dominant for simple bimanual in-phase movement. The smaller influence of contralateral stimulation and the greater effect of ipsilateral stimulation during bimanual in-phase movement compared with unimanual movement suggest hemispheric coupling. The antiphase movements were resistant to TMS disruption, and this suggests that control of rhythm differs in the 2 tasks. TMS produced a transient asynchrony of movements on the 2 sides, indicating that both motor cortices might be downstream of the clocking command or that the clocking is a consequence of the 2 hemispheres communicating equally with each other.

Hemichorea-hemiballism associated with hyperintense putamen on T1-weighted MR images: an update and a hypothesis

In 1998 some patients with hyperglycemia-related hemichorea-hemiballism have been reported with a hyperintense putamen on T1-weighted MR images, presumably resulting from petechial hemorrhage. I questioned this explanation from my experience because (1) the areas of hyperintense lesions and their time evolutions did not match with those of the high density lesions on CT, (2) these hyperintense lesions persisted for years, and (3) the hyperintense lesions extended inferiorly to the midbrain. Therefore, a biopsy was performed in one patient and disclosed a fragment of gliotic brain tissue with abundant gemistocytes, which I proposed was sufficient to explain the shortening of T1 relaxation time. In addition, because two of our patients were associated with cortical infarcts and without hyperglycemia, I have suggested that cerebral ischemia might be a more important cause. In 1999 Fujioka et al reproduced the MR finding in animals 7 days after 15-minute occlusion of the middle cerebral artery. Therefore, both studies have suggested that the MRI finding resulted from a progressive pathological reaction in an incomplete infarction. In 2003 Fujioka et al further reported that the hyperintensity on T1-weighted MR images after mild ischemia may involve a paramagnetic effect resulting from tissue manganese accumulation in reactive astrocytes.

Presence of spinocerebellar ataxia type 2 gene mutation in a patient with apparently sporadic Parkinson's disease: Clinical implications

Among 242 patients with apparently sporadic Parkinson's disease, a 70-year-old man with a CAG repeat number of 37 in the SCA2 gene was identified. He has remained responsive to levodopa 14 years after onset and has had no overt signs suggesting cerebellar dysfunction. Although it is not possible to confirm if this patient has a de novo mutation of the SCA2 gene, this genetic defect seems to be contributing to his parkinsonian features and further supports the concept that apparently sporadic, late-onset, levodopa-responsive Parkinson's disease may have multiple causes.

Hypotension Due to Interaction Between Lisinopril and Tizanidine

OBJECTIVE

To report a case in which significant hypotension occurred after initiation of tizanidine in a patient using the antihypertensive agent lisinopril.

CASE SUMMARY

A 48-year-old woman was admitted due to cerebral hemorrhage at the midbrain and pons, with extension to the fourth ventricle. Consciousness disturbance (Glasgow coma scale 4) with a decerebrate posture improved 5 days after stroke onset. As the BP was fairly high, antihypertensive agents, including lisinopril, were initiated. Three weeks later, the decerebrate rigidity and high BP remained, and tizanidine was initiated to see whether the decrease in muscle tone could facilitate hypertension control and motor recovery. However, the BP dropped dramatically within 2 hours after the first dose of tizanidine. The tizanidine and all of the antihypertensive medications were withdrawn. Tizanidine was used again after her BP had stabilized, but did not produce similar problems.

DISCUSSION

A similar event was reported in 2000. The reaction in our patient appeared after tizanidine initiation and improved after both lisinopril and tizanidine were discontinued. According to the Naranjo probability scale, this was classified as a possible drug interaction. This kind of reaction is seldom mentioned as occurring during co-administration with tizanidine. With its characteristics, tizanidine has the potential to compromise hemodynamic stability during concomitant angiotensin-converting enzyme inhibitor use.

CONCLUSIONS

Based upon the literature review, the hypotension in this patient was possibly due to the interaction between tizanidine and lisinopril.

Multiple sclerosis in Taiwan

BACKGROUND

There is only 1 report about multiple sclerosis (MS) prevalence in Taiwan, and this was published in 1976 and involved only 25 patients. The clinical features and prevalence of MS in Taiwan still remain to be clarified. The aim of this study was to determine the prevalence and delineate the clinical features of MS in Taiwanese patients.

METHODS

We retrospectively identified 43 ethnic Chinese multiple sclerosis (MS) patients over a 14-year period. The MS prevalence in Taiwan was estimated based on Bureau of National Health Insurance (BNHI) data. The clinical data (gender, family history, age at onset, initial symptoms, clinical course, disability and laboratory findings, evoked response and neuroimaging) were recorded, collected and analyzed.

RESULTS

The MS prevalence in Taiwan was as low as 1.9 per 100,000. The distribution of most of the clinical features of our patients, like those in other Asian series, was different from Western series except for the percentage of the conventional form and sensory disturbances. Cerebrospinal fluid analysis for IgG index and OCB seemed to be less sensitive in the diagnosis of MS in our series.

CONCLUSIONS

The prevalence of MS in Taiwan, as in other Asian countries, was low; the optic-spinal form occurred very often, but predominant spinal cord involvement was not unusual, as well as there being less functional disability. A larger, prospective study is needed to provide more conclusive information.

Guillain-Barré syndrome coexisting with pericarditis or nephrotic syndrome after influenza vaccination

A 68-year-old woman and a 72-year-old man presented with distal weakness of the limbs and numbness following an influenza vaccination within 2 weeks. Moreover, Guillain-Barré syndrome (GBS) was diagnosed in two patients. Pericarditis was diagnosed in the first patient who also had precordial chest pain with referral to trapezius ridge, and nephrotic syndrome, was observed in the second patient who had leg edema and proteinuria. The relationship among GBS, pericarditis and nephrotic syndrome after an influenza vaccination is discussed.

Transcranial magnetic stimulation in patients with transient ischemic attacks

BACKGROUND

By definition, transient ischemic attacks (TIAs) do not leave a neurological deficit beyond 24 hours after onset. However, a subgroup of TIA patients is characterized by persistent perfusion defect on single photon emission computed tomogram or infarction on brain computerized tomogram and magnetic resonance imaging. Here, we applied transcranial magnetic stimulation (TMS) to study whether TIA could produce persistent subclinical dysfunction for more than 24 hours.

METHODS

The study included 23 TIA patients who had the criteria of hand weakness as one of their clinical manifestations. TMS was done twice in each TIA patient. The first time was during the period of 24-48 hours after onset and the second 7 days after onset. We studied the cortical motor threshold, the latencies and the amplitudes of the motor evoked potentials, the central motor conduction time, and the cortical silent period at the intensity of 1.5 times motor threshold with maximal voluntary isometric contraction. The recording was at the first dorsal interosseous muscle.

RESULTS

There was no significant difference between the whole group of TIA patients and normal control. However, in the subgroup of TIA patients who had hand weakness more than 1 hour, they had increased motor threshold and prolonged cortical silent period during the first test. Both improved 1 week after onset. On the contrary, in TIA patients who had hand weakness less than 1 hour, their data were all within normal limits during the first and the second studies.

CONCLUSIONS

Our results indicate that the motor function of TMS study will recover to full if the motor symptoms subside within 1 hour in TIA patients. Subclinical motor deficits may persist in TIA patients who have motor symptoms more than 1 hour.

Impaired gastric myoelectrical activity in patients with Parkinson's disease and effect of levodopa treatment

The aim of this study was to evaluate gastric myoelectrical activity in patients with Parkinson's disease during and after levodopa treatment. Thirteen Parkinson's patients and 13 age-matched Parkinson's-free controls were enrolled. Electrogastrography was used to record gastric myoelectrical activity in all subjects for 30 min before and 30 min after a standard meal. In the group with Parkinson's disease, gastric myoelectrical activity was recorded during both the "on" (with levodopa treatment) and the "wearing-off" (without levodopa for at least 12 hr) periods. Results were as follows. (1) The patients without treatment showed a significantly lower percentage of regular slow waves and a significantly higher instability coefficient of the dominant frequency; (2) the patients showed an absence of the normal postprandial increase in gastric slow wave frequency which was seen in the controls: and (3) treatment with levodopa resulted in an improvement in the fed state, including a marginal increase in the percentage of regular slow waves (P = 0.1), a significant decrease in the instability coefficient, and an enhanced postprandial power increase. In conclusion, patients with Parkinson's disease have reduced slow wave rhythmicity and an impaired postprandial response in gastric myoelectrical activity. These abnormalities may be partially corrected with levodopa treatment in the fed state.

Subtle brain dysfunction in treated 6-pyruvoyl-tetrahydropterin synthase deficiency: relationship to motor tasks and neurophysiological tests

6-Pyruvoyl-tetrahydropterin synthase (6PTPS) deficiency is a major cause of biopterin deficiency. 6PTPS patients usually have an elevated serum phenylalanine level, a deficiency of neurotransmitters (serotonin and dopamine), and neurological symptoms, if without treatment. We herein investigated the possibility of neurological dysfunction in early-treated patients. In the study, 12 early-treated 6PTPS patients were studied. Their auditory simple reaction time, movement rhythm variation (MRV), somatosensory evoked potentials to median nerve stimulation, and hand muscle responses to transcranial magnetic stimulation, were measured. MRV is a test of repetitive voluntary movements, and was used with and without auditory cues at 0.3 Hz. The 6PTPS patients had an increased motor threshold but normal motor and sensory central conduction times. They performed very well in simple reactions (6PTPS 208.4+/-16.7 ms, control 200.3+/-11.7 ms, p=0.18), but not in continuous tasks. The continuous performance tests showed that MRV had increased in the 6PTPS patients (with cues: 6PTPS 7.35+/-0.94, control 5.47+/-0.80, p<0.0001; without cues: 6PTPS 9.87+/-1.44, control 6.59+/-0.68, p<0.0001). Without cues, MRV had increased in both the 6PTPS and control groups, but more significantly in the 6PTPS patients (6PTPS 2.51+/-0.97, control 1.25+/-0.42; p=0.0001). Our findings indicate that early-treated 6PTPS patients have subtle neurological dysfunctions. They may not maintain movement rhythm as well as normal subjects, even with external cues. Hence, MRV is a good method to assess motor control.

Efficacy, safety, and tolerability of pramipexole in untreated and levodopa-treated patients with Parkinson's disease

OBJECTIVE

To evaluate the efficacy and safety of the non-ergot dopamine agonist pramipexole in untreated and levodopa-treated Chinese patients with early or advanced Parkinson's disease.

METHODS

This randomized, double-blind, placebo-controlled, parallel-group study, which was conducted in Hong Kong and Taiwan, comprised a screening period of at least 1 week, a dose-escalation period of 7 weeks, and a maintenance period of 8 weeks (total duration of treatment: 15 weeks). During the dose-escalation period, the dose of pramipexole (or number of placebo tablets) was escalated in a blinded fashion according to a predetermined schedule to the optimum tolerated dose of pramipexole, administered three times a day (minimum dose=0.375 mg/day; maximum dose=4.5 mg/day). This dose was then maintained for the duration of the maintenance period. Efficacy was primarily assessed by the Unified Parkinson's Disease Rating Scale (UPDRS). Safety and tolerability were evaluated by treatment-emergent adverse event reports, clinical laboratory test results (blood chemistry, hematology, and urinalysis), vital signs, and electrocardiograms.

RESULTS

Pramipexole was significantly more effective than placebo in reducing the total scores of the UPDRS Part II, Part III, and Parts II and III combined. Approximately 70% of both the placebo- and pramipexole-treated patients evaluated in this analysis were on levodopa. Regardless of levodopa use, the mean UPDRS total scores showed a consistently greater improvement in pramipexole patients than in placebo patients. Mean scores for pramipexole patients not on levodopa showed a greater improvement than did pramipexole patients on levodopa. The mean improvement for the pramipexole/no levodopa group relative to the placebo/no levodopa group at week 15 was 10.93 points (i.e., -14.43 points minus -3.50 points). The mean improvement for the pramipexole/levodopa group relative to the placebo/levodopa group at week 15 was 9.04 points (i.e., -10.26 points minus -1.22 points). Pramipexole was also superior to placebo as measured by improvement in the modified Hoehn and Yahr Scale and a reduction in the number of "off" hours for patients on concomitant levodopa therapy.

CONCLUSIONS

Pramipexole is an effective and well-tolerated therapy, with or without concomitant levodopa, for Chinese patients with Parkinson's disease.

Using electrodiagnostic machine to study movement rhythm variation

BACKGROUND

Hand movement constitutes the most common daily activities in our life. Hand dexterity is often impaired in patients with neurological disease. We developed an adjunct method, based upon the electrodiagnostic software, for study of motor control and hand dexterity.

METHODS

Thirty-two normal subjects, 2 stroke patients and 2 Parkinson patients were included in the study. All of them were right-handed, and were asked to pace rhythmic finger tapping at a comfortable rate without cue or any external stimuli. A trigger kit was designed to transform the finger tapping. After using the triggering mode and adjusting the sweep speed, 2 tapping signals were simultaneously displayed on the screen. The first signal was the triggering potential, and the variation in timing of the second signal represented the variation in timing of the inter-response interval. Twenty sweeps were recorded, superimposed and measured on the screen. Movement rhythm variation (MRV) was defined as b/a x 100 (b = [maximal interval of finger tapping - minimal interval of finger tapping]; a = [maximal interval of finger tapping + minimal interval of finger tapping]/2). Each subject started with right hand and then left hand.

RESULTS

MRV measurement showed excellent intrarater (r = 0.97) and interrater (r = 0.97) reliability. In normal right-handed subjects, the MRV was better in right hand than in left hand (right 16.5 +/- 4.1% and left 21.0 +/- 7.6%; p < 0.05). The MRV improved in stroke patients along with the recovery and improved in Parkinson patients after levodopa treatment.

CONCLUSIONS

MRV was a good method to provide quantitative data for assessment of hand dexterity. Our study also showed the potential role of MRV in motor control study.

Genetic polymorphism of the CYP2E1 gene and susceptibility to Parkinson's disease in Taiwanese

Cytochrome p450IIE1 (CYP2E1), an ethanol-inducible cytochrome p450 enzyme, is expressed in the basal ganglia and is probably involved in the activation of neurotoxicants, producing free radical metabolites and resulting in oxidative stress. To examine the association between CYP2E1 polymorphism and the risk of Parkinson's disease (PD), we performed a case-control study on a large population of Taiwanese PD patients, focusing especially on early-onset PD patients (onset at, or before, the age of 50). Two hundred and thirty-four PD patients and 251 age- and sex-matched controls were recruited. A much higher frequency of the uncommon c2 allele was seen in our control subjects than in Caucasians (0.23 vs. 0.02). There were no significant differences between PD patients and controls in the distribution of either allelic or genotype frequencies. Our results suggest that CYP2E1 is not a major or independent determinant in the occurrence of PD in Taiwanese.

Clinical, 18F-dopa PET, and genetic analysis of an ethnic Chinese kindred with early-onset parkinsonism and parkin gene mutations

We report on clinical (18)F-labeled 6-fluorodopa ((18)F-dopa) positron emission tomography (PET) and molecular genetic analyses of an ethnic Chinese family in which three siblings presented with early-onset Parkinson's disease. As described in some parkin patients, neither sleep benefit nor diurnal fluctuation was noted. Interestingly, depression, anxiety, and obsessive-compulsive disorders were manifest. The (18)F-dopa PET scans showed bilateral presynaptic dopaminergic dysfunction without marked lateralization. Molecular genetic analysis showed identical chromosome 6 haplotypes inherited by affected subjects, with alternate allelic deletions of parkin exons 3 and 4. Furthermore, mRNA analyses identified aberrantly spliced parkin transcripts, suggesting that unusual parkin protein isoforms may be expressed in the brain and retain some function.

Spinocerebellar ataxia type 2 presenting as familial levodopa-responsive parkinsonism

A genetic analysis identified 2 patients, approximately one-tenth of our patients with familial parkinsonism, who had expanded trinucleotide repeats in SCA2 genes. The reduction of 18F-dopa distribution in both the putamen and caudate nuclei confirmed that the nigrostriatal dopaminergic system was involved in parkinsonian patients with SCA2 mutation.

Single-pulse transcranial magnetic stimulation reset the rhythm of essential tremor but not heart beat

BACKGROUND

Human oscillator is observed in and outside the nervous system. Cardiac rhythm is generated by heart itself but can be modulated by brain. Using the technique of transcranial magnetic stimulation (TMS) and resetting index, we studied if single-pulse TMS could reset the cardiac rhythm and help differentiate oscillator of neurogenic or non-neurogenic origin.

METHODS

In addition to the study of 4 patients with essential tremor, cardiac rhythm was studied in 6 normal subjects. The magnetic intensity was initiated from motor threshold of hand muscle, and then with an increment of 10% up to the maximal output of magnetic stimulator. We used the resetting index (RI) to quantify the influence of the TMS.

RESULTS

The resetting phenomenon was observed in essential tremor (RI = 0.92) but not in cardiac rhythm (RI = 0.02).

CONCLUSIONS

Single-pulse TMS is able to reset the rhythm of essential tremor but not heart beat. The pacing mechanism is different between essential tremor and heart beat. The cardiac rhythm is regulated and modulated chiefly by heart itself. Essential tremor should not share the same mechanism with heart beat.

The COMT L allele modifies the association between MAOB polymorphism and PD in Taiwanese

OBJECTIVE

Reports suggest that catechol-O-methyltransferase (COMT(L/L)) (Val(158)/Met) and monoamine oxidase B (MAOB) intron 13 genotype polymorphism is associated with PD. To understand the ethnicity-specific effects of genetic polymorphism, we performed a case-control study of the association between PD susceptibility and polymorphism of MAOB and COMT, both separately and in combination, in Taiwanese.

METHODS

Two hundred twenty-four patients with PD and 197 controls, matched for age, sex, and birthplace, were recruited. MAOB and COMT polymorphism genotyping was performed by using PCR-based restriction fragment length polymorphism (RFLP) analyses. chi(2), OR, and Fisher's exact tests were used to compare differences in allelic frequencies and genotypes.

RESULTS

The MAOB G genotype (G in men and G:/G in women) was associated with a 2.07-fold increased relative risk of PD. COMT polymorphism, considered alone, showed no correlation with PD risk; however, a significant synergistic enhancement was found in PD patients harboring both the COMT(L) and MAOB G genotypes.

CONCLUSIONS

These results suggest that, in Taiwanese, PD risk is associated with MAOB G intron 13 polymorphism, and this association is augmented in the presence of the COMT(L) genotype, indicating an interaction of these two dopamine-metabolizing enzymes in the pathogenesis of sporadic PD. However, the relatively low frequencies of these combined genotypes in our study necessitates confirmation with a larger sample size.

Gait analysis in advanced Parkinson's disease--effect of levodopa and tolcapone

OBJECTIVE

To determine the therapeutic effect of levodopa/benserazide and tolcapone on gait in patients with advanced Parkinson's disease.

METHODS

Instrumental gait analysis was performed in 38 out of 40 patients with wearing-off phenomenon during a randomized, double-blind, placebo-controlled trial of tolcapone.

RESULTS

Gait analysis disclosed a significant improvement by levodopa/benserazide in walking speed, stride length and the range of motion of hip, knee and ankle joints. At the end of the study, both the UPDRS motor scores during off-period and the percentage of off time improved significantly using tolcapone. However, gait analysis could not confirm this improvement. With respect to levodopa/benserazide effect, the reduction in rigidity correlated with improved angular excursion of the ankle, whereas the decreased bradykinesia correlated with improved stride length and angular excursion of the hip and knee joints.

CONCLUSION

The results of our gait analysis confirmed that in parkinsonian patients with fluctuating motor symptoms levodopa/benserazide, but not tolcapone, produced a substantial improvement.

Clinical manifestations of tardive truncal dystonia--abdominal movements: report of two cases

A variety of involuntary abdominal movements may result from peripheral insults or have a central origin. However, the spectrum of differential diagnoses can be broadened by this report of two patients whose involuntary abdominal movements were related to chronic use of haloperidol or sulpiride. Electromyographic studies revealed two patterns of muscle activity in these two patients. The first patient showed long-duration bursts of the thoracic and lumbar paraspinal muscles, causing repetitive backward tilting of the pelvis and downward shifting of the umbilicus. The second patient showed persistent contraction of the rectus and the external oblique abdominal muscles, causing sustained retraction of the abdominal wall and episodic jerking. Both patients improved dramatically after treatment with reserpine. We conclude that electromyographic study is useful in identifying truncal dystonia and abdominal dystonia, two variants of tardive syndrome.

Detection of oligoclonal bands in patients with neurologic diseases: comparison between agarose gel-, immunofixation- and isoelectric-focusing electrophoresis

BACKGROUND

The presence of oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) often implies the involvement of the humoral immune response in the disease process. We compared three methods of electrophoresis to determine the frequency and pattern of OCBs in Chinese patients with various neurologic diseases.

METHODS

CSF samples and matched serum samples were collected from 122 patients. OCBs were examined in all the CSF samples after agarose gel electrophoresis (AGE) or isoelectric-focusing electrophoresis (IEF); some samples were selected and concentrated for immunofixation electrophoresis (IFE).

RESULTS

While 46.7% of the CSF samples showed elevated immunoglobulins using AGE, OCBs were unequivocally identified in 16.4% of samples. In contrast, the detection rate of OCBs using IEF was 54.1%, while that of monoclonal bands was 4.9%. Some OCBs could be detected by IFE, which demonstrated that most of them were IgG-kappa. Using IEF, the sensitivity was 66.7% in multiple sclerosis, 47.8% in myelopathy, 88.9% in chronic inflammatory demyelinating polyradiculoneuropathy, 62.5% in acute inflammatory demyelinating polyradiculoneuropathy, 80.0% in meningoencephalitis and 23.0% in other neurologic diseases.

CONCLUSIONS

IEF was the most sensitive method for detecting OCBs. Most patients with type 2 or type 3 patterns of OCBs had multiple sclerosis or meningoencephalitis, although some of these patients may present with a type 4 pattern. Most patients with other diseases had identical patterns of OCBs in both serum and CSF.

Hemichorea-hemiballism: an explanation for MR signal changes

PURPOSE

Some cases of hemichorea-hemiballism (HCHB) are associated with a hyperintense putamen on T1-weighted MR images, the cause of which remains unclear. Our purpose was to determine the cause and significance of these MR signal changes.

METHODS

We analyzed the clinical and neuroimaging findings in 10 patients with HCHB, focusing on locations of the hyperintense lesions on T1-weighted images, comparing them with those on CT scans, and evaluating their changes after years of follow-up. A biopsy was performed in one patient.

RESULTS

Seven patients had hyperglycemia and two had cortical infarcts. HCHB recurred in four patients. A hyperintense putamen preceded the occurrence of HCHB in two patients. T1-weighted MR images revealed hyperintense lesions limited to the ventral striatum in six patients. Hyperintense lesions extended to the level of the midbrain in one patient and persisted for as long as 6 years in another patient. T2-weighted MR images revealed slit-shaped cystic lesions in the lateral part of the putamina 2 to 6 years after the onset of symptoms in two patients. A biopsy specimen from the hyperintense putamen in one patient revealed a fragment of gliotic brain tissue with abundant gemistocytes. Proton MR spectroscopy of the specimen showed an increase in lactic acid, acetate, and lipids, and a decrease in N-acetylaspartate and creatine, suggesting the presence of pronounced energy depletion and neuronal dysfunction.

CONCLUSION

Gemistocytes are sufficient to explain the shortening of T1 relaxation time. Our investigation suggests that neurons in the ventral striatum and striatonigral pathway may play a critical role in generating ballism.

A SPECT study of patients with gait apraxia without evidence of frontal lobe dysfunction

BACKGROUND

The pathogenesis of gait apraxia (GA) is unknown. Even though imaging studies provide excellent assessment of brain morphology, there is still a lack of congruous results. Single photon emission computed tomography (SPECT) using Tc-99m hexamethylpropyleneamine oxime (HMPAO) may show alterations in regional cerebral blood flow (rCBF) and provide indirect information about brain metabolism.

METHODS

We conducted a SPECT study of GA patients and evaluated the related cortical function. rCBF was assessed in 16 GA patients (15 male, one female; age range 65-79 years, mean 70.5 years) by SPECT using HMPAO. Mean HMPAO cortical or basal ganglia/cerebellum activity ratios were calculated. The regions of interest included the frontal lobe, parietal lobe and basal ganglia. A battery of GA tests and magnetic resonance imaging (MRI) of the brain were also performed in these 16 patients.

RESULTS

Nine of the patients had equilibrium disorder, and all 16 patients had locomotion disorder. The MRI findings were lacunar infarct (16/16 in basal ganglia, or 6/16 in thalamus), leukoaraiosis (4/16), enlarged ventricle (3/16), frontal lesion (3/16) and parietal lesion (1/16). Lower rCBF was noted in the frontal lobe (3/16), occipital lobe (1/16, thalamus (7/16) and basal ganglia (9/16). Though SPECT showed decreased rCBF in nine patients (9/16), mean cortical and basal ganglia regional uptake ratios in the patient group were not significantly different from values in the control group (cortical p = 0.0613; basal ganglia p = 0.0576, by Student's t-test).

CONCLUSIONS

Though only a small number of patients were studied, it was clear that brain SPECT and MRI did not show any significant abnormalities in the frontal or parietal lobes of patients with GA. Thus, the pathogenesis of GA and its related anatomic lesion should be further investigated.

Genetic screening for Huntington's disease in Chinese patients with involuntary movements

The diagnosis of Huntington's disease (HD) can be confirmed by detecting the expanded CAG repeat in the IT15 gene. Besides chorea, patients with HD may present with a variety of bizarre involuntary movements, resulting in confusion in making the diagnosis. Under such conditions, genetic analysis is the final confirmatory test. To determine if any patient with involuntary movements of undetermined etiology might be related to HD, we did genetic analysis on 22 patients and identified three with expanded CAG repeat. We could not obtain family history of HD in these patients due to adoption, early death of parents, or a vague history. All three patients were among the group with generalized chorea, but one had additional marked dystonic posturing. Together with four clinically recognizable HD patients, the relative frequency of HD among the 103 patients with choreiform movements in this hospital is 6.8%.

Polyneuropathy associated with acute monoblastic leukemia: a case report

Polyneuropathy associated with acute myelocytic leukemia is rare. We report a woman aged 34 years with acute monoblastic leukemia and polyneuropathy in hematology remission. The clinical, electrophysiological and pathological findings revealed acute symmetrical sensorimotor axonal polyneuropathy that differs from previous reports of three cases.

An add-on study of selegiline to Madopar in the treatment of parkinsonian patients with dose-related fluctuations: comparison between Jumexal and Parkryl

BACKGROUND

To improve dose-related fluctuations in patients with Parkinson's disease, the efficacy of selegiline, a selective inhibitor of monoamine oxidase B, was determined.

METHODS

Twenty parkinsonian patients were selected for a short-term, single-blind, cross-over trial. Each patient received one of the two brands of selegiline, Parkryl (Mei-Shih), 10 mg per day as an adjunct to Madopar. After a 6-week treatment period and a 4-week wash-out period, the treatment was switched to the other brand of selegiline, Jumexal (Labatec), for another 6 weeks.

RESULTS

Five patients dropped out of the study because of the development of intolerable dyskinesia, hallucination or agitation. The 15 patients that completed the study made a mild improvement in the total motor scores of the on-period during both treatments of Parkryl (p < 0.01) and of Jumexal (p < 0.05). The recorded daily off-time decreased from 37.8% to 20.7% in the Parkryl group (p < 0.01), and to 21.0% in the Jumexal group (p < 0.01).

CONCLUSION

Selegiline, as an adjunct therapy to Madopar, has a moderate effect in prolonging the duration of on-time in parkinsonian patients with dose-related fluctuations. Jumexal seemed to produce no greater effect than Parkryl.

Experience of pergolide in the treatment of Chinese parkinsonian patients with dose-related fluctuations

BACKGROUND

To improve dose-related fluctuations in patients with Parkinson's disease, the efficacy of pergolide, a long-acting dopamine receptor agonist, was determined.

METHODS

Using a stringent diagnostic criterion for Parkinson's disease, 20 patients were selected for a short-term open-label trial, and were divided into three groups based on the accuracy of clinical diagnosis.

RESULTS

Nineteen patients completed the study. The mean dosage of pergolide was 2.89 mg per day. The total motor score improved by 34.1% during the "on" period and by 34.8% during the "off" period (p < 0.001). The recorded daily off time decreased from 40.3% to 11.5% (p < 0.001). There was no statistically significant difference in the magnitude of response among different groups of patients; however, patients with shorter duration of illness also received significantly lower dosage of pergolide. Hallucination, worsening of peak-dose dyskinesia, and lowering of blood pressure were major adverse effects. Pergolide could not prevent the occurrence of neuroleptic malignant syndrome in one patient.

CONCLUSIONS

Pergolide is very effective for moderate to advanced Parkinson's disease.

Isolated lateropulsion of the trunk in cerebellar infarct

MRI in a 63-year-old male with isolated lateropulsion of the trunk disclosed an infarct in the inferior portion of the right cerebellar hemisphere, suggesting an end-zone type infarct in the lateral branch of the right posterior inferior cerebellar artery (1PICA) or a borderzone infarct between 1PICA and superior cerebellar artery. A close clinico-topographical relationship between isolated lateropulsion of the trunk and lesion in the territory of 1PICA was demonstrated.

Absence of 4,977-bp deletion of blood cell mitochondrial DNA in patients with young-onset Parkinson's disease

Decreased mitochondrial Complex I activities and a 4,977-bp deletion in mitochondrial DNA (mtDNA) have been reported in patients with Parkinson's disease. Based on the assumption of possible links between this 4,977-bp deletion and the etiology of Parkinson's disease, we analyzed mtDNA of blood cells from 15 patients with young-onset Parkinson's disease after the DNA was amplified by polymerase chain reaction. We could not detect the 4,977-bp mtDNA deletion in any of these patients. This result suggests that Parkinson's disease is not a mitochondrial disease due to the 4,977-bp mtDNA deletion. The 4,977-bp deletion in mtDNA appears to be an age-related phenomenon.

Sympathetic skin response and R-R interval variation in Parkinson's disease

We investigated autonomic function in patients with idiopathic Parkinson's disease (PD) by measuring sympathetic skin response (SSR) and R-R interval variation (RRIV). Sixty-two PD patients and 62 age-matched normal subjects were recruited. Abnormal SSR was noted in nine (14.5%) PD patients, including three in Stage II, three in Stage III, and three in Stage IV, but not in Stage I patients or normal subjects. Four of these nine patients had postural hypotension. Abnormal SSR was correlated with duration of illness and impotence. In PD patients, abnormal SSR may be due to intermediolateral column dysfunction. After logarithmic transformation and age adjustment, 19 (31.6%) of 60 PD patients had abnormal RRIV during rest and deep breathing. Abnormal RRIV was not related to staging or duration of illness. Patients with constipation had significantly lower RRIV, indicating parasympathetic dysfunction. RRIV was not affected by acute or chronic L-dopa treatment. The agreement between RRIV and SSR in PD patients was poor (kappa = -0.07). It appears that abnormal SSR, but not RRIV, may be associated with more autonomic disturbances in PD patients.

Technetium-99m hexamethylpropylene amine oxime single photon emission tomography of the brain in early Parkinson's disease: correlation with dementia and lateralization

Regional cerebral blood flow was assessed in 19 patients with early idiopathic Parkinson's disease (PD) and 12 control subjects of similar age by single-photon emission tomography using technetium-99m hexamethylpropylene amine oxime (HMPAO). Of the patients with PD, seven were mildly demented and 15 presented with hemiparkinsonism. Mean HMPAO cortical or basal ganglia/cerebellum activity ratios were calculated. Mean cortical and regional uptake ratios in non-demented PD patients were not significantly different from values in the controls. In contrast, besides generalized cortical hypoperfusion, demented PD patients had significantly lower HMPAO uptake in the frontal and basal ganglia regions than non-demented patients. These observations support the hypothesis of impaired neuronal activity in both cortical and subcortical regions of the brain in demented PD patients. In hemiparkinsonian patients, the only asymmetrical finding was a relative hypoperfusion in the contralateral parietal region. This may be due to deafferentation of the thalamoparietal pathways. The lack of asymmetrical uptake in basal ganglia in our PD patients may be explained by their staging at the time of the investigation (stage I and II, Hoehn and Yahr scale).

Cognition and 99Tcm-HMPAO SPECT in Parkinson's disease

99Tcm-hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) of brain was performed in 43 unselected patients with Parkinson's disease to evaluate whether low cerebral perfusion on SPECT correlated with cognitive impairment in the patients. All patients received neurological, Mini-Mental State Examination and a neuropsychological assessment. Eighteen (41.9%) of the 43 patients were demented. Thirty patients (69.8%) had abnormal SPECT: 17 had perfusion defects in cortical regions, eight in basal ganglia and five in both regions. Of the 22 patients with abnormal cortical perfusion, 15 (68.2%) were demented; only three (14.3%) of the 21 patients without cortical defect were demented (P < 0.01). Twelve of the 15 demented patients had low perfusion in the parietal region alone or in parietal and occipital regions. The cortical perfusion defects, present in 22 (51.2%) Parkinson's patients, are highly correlated with cognitive impairment. The pattern of SPECT abnormality in most demented patients with Parkinson's disease is similar to that seen in Alzheimer's disease, suggesting that the underlying pathophysiology for dementia in patients with Parkinson's disease may be similar to that in Alzheimer's disease.

Reverse-phase high-performance liquid chromatography of nerve growth factor receptor-like proteins identified with monoclonal antibodies

Human neuroblastoma SK-N-SH-SY5Y (SY5Y) and rat pheochromocytoma PC12 cells are model cell lines used in the study of nerve growth factor (NGF) effect. The effects of NGF are initiated by binding to cell surface receptors (NGFR). The amino acid sequence for NGFR has been deduced based on the identification of a single gene for NGFR. However, there are two kinds of NGF binding activities and several reported molecular weights of NGFR. We report here on the demonstration of NGFR-like proteins from PC12 and SY5Y cells by sequential lectin chromatography, reverse-phase HPLC, and SDS-PAGE analysis of immunoprecipitates obtained with NGFR-specific monoclonal antibodies. For both human and rodent NGFR, there was a tendency for the higher molecular-weight species of NGFR-like proteins to be eluted in more hydrophobic fractions. Also, the expression of different species of NGFR could be modified by treatment with retinoic acid (RA). These results are consistent with the hypothesis that the different molecular species of NGFR may result from the generation of a truncated form of NGFR, the presence of sugar residues on the NGFR protein, dimer formation between NGFR, or the association of NGFR with a receptor-associated protein.

Non-obstructive idiopathic pachymeningitis cervicalis hypertrophica

Two young men had similar nonobstructive idiopathic pachymeningitis cervicalis hypertrophica, causing chronic (13 and 11 years respectively) C8-T1 radiculomyelopathy proved by surgical and pathological findings. The preoperative Queckenstedt tests and myelography showed no evidence of CSF obstruction. These unusual findings contrast with previous reports which all described complete or at least partial, block. The findings on metrizamide computed tomogram have not been described before. In the two patients it revealed diffuse cord atrophy from C7 to T2 and hemiatrophy with lateral beaking from C4 to C7. The patients benefited from multiple transverse durotomies. The main pathogenesis of the cord atrophy was the compromizing of feeding radicular arteries rather than direct compression.