Differentiation of Parkinsonism-Predominant Multiple System Atrophy from Idiopathic Parkinson Disease Using 3T Susceptibility-Weighted MR Imaging, Focusing on Putaminal Change and Lesion Asymmetry

BACKGROUND AND PURPOSE

Asymmetric presentation of clinical feature in parkinsonism is common, but correlatable radiologic feature is not clearly defined. Our aim was to evaluate 3T susceptibility-weighted imaging findings for differentiating parkinsonism-predominant multiple system atrophy from idiopathic Parkinson disease, focusing on putaminal changes and lesion asymmetry.

MATERIALS AND METHODS

This retrospective cohort study included 27 patients with parkinsonism-predominant multiple system atrophy and 50 patients with idiopathic Parkinson disease diagnosed clinically. Twenty-seven age-matched subjects without evidence of movement disorders who underwent SWI were included as the control group. A consensus was reached by 2 radiologists who visually assessed SWI for the presence of putaminal atrophy and marked signal hypointensity on each side of the posterolateral putamen. We also quantitatively measured putaminal width and phase-shift values.

RESULTS

The mean disease duration was 4.7 years for the patients with parkinsonism-predominant multiple system atrophy and 7.8 years for the patients with idiopathic Parkinson disease. In the patients with parkinsonism-predominant multiple system atrophy, putaminal atrophy was frequently observed (14/27, 51.9%) and was most commonly found in the unilateral putamen (13/14). Marked signal hypointensity was observed in 12 patients with parkinsonism-predominant multiple system atrophy (44.4%). No patients with idiopathic Parkinson disease or healthy controls showed putaminal atrophy or marked signal hypointensity. Quantitatively measured putaminal width, phase-shift values, and the ratio of mean phase-shift values for the dominant and nondominant sides were significantly different between the parkinsonism-predominant multiple system atrophy group and the idiopathic Parkinson disease and healthy control groups (P < .001).

CONCLUSIONS

3T SWI can visualize putaminal atrophy and marked signal hypointensity in patients with parkinsonism-predominant multiple system atrophy with high specificity. Furthermore, it clearly demonstrates the dominant side of putaminal changes, which correlate with the contralateral symptomatic side of patients.

Clinical utility of arterial spin-labeling as a confirmatory test for suspected brain death

Diagnosis of brain death is made on the basis of 3 essential findings: coma, absence of brain stem reflexes, and apnea. Although confirmatory tests are not mandatory in most situations, additional testing may be necessary to declare brain death in patients in whom results of specific components of clinical testing cannot be reliably evaluated. Recently, arterial spin-labeling has been incorporated as part of MR imaging to evaluate cerebral perfusion. Advantages of arterial spin-labeling include being completely noninvasive and providing information about absolute CBF. We retrospectively reviewed arterial spin-labeling findings according to the following modified criteria based on previously established confirmatory tests to determine brain death: 1) extremely decreased perfusion in the whole brain, 2) bright vessel signal intensity around the entry of the carotid artery to the skull, 3) patent external carotid circulation, and 4) "hollow skull sign" in a series of 5 patients. Arterial spin-labeling findings satisfied the criteria for brain death in all patients. Arterial spin-labeling imaging has the potential to be a completely noninvasive confirmatory test to provide additional information to assist in the diagnosis of brain death.

Pantothenate kinase-associated neurodegeneration in Korea: recurrent R440P mutation in PANK2 and outcome of deep brain stimulation

BACKGROUND AND PURPOSE

The purpose of this study was to evaluate the mutation status of PANK2 among Korean patients with pantothenate kinase-associated neurodegeneration (PKAN) and to document the outcome of pallidal deep brain stimulation (DBS).

METHODS

Direct sequencing and deletion/duplication analysis of PANK2 were conducted in 12 patients (11 unrelated) with PKAN, diagnosed on the basis of extrapyramidal dysfunction and the 'eye-of-the-tiger sign' on brain magnetic resonance imaging (MRI). Pallidal DBS was conducted in four patients, and the outcomes were measured using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS).

RESULTS

A PANK2 mutation was identified in both alleles in all patients. The most prevalent mutation was c.1319G>C (p.R440P) in 8/22 mutated alleles (36%). An intragenic deletion ranging from exons 2 to 4 was found in one allele (1/22, 4.5%) using deletion/duplication analysis. The outcome of pallidal DBS was favorable in two patients with atypical PKAN and moderate severity of dystonia. However, two patients with typical PKAN and relatively severe symptoms showed variable responses.

CONCLUSIONS

The c.1319G>C (p.R440P) mutation appears to be a founder genotype among Korean patients with PKAN. Furthermore, this study provides additional data for the recent international effort to evaluate the efficacy of pallidal DBS in the treatment of patients with PKAN.

Spinocerebellar ataxia type 17 mutation as a causative and susceptibility gene in parkinsonism

OBJECTIVE

To investigate the role of spinocerebellar ataxia type 17 (SCA17) in the development of parkinsonism.

METHOD

We screened 1,155 parkinsonian patients (931 with Parkinson disease and 224 with multiple system atrophy) and 400 normal subjects for SCA17. 99mTc-TRODAT-1 SPECT was used to evaluate the striatal dopamine transporter (DAT) status.

RESULTS

Trinucleotide expansion in the SCA17 gene was found in 10 parkinsonian patients (8 with Parkinson disease, 2 with multiple system atrophy) using 42 repeats as an upper normal limit. The repeat sizes in the patients ranged from 43 to 46, which are considered to be low-range expansions. All patients had interrupted sequences. Three probands and three asymptomatic carriers underwent 99mTc-TRODAT-1 SPECT. Striatal DAT binding was markedly reduced in all probands and mildly decreased in one asymptomatic carrier. Among the 400 normal control subjects, there was one individual with an expansion of 44 repeats, another with 43 repeats, and two with 42 repeats. Striatal DAT binding was decreased not only in the control subjects with 44 or 43 repeats, but in ones with 42 repeats, suggesting that an expansion as low as 42 repeats might constitute a susceptibility gene for parkinsonism.

CONCLUSIONS

Low-range expansion of the SCA17 gene is not a rare genetic cause of parkinsonism without ataxia in our population. Reduced penetrance or variable expressivity in low-range expansion might be an explanation for the blurred cutoff point for normal expansion in SCA17.

Survivors from beta-fluoroethyl acetate poisoning show a selective cerebellar syndrome

AIM/ BACKGROUND: beta-Fluoroethyl acetate (FEA), a derivative of sodium fluoroacetate (Compound 1080, FA), is one of the high-potency toxic chemicals, and it has been used against rats and wild animals. Human casualties from FA or FEA poisoning, accidental or suicidal, have been reported. Survivors of the poisoning are extremely rare. The objective of this study is to present survivors of FEA poisoning.

METHOD

Data on the survivors were collected at the Department of Neurology over the past 20 years. Reviews of the medical record and brain imaging were performed.

RESULTS

A total of 10 survivors of FEA poisoning were found. All of the cases were suicide attempts. The amount of FEA ingested varied from 600 to 1800 mg with a mean of 1200 mg, which is close to the lethal dose of FEA. Immediately after ingestion, all of the patients had an altered mental status. On awakening, all of the patients had severe cerebellar dysfunction, such as ataxic gait, dysarthria and intention tremor. The cerebellar dysfunction usually improved gradually over the years after the event, but this improvement eventually plateaued, resulting in residual and persistent cerebellar dysfunction. Serial imaging showed swelling in the posterior fossa during the acute phase and progressive cerebellar atrophy on follow-up.

CONCLUSION

In summary, FEA poisoning causes a selective cerebellar syndrome in its survivors. The pathomechanism underlying the selective cerebellar toxicity of FEA remains to be elucidated. The selective involvement of the cerebellum might provide a useful model for cerebellar degeneration.

alpha-Synuclein gene duplication is present in sporadic Parkinson disease

OBJECTIVE

alpha-Synuclein gene (SNCA) multiplication was found in familial Parkinson disease (PD). We examined SNCA multiplication in patients with familial and sporadic PD and multiple system atrophy (MSA).

METHODS

We screened 1,106 patients with parkinsonism (PD = 906, MSA = 200) for SNCA multiplication by multiplex PCR. Fluorescent in situ hybridization was done to confirm the multiplication. [(123)I]N-omega-Fluoropropyl-2 beta-carbomethoxy-3beta-(4-iodophenyl)-tropane ([(123)I]FP-CIT) SPECT was done in the patients with SNCA multiplication and their family members.

RESULTS

Three patients were identified as having SNCA duplication. One patient had a positive family history, and two patients were sporadic. Each patient had asymptomatic carriers in their families. The familial case had early onset parkinsonism with rapidly progressive course, cognitive impairment, and dysautonomia. Sporadic cases were more typical of PD. [(123)I]FP-CIT SPECT was abnormal in the patients and normal in the asymptomatic carriers.

CONCLUSION

SNCA multiplication is present in sporadic Parkinson disease (PD) and needs to be screened. Low penetrance, clinical heterogeneity, and normal dopamine transporter imaging in asymptomatic carriers may suggest the presence of other genetic modifiers or environmental triggers that play a role in the pathogenesis of PD due to SNCA duplication.

Fermented mushroom milk-supplemented dietary fibre prevents the onset of obesity and hypertriglyceridaemia in Otsuka Long-Evans Tokushima fatty rats

AIM

Fermented milk product containing edible mushroom water extracts (mushroom yogurt; MY) has been reported to have glycaemic control and triglyceride-lowering effects in streptozotocin (STZ)-induced diabetic rats and Zucker diabetic fatty (ZDF) rats. Here, we investigated how MY-supplemented dietary fibre (10 and 20%, v/w) influences the onset of obesity and hypertriglyceridaemia in Otsuka Long-Evans Tokushima fatty (OLETF) rats.

METHODS

The OLETF rats were fed a powdered chow diet supplemented with MY at the levels of 10 (v/w) and 20% for 6 weeks from 10 weeks of age, but the OLETF control rats were not supplemented. Their weight, fat distribution and lipid profile have been determined.

RESULTS

The body weights in MY-fed rats were reduced compared with the control rats. The perirenal fat was decreased in both MY groups, but the visceral and epididymal fats reduced only in the MY 20% group. The concentrations of serum triglyceride and non-esterified fatty acid in MY-fed rats were decreased in a dose-dependent manner. However, the levels of other serum lipid profiles [total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol] were comparable among all rats.

CONCLUSION

Anti-obesity and triglyceride lowering by MY-supplemented dietary fibre in OLETF rats might have resulted from the synergistic effect of components in the fermented mushroom-milk product.

Unusual neurological presentations of vitamin B12 deficiency

Vitamin B(12) deficiency (B(12)D) has a wide variety of neurological symptoms and signs. However, cerebellar dysfunction and cranial neuropathies other than optic neuropathy have been rarely reported. Herein, we describe two cases of unusual neurological manifestations of B(12)D. One patient showed prominent hoarseness with vocal cord paralysis, myelopathy, and peripheral neuropathy. The other had gait disturbance, lateral gaze limitation and cerebellar dysfunction in addition to the typical manifestations of subacute combined degeneration. Vitamin B(12) deficiency can rarely affect cerebellum and cranial nerves other than optic nerve.

Molecular analysis of Spinocerebellar ataxias in Koreans: frequencies and reference ranges of SCA1, SCA2, SCA3, SCA6, and SCA7

Spinocerebellar ataxias (SCAs) are a heterogeneous group of neurodegenerative disorders. CAG repeat expansions in the causative genes have been identified as the basic cause of several types of SCAs, and have been used for the diagnoses and classifications of patients with ataxia. In order to assess the frequency and CAG repeat size ranges of SCAs, and to establish an effective strategy for molecular diagnosis, we performed a molecular analysis of SCA1, SCA2, SCA3, SCA6, and SCA7 in 76 patients. These patients were as follows: 32 with dominant inheritance, 39 sporadic cases, and 5 with unknown family histories. The normal and affected CAG repeat size ranges were established at five SCA loci in Koreans, which was consistent with previous reports. The total prevalence of the five types of SCAs was 39.5% in the 76 patients with ataxia, regardless of their family history. It was 75.0% in the 32 families with a dominant inheritance. The most frequent type was SCA3 (15.8%), followed by SCA2 (14.5%). Both types combined formed 76.7% of the 30 patients with CAG expansions. SCA1, SCA6, and SCA7 were less frequent, affecting 3.9%, 2.6%, and 2.6% of the cases, respectively. This mutation spectrum is quite different from a previous report concerning Koreans, but is similar to the distributions that are seen in several ethnic populations worldwide. For a correct and effective diagnosis of SCAs, we suggest that a molecular diagnosis be undertaken, even in patients without a family history, as well as those with a family history. A stepwise approach is also recommended. Patients with ataxia should be tested for SCA2 and SCA3. Individuals testing negative should be tested for SCA1, SCA6, and SCA7.

Identification of the catalytic residue of Thermococcus litoralis 4-alpha-glucanotransferase through mechanism-based labeling

Thermococcus litoralis 4-alpha-glucanotransferase (TLGT) belongs to family 57 of glycoside hydrolases and catalyzes the disproportionation and cycloamylose synthesis reactions. Family 57 glycoside hydrolases have not been well investigated, and even the catalytic mechanism involving the active site residues has not been studied. Using 3-ketobutylidene-beta-2-chloro-4-nitrophenyl maltopentaoside (3KBG5CNP) as a donor and glucose as an acceptor, we showed that the disproportionation reaction of TLGT involves a ping-pong bi-bi mechanism. On the basis of this reaction mechanism, the glycosyl-enzyme intermediate, in which a donor substrate was covalently bound to the catalytic nucleophile, was trapped by treating the enzyme with 3KBG5CNP in the absence of an acceptor and was detected by matrix-assisted laser desorption ionization time-of-flight mass spectrometry after peptic digestion. Postsource decay analysis suggested that either Glu-123 or Glu-129 was the catalytic nucleophile of TLGT. Glu-123 was completely conserved between family 57 enzymes, and the catalytic activity of the E123Q mutant enzyme was greatly decreased. On the other hand, Glu-129 was a variable residue, and the catalytic activity of the E129Q mutant enzyme was not decreased. These results indicate that Glu-123 is the catalytic nucleophile of TLGT. Sequence alignment of TLGT and family 38 enzymes (class II alpha-mannosidases) revealed that Glu-123 of TLGT corresponds to the nucleophilic aspartic acid residue of family 38 glycoside hydrolases, suggesting that family 57 and 38 glycoside hydrolases may have had a common ancestor.

Magnetic resonance reflects the pathological evolution of Wernicke encephalopathy

BACKGROUND AND PURPOSE

Wernicke encephalopathy (WE) is an acute phase of Wernicke-Korsakoff syndrome. Pathologic findings change between acute and chronic phases. Only a few magnetic resonance imaging (MRI) studies have been done to date.

METHODS

To correlate the MRI findings in acute and chronic stages of WE with the known pathologic information, 15 consecutive patients with WE were examined with MRI: 3 before thiamine treatment, 7 within 24 hours of thiamine treatment, 4 between the second and sixth day after thiamine treatment, and 1 fifty-five days after thiamine treatment. Nine of the patients had follow-up MRI between 2 days and 33 months. T1-weighted, proton, and T2-weighted axial images were obtained with additional 5-mm-thick T1-weighted sagittal and coronal images to better visualize the mammillary bodies.

RESULTS

In the acute WE, MRI showed high signal intensityon T2-weighted images in periaqueduct and medial thalamic regions. In a few patients with alcoholism, vermian and mammillary body atrophies and third ventricular enlargements were noted. In the chronic phase of WE, T2 hyperintensity disappeared but mammillary bodies and cerebellar vermis became atrophic and third ventricular enlargements were evident. High signal intensity on T2-weighted images disappeared as early as 2 days, and atrophic changes appeared as early as 1 week.

CONCLUSION

MRI is useful for in vivo monitoring and reflects the pathological evolution in acute and chronic phases of WE.

Case of essential palatal tremor: atypical features and remarkable benefit from botulinum toxin injection

We describe a 21-year-old man with essential palatal tremor. The patient had rhythmic contractions not only of tensor veli palatini but also of facial, lingual, temporalis, pharyngeal, and neck muscles. He had some voluntary control of palatal tremor and ear clicks. He was treated with 5 units of botulinum toxin-A (BOTOX) injected into each tensor veli palatini, and had complete resolution of all the symptoms.

An apparently sporadic case with parkin gene mutation in a Korean woman

OBJECTIVE

To report the clinical features and results of iodine I 123-2beta-carbomethoxy-3beta-(4-iodophenyl)-tropane (CIT) single photon emission computed tomography and molecular genetic analysis in a Korean woman with juvenile Parkinson disease with deletion in exon 4 of the parkin gene.

DESIGN

Case report with molecular genetic analysis.

PATIENT AND RESULTS

The patient had bradykinesia, postural imbalance, and postural tremor since the age of 12 years. She developed wearing off early in the disease course. The [(123)I]-2beta-carbomethoxy-3beta-(4-iodophenyl)-tropane single photon emission computed tomography showed severe reduction of specific striatal CIT binding, comparable to that of Parkinson disease. The polymerase chain reaction products from the parkin gene showed homozygous exon 4 deletion.

CONCLUSION

In this sporadic juvenile Parkinson disease case, severe nigrostriatal dopaminergic damage and homozygous exon 4 deletion in the parkin gene were demonstrated.

Primary leptomeningeal lymphoma with long-term survival: a case report

Primary leptomeningeal lymphoma (PLML) is a rare disease. The most common presentation is symptoms of increased intracranial pressure. Confusion, dysarthria, hearing loss, paraparesis and lumbosacral spinal root symptoms have also been reported. Chemotherapy and radiotherapy have been tried, but its prognosis is usually poor. We experienced a case of PLML with a relatively benign course in an 18-year-old girl. Initial diagnosis was made as idiopathic intracranial hypertension. Lumbosacral shunt was done with good response for 3 years. When headache recurred, she was reevaluated and was correctly diagnosed as PLML.

Hemimasticatory spasm associated with localized scleroderma and facial hemiatrophy

OBJECTIVES

To report a case and discuss the mechanism of hemimasticatory spasm.

DESIGN

Case report.

PATIENT

A 37-year-old woman had a 3-year history of involuntary spasms of the right masseter muscle in association with localized scleroderma and facial hemiatrophy. Electrophysiological studies revealed a normal blink reflex. However, the masseter reflex and silent period were absent on the affected side. Distal latency and compound muscle action potential of the masseter nerve were normal. Needle electromyography demonstrated irregular bursts of motor unit potentials similar to those described in hemifacial spasm. A magnetic resonance imaging scan of the head showed mild hypertrophy of the masseter muscle and atrophy of subcutaneous fatty tissues on the affected side. Local injection of botulinum toxin A into the masseter muscle resolved the patient's symptoms.

CONCLUSION

On the basis of clinical and electrophysiological findings, focal demyelination of motor branches of the trigeminal nerve owing to deep tissue changes is suggested as the cause of abnormal excitatory electrical activities resulting in involuntary masticatory movement.

Relative sparing of calretinin containing neurons in the substantia nigra of 6-OHDA treated rat parkinsonian model

A certain calcium binding protein (CaBP) has been known to exert a neuroprotective effect in various neurodegenerative diseases. Using the 6-OHDA induced rat Parkinsonian model, we examined if calretinin (CR), one of CaBP family, could play the similar role in the Parkinson's disease because CR is profusely localized in dopaminergic neurons of the substantia nigra pars compacta (SNPC) of the rat. Employing immunohistochemical analyses, we found that the survival rate of CR neurons was significantly higher than that of tyrosine hydroxylase (TH) neurons in the SNPC of the Parkinsonian rat. Furthermore double-labeled fluorescent microscopy revealed that almost all surviving TH neurons were also positive to CR. Our data suggest that CR-positive neurons are less vulnerable to 6-OHDA and CR in the dopaminergic neurons may have a protective function for survival of these neurons in the experimentally induced Parkinsonian rat.

Spinocerebellar ataxia type 2 in seven Korean families: CAG trinucleotide expansion and clinical characteristics

Studies on spinocerebellar ataxias (SCA) have been hampered by a lack of disease markers. Clinical and pathological heterogeneity also made the classification unreliable. Linkage studies established that there are multiple subtypes of SCA. Five types are found to have unstable CAG expansion; the diagnosis can be established by molecular genetic study. Therefore, we systemically screened degenerative ataxia patients for these five SCA types, and identified eight patients with SCA2 (seven from six families and one sporadic case). This paper presents the clinical information on the seven patients, whose clinical information was available in detail. CAG repeat expansion in the patients ranged from 38 to 47 (normal control, 19 to 27). The onset ages ranged from 16 to 41 with 27.1 years as the mean, which correlated inversely with repeat lengths. All patients presented dysarthria and gait ataxia. Upper limb dysmetria or dysdiadochokinesia appeared later but progressed, causing severe disability. Slow saccade (4 patients in 7) and decreased DTR (4 in 7) were common. MRIs showed severe atrophy of the brainstem and cerebellum in all patients. We conclude that SCA2 is the most frequent type in Korea and carries rather pure cerebellar syndrome, slow saccade, and hyporeflexia.

Activation of caspase-3 in developmental models of programmed cell death in neurons of the substantia nigra

Programmed cell death has been proposed to play a role in the death of neurons in acute and chronic degenerative neurologic disease. There is now evidence that the caspases, a family of cysteine proteases, mediate programmed cell death in various cells. In neurons, caspase-3 (CPP32/Yama/apopain), in particular, has been proposed to play a role. We examined the expression of caspase-3 in three models of programmed cell death affecting neurons of the substantia nigra in the rat: natural developmental neuron death and induced developmental death following either striatal target injury with quinolinic acid or dopamine terminal lesion with intrastriatal injection of 6-hydroxydopamine. Using an antibody to the large (p17) subunit of activated caspase-3, we have found that activated enzyme is expressed in apoptotic profiles in all models. Increased p17 immunostaining correlated with increased enzyme activity. The subcellular distribution of activated caspase-3 differed among the models: In natural cell death and the target injury model, it was strictly nuclear, whereas in the toxin model, it was also cytoplasmic. We conclude that p17 immunostaining is a useful marker for programmed cell death in neurons of the substantia nigra.

Dopamine transporter density measured by [123I]beta-CIT single-photon emission computed tomography is normal in dopa-responsive dystonia

The clinical distinction between dopa-responsive dystonia (DRD) and juvenile Parkinson's disease JPD) can pose a diagnostic challenge. Both conditions are dopa responsive. However, long-term L-dopa benefit is very different between the two. The difference in the prognosis is due to presence or absence of nigral cell loss. In JPD, there is degenerative nigral cell loss, whereas there are enzymatic defects in dopamine synthesis without cell loss in DRD. Mutations have been found in the GTP cyclohydrolase I (GCH-I) and tyrosine hydroxylase genes in DRD. As the discovered mutations are multiple and more are expected to be found, it is difficult to confirm or exclude DRD by mutation studies. Measurement of cerebrospinal fluid (CSF) neopterin will detect DRD from mutations in the GCH-I gene but not from mutations in tyrosine hydroxylase. The dopamine transporter (DAT) is a protein in the dopaminergic nerve terminals. (1R)-2beta-Carbomethoxy-3beta-(4-[123I]iodophenyl)tropane ([123I]beta-CIT) is a ligand for the DAT, and it was shown to be a useful nuclear imaging marker for neurons that degenerate in Parkinson's disease (PD). As DRD was shown to have a normal DAT without nigral cell loss in a postmortem study, we predicted that the DAT measured in vivo by nuclear imaging will be normal in DRD and will differentiate DRD from JPD. Therefore, we performed [123I]beta-CIT single-photon emission computed tomography ([123I]beta-CIT SPECT) in clinically diagnosed DRD, PD, and JPD, and examined whether DAT imaging can differentiate DRD from PD and JPD. We then examined whether DAT imaging can provide a screening tool for molecular genetic studies, by studying mutations in the candidate gene GCH-I and measuring CSF neopterin. Five females (4 from two families, and 1 sporadic) were diagnosed as DRD based on early-onset foot dystonia and progressive parkinsonism beginning at ages 7 to 12. All patients were functioning normally on L-dopa 100 to 250 mg/day for up to 8 years. SPECT imaging was obtained after intravenous injection of [123I]beta-CIT; 15 healthy volunteers served as normal control, and 6 PD and 1 JPD as disease controls. [123I]beta-CIT striatal binding was normal in DRD, whereas it was markedly decreased in PD and JPD. Gene analysis showed a novel nonsense mutation in the GCH-I gene in one family. No mutation was found in the other family or in the sporadic case. CSF neopterin was markedly decreased in the 4 tested patients. [123I]beta-CIT SPECT is a sensitive method for probing the integrity of nigrostriatal dopaminergic nerve terminals. A normal striatal DAT in a parkinsonian patient is evidence for a nondegenerative cause of parkinsonism and differentiates DRD from JPD. Finding a new mutation in one family and failure to demonstrate mutations in the putative gene in other cases supports the usefulness of DAT imaging in diagnosing DRD.

Acetazolamide-responsive hereditary paroxysmal ataxia: report of a family

Hereditary paroxysmal ataxia is a rare dominantly inherited disorder characterized by recurrent attacks of cerebellar ataxia, dysarthria, and nystagmus. Each attack lasts from several minutes to few hours or days. Usually there are no motor difficulties between attacks. We report a patient who had had recurrent ataxic episodes since early childhood. Four members of the family over two generations had similar attacks. There were no abnormalities in the laboratory studies including plasma amino acid, lactate, pyruvate, and EEG. Treatment with acetazolamide resulted in complete abolition of the attacks. Because of its dramatic response to acetazolamide, the recognition of this rare disorder is important.

Nervous system involvement by metastatic hepatocellular carcinoma

Nineteen patients with nervous system metastasis of hepatocellular carcinoma (HCC) were evaluated retrospectively. Nervous system metastasis was frequently initial presentation of HCC (seven out of 19 patients). Seven patients had metastases of the brain, of whom four had a stroke-like presentation. CT or MRI in these patients showed intracerebral hematomas in watershed areas. Enhancing lesion or edema adjacent to the hematoma helped differentiate these lesions from classical hypertensive hematomas. One patient with metastasis to the clivus presented with isolated six nerve palsy. The remaining 11 patients had spinal epidural metastases producing myelopathy in seven and radiculopathy in four. Radiation therapy failed to control the clinical course.

4-alpha-glucanotransferase from the hyperthermophilic archaeon Thermococcus litoralis--enzyme purification and characterization, and gene cloning, sequencing and expression in Escherichia coli

4-Alpha-Glucanotransferase was purified from cells of Thermococcus litoralis, a hyperthermophilic archaeon. The molecular mass of the enzyme was estimated to be approximately 87 kDa by gel filtration. The optimal temperature for its activity was 90 degrees C. The enzyme catalyzed the transglycosylation of maltooligosaccharides, yielding maltooligosaccharides of various lengths and glucose. When maltoheptaose was used as the substrate, glucoamylase-resistant and glucoamylase-sensitive saccharides were produced. On incubation of amylose with the T. litoralis enzyme, glucoamylase-resistant but alpha-amylase-sensitive molecules were produced, but the amount of reducing sugar showed only slight increases. These results indicate that the T. litoralis enzyme catalyzes not only intermolecular transglycosylation to produce linear alpha-1,4-glucan, but also intramolecular transglycosylation to produce cyclic alpha-1,4-glucan (cycloamylose), similarly to potato 4-alpha-glucanotransferase (called disproportionating enzyme). The gene encoding the T. litoralis 4-alpha-glucanotransferase was cloned, sequenced and expressed in Escherichia coli. The nucleotide sequence of the gene encoded a 659-amino acid protein with a calculated molecular mass of 77,883 Da. The amino acid sequence of the T. litoralis enzyme showed high similarity with those of alpha-amylases of Pyrococcus furiosus, a hyperthermophilic archaeon, and Dictyoglomus thermophilum, an extremely thermophilic bacterium, but little similarity with those of other known 4-alpha-glucanotransferases.

Dopa-responsive dystonia: a syndrome of selective nigrostriatal dopaminergic deficiency

Dopa-responsive dystonia (DRD) is no longer a rare oddity. For the clinician, DRD poses a diagnostic challenge as its clinical presentation can be quite diverse. Marked and sustained response to L-dopa is the most crucial and absolute hallmark in confirming a diagnosis. Absence of degenerative nigral cell loss underlies the remarkable L-dopa response. The broadening spectrum of the clinical presentations, progress in molecular genetics with evidence of incomplete penetrance and phenotypic variability, biochemistry, utility of nuclear imaging in differential diagnosis, and treatment are discussed. I propose the concept of DRD as a syndrome, defined as selective nigrostriatal dopamine deficiency caused by genetic defects in dopamine synthesis without degenerative cell loss. I further propose the term DRD-plus, defined as inherited metabolic disorders which have symptomatic features of DRD, and those features not seen in DRD as well.

Unilateral fetal mesencephalic grafting in two patients with Parkinson's disease: short-term result after transplantation

Fundamental pathological and neurochemical changes in Parkinson's disease are loss of midbrain dopamine neurons that innervate the caudate and putamen. In an effort to replenish the striatal dopaminergic innervation, fetal mesencephalic tissue containing dopamine cells was implanted into the unilateral putamen in two patients with severe Parkinson's disease. The tissue was obtained from three fetuses with gestational ages of 7 to 9 weeks. The cell suspension was stereotactically injected into the unilateral putamen using 5 needle trajectories. Postoperative immune suppression was not performed. Clinical improvement appeared after 2 months. Both patients showed improvement according to the Activities of Daily Living Scale during the off and practically-defined off state 9 and 14 months after surgery. The motor scores of the Unified Parkinson's Disease Rating Scale improved during the off and practically-defined off state 9 and 14 months after surgery. Dyskinesia and off state were shorter and less severe than before the transplantation. Although the long-term effects need to be ascertained, our short-term observation in these two patients with unilateral transplantation is encouraging and justifies further research trials in selected patients.

6-Hydroxydopamine lesion of the rat substantia nigra: time course and morphology of cell death

The 6-hydroxydopamine (6-OHDA) model of nigral injury in rats has been in use as a standard animal model of parkinsonism for many years. While earlier studies established the time course for loss of catecholamine histofluorescence or tyrosine hydroxylase immunostaining in the cell bodies and terminals, these alterations in phenotypic expression do not define the time course of morphologic degeneration. We have therefore used a silver impregnation method to characterize the time course and morphology of the degeneration of neurons in the nigrostriatal system. Abundant neuronal death was observed in substantia nigra pars compacta (SNpc) as early as 12 hours after nigral 6-OHDA injection, and prior to any evidence of striatal terminal degeneration. From 1 to 7 days neuron death was accompanied by striatal fibre degeneration. After 7 days, fibre degeneration was no longer seen, but identifiable neuron death continued at low levels for as long as 31 days, and stained amorphous material was present at 60 days. The morphologic pattern of cell death in the early phase was similar to that in the late phase, and included cytoplasmic silver deposits and dark staining of the nucleolus. At no time was the morphology of apoptosis observed. We conclude that neuron death is a progressive process following 6-OHDA lesion, with similar morphology throughout the course of degeneration.