Review: neuropathology of acute phase encephalitis lethargica: a review of cases from the epidemic period

INTRODUCTION

Encephalitis lethargica (EL), an epidemic disease of the early 20th century, has continued to be diagnosed sporadically since that time, including a report of 20 new cases in 2004. Many of the recent case reports state that the primary neuropathology of acute EL consists of inflammatory changes and lesions within the midbrain, basal ganglia and substantia nigra. However, the neuropathology of acute EL cases from the epidemic period was actually much more widespread.

METHODS

In order to characterize the neuropathology of acute phase EL, we developed a database of EL pathology based on 112 cases from the years 1915 to 1940, of which most died within 2 weeks of EL onset.

RESULTS

Our analysis revealed that cortical damage was prevalent in 75% of the 112 cases; damage to the meninges and brainstem occurred in approximately half of the cases; and the substantia nigra was damaged in only 13% of these acute cases. We also found that after 1921, damage to cranial nerve nuclei was not reported. An analysis of the neuropathology and clinical symptoms revealed little correlation.

CONCLUSIONS

Based on these findings, putative modern cases of acute EL with MRI/CT indicated lesions confined solely to the midbrain, brainstem, and/or basal ganglia should not be considered, consistent with that reported during epidemic period.

Mutation in the alpha-synuclein gene identified in families with Parkinson's disease

Parkinson's disease (PD) is a common neurodegenerative disorder with a lifetime incidence of approximately 2 percent. A pattern of familial aggregation has been documented for the disorder, and it was recently reported that a PD susceptibility gene in a large Italian kindred is located on the long arm of human chromosome 4. A mutation was identified in the alpha-synuclein gene, which codes for a presynaptic protein thought to be involved in neuronal plasticity, in the Italian kindred and in three unrelated families of Greek origin with autosomal dominant inheritance for the PD phenotype. This finding of a specific molecular alteration associated with PD will facilitate the detailed understanding of the pathophysiology of the disorder.

Mutation in the alpha-synuclein gene identified in families with Parkinson's disease

Parkinson's disease (PD) is a common neurodegenerative disorder with a lifetime incidence of approximately 2 percent. A pattern of familial aggregation has been documented for the disorder, and it was recently reported that a PD susceptibility gene in a large Italian kindred is located on the long arm of human chromosome 4. A mutation was identified in the alpha-synuclein gene, which codes for a presynaptic protein thought to be involved in neuronal plasticity, in the Italian kindred and in three unrelated families of Greek origin with autosomal dominant inheritance for the PD phenotype. This finding of a specific molecular alteration associated with PD will facilitate the detailed understanding of the pathophysiology of the disorder.

Mapping of a gene for Parkinson's disease to chromosome 4q21-q23

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease, affecting approximately 1 percent of the population over age 50. Recent studies have confirmed significant familial aggregation of PD and a large number of large multicase families have been documented. Genetic markers on chromosome 4q21-q23 were found to be linked to the PD phenotype in a large kindred with autosomal dominant PD, with a Zmax = 6.00 for marker D4S2380. This finding will facilitate identification of the gene and research on the pathogenesis of PD.

Clinical genetic analysis of Parkinson's disease in the Contursi kindred

We performed a clinical genetic analysis of a kindred originating in the town of Contursi in Salerno province, Italy, in which 60 individuals in 5 generations are known to have had Parkinson's disease (PD). Two previously reported autopsy cases showed typical PD with Lewy bodies. The inheritance pattern is apparently autosomally dominant with a segregation ratio of 40.1% for kindred members aged 50 years and older. The mean age at PD onset is 45.6 years (standard deviation, 13.48; range, 20-85) with a mean course to death of 9.2 years (standard deviation, 4.87; range, 2-20). Otherwise, clinical characteristics of PD in the kindred, including variance in onset age and incidence of tremor and levodopa responsiveness, are similar to those of PD in the community. The presence of tremor tended to be concordant in affected parent-child pairs, but there was no parent-child correlation for age at onset or intrasibship clustering of tremor or onset age. A suggestion of anticipation disappeared after adjustment for age-related ascertainment bias. The findings show that a presumably single mutation can produce a heterogeneous PD phenotype, even among siblings. This is consistent with the hypothesis that PD in the community may in fact be caused by such a mutation, but one producing a lower penetrance and older age at onset than those in this kindred.

Clinical research criteria for the diagnosis of progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome): report of the NINDS-SPSP international workshop

To improve the specificity and sensitivity of the clinical diagnosis of progressive supranuclear palsy (PSP, Steele-Richardson-Olszewski syndrome), the National Institute of Neurological Disorders and Stroke (NINDS) and the Society for PSP, Inc. (SPSP) sponsored an international workshop to develop an accurate and universally accepted set of criteria for this disorder. The NINDS-SPSP criteria, which were formulated from an extensive review of the literature, comparison with other previously published sets of criteria, and the consensus of experts, were validated on a clinical data set from autopsy-confirmed cases of PSP. The criteria specify three degrees of diagnostic certainty: possible PSP, probable PSP, and definite PSP. Possible PSP requires the presence of a gradually progressive disorder with onset at age 40 or later, either vertical supranuclear gaze palsy or both slowing of vertical saccades and prominent postural instability with falls in the first year of onset, as well as no evidence of other diseases that could explain these features. Probable PSP requires vertical supranuclear gaze palsy, prominent postural instability, and falls in the first year of onset, as well as the other features of possible PSP. Definite PSP requires a history of probable or possible PSP and histopathologic evidence of typical PSP. Criteria that support the diagnosis of PSP, and that exclude diseases often confused with PSP, are presented. The criteria for probable PSP are highly specific, making them suitable for therapeutic, analytic epidemiologic, and biologic studies, but not very sensitive. The criteria for possible PSP are substantially sensitive, making them suitable for descriptive epidemiologic studies, but less specific. An appendix provides guidelines for diagnosing and monitoring clinical disability in PSP.

Follow-up study of risk factors in progressive supranuclear palsy

The cause of progressive supranuclear palsy (PSP) is not known and has been little studied. The one previous controlled epidemiologic survey, performed at our center in 1986, found small-town experience and greater educational attainment as PSP risks, but, in retrospect, these results may have been produced by ascertainment bias. Since that time, several anecdotal reports have implicated heredity and various environmental exposures in the cause of some cases of PSP. To clarify the results of the previous study and to evaluate the more recently implicated candidate factors in a controlled fashion, we mailed a validated 69-item questionnaire to 91 personally examined patients with PSP and 104 unmatched controls with other neurologic conditions for which they had been referred to our tertiary neurologic center. We were able to match 75 subjects from each group by year of birth, sex, and race and subjected them to a separate matched-pair analysis. We allowed surrogates to supply any or all of the responses. Questions concerned hydrocarbon, pesticide, and herbicide exposure; urban/rural living; auto repair and other occupations; head trauma; educational attainment; maternal age; and family history of PSP, parkinsonism, dementia, and other neurologic conditions. A statistically significant finding was that patients with PSP were less likely to have completed at least 12 years of school (matched odds ratio = 0.35, 95% CI = 0.12-0.95, p = 0.022; unmatched odds ratio = 0.44, 95% CI = 0.21-0.89, p = 0.020). We hypothesize that this result may be a proxy for poor early-life nutrition or for occupational or residential exposure to an as-yet unsuspected toxin. Future studies should examine these potential risk factors in PSP.

Binswanger's disease presenting as levodopa-responsive parkinsonism: clinicopathologic study of three cases

We report three cases of autopsy-proven Binswanger's disease (subcortical arteriosclerotic encephalopathy) with unusual clinical features. Two patients had supranuclear gaze disturbances, early gait dysfunction, and speech disorders suggestive of progressive supranuclear palsy. One of these patients was not demented at the time of death. The third patient had features typical of Parkinson's disease. All three patients were responsive to treatment with levodopa. The clinical spectrum of Binswanger's disease should be expanded to include levodopa-responsive parkinsonism.

Meige syndrome in the spectrum of Lewy body disease

We report a patient with Meige syndrome (segmental cranial dystonia) who had neuropathologic changes of Parkinson's disease on postmortem examination. Neuropathologic examination showed typical and atypical Lewy bodies in the pigmented nuclei of the brainstem (substantia nigra, locus ceruleus), the nucleus basalis of Meynert, and the nucleus ambiguus. Neurochemical analysis of postmortem brain tissue showed evidence for decreased dopamine turnover in the substantia nigra, striatum, and nucleus accumbens. We propose that some cases of Meige syndrome may be included in the spectrum of Lewy body disease.

A clinical genetic study of Parkinson's disease: evidence for dominant transmission

We used a family history questionnaire, semi-structured interview, and personal examination of secondary cases to collect data on the prevalence of Parkinson's disease (PD) in relatives of patients seen consecutively for 1 year and assessed the proportion of secondary cases of PD as a function of pedigree completeness. Survival analysis methods were applied to estimate the lifetime risk and age-at-onset distribution of PD among first-degree relatives of probands. When we considered siblings of probands with affected parents, the cumulative risk increased significantly over siblings of probands without affected parents, suggesting significant familial aggregation in a subset of randomly ascertained families. We further analyzed 80 multicase families with two or more affected individuals. Age-adjusted segregation ratios approaching 0.5 and similar proportions of affected parents and siblings, as well as the distribution of ancestral secondary cases, were compatible with an autosomal dominant mode of inheritance with reduced penetrance in a subset of PD.

Differential diagnosis of PSP

The clinical diagnosis of PSP depends primarily on the history and the physical findings. Clinicians should be alerted to the possibility of this condition in assessing patients presenting with atypical parkinsonism and other complex extrapyramidal syndromes in late middle age or later. The differential diagnosis includes MSA (both OPCA and SND), PD, CBD and cerebrovascular disease. PD is probably the most common erroneous diagnosis. Unfortunately, pathognomonic signs do not usually appear until several years, after symptom onset. No specific laboratory test is yet available. Neuroimaging studies show characteristic anatomic alterations only late in the course of the illness and must be correlated with the clinical findings.

Autosomal dominant parkinsonism with benign course and typical Lewy-body pathology

The few previously reported patients with familial parkinsonism and Lewy-body pathology in the substantia nigra displayed a variety of clinical and pathologic syndromes. We now describe a family with very slowly progressive Parkinson's disease (PD) that has, in most cases, responded poorly to levodopa and includes subjective visual difficult. Four personally confirmed cases--with onset at ages 35, 25, 16, and 16-have occurred in three generations, and four suspicious cases have occurred in three other generations. There has been a trend toward progressively younger age of onset. One autopsied case showed a distribution of cell loss and Lewy bodies typical of PD. The hereditary pattern is most compatible with autosomal dominance. This kindred's illness shows that a presumably single Mendelian dominant gene can cause the clinical and pathologic features of PD, and further extends the clinical spectrum of pathologically typical Lewy-body PD.

A 17th-century founder gives rise to a large north American pedigree of autosomal dominant spinocerebellar ataxia not linked to the SCA1 locus on chromosome 6

There have been three reports since 1969 of members of a "W" family with autosomal dominant spinocerebellar ataxia (SCA), and various conclusions have been drawn about the nosology. This pedigree has been traced back over 300 years through 11 generations. Although phenotypically similar to the disorder in the Schut-Swier, Nino, and other kindreds, the disorder in the W family is not linked to the SCA1 locus on chromosome 6, as reported in those hereditary ataxia pedigrees. The W family represents the largest such North American kindred yet reported. We examined 33 family members of a distantly related branch of the W family, determined the cumulative age of onset, and projected the number of present-day gene carriers. Two cases illustrate the spectrum of symptoms among family members. Age of onset and presenting symptom, however, seem to correlate both in our patients and in those previously reported. Between 2,000 and 5,000 individuals are estimated to be at risk of developing the disorder within this pedigree alone. The pedigree reported here will be valuable in the identification and cloning of a gene for hereditary ataxia, designated "SCA2" at the Eleventh International Workshop on Human Gene Mapping.

Conferencia Cotzias de 1991 de la Sociedad Española de Neurologá. The genetic etiology of Parkinson's disease. A review of the evidence

It has been amply documented that Lewy body PD can occur on genetic basis. The pedigrees described thus far have constantly shown an autosomal dominant pattern of inheritance. It remains to be determined what proportion of PD generally is familial? Accumulating clinical data indicate the proportion is quite large. The clinical data now available confirm the observations and conclusions of Mjones' pioneering study and are most consistent with the hypothesis that PD is an autosomal dominant disorder with reduced penetrance, markedly age-related expression and a broad range of clinical manifestations extending beyond our traditional clinical concepts of PD and including many atypical cases and formes frustes as Mjones had suggested. As a practical matter of research strategy the study of pedigrees offers the most promising approach available today to clarifying the etiology of PD for they make possible DNA linkage-mapping studies in search of gene loci.

Parkinson's disease in twins studied with 18F-dopa and positron emission tomography

We used 18F-dopa PET to examine concordance for dysfunction of the nigrostriatal dopaminergic system in 18 co-twins of patients with Parkinson's disease (PD) and scanned one clinically concordant monozygotic (MZ) twin pair, 17 asymptomatic co-twins (10 MZ, 7 dizygotic [DZ]), and 13 twins with PD (8 MZ, 5 DZ). Mean 18F-dopa uptake of the twins with PD was significantly reduced in putamen to 38% and in caudate to 66% of normal. Mean putamen 18F-dopa uptake for the 17 asymptomatic co-twins was also significantly reduced (86% of normal), as was putamen tracer uptake for the 10 MZ (87% of normal) and seven DZ (83% of normal) asymptomatic co-twin subgroups. Four of 10 MZ and two of seven DZ asymptomatic co-twins had putamen 18F-dopa uptake reduced more than 2 SDs below the normal mean. Three of these four asymptomatic MZ co-twins had tremor on examination at the time of PET and one has now developed PD 2 years later. Our PET findings give concordances for nigral dysfunction of 45% in the MZ pairs and 29% in the DZ pairs at a 2-SD threshold, and 18% in MZ and 0% in DZ pairs at a 3-SD threshold of significance. These data suggest that the concordance for nigral pathology in PD twins may be higher than previously realized and that the presence of an isolated postural or rest tremor may be a phenotypic expression of PD.

Hereditary Lewy-body parkinsonism and evidence for a genetic etiology of Parkinson's disease

The first systematic genetic study of Parkinson's disease (PD) was carried out by Mjönes in 1949. His results indicated autosomal dominant transmission with 60% penetrance. These conclusions, however, were long discounted because oligosymptomatic and atypical relatives were counted as secondary cases without clear justification. Subsequent surveys of patient and twin studies failed to confirm evidence of familial concentration and the hypothesis of a genetic etiology was over-shadowed by interest in possible environmental neurotoxins. A growing accumulation of pedigrees of histologically confirmed Lewy-body PD over the past several years has refocused attention on genetic factors. Fluorodopa positron emission tomography (PET) studies in oligosymptomatic co-twins of probands and recent clinicopathologic studies of atypical cases have provided retrospective support for Mjönes' methodology. A survey of a personal series of PD patients showed that the majority of those for whom pedigree information was available were familial. This along with another recently reported series confirm Mjönes' data showing similar segregation ratios for siblings and parents, a low ratio of maternal:paternal transmission and a marked asymmetry in the distribution of ancestral secondary cases. These findings favor monogenic autosomal dominant inheritance and show reason to argue against a multifactorial etiology or heteroplasmy. The clinical evidence justifies searching for gene loci linked to PD. Available methods are briefly outlined. Preliminary investigations have examined possible allelic associations, e.g., with alleles of MAO-A and debrisoquine hydroxylase and linkage to the tyrosine hydroxylase gene on chromosome 11p15.5 has been excluded in one study of juvenile familial parkinsonism. Linkage mapping studies are presently underway.

Levodopa-nonresponsive Lewy body parkinsonism: clinicopathologic study of two cases

We report two patients with a primarily akinetic form of parkinsonism who were nonresponsive to treatment with levodopa. At autopsy, both patients had many Lewy bodies in brainstem and diencephalic nuclei, with sparse Lewy bodies in association cortices and more numerous Lewy bodies in the limbic cortices, consistent with the transitional form of Lewy body disease. These cases emphasize that (1) Lewy body Parkinson's disease cannot be excluded on the basis of atypical presentation or levodopa nonresponsiveness, and (2) the clinicopathologic spectrum of Lewy body disease is varied.

A brief history of parkinsonism

The growth of our knowledge of Parkinson's disease over the past 175 years represents an enormous and at times stormy intellectual voyage. It required the contributions of many scientists and clinicians in many disciplines, and its progress inevitably reflected the general progress of biomedical science over the past 2 centuries. The advances in the past half century clearly depended on the great advances achieved in that time in histochemistry, neurochemistry, and neuropharmacology as well as in clinical neurology and neuropathology. Advances in the future will similarly depend on progress in modern neuroscience.

A large kindred with autosomal dominant Parkinson's disease

We report two large kindreds with Parkinson's disease (PD) apparently inherited in autosomal dominant fashion. Forty-one persons in four generations have been affected; we have examined 7 of them. The two kindreds originated in a single small town in southern Italy and therefore are probably related. The illness was typical for PD except for early onset at a mean age of 46.5 years and a rapid course that averaged 9.7 years from onset to death. Clinical appearance and response to levodopa were typical for PD. Only one instance of definite nonpenetrance is known. Autopsy of 2 patients in one kindred showed the pathological changes typical of PD with Lewy bodies. Disease duration among affected persons who spent most of their lives in Italy was longer than for their affected US relatives, suggesting that exogenous agents may influence the course of this genetic illness. We conclude that what is probably a single gene without an additional environmental insult can cause the pathological changes typical of PD. Our findings therefore enhance the likelihood of a significant genetic component in the cause of sporadic PD. By identifying a toxic gene product, future molecular genetic studies in our kindred(s) may provide insight into the pathogenesis of sporadic PD.

Clinically atypical expression of pathologically typical Lewy-body parkinsonism

Six patients autopsied by the neuropathology service at UMDNJ-Robert Wood Johnson Medical School between 1985 and 1988 had pathologically typical Lewy-body Parkinson's disease (PD). Review of their clinical records revealed that none had clinically typical PD. Atypical clinical features included juvenile onset, retrocollis, strong family history, and absence of tremor, flexed posture, or levodopa response. One patient had dementia without parkinsonism. We conclude that the clinical spectrum of Lewy-body PD is wider than is generally assumed and that the diagnosis of pathologically typical Parkinson's disease cannot be excluded on clinical grounds alone.

Steady plasma levodopa concentrations required for good clinical response to CR-4 in patients with 'on-off'

Ten patients with Parkinson's disease and severe motor fluctuations were given Sinemet (25/100) for 4 weeks followed by 4 weeks of Sinemet (CR-4). After each drug preparation was optimized, patients were rated by neurological examination and plasma levodopa (LD) measured at hourly intervals (9 a.m.-4 p.m.). For the group as a whole, variations throughout the day of plasma LD and clinical state were no different on the 2 formulations. Three patients whose fluctuations responded well to CR-4 had either much less variable plasma LD levels on CR-4 or were able to maintain plasma LD above a minimum threshold. In severe fluctuators, a major benefit from CR-4 can be expected only in those patients who can maintain steady plasma LD levels above the threshold for achieving the 'on' state.

Magnetic stimulation in the diagnosis of lumbosacral radiculopathy

Five patients presenting with sensory-motor disturbances consistent with a clinical diagnosis of L5 or S1 radiculopathy were studied. All had conventional nerve conduction tests and electromyography. The lumbosacral roots were stimulated in the lumbosacral region by using the Cadwell MES-10 Magneto-electric stimulator. The compound muscle action potentials were recorded bilaterally by surface electrodes applied to the soleus and tibialis anterior muscles. The latencies to the affected muscles were significantly prolonged. The appropriate root dysfunction was confirmed at operation or by the imaging techniques. It was concluded that surface stimulation of the lumbosacral roots by a magnetic coil is a potentially useful technique for the non-invasive evaluation of the function of the lumbosacral roots.

Seizures in progressive supranuclear palsy

Among 62 patients with progressive supranuclear palsy (PSP) seen over a 9-year period, we encountered seven who had seizure phenomena. We suggest that PSP patients have seizures more frequently than has been appreciated.

Paraneoplastic degeneration of the substantia nigra with dystonia and parkinsonism

A 42-year-old woman suffered unexplained weight loss followed by action tremor and difficulty initiating gait. Three months after onset of symptoms, infiltrating ductal carcinoma of the breast, metastatic to liver and lymph nodes, was diagnosed and treated briefly with cyclophosphamide, methotrexate, and 5-flourouracil (5FU). Severe symmetric action and postural tremor with a myoclonic component developed, with minimal rest tremor, severe dysarthria and dysphagia, small-stepped and slightly ataxic gait progressing to a bedbound state, and severe widespread dystonic posturing. The latter began as a typical parkinsonian posture of trunk and upper extremities and progressed to a fixed and painful flexion of the elbows and wrists and extension of fingers and neck. Sinemet, anticholinergics, baclofen, diazepam, and plasmapheresis gave no benefit. The patient died of complications of immobility 5 months after neurologic symptom onset. Autopsy revealed many pigment-laden macrophages in substantia nigra and moderate loss of pigmented neurons. Inflammation, Lewy bodies, and tumor were absent. Cerebellar Purkinje cells were moderately depleted. Mild neuronal loss and gliosis were present in globus pallidus and cerebellar cortex. Stains for anti-human IgG, IgM, kappa, and lambda were negative. This, to our knowledge, is the first report of paraneoplastic degeneration of substantia nigra or paraneoplastic parkinsonism.

Low leukocyte glutamate dehydrogenase activity does not correlate with a particular type of multiple system atrophy

Leucocyte glutamate dehydrogenase (GDH) activity was measured in 26 normal control subjects, 20 patients with multiple system atrophy presenting features of either olivopontocerebellar atrophy or striatonigral degeneration and in a heterogenous group of 15 patients with spinocerebellar degenerations. A broad range of GDH activity was found in all three groups. Low activity failed to correlate with a specific clinical entity. Patients followed to post-mortem examination to date have demonstrated histological features of at least three distinct morbid entities. It is concluded, contrary to earlier reports including the authors', that low leukocyte GDH activity does not identify a particular type of multiple system atrophy.

Supranuclear disturbances of ocular motility in Lytico-Bodig

We found abnormal supranuclear ocular or lid motility in all of 37 patients with Lytico-Bodig (amyotrophic lateral sclerosis/parkinsonism-dementia complex). Twenty-one patients had pursuit paresis, 18 abnormal vestibulo-ocular reflex (VOR) cancellation, 15 abnormal convergence, 13 abnormal optokinetic nystagmus (OKN), 12 conjugate gaze limitation, nine nystagmus, nine saccadic paresis, and six abnormal fixation. Lid abnormalities included glabellar hyperreflexia in 21, involuntary levator inhibition in three, and blepharospasm in two. Earlier reports have indicated infrequent ocular disturbances in Lytico-Bodig, but we now find supranuclear eye and lid deficits are universal and sometimes very prominent.

Risk factors for progressive supranuclear palsy

To explore possible risk factors for progressive supranuclear palsy (PSP), we conducted a case-control study of 50 cases in New Jersey. Two neurologists confirmed the diagnosis in the 41 living patients. Two hospital controls were matched by age, sex, race, date of death, and relationship of next-to-kin to each case. A structured interview was administered in person to the next-of-kin of cases and controls. Genetic, viral, toxic, medical, surgical, and personality factors were investigated. Cases lived in areas with low population as adults significantly more frequently than controls. The study identified no other factors associated with PSP including a history of stroke, hypertension, or smoking.

Long-term duodenal infusion of levodopa for motor fluctuations in parkinsonism

We report the long-term clinical responses of 2 parkinsonian patients with severe "on-off" phenomena who have been receiving continuous duodenal levodopa (LD) infusions. The rate of LD infusion needed to keep the patients just "on" declined gradually during the initial 60 days of infusion and then remained constant. Total LD intake declined rapidly during the first several days and gradually for another 60 days, after which it remained stable. Motor fluctuations virtually disappeared in both patients during the time of the day when the pump was in use. This was accompanied by a decline in the plasma LD concentration needed to just maintain the "on" stage in one patient.

Prevalence and natural history of progressive supranuclear palsy

We surveyed neurologists and chronic care facilities in and near two New Jersey counties with a combined population of 799,022, regarding cases of progressive supranuclear palsy. All suspected cases were examined personally, using rigid criteria. The prevalence ratio was 1.39/100,000. A total of 50 New Jersey cases yielded median intervals to onset of requiring gait assistance, 3.1 years; visual symptoms, 3.9 years; dysarthria, 3.4 years; dysphagia, 4.4 years; requiring wheelchair, 8.2 years; and death, 9.7 years.

Isolated jejunal pouches for levodopa delivery in parkinsonian patients with "on-off". Successful experimental model in dogs

In eight dogs, a 20 cm section of isolated jejunum with intact blood supply was externalized to the abdominal wall and used as a device for levodopa (LD) administration. Overall, Sinemet tablets and LD suspension produced similar plasma levodopa concentrations with oral and pouch administration. The most ideal plasma concentration curves were obtained for CR-3, a sustained release Sinemet preparation, given through the jejunal pouches. Plasma LD concentrations rose within the first hour after administration of CR-3 and remained constant for the next 3 h, before falling slowly. Isolated jejunal pouches may therefore be an effective, simple means of maintaining constant plasma LD concentrations in parkinsonian patients with motor fluctuations and may diminish the deleterious effects of erratic gastric emptying and competition with food-derived amino acids at the gut/blood transport system.

Role for monoamine oxidase-A (MAO-A) in the bioactivation and nigrostriatal dopaminergic neurotoxicity of the MPTP analog, 2'Me-MPTP

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration leads to the selective destruction of the dopaminergic neurons of the nigrostriatal pathway in experimental animals including monkeys and mice. The neurotoxicity of MPTP is dependent upon its monoamine oxidase-B (MAO-B)-catalyzed conversion to the 1-methyl-4-phenylpyridinium species (MPP+). A methylated analog of MPTP. A methylated analog of MPTP, namely 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'Me-MPTP), is a more potent dopaminergic neurotoxin than MPTP in mice. Although the selective inhibition of MAO-B is sufficient to protect mice against MPTP-induced neurotoxicity, it is reported here that complete inhibition of MAO-B failed to prevent 2'Me-MPTP-induced dopaminergic neurotoxicity. However, the neurotoxicity of 2'Me-MPTP was completely prevented and 2'Me-MPP+ formation was markedly attenuated in mice in which both MAO-A and MAO-B were almost totally inhibited. This information about the role of MAO-A in the bioactivation of 2'Me-MPTP may be of relevance to those who speculate that the MAO-B catalyzed bioactivation of MPTP or a similar compound may be the cause of idiopathic Parkinson's disease.

Continuous duodenal infusions of levodopa: plasma concentrations and motor fluctuations in Parkinson's disease

Four parkinsonian patients received continuous duodenal infusions of levodopa (LD) for severe "on-off" phenomena associated with Sinemet (carbidopa/levodopa) therapy. All patients had marked decreases in motor fluctuations on the infusions compared with tablets. Two factors that appear related to this improvement are the ability of duodenal infusions to produce steadier plasma LD concentrations and/or to maintain LD concentrations above a minimum threshold needed to achieve the "on" state.

Deprenyl in the treatment of symptom fluctuations in advanced Parkinson's disease

Deprenyl, a selective inhibitor of monoamine oxidase, type B, which is free of the "tyramine effect," may ameliorate symptom fluctuations in advanced Parkinson's disease (PD). We randomized 96 patients with marked symptom fluctuations at three centers to receive either deprenyl 5 mg b.i.d. or placebo in parallel fashion in addition to a previously optimized levodopa/carbidopa (Sinemet) regimen. Disability was recorded hourly at home by patients 3 days weekly during the 2-week baseline and the 6-week treatment period. Disability during the "on" state was assessed each week by examination. Mean hourly self-assessment of gait improved in 28 of 50 patients (56%) receiving deprenyl (mean degree of improvement 0.25 points on a 0-2 scale) and in 14 of 46 (30.4%) taking placebo (mean 0.15). Mean hourly overall symptom control improved in 29 (58%) taking deprenyl (mean 0.34) and in 12 (26.1%) taking placebo (mean 0.15) (p less than 0.01 for each parameter). No significant improvement occurred in the objective quality of the "on" state with deprenyl. Mean daily Sinemet dosage decreases were 17% in the deprenyl group and 7% in the placebo group. Adverse effects included nausea, light-headedness, dyskinesias, and hallucinations, all of which abated after the Sinemet dose was reduced. We conclude that deprenyl is of moderate benefit in a majority of patients with symptom fluctuations complicating PD and is generally well tolerated.

Progressive supranuclear palsy

Progressive supranuclear palsy (PSP) was first recognized as a distinct morbid entity by Richardson, Steele and Olszewski a quarter century ago. Subsequent experience has confirmed and extended their original observations. PSP has become familiar as a chronic progressive disorder with extrapyramidal rigidity, bradykinesia, gait impairment, bulbar palsy, dementia and a characteristic supranuclear ophthalmoplegia. It is an important cause of parkinsonism. Its etiology remains obscure. Familial concentrations have not been observed. Some cases exhibit no oculomotor dysfunction. Dementia is usually mild. Recent neuropsychological studies have defined features consistent with frontal lobe cortical dysfunction. Seizures and paroxysmal EEG activity may occur. CT and MRI scans show midbrain atrophy early and later atrophy of the pontine and midbrain tegmentum and the frontal and temporal lobes. PET scans have shown frontal hypometabolism and loss of striatal D-2 dopamine receptors. Postmortem studies have documented involvement of both dopaminergic and cholinergic systems. Treatment remains palliative and unsatisfactory.

A physiologic and pharmacologic study in anticholinergic-responsive essential myoclonus

We report the physiologic and pharmacologic analysis in two women, aged 18 and 17 years, with essential myoclonus. Both responded to benztropine mesylate and had been functioning normally. The physiologic analysis suggested ballistic movement overflow and audiogenic stimulus-sensitive myoclonus. The pharmacologic study showed a direct and mutual antagonism of physostigmine and anticholinergic agent on myoclonus, implying cholinergic hyperactivity in the pathophysiology of myoclonus.

Computed tomographic findings in progressive supranuclear palsy: correlation with clinical grade

We report clinical and computed tomography (CT) findings in 17 patients with progressive supranuclear palsy (PSP). Patients were divided into four clinical groups according to the severity of the disease and functional disability. In Grade 1, patients demonstrated minor disability and decreased anteroposterior (AP) diameter of the midbrain tegmentum was present. As the disease progressed clinically to Grade 2, more severe atrophy of the pons and midbrain and dilatation of the quadrigeminal plate cistern were noted. The most severe stages of clinical disability (Grades 3 and 4) were characterized radiologically by dilatation of the aqueduct, progressive dilatation of the third and fourth ventricles and atrophy of the temporal lobes. Cortical atrophy was variable and not a prominent radiological feature. Midbrain and pontine AP diameters were significantly smaller in PSP patients than normal patients. Serial studies showed progressive involution of the pons and midbrain and enlargement of the third ventricle. While the most obvious CT changes in PSP occur late in the disease, CT may in fact suggest the correct diagnosis long before the classic clinical picture is evident.

Hereditary dystonia-parkinsonism syndrome of juvenile onset

We studied a family with an extrapyramidal disorder characterized by childhood onset of lower-limb and axial dystonia, followed by parkinsonism. Dramatic response to levodopa therapy and minimal progression in adult life was seen. The family included five generations of affected members of both sexes in an autosomal dominant pattern.