Postencephalitic Patients Research Articles

What Is the Most Important and Impactful Paper Related to Movement Disorder Therapy Published in the 20th Century?

What Is the Most Important and Impactful Paper Related to Movement Disorder Therapy Published in the 20th Century?

Visuo-spatial memory deficits following medial temporal lobe damage: A comparison of three patient groups

The contributions of the hippocampal formation and adjacent regions of the medial temporal lobe (MTL) to memory are still a matter of debate. It is currently unclear, to what extent discrepancies between previous human lesion studies may have been caused by the choice of distinct patient models of MTL dysfunction, as disorders affecting this region differ in selectivity, laterality and mechanisms of post-lesional compensation. Here, we investigated the performance of three distinct patient groups with lesions to the MTL with a battery of visuo-spatial short-term memory tasks. Thirty-one subjects with either unilateral damage to the MTL (postsurgical lesions following resection of a benign brain tumor, 6 right-sided lesions, 5 left) or bilateral damage (10 post-encephalitic lesions, 10 post-anoxic lesions) performed a series of tasks requiring short-term memory of colors, locations or color–location associations. We have shown previously that performance in the association task critically depends on hippocampal integrity. Patients with postsurgical damage of the MTL showed deficient performance in the association task, but performed normally in color and location tasks. Patients with left-sided lesions were almost as impaired as patients with right-sided lesions. Patients with bilateral post-encephalitic lesions showed comparable damage to MTL sub-regions and performed similarly to patients with postsurgical lesions in the association task. However, post-encephalitic patients showed additional impairments in the non-associative color and location tasks. A strikingly similar pattern of deficits was observed in post-anoxic patients. These results suggest a distinct cerebral organization of associative and non-associative short-term memory that was differentially affected in the three patient groups. Thus, while all patient groups may provide appropriate models of medial temporal lobe dysfunction in associative visuo-spatial short-term memory, additional deficits in non-associative memory tasks likely reflect damage of regions outside the MTL. Importantly, the choice of a patient model in human lesion studies of the MTL significantly influences overall performance patterns in visuo-spatial memory tasks.

Emotion recognition from stimuli in different sensory modalities in post-encephalitic patients

Emotion recognition from facial and non-facial stimuli was investigated in two post-encephalitic patients a few months after the onset of the disease. One patient who had a lesion relatively restricted to the amygdala and hippocampus experienced difficulty in recognizing fear from facial expressions. In contrast, the other patient who had a lesion that extended beyond the amygdala experienced difficulty in recognizing fear from non-facial (prosodic and written verbal) stimuli. We showed that impairment of emotion recognition was evident within a short duration after encephalitis and that recognizing emotion from different sensory modalities relies partly on integration of different neural systems.

Auditory auras in patients with postencephalitic epilepsy: Case series

Many previously healthy patients who present with new seizures or status epilepticus appear to have encephalitis for which no specific pathogen is identified. A significant portion of these patients develop epilepsy. We describe five patients with adult-onset, medically intractable, postencephalitic epilepsy characterized by auditory auras ranging from unformed buzzing to structured language. Auras of any type were common among patients with postencephalitic epilepsy in our referral database: 62% experienced at least one type of aura. The proportion of postencephalitic patients with auditory auras (38%), which may reflect lateral temporal cortical pathology, was higher than that of other adult epilepsy populations. Although no pathogen was identified in four of the five cases, we suggest that the pathophysiology of viral encephalitides may share common targets in the temporal lobes, especially the superior temporal gyrus and surrounding areas, which may account for possibly increased occurrence of auditory auras in this population.

Post-encephalitic parkinsonism: clinical features and experimental model

Post-encephalitic parkinsonism has been well documented by now. Recently, an Indian group reported some post-encephalitic parkinsonism patients that resembled Japanese encephalitis cases with bilateral substantia nigra lesions that were detected by MRI. Post-encephalitis parkinsonism has been described following Coxsackie B virus, influenza A, poliovirus and measles virus infections. The possible involvement of virus infection has also been supported by experimental animal models. We have demonstrated pathological and to a certain extent clinical features consistent with Parkinson's disease following infection of rats with Japanese encephalitis virus (JEV). We evaluated new treatments with Parkinson's disease using this model. It was reported that tremor primarily involving the fingers, tongue and eyelids, muscle rigidity and masked face as the clinical features by JEV. Recently brainstem lesions produced by West Nile virus, which is a flavivirus like JEV, were documented by MRI. In the future, post-encephalitic parkinsonism may be found elsewhere in the world. In adult Fischer rats sacrificed 12 weeks after infection with JEV at the age of 13 days, neuronal loss with gliosis was confined mainly to the zona compacta of the bilateral substantia nigra, without lesions in the cerebral cortex and cerebellum. Furthermore, the most severe lesions were in the central part of zona compacta; the lateral cell groups were less affected. Thus, the distribution of the pathologic lesions in infected rats resembled those found in Parkinson's disease. JEV-infected rats showed marked bradykinesia. Significant behavioral improvement was observed upon administration of L-DOPA and monoamine oxidase (MAO) inhibitor. The findings suggest that JEV infection of rats under the conditions described may serve as a model of virus induced Parkinson's disease.

Semantic knowledge in patient H.M. and other patients with bilateral medial and lateral temporal lobe lesions

We investigated the effects of damage to the medial temporal lobe (MTL) and anterolateral temporal cortex on semantic knowledge. We studied eight male controls, two patients with lesions limited to the hippocampal formation, three postencephalitic patients with extensive MTL lesions and variable damage to the lateral temporal cortex, and patient H.M. (whose lesion is limited mostly to the MTL, but who also has minimal damage to the anterolateral cortex). On 13 tests of semantic memory, patients with lesions limited to the hippocampal formation performed similarly to controls. Postencephalitic patients were mildly to moderately impaired on most tests. Patient H.M.'s performance was impaired on only a few tests and was less severely impaired overall than the three postencephalitic patients. A ranking of test scores showed a direct relationship between impairment and the extent of damage to lateral temporal cortex. These findings, and related findings from other studies, point to the importance of anterolateral temporal cortex for semantic knowledge. Patient H.M. performed uniquely in certain respects. For example, when providing definitions of objects, he made many grammatical errors. In contrast, the other patients with large MTL lesions made no more errors than those made by controls. Considering that H.M.'s lesion, both medially and laterally, is less extensive than the lesions in these other patients, it appears unlikely that his shortcomings in language production are related to his temporal lobe lesion.

Encephalitis lethargica: lessons for contemporary neuropsychiatry.

Encephalitis lethargica (von Economo's encephalitis), pandemic from 1917 to 1926, opened a window on the study of behavioral consequences of infection-induced subcortical disorder. Widely varying acute manifestations included extrapyramidal disorders, myoclonus, eye movement disorders, paralyses, delirium, mood changes, inverted diurnal rhythms, and catatonia. Major pathological changes involved the substantia nigra, globus pallidus, and hypothalamus. A symptom-free recovery period was often followed by postencephalitic disturbances, typically parkinsonism in adults and conduct disorder in children. Occurrence of depression, mania, obsessive-compulsive disorder, and hyperactivity in post-encephalitic patients anticipated current concepts of the role of the basal ganglia in mood, personality, and obsessional syndromes. Observations of deferred onset and "tardy" hyperkinesias presaged current theories of the pathophysiology of tardive dyskinesia.

Old photographs: postencephalitic Parkinsonism in two small boys.

My interest in posture and its central nervous control dates from my early days in neurology. That was also the time of the epidemic of encephalitis lethargica. A few years ago I came upon some old photographs dating from this period and among them were several of two small boys suffering from the after-effects of encephalitis with severe disorders of postural control. Each of these boys, if placed on an ordinary chair would let his body fall forward and would "roll" off the chair and lie motionless on the floor. In more recent years it has been shown experimentally that similar symptoms in monkeys are associated with bilateral lesions of the globus pallidus; in post-encephalitic patients of long standing degenerative changes are present in the pallida, but it now seems likely that deficiency of the neuro-transmitter, dopamine, may bear as much responsibility for their symptoms as anatomical lesions. Neurology was slow to appreciate the contribution of the basal ganglia to postural activity.

Influenza virus antibodies in Parkinsonism. Comparison of postencephalic and idiopathic Parkinson patients and matched controls.

Hemagglutination inhibiting antibodies to four influenza virus strains: A/Swine/1976/30 (HswN1), A/PR/8/34 (HON1), A/England/1/51 (H1N), and A/Singapore/1/57 (H2N2), were studied in blood serum specimens from 20 patients with postencephalitic and 55 patients with idiopathic Parkinson disease and their age- and sex-matched controls. No significant differences were observed in the distribution or the mean titers of antibodies to any of the four strains tested, when the postencephalitic patients and their controls were compared. The postencephalitic group was also similar to the idiopathic group with regard to the influenza antibodies.

Epidemiology of Parkinson's disease in Finland.

This investigation was conducted to clarify the epidemiology of Parkinson's disease in Finland. A community survey was made in a selected area in southwest Finland in addition to an analysis of Finnish mortality statistics for Parkinson's disease. The annual mortality rate from Parkinson's disease was found to average 2 per 100,000 population. Almost 70 per cent of the deaths occurred between 65-79 years of age. The total and age-specific mortality rates for males were greater than those for females whereas the proportionate mortality rates were almost identical. This was considered to indicate that suggestions of greater male prevalence, based on mortality statistics, do not appear justified. On prevalence day, Dec. 31st, 1971, 484 patients with Parkinson's disease (of which 444 were personally examined) lived in the area of investigation (population 402,988), the prevalence rate being 120.1 per 100,000 population. The highest annual incidence rate was 16.6 per 100,000 population. The age-specific prevalence rates showed a rapid increase after the 50th year of age. The greatest prevalence was shown by the age group 70-79 years of age in which almost 0.8 per cent of the population are affected. Age-specific incidence rates also displayed an increase after the 50th year of age. The greatest incidence was observed in the age group 70-79 years of age in which almost 1 per 1,000 of the population are annually affected by the disease. A difference between the sexes was demonstrable in the prevalence and incidence rates showing greater values for females, but in the age-specific frequencies the differences were reduced. This probably reflects the difference between the age structures of the male and female populations, suggesting that both sexes have a similar risk of being affected by the disease. The permanent age structure shown by idiopathic patients in comparison with previous investigations as well as the increased mean age and proportionate decrease of postencephalitic patients was found to be in disagreement with the cohort theory according to which all parkinsonian patients are previously victims of encephalitis lethargica.

Some comments on Warrington and Baddeley's report of normal short-term memory in amnesic patients

While Warrington and Baddeley have reported that their amnesic patients have normal short-term memory (STM), Cermak and Butters have found consistent and severe STM impairments in their Korsakoff population. A review of Warrington's test procedures indicates that her patients may have been able to rehearse during the delay periods. Also, since different groups of amnesics (postencephalitic patients, alcoholic Korsakoffs) appear to have qualitatively and quantitatively distinct memory deficits, Warrington's combining of patients with diverse etiology into a single “amnestic” group is questioned. Evidence is provided that the difference in the two sets of data cannot be related to dementia.

Psychological evaluation of intelligence and personality in parkinsonism before and after stereotaxic surgery.

In a series of Parkinsonian patients subjected to stereotaxic surgery, the mental function was studied by means of psychological tests. The purpose was to throw light on the possible postoperative mental changes which together with fear of speech disturbances seem to be the most important contra-indications for neurosurgical treatment. In the study, 41 patients operated on for Parkinsonism were subjected to preoperative and postoperative psychological tests (average observation period 8.7 months). Bilateral operation was performed in seven cases. The mean age of the patients was 60 years. The tests used were the Wechsler Adult Intelligence Scale and the Rorschach test. In the series as a whole, no significant quantitative changes in the postoperative mental function were revealed by the two tests. The Rorschach test revealed as an interesting finding that all the Parkinsonian patients preoperatively showed some mental reduction and that there was no significant difference between the patients with paralysis agitans and those with postencephalitic Parkinsonism. Slight postoperative changes, viz. a diminished and more rigid activity, were demonstrated in three clinical groups: patients subjected to operation on the globus pallidus, patients with postencephalitic Parkinsonism, and those with unilateral affection in the dominant hemisphere. The results of the study thus seem to indicate that a certain reluctance should be exercised in offering stereotaxic surgery to postencephalitic patients and to those with unilateral affection in the dominant hemisphere. Apart from this, it seems justified to conclude that in patients who otherwise meet the indications, the risk of postoperative mental impairment does not constitute a contra-indication for this type of surgery.

Auditory behavior in parkinsonism.

Both conventional and special auditory tests were administered to 16 patients with Parkinson's disease and 16 age-matched controls. Results showed no appreciable difference between experimentals and controls on routine audiometric measures, such as the pure-tone audiogram and the conventional PB discrimination score. On more difficult auditory tasks, however, a deficit, closely related to the clinical types of the disease, was observed in parkinsonism. Idiopathic patients were unaffected, but arteriosclerotic and, to a lesser extent, post-encephalitic patients, did not perform as well as their age-matched controls. These results suggest involvement of the central auditory system in some parkinsonian patients.

PAROXYSMAL AUTONOMIC CRISES IN THE POSTENCEPHALITIC STATE

PAROXYSMAL autonomic crises or attacks as a manifestation in the postencephalitic state have not been described in standard neurologic textbooks. Reports of this syndrome in the literature have been exceedingly rare in spite of the voluminous material on the sequelae of epidemic encephalitis. Consequently, when one is confronted with the striking group of symptoms that constitute the autonomic crisis in postencephalitic patients, many apparently new and troublesome questions present themselves. For this reason the following unusual case is reported. REPORT OF CASE The patient, a 41 year old Negro, had a high school education and was rather intelligent. The family history was noncontributory. In 1918, at the age of 15, he had a severe bout of influenza, and in the following year he exhibited behavior difficulties, necessitating his remaining away from school for about a year. In 1923, at the age of 20, he had an attack or a relapse