Tauopathies with parkinsonism: clinical spectrum, neuropathologic basis, biological markers, and treatment options

Tauopathies with parkinsonism represent a spectrum of disease entities unified by the pathologic accumulation of hyperphosphorylated tau protein fragments within the central nervous system. These pathologic characteristics suggest shared pathogenetic pathways and possible molecular targets for disease-modifying therapeutic interventions. Natural history studies, for instance, in progressive supranuclear palsy, frontotemporal dementia with parkinsonism linked to chromosome 17, corticobasal degeneration, and Niemann-Pick disease type C as well as in amyotrophic lateral sclerosis/Parkinson-dementia complex permit clinical characterization of the disease phenotypes and are crucial to the development and validation of biological markers for differential diagnostics and disease monitoring, for example, by use of neuroimaging or proteomic approaches. The wide pathologic and clinical spectrum of the tauopathies with parkinsonism is reviewed in this article, and perspectives on future advances in the understanding of the pathogenesis are given, together with potential therapeutic strategies.

The relationship between encephalitis lethargica and influenza: a critical analysis

Since encephalitis lethargica's (EL) prevalence in the 1920s, epidemiologic and clinical debate has persisted over whether EL was caused by, potentiated by, or merely coincident with the Spanish influenza pandemic. Epidemiologic analyses generally suggest that the disorders were coincidental. Beginning in the 1970s, modern experiments on archival brain samples mainly failed to confirm a direct relationship between influenza and EL. These experimental studies have technical limitations, e.g., the appropriateness of antibodies, polymerase chain reaction (PCR) primers and controls, and the extreme paucity and age of available material. These factors render the case against influenza less decisive than currently perceived. Nevertheless, there is little direct evidence supporting influenza in the etiology of EL. Almost 100 years after the EL epidemic, its etiology remains enigmatic, raising the possibility of a recurrence of EL in a future influenza pandemic.

Contemporary encephalitis lethargica presenting with agitated catatonia, stereotypy, and dystonia-parkinsonism

Encephalitis lethargica (EL) syndrome was classically described by Von Economo and has somnolent-ophthalmoplegic, hyperkinetic, and amyostatic-akinetic forms. We describe 2 recent cases of EL characterized by an acute encephalitis with mixed movement disorders (dystonia-Parkinsonism plus stereotypy) and psychiatric disorders (agitated catatonia, coprolalia, and echo phenomena). Both patients suffered concurrent hyperkinetic and Parkinsonian features resulting in therapeutic challenges. Bradykinetic features responded to dopamine replacement therapy and both patients also had adverse affects to dopamine antagonists (oculogyric crises plus neuroleptic malignant syndrome). Investigation was unremarkable other than the presence of CSF lymphocytosis and oligoclonal bands. Despite prolonged in-patient stays and intensive care management, both patients have made complete recoveries. We believe these cases support the hypothesis that this syndrome is an inflammatory encephalitis that specifically effects dopamine neurotransmission.

Steroid-responsive encephalitis lethargica syndrome with malignant catatonia

We report a 47-year-old man who is considered to have sporadic encephalitis lethargica (EL). He presented with hyperpyrexia, lethargy, akinetic mutism, and posture of decorticate rigidity following coma and respiratory failure. Intravenous methylprednisolone pulse therapy improved his condition rapidly and remarkably. Electroencephalography (EEG) showed severe diffuse slow waves of bilateral frontal dominancy, and paralleled the clinical course. Our patient fulfilled the diagnostic criteria for malignant catatonia, so we diagnosed secondary malignant catatonia due to EL syndrome. The effect of corticosteroid treatment remains controversial in encephalitis; however, some EL syndrome patients exhibit an excellent response to corticosteroid treatment. Therefore, EL syndrome may be secondary to autoimmunity against deep grey matter. It is important to distinguish secondary catatonia due to general medical conditions from psychiatric catatonia and to choose a treatment suitable for the medical condition.

Supranuclear gaze palsy and eyelid apraxia in postencephalitic parkinsonism

We describe six patients with clinicopathologically confirmed post-encephalitic parkinsonism (PEP) in whom oculomotor abnormalities developed several years after suffering the initial episode of encephalitis lethargica. Four of the cases had vertical supranuclear gaze palsy and two eyelid apraxia, features typically associated with progressive supranuclear palsy (PSP). Our findings indicate that the presence of gaze palsy alone may not be a reliable clinical discriminator between PEP and PSP. Involvement of the dorsal central gray nucleus, nucleus centralis pontis oralis, nucleus dorsal raphe interpositus, rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), nucleus interstitialis of Cajal, nucleus of the posterior commissure, pedunculopontine nuclei and frontal cortex was observed in several of our PEP cases and may contribute to the oculomotor abnormalities in this disorder. Whether the dorsal tegmental nucleus, caudal to the supratrochlear nucleus, severely affected in all our PEP cases, has a role in vertical gaze needs to be further studied.

Dementia in Parkinson's disease

The occurrence of dementia in patients with Parkinson's disease was studied in a Parkinsonian population consisting of all traceable patients residing in a defined area. The prevalence of dementia was found to be 29 per cent in 444 patients studied. The frequency of dementia increased with advancing age and the patients showing signs of clinical arteriosclerosis were more often demented than the patients without arteriosclerosis. There was, however, an evident association between the stage of the disease and the frequency of dementia. The most severely disabled patients displayed dementia more often than the mildly affected, both among the patients with and without arteriosclerosis. The demented patients showed significantly more severe rigidity and hypokinesia when compared with the non-demented. Increasing severity of rigidity and hypolinesia, in particular was found to have a positive correlation with the degree of dementia. The association between dementia and the degree of motor involvement is considered to suggest the role of subcortical structures in the patholophysiology of dementia in Parkinson's disease.

The homeless person and the psychiatric services: an Edinburgh survey

A representative sample (R.S.) of 79 subjects living in Edinburgh common lodging houses was compared with a clinical series (C.S.) of 44 patients from the same type of resisence. C.S. patients were more likely to be out of work, to be under 55 years of age, and to have been married as some time. They had spent much shorter times in lodging houses, in Edinburgh and at their current address. Alcoholism was rather more often diagnosed in the C.S., and personality disorder much more often. Schizophrenia tended to be found more in the R.S. The C.S. obtained higher Personal Illness and 'Character Disorder' scores. It is concluded that those subjects presenting to the psychiatric services are a highly selected group quite unrepresentative of homeless single persons in general.

Depression in patients with Parkinsonism

Forty-five patients with parkinsonism were carefully matched for age and sex with 45 chronically disabled control patients with a significantly more severe grade of physical handicap. Depression was measured by the Hamilton Rating Scale, and it was found that the parkinsonian group was very significantly more depressed than the control group (p less than 0-0001). Depression scores in both groups were unaffected by the patients's sex or by the severity of the disability. Analysis of the individual ratings of the Hamilton Scale showed that parkinsonian patients had significantly higher scores on items relating to suicide, work and interests, retardation, psychic anxiety, general somatic symptoms, and loss of insight. It was concluded that patients with parkinsonism suffer a degree of depression which cannot be solely a reaction to the stress of physical disability. This finding is discussed with reference to the monoamine hypothesis of depressive illness.