Five patients with progressive supranuclear palsy are described, in whom the ophthalmoplegia developed late in the course of the disease. In two, an internuclear component was identified in the ophthalmoplegia, and one patient had an alternating nystagmus of a type not previously described in this condition.
The late appearance of the ophthalmoplegia, with a corresponding delay in establishing the diagnosis, is compared to the similar experience of Pfaffenbach et al (1972) in six patients.
Other clinical features, previously seldom described, have been encountered. Dysphasia was seen in two cases, both of whom had evidence of cortical atrophy on neuro-radiological investigation. The evidence that cortical changes, in particular the presence of neurofibrillary tangles, may be a specific morphological characteristic of the disease rather than a chance association is discussed. Disorders of respiratory rhythm in four patients were similar to those described by Mastaglia et al. (1973), and indistinguishable from those occurring after encephalitis lethargica.
A review of cases resembling progressive supranuclear palsy in the early part of the century fails to show any with post-encephalitic features, nor does a search of reviews of eye movement disorders in encephalitis lethargica and post-encephalitic Parkinsonism provide comparable cases. None of the forty patients with post encephalitic Parkinsonism examined at the Highlands Hospital had a clinical picture resembling progressive supranuclear palsy.
It is suggested that neither on clinical nor pathological grounds is it justifiable to equate this disorder with known postencephalitic syndromes.