Editorial |
Editorial
Cambridge
In the ‘Tales that neurologists tell’, Michael Trimble and Edmund Rolls (page 688) review the professional lives and scientific opinions of six individuals, and one institution, active across the latter half of the 20th century. These accounts combine the syntheses of quick minds (and, in the case of Sir Roger Bannister, also a speedy pair of legs) watching and contemplating the nervous system in health and disease over their working lifetimes. For some, the perspective on looking back is a scientific analysis; for others it is the social climate in which these professional activities occurred; for each, there is the wish to set down a record of observation and advancement. Professor Rolls places the formulations of Jean-Pierre Changeux on The Physiology of Truth in the context of work on models of neural function that reflects his own ideas on computational neuroscience. Professor Trimble puts five individuals (Bryan Ashworth, Roger Bannister, Edmund Critchley, William Gooddy and Case Vanderwolf) in the psychiatrist's chair, and dissects motivations behind the setting down of a personal record ... but confesses to be sharpening his own pen. These neurologists join a long list of previous autobiographers, amongst whom, as Professor Trimble reminds us, is Wilder Penfield. He wrote No Man Alone (1971), an autobiography covering the period 1891–1934.
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Penfield's father came to the American West as a pioneer to hunt but settled as the first physician in Spokane, Washington. Wilder Penfield served as professor of Neurology and Neurosurgery, McGill University (1933–1954), and was founder and director of the Montreal Neurological Institute from its inception in 1934 until 1960. Through the detailed observation of individuals with epilepsy and the opportunity to study the functional consequences of stimulating the exposed cortex in awake subjects—in the interests of identifying those parts that might and might not be sacrificed surgically so as better to control the seizures—Wilder Penfield (1891–1976) brought functional localization into the modern era. In 1950, Penfield published his 1947 Lane Medical Lectures as The cerebral cortex of man: a clinical study of localisation of function with Theodore Rasmussen (1910–2002). Dr Rasmussen succeeded Penfield as director of the Montreal Neurological Institute in 1960, two years after his description of a condition in children characterized by progressive hemisphere disorder, severe seizures with hemiparesis, and brain inflammation (T. Rasmussen, J. Olszewski, D. Lloyd-Smith. Focal seizures due to chronic localized encephalitis. Neurology 1958: 8; 435–445). Evidently there is still much to debate on Rasmussen's encephalitis. Christian Bien and colleagues offer a European consensus statement with an algorithm for diagnosis and treatment (page 454). Their formulation has an immunological flavour. But (as one reviewer points out) Dr Penfield said to Dr Rasmussen: ‘I will buy you a new hat, if you ever show this mechanism is the underlying cause’.
Down the years, Brain has published definitive series of cases, expecting that general concepts will emerge through the analysis of large numbers. Guillaume Sébire and colleagues from Canada, Belgium, France and the UK describe the clinical and radiological features, and the predisposing events and prognostic indicators, in 42 children with cerebral venous sinus thrombosis (page 477). Many patients have background nutritional and haematological disorders and, in the remainder, most have had preceding infections. There is an equal proportion of ischaemic and haemorrhagic strokes. Mortality is appreciable and morbidity probable in survivors. The main determinants of improved prognosis are anticoagulation and sparing of the sagittal sinus. Marloes Hagemans and a group from Rotterdam describe 54 Dutch patients with Pompe's disease (page 671). Seemingly, clinicians have a low threshold for making this diagnosis. Most probands had a long period of emerging limb-girdle weakness, often dating from childhood, prior to diagnosis, and accurate diagnosis is usually delayed for several years after first seeking medical advice. With some variation, disabilities are eventually common, with loss of mobility and the requirement for assisted ventilation. Details of a new disorder are drawn together by Neil Scolding and colleagues from Bristol, Aberdeen, Cambridge, Newcastle, Plymouth and Southampton, in the UK, and from Iowa, USA (page 500). Nine new patients, together with cases from the prior literature, are used to define granulomatous amyloid ß peptide-related cerebral angiitis. It will take an astute clinician to separate these cases from those with regular primary angiitis of the central nervous system, and the distinctions are mainly histological. Aside from the potential therapeutic implications for this category of cerebral amyloid angiopathy, the series illuminates the general topic of inflammatory mechanisms in disorders characterized by deposition of amyloid in the central nervous system. But does it always make sense to suppress brain inflammation? Using the taiep rat myelin mutant, characterized by chronically demyelinated axons set in an astrocytic environment but without acute inflammation, Alastair Foote and William Blakemore (page 528) from the Department of Veterinary Medicine in Cambridge show that transplanted oliogodendrocyte precursors compete unsuccessfully with endogenous cells for access to lesions, whereas they enter areas denuded of host oligodendrocytes; but this repopulation only leads to remyelination in the presence of acute inflammation. Thus, for cells in the proximity of demyelinated axons, the major factor limiting remyelination may be the absence of a local inflammatory response. Corinne Bachelin and teams at the Pitié-Salpêtrière in Paris scale up the evidence that primate Schwann cells might provide a surrogate for oligodendrocytes in successfully remyelinating the demyelinated spinal cord (page 540). Monkey Schwann cells obtained from peripheral nerve biopsies in adults, manipulated with growth factors and labelled with a lentivirus vector green fluorescent protein in vitro, repaired structure and function in the demyelinated nude mouse spinal cord, especially in acute inflammatory lesions, where 55% of axons were sheathed by transplanted cells, and many others remyelinated with host oligodendrocytes.
But back to Wilder Penfield: Montreal has a long tradition of excellence in the clinical neuroscience of cerebral localization using direct electrical stimulation as part of the work-up for epilepsy surgery. Nathalie Gosselin and groups from the Departments of Psychology and Music at McGill, working with colleagues at the Pitié-Salpêtrière in Paris, maintain this tradition, tying together the roles of the amygdala in recognition of fear and of music by evaluating the appreciation of emotional content in instrumental music (page 628). By comparison with controls, patients who had undergone either right or left medial temporal resection for the relief of intractable epilepsy showed selective impairment of the ability to appreciate scary but not peaceful, happy or sad music. The tunes were composed for the purpose—not borrowed from the ‘Ride of the Valkyries’ or the canon of Mr Ozzy Osborne. ‘The happy excerpts were written in a major mode at an average tempo of 137 metronome marking with the melodic line lying in the medium–high pitch range, and the pedal was not used. The sad excerpts were written in a minor mode at an average slow tempo of 46 metronome marking with the pedal. The peaceful music was composed in a major mode, had an intermediate tempo (mean metronome marking 74), and was played with pedal and arpeggio accompaniment. The scary music was relatively fast (tempo varies from 96 to 172 metronome marking) and composed with minor chords on the third and sixth degree, hence implying the use of accidentals.’ Thus, the anteromedial temporal lobe is required for appreciating the fearful overtones of music. As we discuss in ‘From the Archives’, Wilder Penfield and Phanor Perot first drew together their thoughts on the functional anatomy of musical experiential epilepsy and experiential responses to brain stimulation in Brain.
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