Sesquicentenary of the knee jerk reflex: The contributions of Hughlings Jackson, Horsley, and Sherrington.

The knee jerk reflex, emblematic of neurology and central to clinical practice, marks its 150th anniversary in 2025. First introduced to the neurological literature in 1875 through independent reports by Wilhelm Erb and Carl Westphal, this reflex has since evolved from a clinical curiosity to a diagnostic staple, although its initial interpretation was debated. Erb viewed it as a spinal reflex, whereas Westphal questioned its reflex nature, considering mechanical muscle excitation.

David Ferrier's second monkey ('monkey F'): The inaugural experimental studies of the auditory cortex.

The story of David Ferrier's demonstration at the International Medical Congress in London in August 1881 of a monkey experimentally rendered hemiplegic by a focal surgical brain lesion-prompting Charcot's observation, "C'est un malade!"-is well known as a seminal event in the history of the localization of functions in the cerebral cortex. Less well known is the fact that, on the same occasion, Ferrier demonstrated a second monkey, known as monkey F, apparently deaf as a consequence of bilateral temporo-sphenoidal brain lesions. The purpose of this article is, first, to give a chronological account of this demonstration and subsequent related events, including Ferrier's trial under the Vivisection Act, the publication of the pathological findings in the animal's brain, the dispute about the localization of the "auditory centre" with Edward Schäfer, and the first glimmerings of human homologues of cortical deafness.

Cognitive screening instruments: time for retirement.

Cognitive screening instruments are used daily in clinics devoted to the assessment of cognitive disorders and also in general neurology clinics where patients with complaints of memory disorder may be encountered. However, these instruments have significant theoretical and practical shortcomings that are generally overlooked or ignored. In pursuit of biological rather than nosological diagnosis, and in light of these shortcomings, I recommend that cognitive screening instruments should now be abandoned.

Hughlings Jackson's Second Thoughts on Mental States in Epilepsy.

John Hughlings Jackson (1835-1911) was the pre-eminent British neurologist of the last 3 decades of the 19th century whose most seminal contributions related to the understanding of epileptic seizures. Jackson instructed that his personal papers should be destroyed at his death, and consequently, few examples of his handwriting now survive. We discovered a series of marginalia in Jackson's handwriting annotating one of his papers, "On temporary mental disorders after epileptic paroxysms," first published in 1875 in the .

Pioneers of cortical cytoarchitectonics: the forgotten contribution of Herbert Major.

The study of cortical cytoarchitectonics and the histology of the human cerebral cortex was pursued by many investigators in the second half of the nineteenth century, such as Jacob Lockhart Clarke, Theodor Meynert, and Vladimir Betz. Another of these pioneers, whose name has largely been lost to posterity, is considered here: Herbert Coddington Major (1850-1921). Working at the West Riding Asylum in Wakefield, United Kingdom, Major's thesis of 1875 described and illustrated six-layered cortical structure in both non-human primates and man, as well as "giant nerve cells" which corresponded to those cells previously described, but not illustrated, by Betz.

William Aldren Turner (1864-1945).

William Aldren Turner (Fig. 1) was born in Edinburgh, the son of William Turner (1832-1916) who at the time was senior demonstrator in Anatomy at the University, later Professor (1867). His paternal grandmother was Margaret Aldren.

Herbert Major on the insula: An early depiction of von Economo neurones?

Herbert Major (1850-1921) undertook histopathological studies of human and non-human primate brains at the West Riding Lunatic Asylum in Wakefield, England, during the 1870s. Two of his papers specifically investigated the structure of the island of Reil, or insula, "with the view of ascertaining its exact structure". In addition to describing and illustrating its lamination as six-layered, Major also identified "spindle-shaped" cells in the lower layers of human brains, but not in non-human primates.

The trial of David Ferrier, November 1881: Context, proceedings, and aftermath.

In November 1881, the eminent physiologist and physician David Ferrier was prosecuted under the Cruelty to Animals Act 1876. The prosecution was raised by the Victoria Street Society, formerly known as the Society for the Protection of Animals Liable to Vivisection, through its activist founder, Frances Power Cobbe. This article examines the legislative context prior to Ferrier's trial, the personalities involved in the prosecution, and its course and outcome.

On the Dependence of the Critical Success Index (CSI) on Prevalence.

The critical success index (CSI) is an established metric used in meteorology to verify the accuracy of weather forecasts. It is defined as the ratio of hits to the sum of hits, false alarms, and misses. Translationally, CSI has gained popularity as a unitary outcome measure in various clinical situations where large numbers of true negatives may influence the interpretation of other, more traditional, outcome measures, such as specificity (Spec) and negative predictive value (NPV), or when unified interpretation of positive predictive value (PPV) and sensitivity (Sens) is needed.

Free-Cog revisited: the diagnostic contribution of cognitive and executive function.

To examine Free-Cog, a recently described, hybrid screening instrument, as separate tests of cognitive (Free-Cog-Cog) and executive function (Free-Cog-Exec) to see if this improved screening accuracy for cognitive impairment compared with standard Free-Cog. Free-Cog-Cog and Free-Cog-Exec were combined using Boolean logical 'AND' and 'OR' operators (serial and parallel combination), and also used to construct a stepwise decision tree. Serial combination improved specificity and positive predictive value whereas parallel combination improved sensitivity, typical findings with these operators.

Critical success index or F measure to validate the accuracy of administrative healthcare data identifying epilepsy in deceased adults in Scotland.

Background: Methods to undertake diagnostic accuracy studies of administrative epilepsy data are challenged by lack of a way to reliably rank case-ascertainment algorithms in order of their accuracy. This is because it is difficult to know how to prioritise positive predictive value (PPV) and sensitivity (Sens). Large numbers of true negative (TN) instances frequently found in epilepsy studies make it difficult to discriminate algorithm accuracy on the basis of negative predictive value (NPV) and specificity (Spec) as these become inflated (usually >90%).

Herbert Coddington Major (1850-1921).

Herbert Coddington Major (Fig. 1) was a late nineteenth century pioneer in neuropathology and comparative neurology. No previous biographical article has been identified, suggesting he is now almost totally, yet unjustifiably, forgotten.

The West Riding Lunatic Asylum Medical Reports: the precursor of Brain?

First published in 1878, Brain: A Journal of Neurology is generally considered to be the world's first neuroscientific journal. However, this claim might be challenged since the West Riding Lunatic Asylum Medical Reports, another journal with significant neuroscientific content, was published between 1871 and 1876. Some have suggested this journal was the precursor of Brain, since it shared similar subject matter as well as editorial and authorial contributors, including James Crichton-Browne, David Ferrier and John Hughlings Jackson.

Using Critical Success Index or Gilbert Skill Score as composite measures of positive predictive value and sensitivity in diagnostic accuracy studies: Weather forecasting informing epilepsy research.

The Critical Success Index (CSI) and Gilbert Skill score (GS) are verification measures that are commonly used to check the accuracy of weather forecasting. In this article, we propose that they can also be used to simplify the joint interpretation of positive predictive value (PPV) and sensitivity estimates across diagnostic accuracy studies of epilepsy data. This is because CSI and GS each provide a single measure that takes the weather forecasting equivalent of PPV and sensitivity into account.