Pascal’s disease

Bo Laestadius
Stockholm, Sweden (Winter 2016)

Retour sur les maladies et la mort de Pascal. B. Laestadius, Chroniques de port-royal, Paris 2015


The French mathematician, physicist and philosopher Blaise Pascal was born in 1623. At the age of twelve he had already studied Euclid´s geometry on his own and had written a paper about sound waves. A few years later he designed and built a calculator. In mathematics he has given his name to Pascal´s triangle and is regarded as one of the mathematicians behind probability calculus. In physics he studied hydrodynamics. Using mercury and a glass tube he showed that air can be weighed and that its weight varies with the height above the earth´s surface level. He proved that vacuum exists, something previously considered impossible. The “horror vacui” postulated by Aristotle was still accepted. The unit for pressure in the international SI-systemwas named Pascal in recognition of his contributions to physics.

In 1654, Pascal had a religious revelation and afterwards defended Christianity against atheism. He searched for a mathematical and scientific model to prove God´s existence and defended the mysteries of religion with wit and satire. He wrote under a pseudonym in “Les Provenciales.” These writings and his literary work “Les pensées” are considered to be among the best in the French language. “Le coeur a ses raisons, que la raison ne comprehend pas” is one of the aphorisms in “Les Pensees.”

In 1658, Pascal became weaker in both body and mind. In August 1660, he wrote to the mathematician Pierre Fermat that “I know that mathematics is the most valuable part of our intellect, but my ability to concentrate is now so poor that I can no longer deal with mathematics. I cannot walk without a stick and cannot remain sitting on a horse for long.”

In Pascal´s lifetime, a diagnosis had little in common with what is meant by a diagnosis today. Humoral pathology had held a strong position in leading universities since Aristotle’s time. Disease was thought to be caused by the uneven distribution of body fluids (blood, bile, lymph and slime). Treatment aimed at restoring “the humoral balance” with available methods—namely bloodletting, emetics, diaphoretics, and laxatives. There were no objective measures of efficacy, so results were assessed by doctors in an arbitrary way.

In December 1661, Pascal had an epileptic seizure and in August 1662, his headaches increased to an almost unbearable pain. The doctors who were summoned noted that his pulse was distinct and regular, and therefore the prognosis was considered good. A combination of migraine and excess fluid was thought to be the reason for his headache. The following night, he had several more seizures and died twenty-four hours later (1662). At autopsy a surprisingly enlarged and solid cerebellum was found. Impressions with coagulated blood were found on each side of the cranium, causing gangrene of the durae.  That thrombi could form in vivo was not known at this time. The findings were probably thrombi located in the sinuses.

As a neurologist reading about Pascal´s gradual deterioration, premature death, and autopsy reports, I was struck by the notion that the findings could be compatible with a rare neurological syndrome. A similar structure in the posterior cranial cavity was described by the neurologist J. L. Hermitte and doctor P. Duclos in the “Bullentin de l´association Francaise” in 1920. Since then about a hundred cases have been diagnosed and the disease has been named Lhermitte – Duclos disease. Cardinal symptoms are gradually worsening headache, ataxia,and disturbed balance. The increase in intracranial pressure causes a compression in the foramen magnum and leads to death. This usually occurs  between forty and fifty years of age. The new structure in the cerebellum is a type of hamartoma, also called “dysplastic cerebellar gangliocytoma.” It is perhaps caused by a hereditary mutation. Several of Pascal´s close relatives on the maternal side had died before age forty. The clinical course together with tactile and visual macro diagnostics described in the autopsy report support the diagnosis.

A congenital facial asymmetry has been noted in several patients with Lhermitte – Duclos syndrome. A death mask made of Pascal showed a facial asymmetry that was observed by Gilles de la Tourette (1857-1904) at the Salpetrière Hospital in Paris. The left half of the face is distinctly atrophic. This is true both for the bone structure and the facial tissues. Tourette refrained from drawing conclusions about a possible connection between Pascal´s facial morphology and his character and intelligence.

Many causes for Pascal´s early deterioration and death have been proposed over the years. In the eighteenth century, the uncertainty about Pascal´s disease was evident in the Enlightenment’s philosophical and medical debates. Voltaire and others claimed that his disease was mental. Hysteria, melancholia, and post traumatic neurosis were dominating explanations. Pascal´s ataxia was considered, since he once almost fell from a bridge into the Seine.  Afterwards he imagined that he had an abyss at his side and therefore needed support. Pascal´s presumed disease became a model in the psychosomatic doctrine and came to dominate the interpretation of his medical problems into the nineteenth century (with support from Charcot and Freud).

My own studies of his clinical history and the autopsy report strongly suggest that an enlarging lesion in the posterior cranial cavity, as described in Lhermitte – Duclos disease, was the cause of his disease and death.



BO LAESTADIUS, MD, is a neurologist who while living in Paris had the opportunity to follow the progress of medicine over four centuries through medical textbooks and scientific articles in the history department of the Bibliothèque de médicine d’Université Sorbonne  and also at the archives of ancient manuscripts of the Bibliothèque Nationale. The symptoms that afflicted Blaise Pascal have been subject to various interpretations consonant with the medical knowledge of the times. It is in that tradition that Dr. Laestadius has presented a diagnosis to account for his illness consonant with present day knowledge.