Jackson's epilepsy

Seizures involving one or several parts of the body on the same side. Contraction starts from a focus such as tip of toe, corner of mouth, and then gradually spreads to other muscles. If it remains hemilateral, consciousness is preserved. Sometimes proceeding to a generalized fit with loss of consciousness. Jacksonian seizures indicate focal lesions on the contralateral side of the brain, usually in the area of the motor cortex.

This focal fit, or convulsion beginning unilaterally, had been described earlier by Louis François Bravais (1801-1843) and by others, but its significance had remained unknown.

"The fit usually begins, it is to be observed, in that part of the face, of the arm, and oft the leg, which has the most varied uses. ... the fits which begin in the hand begin usually in the index finger and thumb; fits which begin in the foot begin usually in the great toe."

• L. F. Bravais:
  Recherches sur les symptômes et le traitement de l’épilepsie hémiplégique.
  Thèse de Paris, no 118. 1827.
• Richard Bright (1789-1858):
  Fatal epilepsy, from suppuration between the dura mater and arachnoid, in consequence of blood having been effused in that situation.
  Guy's Hospital Reports, London, 1836, 1: 36-40.
• J. H. Jackson:
  Unilateral epileptiform seizures, attended by temporary defect of sight.
  Medical Times and Gazette, London. 1863, 1: 588-589.
• Epileptiform convulsions from cerebral disease.
  Transactions of the International Medical Congress, 1881, 2: 6-15.
• Loss of speech: its association with valvular disease of the heart, and with hemiplegia on the right side. Defects of smell. Defects of speech in chorea. Arterial regions in epilepsy.
  Clinical Lectures and Reports by the Medical and Surgical Staff of the London Hospital, 1864, 1: 388-471.
• J. M. Charcot:
  Épilepsie Bravais-Jacksonienne avec paralysie longtemps limitée au membre supérier.
  La Médecine moderne, 1894, 5: 1605.