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Synonyms: Kennedy's phenomenon; Gowers-Paton-Kennedy syndrome

Foster Kennedy's syndrome (FKS) is a rare neurological sign first described in 1911 by Robert Foster Kennedy. [1] He was a British neurologist, who spent the majority of his working life in America (1884-1952). It consists of:[2]

  • Unilateral, ipsilateral optic atrophy, produced by direct pressure on the optic nerve.
  • Contralateral papilloedema secondary to raised intracranial pressure (ICP).
  • Central scotoma.
  • Anosmia.

Pseudo-FKS has also been described, in which there is unilateral optic disc swelling with contralateral optic atrophy in the absence of an intracranial mass.[3] This occurs typically due to bilateral sequential optic neuritis or ischaemic optic neuropathy. Cases secondary to other pathologies have also been reported.

It is most commonly caused by a tumour on the inferior surface of the frontal lobe. This is usually an olfactory groove meningioma or a medial third sphenoidal wing meningioma.

It has also been reported as a consequence of:

  • A metastatic cerebral tumour.[4]
  • Arteriovenous malformation, in which chronic venous hypertension was the likely aetiology.[5]
  • Juvenile nasopharyngeal angiofibroma (a rare benign tumour of the nasopharynx that occurs in adolescent boys with epistaxis and nasal obstruction).[6]
  • Trigeminal cystic schwannoma.[7]

A review of the 36 previously reported cases of FKS revealed that only eight (22%) of the cases satisfied Foster Kennedy's original hypothesis for the pathogenesis of his syndrome. 12 cases (33%) were probably caused by bilateral optic nerve compression.[8] The authors conclude that as more sophisticated imaging permits earlier and more precise diagnosis, future cases of FKS caused by a mass will probably be found to result from bilateral direct optic nerve compression.

These include:

  • Nausea.
  • Vomiting.
  • Memory loss.
  • Emotional lability, ie other frontal lobe signs.

Both depend on the underlying cause.

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Further reading and references

  • Yeh WY, Cheng CK, Peng PH, et al; Foster Kennedy Syndrome in a Case with Retinitis Pigmentosa. Ophthalmic Surg Lasers Imaging. 2010 Mar 9:1-3. doi:

  • Ramdasi R, Thorve S, Vekariya M, et al; Reverse Foster Kennedy Syndrome Caused by an Intra-axial Tumor. Neurol India. 2022 Jul-Aug70(4):1655-1657. doi: 10.4103/0028-3886.355138.

  • Ayele B, Mengesha A, Wotiye A, et al; Giant Pituitary Adenoma Presenting with Foster-Kennedy Syndrome in a 21-Year Old Ethiopian Patient: A Rarely Reported Phenomenon: A Case Report. Ethiop J Health Sci. 2020 Mar30(2):311-314. doi: 10.4314/ejhs.v30i2.19.

  1. Stone JL, Vilensky J, McCauley TS; Neurosurgery 100 years ago: the Queen Square letters of Foster Kennedy. Neurosurgery. 2005 Oct57(4):797-808

  2. Musa MJ, Zeppieri M; Foster Kennedy Syndrome.

  3. Egbu E, Ihemedu C, Eze UA, et al; Steroid-Induced Hiccups in a Patient Managed for Pseudo Foster-Kennedy Syndrome: A Case Report of Good Outcome With the use of Gabapentin. Cureus. 2021 Jan 2513(1):e12893. doi: 10.7759/cureus.12893.

  4. Yildizhan A; A case of Foster Kennedy syndrome without frontal lobe or anterior cranial fossa involvement. Neurosurg Rev. 199215(2):139-42.

  5. Liang F, Ozanne A, Offret H, et al; An atypical case of Foster Kennedy syndrome. Interv Neuroradiol. 2010 Dec16(4):429-32. Epub 2010 Dec 17.

  6. Aga A; Juvenile nasopharyngeal angiofibroma presenting as Foster Kennedy Syndrome. Ethiop Med J. 2001 Jul39(3):251-60.

  7. Mahjoub Y, Wan M, Subramaniam S; Pearls & Oy-sters: Trigeminal Cystic Schwannoma Presenting With Foster Kennedy Syndrome, Sixth Nerve Palsy, and Focal Seizures. Neurology. 2023 Mar 21100(12):587-590. doi: 10.1212/WNL.0000000000201700. Epub 2022 Dec 19.

  8. Watnick RL, Trobe JD; Bilateral optic nerve compression as a mechanism for the Foster Kennedy syndrome. Ophthalmology. 1989 Dec96(12):1793-8.