James Watson Kernohan, M.D. (1896–1981) was an Irish-American

pathologist Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...

born October 1, 1896, in

County Antrim County Antrim (named after the town of Antrim, County Antrim, Antrim, ) is one of the six counties of Northern Ireland, located within the historic Provinces of Ireland, province of Ulster. Adjoined to the north-east shore of Lough Neagh, the c ...

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

. He studied medicine at

Queen's University Belfast The Queen's University of Belfast, commonly known as Queen's University Belfast (; abbreviated Queen's or QUB), is a public research university in Belfast, Northern Ireland, United Kingdom. The university received its charter in 1845 as part of ...

, and in 1922 he emigrated to the United States and subsequently worked as a pathologist at the

Mayo Clinic Mayo Clinic () is a Nonprofit organization, private American Academic health science centre, academic Medical centers in the United States, medical center focused on integrated health care, healthcare, Mayo Clinic College of Medicine and Science ...

Rochester, Minnesota Rochester is a city in Olmsted County, Minnesota, United States, and its county seat. It is located along rolling bluffs on the Zumbro River's south fork in Southeast Minnesota. At the 2020 United States census, 2020 census, the city had a popul ...

. Kernohan retired from active medical practice in 1962 and died May 5, 1981. Kernohan is remembered for his work in

neuropathology Neuropathology is the study of disease of nervous system tissue, usually in the form of either small surgical biopsies or whole-body autopsies. Neuropathologists usually work in a department of anatomic pathology, but work closely with the clini ...

, particularly research of

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

tumors, brain abscesses and

metastatic Metastasis is a pathogenic agent's spreading from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, ...

brain lesions. He is credited with developing a widely used classification system for

brain tumor A brain tumor (sometimes referred to as brain cancer) occurs when a group of cells within the Human brain, brain turn cancerous and grow out of control, creating a mass. There are two main types of tumors: malignant (cancerous) tumors and benign ...

s. The eponymous ''

Kernohan's notch Kernohan's notch is a cerebral peduncle indentation associated with some forms of transtentorial herniation (uncal herniation). It is a secondary condition caused by a primary injury on the ''opposite'' hemisphere of the brain. Wolf et al, 1995 Ke ...

'' is named after him, which is a groove in the

cerebral peduncle The cerebral peduncles (In Latin, ''ped-'' means 'foot'.) are the two stalks that attach the cerebrum to the brainstem. They are structures at the front of the midbrain which arise from the ventral pons and contain the large ascending (sensor ...

caused by displacement of the

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is conti ...

against the incisura of the

tentorium cerebelli The cerebellar tentorium or tentorium cerebelli (Latin for "tent of the cerebellum") is one of four dural folds that separate the cranial cavity into four (incomplete) compartments. The cerebellar tentorium separates the cerebellum from the cere ...

in some cases of transtentorial herniation. In 1952 he published an atlas of tumor pathology titled ''Tumors of the Central Nervous System'', and with Mayo

neurosurgeon Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty that focuses on the surgical treatment or rehabilitation of disorders which affect any portion of the nervous system including the brain, ...

Alfred Uihlein (1908–1990) he published ''Sarcomas of the Brain''.

References

European Neurology; Kernohan's Notch J.M.S.Pearce
* 1930 United States Census, Rochester, Olmsted County, Minnesota. * Minnesota Death Index, 1908-2002, Certificate No. 012459, Record No. 2044236. {{DEFAULTSORT:Kernohan, James Watson 1896 births 1981 deaths American pathologists Irish emigrants to the United States