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Kuru Clinical Presentation

  • Author: Zartash Zafar Khan, MD, FACP; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
Updated: Feb 17, 2016


Before kuru had nearly disappeared following cessation of the ritual of endocannibalism, the disease affected only the Fore, a New Guinea highland tribe. Case histories were usually obtained with the aid of a pidgin English–speaking man of the same tribal group as the infected individuals, but, in some cases, a European linguist who spoke the appropriate language was available. Only rarely were infected individuals able to communicate in pidgin English.[27] Kuru has not been reported outside this context. Therefore, the potential for any practitioner encountering a case of kuru in the current era is extremely remote.

Kuru is a cerebellar syndrome with a characteristic and relentless progression of neurological symptoms through well-defined clinical stages. Kuru is invariably fatal. Initially, cognition is fairly well-preserved, and the disease presentation is sufficiently distinctive to be easily recognized by patients, their relatives, and the local community.[13] The initial clinical presentation includes a prodrome of headache and arthralgia followed by the following clinical features:[27, 28]

  • Cerebellar ataxia
  • Voluntary tremor
  • Involuntary movements (choreoathetosis, myoclonic jerks, fasciculations)
  • Euphoria, dementia, emotional liability, and a loss of grasp reflexes in advanced stages

Upon disease progression, infected individuals become sedentary and develop sensory and motor and cranial nerve deficits that lead to progressive wasting, malnutrition, and intercurrent pneumonia. Death typically follows a clinical course of 4 months to 2 years, with most patients dying within a year of symptom onset.

Compared with other prion diseases, kuru’s clinical features most closely resemble those of vCJD. Clinical symptoms of vCJD consist of behavioral, psychiatric, and peripheral sensory disturbances and cerebellar ataxia. Common early psychiatric features include depression, withdrawal, anxiety, insomnia, and apathy.[2] The symptoms of iatrogenic CJD are similar to those of sporadic CJD, which include a prodrome of malaise, headache, and ill-defined pain. Other symptoms include cognitive deterioration, myoclonus, extrapyramidal signs, cerebellar ataxia, pyramidal signs, and cortical blindness. The median age of onset for sporadic CJD is 45-75 years, whereas the median age of onset for vCJD is 26 years.[2]

Among the group of inherited prion diseases, GSS typically presents as a chronic cerebellar ataxia with pyramidal features, with dementia occurring much later. The clinical course is typically longer than that of classic CJD.

FFI is characterized by progressive untreatable insomnia, dysautonomia and dementia, and selective thalamic degeneration.[29, 2]



Physical findings during the initial course of kuru are characterized by ataxia and muscular weakness. This results in tremulous legs and walking difficulties that eventually necessitate dependence on sticks, crutches, or human assistance for locomotion. Slow and clumsy movements can lead to injuries sustained by falls.[27]

In the later stages, signs of psychiatric disturbances develop, including loss of emotion control, depression, euphoria, agitation, and confusion. Dementia can also occur in individuals with kuru, but it is a relatively more common feature of CJD.[27, 2]

Neurological signs of kuru include hyperreflexia, loss of grasp reflex, strabismus, and nystagmus. Involuntary muscle jerking and twitching is observed, along with other cerebellar signs such as tremor on finger-to-nose testing, difficulty with heel-to-toe walking, and dysdiadochokinesis. Plantar responses include flexor, and hypotonia is often present in advanced cases.[27, 20]

Ptosis and oculomotor imbalance are observed in a small number of cases.[27]

Eventually, individuals with kuru become bedridden and may even be unable to sit, raise their head, or roll over. In advanced stages, patients lose the ability to chew, swallow, or control excretory processes and become progressively wasted.[20]

Death results from starvation, complicating pneumonia,[28] or infected decubitus ulcers.

The signs and symptoms of vCJD commonly include disorientation, hallucinations, paranoid ideation, confabulation, impaired self-care, and multiple neurological features (eg, cerebellar signs, chorea, dystonia, myoclonus, upper motor neuron signs, visual symptoms). Classic sporadic CJD presents as a rapidly progressive multifocal dementia with myoclonus. Clinical progression to akinetic mutism occurs fairly rapidly, with a median illness duration of only 5 months. Extrapyramidal signs, cerebellar ataxia, pyramidal signs, and cortical blindness are also observed in sporadic CJD.[2] GSS typically presents as a chronic cerebellar ataxia with pyramidal features, with dementia occurring much later in the clinical course than is typically seen in classic CJD. Fatal familial insomnia (FFI) is characterized by progressive untreatable insomnia, dysautonomia and dementia, and thalamic degeneration.[2]



Kuru is a prion disease transmitted by endocannibalism. There is no evidence for spread in utero or via human milk.[13, 30]

Contributor Information and Disclosures

Zartash Zafar Khan, MD, FACP Infectious Disease Consultant

Zartash Zafar Khan, MD, FACP is a member of the following medical societies: American College of Physicians, Infectious Diseases Society of America, International Society for Infectious Diseases

Disclosure: Nothing to disclose.


Mary Buechler, MD Staff Physician, Emergency Center, Lawrence General Hospital

Mary Buechler, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Occupational and Environmental Medicine, American College of Emergency Physicians

Disclosure: Nothing to disclose.

Paul A Janson, MD Instructor, Tufts University School of Medicine; Consulting Staff, Department of Emergency Medicine, Lawrence General Hospital

Paul A Janson, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians

Disclosure: Nothing to disclose.

Mark Martin Huycke, MD Professor of Medicine, Infectious Diseases Section, University of Oklahoma Health Sciences Center; Chief, Medical Service, Department of Veterans Affairs Medical Center, Oklahoma City

Mark Martin Huycke, MD is a member of the following medical societies: American Association for the Advancement of Science, American Association for Cancer Research, American College of Physicians, American Federation for Medical Research, American Society for Microbiology, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Thomas M Kerkering, MD Chief of Infectious Diseases, Virginia Tech Carilion School of Medicine

Thomas M Kerkering, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, American Public Health Association, American Society for Microbiology, American Society of Tropical Medicine and Hygiene, Infectious Diseases Society of America, Medical Society of Virginia, Wilderness Medical Society

Disclosure: Nothing to disclose.

Chief Editor

Pranatharthi Haran Chandrasekar, MBBS, MD Professor, Chief of Infectious Disease, Program Director of Infectious Disease Fellowship, Department of Internal Medicine, Wayne State University School of Medicine

Pranatharthi Haran Chandrasekar, MBBS, MD is a member of the following medical societies: American College of Physicians, American Society for Microbiology, International Immunocompromised Host Society, Infectious Diseases Society of America

Disclosure: Nothing to disclose.


Rachel H Chung, MD Consulting Staff, Department of Family Practice, North Clinic, North Memorial Hospital

Disclosure: Nothing to disclose.

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