Kuru
Presentation
The disease Kuru grossly affects the cerebellum causing progressive loss of neurological functions. It primarily starts with the onset of headache and arthralgia followed by the below clinical signs and symptoms:
- Pain in the arm and leg region
- Headache
- Difficulty in eating and swallowing food
- Difficulty in feeding oneself
- Problem in coordination
- Cerebellar ataxia
- Myoclonus
- Euphoria, loss of reflexes that coordinate grasp movement
- Involuntary movements
All these symptoms cause the individuals to develop malnutrition and recurrent bouts of pneumonia. Death is the ultimate result of this disease that usually occurs within a year of experiencing the first signs and symptoms.
Entire Body System
Collapse
- Why, yes, that’s exactly the explanation that her campaign gave to the public after she froze up and collapsed in New York on 9/11! Here’s one other visual oddity. An illustration of prions in action, causing tangled protein deformities.[conservativedailypost.com]
- Collapse patient sex year of birth onset age at onset death age at death duration of illness (months) PRNP genotype likelya incubation period (years) YAK male 1948 Nov 1994 46 Dec 1996 48 25 MV 39 PKW female 1946 Aug 1995 49 Dec 1996 50 16 MV MWK male[rstb.royalsocietypublishing.org]
Euthyroid
- He was clinically euthyroid. Eye movements were full without diplopia and visual pursuit was smooth without nystagmus. There was no facial weakness and the pupils were symmetrically responsive to light and accommodation.[rstb.royalsocietypublishing.org]
Gastrointestinal
Abdominal Pain
- He developed headache and abdominal pain in January 1999. There were two episodes of occipital headache with mandibular and right ear pain.[rstb.royalsocietypublishing.org]
Bulimia
- Obesity is common at this stage but may be present in early disease associated with bulimia.[rstb.royalsocietypublishing.org]
Progressive Dysphagia
- Progressive dysphagia occurs and patients become incontinent of urine and faeces. Inanition and emaciation develop. Transient conjugate eye signs and dementia may occur. Primitive reflexes develop in occasional cases.[rstb.royalsocietypublishing.org]
Skin
Piloerection
- Photophobia is common and there may be an abnormal cold sensitivity with shivering and piloerection even in a warm environment. Tendon reflexes are reduced or normal and plantar responses are flexor. Dysarthria usually occurs.[rstb.royalsocietypublishing.org]
Eyes
Diplopia
- In October 1999, he developed diplopia, dysphasia and experienced memory difficulties. By January 2000, he was unable to walk unsupported.[rstb.royalsocietypublishing.org]
Musculoskeletal
Foot Pain
- His symptoms began in June 1998 when he noted interphalangeal foot pain on walking, initially on the right and then bilaterally. He noted unsteadiness in walking and complained of cold feet and shivering despite warm conditions.[rstb.royalsocietypublishing.org]
Arthralgia
- It primarily starts with the onset of headache and arthralgia followed by the below clinical signs and symptoms: Pain in the arm and leg region Headache Difficulty in eating and swallowing food Difficulty in feeding oneself Problem in coordination Cerebellar[symptoma.com]
- 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[emedicine.medscape.com]
Psychiatrical
Impulsivity
- The clumps cause the shaking and abnormal gait, because they make cerebellar cells unable to properly conduct nervous impulses. It is now known that the clumps of abnormally folded prion protein can break down into smaller fragments.[theguardian.com]
Denial
- In an atmosphere of postcolonial guilt, denial about cannibalism was extended to denial on behalf of those we wished to rehabilitate and acknowledge as our equals (Rawson 1997).[medanthrotheory.org]
Neurologic
Headache
- It primarily starts with the onset of headache and arthralgia followed by the below clinical signs and symptoms: Pain in the arm and leg region Headache Difficulty in eating and swallowing food Difficulty in feeding oneself Problem in coordination Cerebellar[symptoma.com]
- The primary aims of Headache Awareness Week are "having headaches taken seriously" and increasing Headache Australia's membership.[themonthly.com.au]
- Symptoms of kuru include: Arm and leg pain Coordination problems that become severe Difficulty walking Headache Swallowing difficulty Tremors and muscle jerks Difficulty swallowing and being unable to feed oneself can lead to malnutrition or starvation[nlm.nih.gov]
- […] alter the internal structures of the brain cells, causing abnormal functioning of the brain and nervous system The common signs and symptoms associated with Kuru include coordination problems with difficulty in walking, tremors, emotional liability, headache[dovemed.com]
Broad-Based Gait
- Gait ataxia, however, worsens and patients develop a broad-based gait, truncal instability and titubation.[rstb.royalsocietypublishing.org]
Poor Coordination
- These help to identify the poor coordination and can also assess the walking ability of the affected individuals. Treatment So far, there is no known treatment for kuru. The disease gradually disrupts the neurological functioning and causes death.[symptoma.com]
- These include: difficulty walking poor coordination difficulty swallowing slurred speech moodiness and behavioral changes dementia muscle twitching and tremors inability to grasp objects random, compulsive laughing or crying Kuru occurs in three stages[healthline.com]
Workup
No laboratory workup or imaging studies are sufficient to diagnose kuru. However, a postmortem evaluation of the tissues of the central nervous system with predominance of PrP plaques can help to detect infections in the brain [8].
In addition, neurological examinations can help detect changes in the coordination and walking abilities of the affected individuals.
Electrodiagnostic tests that include electromyography or nerve conduction velocity are carried out to determine the electrical activity in the brain.
MRI scans can also help derive appropriate conclusions. Cerebrospinal markers like neuronal specific enolase, protein 14-3-3, and S-100 although non-specific can help in the diagnosis of prion diseases in man [9].
EEG
Triphasic Waves
- Repeated EEGs showed symmetrical slowing in one case and periodic generalised bursts of triphasic waves at 1 cps superimposed upon a slow (3-4 cps) background activity in the other.[ncbi.nlm.nih.gov]
Other Pathologies
Amyloid Plaque
- Amyloid plaques, so characteristic of kuru, also did not figure in the similarity, for they had not yet been reported in scrapie. Despite the uncertainty at the time about the pathologic essence of scrapie, the two diseases still looked alike.[ncbi.nlm.nih.gov]
Treatment
So far there is no known treatment for either curing or managing the disease condition. Kuru is a fatal disease that gradually destructs the neurological functioning of the individuals. No medications and therapies can help people affected by kuru.
Prognosis
This disease has a long incubation period causing prevalence of this disease even several years after the practice of cannibalism was banned. There is no cure to this deadly disease and death occurs within 1 year after the appearance of first symptom.
Complications
As there is no known treatment for Kuru, complications are bound to set in. These include:
- Chronic brain failure
- Ataxia
Etiology
The primary and the only causative factor behind development of kuru is the consumption of contaminated protein found in dead human brains which is the most infectious organ in victims [4].
The practice of cannibalism during the funeral rituals lead to the development of kuru amongst the Fore people of the New Guinea. Even after several years of discontinued practice, cases are still being reported due to the long incubation period of this disease [5].
Epidemiology
New Guinea was the only place where such a ritual was practiced and people suffered the deadly disease as a result of it [6]. Cases of kuru were mostly reported during the year 1950 to 1960 when the ritual of cannibalism was still in use.
This decade, witnessed the maximum number of deaths due to kuru. Statistics have revealed about 100 deaths from kuru during this period. Once such a cruel practice was banned by the government, there was a steady decline in the incidences of kuru.
The death rates reduced to 6 per year from the 1990s. Only 2 deaths were reported in the period of 2003 to 2008. In addition, no new case of kuru was detected amongst those born after the year 1959.
Pathophysiology
Kuru belongs to the class of prion disease which is also known as transmissible spongiform encephalopathies (TSEs). In this group of disease, protein molecules have the ability to change shape and function causing irreversible damages in the body.
These proteins bind together to form lumps in the brain. As a result of infection, researchers believe that even the normal proteins mimic the prions and behave in an abnormal fashion. All these sequences of events cause neurological disorder of the brain. Although 15% of prion acquired disorders in humans are associated with an autosomal-dominant mutation involving the PrP gene [7].
Women and children are more affected by this disease than men. This is so because, women generally do the cleaning part of the dead body and the men are offered the choicest part for the meal. Women and children generally feed on the leftovers such as the brain which is the most infectious part. Other diseases that belong to the group of TSEs affect only the animals.
Prevention
The only way to prevent this is disease is to avoid cannibalism which has already been achieved by efforts of the government and society.
As a result, this disease is now a matter of the past and no new cases of kuru are being reported. Researches are still on going in the newer means of transmission of prion diseases to humans like zooanthropologic transmission from bovine species in the Papua New Guinea region [10].
Summary
Kuru is a rare infectious disease characterized by neurological disorders of the brain. This is an incurable disease and is only prevalent amongst the population of New Guinea. This rare form of disease occurs due to infected protein that is found in the human contaminated brain.
The people of New Guinea as a part of a peculiar ritual consumed dead brains of human. This was customary to their funeral process. These dead brains were infected with prion which is a protein that leads to the causation of this deadly disease [1].
Kuru is the most popular example of a prion acquired form of disease in man [2]. This practice has been discontinued since 1960, but the cases were reported at a much later date, as this disease has a long incubation period. The rarity of kuru cases in the turn of the decade is suggestive that the epidemic may come to its conclusion very soon [3].
Patient Information
Definition
Kuru is a rare neurological disorder that occurs due to ingestion of infectious proteins called prions. This disease cannot be cured and has no treatment. The symptoms worsen overtime causing death of the affected individuals. In the past, the practice of cannibalism was prevalent amongst the New Guinea population. This practice called for feeding on the dead bodies as part of the funeral rites. This deadly practice leads to the ingestion of prions that caused Kuru in healthy people.
Cause
Kuru is caused due to consuming the infected human brain or contact with the open sores of the dead. The infected proteins known as “prion” present in the brain of the dead individuals is known to play foul.
Symptoms
Symptoms of kuru include difficulty in eating and swallowing food, lack of coordination, headache, difficulty in walking, pain in the arms and legs, muscle tremors, difficulty in talking, bouts of laughing and crying spells.
Diagnosis
Kuru is diagnosed through neurological examination and electrodiagnostic tests. These help to identify the poor coordination and can also assess the walking ability of the affected individuals.
Treatment
So far, there is no known treatment for kuru. The disease gradually disrupts the neurological functioning and causes death. No medications or therapies have been designed to help treat this condition.
References
Article
- Belay ED, Schonberger LB. The public health impact of prion diseases. Annu Rev Public Health. 2005; 26:191-212.
- Wadsworth JD, Collinge J. Update on human prion disease. Biochim Biophys Acta. Jun 2007; 1772(6):598-609.
- Alpers MP. Review. The epidemiology of kuru: monitoring the epidemic from its peak to its end. Philos Trans R Soc Lond B Biol Sci. Nov 27 2008; 363(1510):3707-13.
- Whitfield JT, Pako WH, Collinge J, Alpers MP. Mortuary rites of the South Fore and kuru. Philos Trans R Soc Lond B Biol Sci.Nov 27 2008; 363(1510):3721-4.
- McKintosh E, Frosh A, Mead S, Hill AF, Brandner S, Thomas D, Alpers MP, Collinge J, Whitfield J. A clinical study of kuru patients with long incubation periods at the end of the epidemic in Papua New Guinea.Philos Trans R Soc Lond B Biol Sci. 2008; 363(1510):3725-39 (ISSN: 1471-2970)
- Wadsworth JD, Joiner S, Linehan JM, Asante EA, Brandner S, Collinge J. The origin of the prion agent of kuru: molecular and biological strain typing. Philos Trans R Soc Lond B Biol Sci. 2008; 363(1510):3747-53 (ISSN: 1471-2970)
- Collinge J. Human prion diseases and bovine spongiform encephalopathy (BSE). Hum Mol Genet. 1997; 6(10):1699-705.
- Brandner S, Whitfield J, Boone K, Puwa A, O'Malley C, Linehan JM. Central and peripheral pathology of kuru: pathological analysis of a recent case and comparison with other forms of human prion disease. Philos Trans R Soc Lond B Biol Sci. 2008; 363(1510):3755-63 (ISSN: 1471-2970)
- Collinge J. New diagnostic tests for prion diseases. N Engl J Med. Sep 26 1996;335(13):963-5
- Collinge J. Lessons of kuru research: background to recent studies with some personal reflections. Philos Trans R Soc Lond B Biol Sci. 2008; 363(1510):3689-96 (ISSN: 1471-2970)