Pantothenate kinase-associated neurodegeneration (PKAN)

General Medical Guideline
Last modified
13 October 2019

Progressive dystonia and atypical retinitis pigmentosa are main characteristics of classical PKAN. Therapy is symptomatic. 

Progressive dystonia and atypical retinitis pigmentosa are main characteristics of classical PKAN. Therapy is symptomatic. A clinical PKAN guideline was published in 2016 (by P Hogarth et al).  From the guideline

The main presenting feature in so-called, classical, PKAN is limb dystonia. Dystonia is a condition of sustained or repetitive unintentional muscle contractions. The muscle contractions result in twisting and repetitive movements or abnormal fixed postures as spasticity. When occurring in the limbs, the first manifestation may be clumsiness and frequent falls. Earlier histories of developmental delay, attention deficit hyperactivity disorder (ADHD), or toe-walking also are common. Another part of PKAN is retinitis pigmentosa (RP). The retina of the eye has abnormally pigmented areas. The pigmentation can be viewed by experienced funduscopy. Most children and some adults with RP will manifest poor vision in low-light conditions and constricted visual fields; these features may contribute to falls in PKAN. While retinopathy is common, clinically significant visual impairment usually lags behind the neurological manifestations. 

Atypical PKAN is an inclusive term for all non-classic PKAN phenotypes. The spectrum of atypical PKAN is broad and more accurately encompasses a continuum from the classic disease. Disease onset is in later childhood, adolescence or adulthood and the rate of progression is slower. Atypical PKAN often presents with neuropsychiatric or speech problems, followed by the development of dystonia or Parkinsonism later, sometimes superimposed on a history of attention deficit hyperactivity disorder (ADHD). Action-induced jaw dystonia occurring with eating or speaking should always prompt consideration of the diagnosis of PKAN, as it rarely occurs in patients without PKAN. Similarly, truncal opisthotonus is common in both classic and atypical disease and is highly suggestive of PKAN.

People suspected to have PKAN based on clinical features should undergo brain MRI using iron sensitive sequences as a first-line diagnostic investigation to identify the characteristic changes. The MRI abnormality, called the ‘eye-of-the-tiger’ sign, is observed on T2- weighted imaging.  When PKAN is suspected, genetic testing is recommended to confirm the diagnosis. Neurodegeneration with Brain Iron Accumulation (NBIA) gene panels are now available and can be a more efficient and cost-effective diagnostic tools in some situations.

Follow up 

The neurologist is important to document the individual's baseline condition at the time of diagnosis and to facilitate subsequent interventions as needed, such as initiating treatment with medication or referral to physical or other therapies. When available co-management with a rehabilitation medicine physician can optimize the treatment. A clinical eye examination is recommended to assess visual function, since retinopathy is common, especially in children with classic PKAN.  Physical, occupational or speech problems should be addressed as early as possible after diagnosis in order to preserve function.  Psychosocial care should be offered to patients and as soon as possible after diagnosis. Guidance in social care should focus on benefits available for disabled persons to prepare them for any adaptations needed for daily activities. Despite the severe degree of motor impairment, children with PKAN retain their obtained cognitive abilities.  In classic PKAN, severe dystonia and postural instability leading to frequent falls cause the most disability, complications and pain. Dystonia leads to stridor, extreme opisthotonic posturing (extreme arched pose), bone fractures, joint dislocation and recurrent tongue-biting. The resulting pain and distress can precipitate a vicious cycle and lead to status dystonicus. Other secondary complications include airway obstruction, orthopaedic deformity and infection.  Atypical PKAN progresses more slowly. Adults with PKAN have graduated from college, served in the armed forces, married and raised children. The range and spectrum of disability vary widely.  Currently,no disease-modifying therapy for PKAN is available.  Medication management is primarily symptomatic. For medical therapy. please view the published guideline. P. Hogarth, et al., Consensus clinical management guideline for pantothenate kinase-associated neurodegeneration (PKAN), Mol. Genet. Metab. (2016)


Rare Condition

Pantothenate kinase-associated neurodegeneration

Pantothenate kinase-associated neurodegeneration (PKAN, formerly Hallervorden–Spatz syndrome), is a disorder characterized by iron accumulation in the brain. The estimated incidence is about 1–3 per million. The cause...


G24.9 Dystonia, unspecified

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