Definition

Neurodegeneration with brain iron accumulation (NBIA) are a group of very rare nervous system disorders. They are passed down through families (inherited). NBIA involves movement problems, dementia, and other nervous system symptoms.

Alternative Names

Hallervorden-Spatz disease; Pantothenate kinase-associated neurodegeneration; PKAN; NBIA

Causes

Symptoms of NBIA begin in childhood or adulthood.

There are 10 types of NBIA. Each type is caused by a different gene defect. The most common gene defect causes the disorder called PKAN (pantothenate kinase-associated neurodegeneration).

People with all forms of NBIA have a buildup of iron in the basal ganglia. This is an area deep inside the brain. It helps control movement.

Symptoms

NBIA mainly causes movement problems. Other symptoms may include:

• Dementia
• Difficulty speaking
• Difficulty swallowing
• Muscle problems such as rigidity or involuntary muscle contractions (dystonia)
• Seizures
• Tremor
• Vision loss, such as from retinitis pigmentosa
• Weakness
• Writhing movements
• Toe walking

Exams and Tests

The health care provider will perform a physical exam and ask about symptoms and medical history.

Genetic tests can look for the defective gene that causes the disease. However, these tests aren't widely available.

Tests such as an MRI scan can help rule out other movement disorders and diseases. The MRI usually shows iron deposits in the basal ganglia, and are called the "eye of the tiger" sign because of the way the deposits look in the scan. This sign suggests a diagnosis of PKAN.

Treatment

There is no specific treatment for NBIA. Medicines that bind iron may help slow the disease. Treatment is mainly focused on controlling the symptoms. The most commonly used medicines to control symptoms include baclofen and trihexyphenidyl.

Outlook (Prognosis)

NBIA damages the nerves over time and symptoms get worse. It leads to a lack of movement, and often death by early adulthood.

Possible Complications

Medicine used to treat symptoms can cause complications. Being unable to move from the disease can lead to:

• Blood clots
• Respiratory infections
• Skin breakdown

When to Contact a Medical Professional

Contact your provider if your child develops:

• Increased stiffness in the arms or legs
• Increasing problems at school
• Unusual movements

Prevention

Genetic counseling may be recommended for families affected by this illness. There is no known way to prevent it.

References

Gregory A, Hayflick S, Adam MP, et al. Neurodegeneration with brain iron accumulation disorders overview. 2013 Feb 28 [updated 2019 Oct 21]. In: Adam MP, Ardinger HH, Pagon RA, et al, eds. GeneReviews [Internet]. Seattle, WA: University of Washington; 1993-2020. PMID: 23447832 pubmed.ncbi.nlm.nih.gov/23447832/.

Jankovic J. Parkinson disease and other movement disorders. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 96.

NBIA Disorders Association. Overview of NBIA disorders. www.nbiadisorders.org/about-nbia/overview-of-nbia-disorders. Accessed September 22, 2022.