Pantothenate kinase-associated neurodegeneration

Hallervorden-Spatz syndrome, now known as pantothenate kinase-associated neurodegeneration (PKAN), is an autosomal recessive disorder causing involuntary spasticity and progressive dementia.  It is a subset of neurodegeneration with brain iron accumulation (NBIA).

Clinical presentation

Described features include:

• rigidity⁹
• dysarthria⁹
• dystonia⁹
• retinitis pigmentosa⁹
• progressive mental retardation⁹
• cognitive impairment 
• spasticity
• tremors

Radiographic features

MRI

• T2: - T2-weighted MRI images often demonstrate hyperintense changes in anteriomedial part of globus pallidus and hypodense lateral part of globus pallidus and pars reticulata of substantia nigra; there is associated T2 hypointensity, which can manifest as hyperintensity if there is associated inflammation and demyelination.  
• SWI/T2*: - shows susceptibility artefact (low signal) in corresponding areas from iron deposition⁷.

Cortical and caudate atrophy may be seen. The "eye of the tiger" sign refers to a central T2 relatively hyperintense spot (line) within the hypointense globi pallidi ³.

MR spectroscopy

• shows decreased NAA peak due to neuronal loss and may show increased myoinositol ⁸ 

EtymologyHistory and etymology

It is named after ⁴:

• Hugo Spatz (1888-1969): Anatomist :, Munich, Germany
• Julius Hallervorden (1882-1965): Neuropathologist :, Germany

Both Hugo Spatz and Julius Hallervorden were involved in the nazi euthanasia program and, as such, the alternative name is preferred by some authors. Brief biographical entries on Spatz and Hallervorden make an interesting reading ¹.