Retinitis pigmentosa in pantothenate kinase-associated neurodegeneration

Retinose pigmentar na neurodegeneração associada à pantotenato quinase

A 16-year-old boy presented to our hospital with 4-year-history of generalized dystonia (predominantly cranio-cervical and upper limbs) (Figure 1) and visual loss. Brain MRI revealed globus pallidus hypointensity with central hyperintense signal (eye-of-the-tiger) (Figure 2). Retinitis pigmentosa was observed in ophthalmologic evaluation (Figure 3). Genetic test confirmed mutation in PANK2 gene.

Figure 1
Dystonia in upper limbs (A). Note marked dystonia involving cranio-cervical segment and facial “grimacing” (B and C).

Figure 2
Axial FLAIR (A), coronal FLAIR (B) and spin echo (C) sequences brain MRI disclose marked hypointense signal of the globus pallidus with central hyperintense signal (eye-of-the tiger appearance) (arrows).

Figure 3
Note grainy appearance of the retinal pigmented epithelium, with fine dots, arteriolar thinning and peripapillary pigmentation on the temporal optic disc border. Those are mild signs of retinal degeneration, due to early retinitis pigmentosa.

Pantothenate kinase-associated neurodegeneration (PKAN) is classically characterized by early-onset dystonia and pyramidal signs but other features may include parkinsonism, choreoathetosis and dementia¹. Brain MRI typically depicts the eye-of-the-tiger pattern¹. When retinitis pigmentosa, an unusual finding³, is observed in the clinical spectrum of PKAN, we must consider variants^2,3,4, such as HARP syndrome (hypoprebetalipoproteinemia, acanthocytosis, retinitis pigmentosa, and pallidal degeneration).

References

• ¹
  Schneider SA, Hardy J, Bhatia KP. Syndromes of neurodegeneration with brain iron accumulation (NBIA): an update on clinical presentations, histological and genetic underpinnings, and treatment considerations. Mov Disord. 2012;27(1):42-53. http://dx.doi.org/10.1002/mds.23971
  » https://doi.org/10.1002/mds.23971
• ²
  Orrell RW, Amrolia PJ, Heald A, et al. Acanthocytosis, retinitis pigmentosa, and pallidal degeneration: a report of three patients, including the second reported case with hypoprebetalipoproteinemia (HARP syndrome). Neurology. 1995;45(3):487-92. http://dx.doi.org/10.1212/wnl.45.3.487
  » https://doi.org/10.1212/wnl.45.3.487
• ³
  Ching KH, Westaway SK, Gitschier J, Higgins JJ, Hayflick SJ. HARP syndrome is allelic with pantothenate kinase-associated neurodegeneration. Neurology. 2002;58(11):1673-4. http://dx.doi.org/10.1212/wnl.58.11.1673
  » https://doi.org/10.1212/wnl.58.11.1673
• ⁴
  Houlden H, Lincoln S, Farrer M, Cleland PG, Hardy J, Orrell RW. Compound heterozygous PANK2 mutations confirm HARP and Hallervorden-Spatz syndromes are allelic. Neurology. 2003;61(10):1423-6. http://dx.doi.org/10.1212/01.wnl.0000094120.09977.92
  » https://doi.org/10.1212/01.wnl.0000094120.09977.92

Publication Dates

• Publication in this collection
  Oct 2014

History

• Received
  29 Apr 2014
• Reviewed
  01 July 2014
• Accepted
  21 July 2014