Pantothenate kinase-associated neurodegeneration

Disease summary: Pantothenate kinase-associated neurodegeneration (PKAN) is a rare autosomal recessive disorder that was first described by the neuropathologist Julius Hallervorden and the neurologist Hugo Spatz in 1922 [1]. The active involvement of Hallervorden in euthanasia in Germany during World War II and the discovery of the defective gene (mutation in pantothenate kinase 2 gene, located on chromosome 20p13) removed the name "Hallervorden Spatz disease" to PKAN (2,3). Prevalence is estimated at 1-3/1,000,000 [4]. It has variable phenotype that is mainly age dependent. The classic form has early onset (usually before six years of age) and rapid progression. Children usually present with gait abnormalities, followed by severe dystonia, seizures, dysartria, spasticity, retinopathy and learning disorders [5]. Atypical PKAN (25% of cases) has later onset and slower progression. Speech abnormality and psychiatric symptoms are more common in this form. Dyskinetic symptoms may be mild [5]. PKAN has a characteristic brain MRI pattern called ‘’ eye of the tiger sign’’, which is a low signal intensity region surrounding a central high signal intensity region in the globus pallidus [6]. Histopathologic findings reveal iron deposition in the globus pallidus and pars reticulata of the substantia nigra [7]. Oropharyngeal dystonia can lead to pulmonary aspiration, dynamic upper airway obstruction and breathing difficulty [8]. Severe dystonia usually fails to respond to pharmacological therapy and intrathecal baclofen pump or stereotactic pallidotomy can be considered. Patients requiring general anesthesia with this syndrome may have many symptoms that influence the pre-anaesthetic management, the induction of anesthesia and the postoperative care.