Late onset atypical pantothenate-kinase-associated neurodegeneration

Treatment of Pantothenate-Kinase Neurodegeneration With Baclofen, Botulinum Toxin, and Deferiprone: A Case Report

Pantothenate kinase-associated neurodegeneration (PKAN) is a rare autosomal recessive disorder characterized by progressive motor symptoms, such as dystonia and spasticity. Classical PKAN is the most common subtype of neurodegeneration with brain iron accumulation (NBIA). Currently, there is no established treatment for PKAN. However, baclofen and botulinum toxin have been reported to improve motor symptoms and ease care in these patients. Additionally, Deferiprone is a well-tolerated iron chelator that has been shown to be effective in reducing brain iron accumulation. In this case report, we present the case of a seven-year-old boy who presented to our ward with spastic gait and extrapyramidal signs. Brain magnetic resonance imaging was performed, which showed features of neurodegeneration secondary to brain iron accumulation with a specific appearance of the eye-of-the-tiger sign. Genetic testing was positive for a homozygous mutation in PANK2, and the diagnosis of early-stage classical PKAN was made. This case report highlights the potent efficacy of baclofen, botulinum toxin, and deferiprone in slowing down the disease progression at an early stage and improving the severity of symptoms.

Pantothenate Kinase-Associated Neurodegeneration (PKAN) With Concomitant Blepharospasm: Unveiling a Clinical Enigma

Pantothenate kinase-associated neurodegeneration (PKAN) is a rare and complex neurodegenerative disorder. It occurs due to mutations in the sequencing of the PANK2 gene. Here, we describe the case of a 22-year-old male patient who presented with severe blepharospasm; he had abnormal facial distortions, shaky limbs, rigid muscles, and a slow pace of movement, making a diagnosis tricky. Accumulation of iron in excessive amounts in the basal ganglia, a part of the brain that governs movement, is linked to PKAN. In this case, the "eye of the tiger" indication, a distinctive pattern only seen by MRI, supported PKAN. The anticholinergic medications helped him alleviate his symptoms to some extent, but he still had some degree of impairment. This instance emphasizes the mysterious character of PKAN and the significance of keeping an eye out for unusual symptoms in neurodegenerative conditions. This case report emphasizes the significance of recognizing unexpected effects that brain disorders can have on people's lives and calls for increased clinician awareness and understanding.

Mitochondrial Dysfunction, Oxidative Stress and Neuroinflammation in Neurodegeneration with Brain Iron Accumulation (NBIA)

The syndromes of neurodegeneration with brain iron accumulation (NBIA) encompass a group of invalidating and progressive rare diseases that share the abnormal accumulation of iron in the basal ganglia. The onset of NBIA disorders ranges from infancy to adulthood. Main clinical signs are related to extrapyramidal features (dystonia, parkinsonism and choreoathetosis), and neuropsychiatric abnormalities. Ten NBIA forms are widely accepted to be caused by mutations in the genes PANK2, PLA2G6, WDR45, C19ORF12, FA2H, ATP13A2, COASY, FTL1, CP, and DCAF17. Nonetheless, many patients remain without a conclusive genetic diagnosis, which shows that there must be additional as yet undiscovered NBIA genes. In line with this, isolated cases of known monogenic disorders, and also, new genetic diseases, which present with abnormal brain iron phenotypes compatible with NBIA, have been described. Several pathways are involved in NBIA syndromes: iron and lipid metabolism, mitochondrial dynamics, and autophagy. However, many neurodegenerative conditions share features such as mitochondrial dysfunction and oxidative stress, given the bioenergetics requirements of neurons. This review aims to describe the existing link between the classical ten NBIA forms by examining their connection with mitochondrial impairment as well as oxidative stress and neuroinflammation.

Identification of a novel mutation in ATP13A2 associated with a complicated form of hereditary spastic paraplegia

Objective

To establish molecular diagnosis for a family with a complicated form of autosomal recessive hereditary spastic paraplegia with intellectual disability, cognitive decline, psychosis, peripheral neuropathy, upward gaze palsy, and thin corpus callosum (TCC).

Methods

Physical examinations, laboratory tests, structural neuroimaging studies, and exome sequence analysis were carried out.

Results

The 3 patients exhibited intellectual disability and progressive intellectual decline accompanied by psychiatric symptoms. Gait difficulty with spasticity and pyramidal weakness appeared at the ages of 20s–30s. Brain MRI revealed TCC with atrophic changes in the frontotemporal lobes, caudate nuclei, and cerebellum. Exome sequence analysis revealed a novel homozygous c.2654C>A (p. Ala885Asp) variant in the ATP13A2, a gene responsible for a complicated form of hereditary spastic paraplegia (SPG78), Kufor-Rakeb syndrome, and neuronal ceroid lipofuscinosis. The predominant clinical presentations of the patients include progressive intellectual disability and gait difficulty with spasticity and pyramidal weakness, consistent with the diagnosis of SPG78. Of note, prominent psychiatric symptoms and extrapyramidal signs including rigidity, dystonia, and involuntary movements preceded the spastic paraparesis.

Conclusions

Our study further broadens the clinical spectrum associated with ATP13A2 mutations.

Parkinson's Disease and Metal Storage Disorders: A Systematic Review

Metal storage disorders (MSDs) are a set of rare inherited conditions with variable clinical pictures including neurological dysfunction. The objective of this study was, through a systematic review, to identify the prevalence of Parkinsonism in patients with MSDs in order to uncover novel pathways implemented in Parkinson’s disease. Human studies describing patients of any age with an MSD diagnosis were analysed. Foreign language publications as well as animal and cellular studies were excluded. Searches were conducted through PubMed and Ovid between April and September 2018. A total of 53 publications were identified including 43 case reports, nine cross-sectional studies, and one cohort study. The publication year ranged from 1981 to 2018. The most frequently identified MSDs were Pantothenate kinase-associated neurodegeneration (PKAN) with 11 papers describing Parkinsonism, Hereditary hemochromatosis (HH) (7 papers), and Wilson’s disease (6 papers). The mean ages of onset of Parkinsonism for these MSDs were 33, 53, and 48 years old, respectively. The Parkinsonian features described in the PKAN and HH patients were invariably atypical while the majority (4/6) of the Wilson’s disease papers had a typical picture. This paper has highlighted a relationship between MSDs and Parkinsonism. However, due to the low-level evidence identified, further research is required to better define what the relationship is.

Novel mutations in PANK2 and PLA2G6 genes in patients with neurodegenerative disorders: two case reports

BACKGROUND

Neurodegeneration with brain iron accumulation (NBIA) is a genetically heterogeneous group of disorders associated with progressive impairment of movement, vision, and cognition. The disease is initially diagnosed on the basis of changes in brain magnetic resonance imaging which indicate an abnormal brain iron accumulation in the basal ganglia. However, the diagnosis of specific types should be based on both clinical findings and molecular genetic testing for genes associated with different types of NBIA, including PANK2, PLA2G6, C19orf12, FA2H, ATP13A2, WDR45, COASY, FTL, CP, and DCAF17. The purpose of this study was to investigate disease-causing mutations in two patients with distinct NBIA disorders.

CASE PRESENTATION

Whole Exome sequencing using Next Generation Illumina Sequencing was used to enrich all exons of protein-coding genes as well as some other important genomic regions in these two affected patients. A deleterious homozygous four-nucleotide deletion causing frameshift deletion in PANK2 gene (c.1426_1429delATGA, p.M476 fs) was identified in an 8 years old girl with dystonia, bone fracture, muscle rigidity, abnormal movement, lack of coordination and chorea. In addition, our study revealed a novel missense mutation in PLA2G6 gene (c.3G > T:p.M1I) in one and half-year-old boy with muscle weakness and neurodevelopmental regression (speech, motor and cognition). The novel mutations were also confirmed by Sanger sequencing in the proband and their parents.

CONCLUSIONS

Current study uncovered two rare novel mutations in PANK2 and PLA2G6 genes in patients with NBIA disorder and such studies may help to conduct genetic counseling and prenatal diagnosis more accurately for individuals at the high risk of these types of disorders.

Intrathecal morphine therapy in the management of status dystonicus in neurodegeneration brain iron accumulation type 1

Neurodegeneration with brain iron accumulation type 1 (NBIA-1) is a rare disorder characterized by progressive extrapyramidal dysfunction and dementia. NBIA-1 encompasses typical iron brain accumulation, mostly in the globus pallidus with secondary dementia, spasticity, rigidity, dystonia, and choreoathetosis. Treatment remains mostly symptomatic and is challenging. We present the case of a 14-year-old boy diagnosed with NBIA-1, presenting intractable progressive generalized dystonia leading to unresponsive status dystonicus (SD). The patient received a SynchroMed II (model 8637) programmable system pump (Medtronic®, Inc.) implant with an Ascenda intrathecal catheter for intrathecal morphine therapy (IMT). The initial dose of morphine was 1.0 mg/day. Overall, we observed no complications with IMT treatment and important improvement of the patient's motor function with stabilization of his incapacitating dystonia and his quality of life. On the Global Dystonia Severity Rating Scale, he presented 52% improvement, 30% improvement on the Unified Dystonia Rating Scale, and 38% improvement on the Fahn-Marsden Rating Scale after 10 months, when the dose was 1.7 mg/day. IMT should be considered as a potential palliative treatment in the management of intractable dystonia and SD secondary to NBIA-1.

Adult-onset case of undiagnosed neurodegeneration with brain iron accumulation with psychotic symptoms

Neurodegeneration with brain iron accumulation (NBIA) is a collective term to indicate a group of neurodegenerative diseases presenting accumulation of iron in the basal ganglia. These disorders can result in progressive dystonia, spasticity, parkinsonism, neuropsychiatric abnormalities, and optic atrophy or retinal degeneration. Onset age ranges from infancy to late adulthood and the rate of progression is very variable. So far, the genetic bases of nine types of NBIA have been identified, pantothenate-kinase-associated neurodegeneration (PKAN) being the most frequent type. The brain MRI “eye-of-the-tiger” sign, T2-weighted hypointense signal in the globus pallidus with a central region of hyperintensity, has been considered virtually pathognomonic for PKAN but recently several reports have denied this. A significant percentage of individuals with clinical and radiographic evidence of NBIA do not have an alternate diagnosis or mutation of one of the nine known NBIA-associated genes (idiopathic NBIA). Here we present an adult-onset case of “undiagnosed” NBIA with the brain MRI “eye-of-the-tiger” sign, and with psychotic symptoms which were successfully treated with antipsychotic and mood stabilizer medications. Here, the term “undiagnosed” is used because the patient has not been screened for all known NBIA genes, but only for two of them.