Follow-up MR studies in Hallervorden-Spatz disease

Clinical and genetic delineation of neurodegeneration with brain iron accumulation

Neurodegeneration with brain iron accumulation (NBIA) describes a group of progressive neurodegenerative disorders characterised by high brain iron and the presence of axonal spheroids, usually limited to the central nervous system. Mutations in the PANK2 gene account for the majority of NBIA cases and cause an autosomal recessive inborn error of coenzyme A metabolism called pantothenate kinase associated neurodegeneration (PKAN). More recently, it was found that mutations in the PLA2G6 gene cause both infantile neuroaxonal dystrophy (INAD) and, more rarely, an atypical neuroaxonal dystrophy that overlaps clinically with other forms of NBIA. High brain iron is also present in a portion of these cases. Clinical assessment, neuroimaging, and molecular genetic testing all play a role in guiding the diagnostic evaluation and treatment of NBIA.

Iron in the Hallervorden-Spatz syndrome

The dark discoloration of globus pallidus and substantia nigra pars reticularis in the Hallervorden-Spatz syndrome is due to the accumulation of iron. Routine iron stains detect the metal mostly in microglia and macrophages, but scattered neurons are also reactive. Axonal spheroids are characteristic of the disease, and many of these expansions give a positive iron reaction. Globus pallidus and substantia nigra are normally rich in iron, and additional "storage" of the metal has often been considered the essential factor in the pathogenesis of Hallervorden-Spatz syndrome. However, other equally iron-rich structures, such as the red nucleus and the dentate nucleus, remain unaffected. In normal globus pallidus and substantia nigra pars reticularis, double-label immunofluorescence microscopy of ferritin, as an indirect marker of cellular iron localization, and phosphorylated neurofilament protein reveal close proximity of ferritin-reactive microglial and oligodendroglial processes to tightly packed axons. It is proposed that a primary axonal disorder allows the seepage of iron into the axoplasm. Iron may contribute to the axonal disease, but accumulation of the metal probably should be viewed as an epiphenomenon. Pallidal and nigral iron excess is not unique to Hallervorden-Spatz syndrome, and some previously reported postmortem examinations may actually represent pallidonigroluysian atrophy.

Hallervorden-Spatz disease: two new early childhood onset cases

Hallervorden-Spatz disease is a rare, autosomal-recessive hereditary condition characterized by early onset of progressive movement alterations such as dystonia, rigidity, and choreoathetosis, which is usually associated with pyramidal signs and mental deterioration. The authors report two cases for which diagnosis of Hallervorden-Spatz disease was based on clinical manifestations that appeared during the first year of life, illness progression, and late-stage magnetic resonance imaging findings. The possibility that these two cases, along with other previously described rare instances with similar clinical features, be considered as a variant of subtype of the early-onset type of Hallervorden-Spatz disease is suggested. The need to differentiate these cases from cases of static encephalopathy with mental retardation and motor impairment is also stressed.

Hallervorden-Spatz disease

In a 22 year old man with dominant extrapyramidal signs, dystonia and mental deterioration, magnetic resonance imaging revealed marked overall low signal from the globus pallidus on each side, with central zones of high signal on T2-weighted spin echo sequences. There was also a strikingly low signal in the zona reticularis of the substantia nigra, consistent with Hallervorden-Spatz disease.

Clinicopathological study of familial late infantile Hallervorden-Spatz disease: a particular form of neuroacanthocytosis

The cases of two sisters with late infantile Hallervorden-Spatz disease are reported, one of whom has died. Autopsy of the deceased patient showed typical pallidal lesions, such as axonal spheroids and iron deposits, without involvement of the substantia nigra. Ultrastructural examination revealed that pallidal axonal enlargements consisted of collection of mitochondria, dense bodies, vesicles and amorphous material. In the living patient, brain MRI showed the classical "tiger's eye" appearance of the globus pallidus. Retinitis pigmentosa, acanthocytosis and slight neuromuscular involvement with an increase in serum creatine kinase were observed in both subjects. The appearance of the globus pallidus on MRI was in line with the pathological abnormalities. Ultrastructural differences between the principal disorders characterized by neuroaxonal dystrophy are compared and the clinical spectrum and similarities of the different forms of neuroacanthocytosis analysed.

In vivo diagnosis of Hallervorden-Spatz disease

The authors present the MRI findings of two children with insidious walking difficulties, signs of corticospinal tract involvement, and signs and symptoms of extrapyramidal dysfunction such as rigidity and generalized dystonia, the latter with predominance of oromandibular involvement. In one child, MRI revealed prominent hypo-intensity in the globus pallidus and in the substantia nigra on T2-weighted spin echo images, consistent with iron deposition and thus with previous post-mortem findings of Hallervorden-Spatz disease. In the other case, the hypo-intensity was restricted to the globus pallidus, in which a small area of hyperintensity in its internal segment was demonstrated--the so called 'eye-of-the-tiger' sign. The authors propose that a combination of previously mentioned neurological signs with these specific MRI findings is highly suggestive of an in vivo diagnosis of the late infantile type of HSD.

Early clinical and imaging (high-field MRI) diagnosis of Hallervorden-Spatz disease

In a 10-year-old girl, with progressive motor disturbance since the age of seven years and dominant pyramidal signs, MRI revealed marked overall low signal from the globus pallidus on each side, with central zones of high signal. There was also strikingly low signal in the zona reticularis of the substantia nigra, indicative of Hallervorden-Spatz disease (HSD).

Bilateral striatal lesions in childhood

From 1983 to 1991, 13 patients were identified with a clinical radiologic association characterized by acute or persistent neurologic dysfunction and bilateral lesions in the basal ganglia region demonstrated by ultrasound, computed tomography, or magnetic resonance imaging. Initial clinical manifestations of this group of patients were characterized by extrapyramidal signs (i.e., dystonia 9, hypotonia 2, athetosis 1, rigidity 1), altered state of consciousness in 5, and seizures in 3. The outcomes of most of these patients were poor: 10 had motor sequelae, 9 cognitive impairment, and 4 died. The outcomes of 2 patients, however, were much better than what was expected from the initial presentation. Based on current and previous reports, the diagnostic approach and classification of patients with neurologic dysfunction and bilateral striatal lesions are presented.

MRI in a case of rigid Huntington's disease

Images

Hallervorden-Spatz disease: clinical and MRI study of 11 cases diagnosed in life

The diagnosis of Hallervorden-Spatz disease (HSD) has usually been made post mortem, although the recent description of characteristic abnormalities in the globus pallidus has suggested the possibility of an in vivo diagnosis. We present the clinical histories, neurological features and MRI findings of 11 patients, diagnosed as having HSD. Generalized dystonia with predominance of oromandibular involvement, behavioural changes followed by dementia and retinal degeneration were present in all the patients. MRI pallidal abnormalities consisted of decreased signal intensity in T2-weighted images, compatible with iron deposits, and of a small area of hyperintensity in its internal segment ("eye of the tiger" sign). We propose that the combination of these neurological signs with these MRI findings could be considered as highly suggestive of a diagnosis of HSD in living patients.

Follow-up magnetic resonance imaging in Hallervorden-Spatz disease

Bilateral high signal emitting areas in the globus pallidus surrounded by low signal emitting areas have been described as a typical MRI finding in Hallervorden-Spatz disease (HSD). We made a diagnosis of HSD in an 11-year-old girl with progressive dystonia of 4 years duration who showed these typical MRI abnormalities. An initial MRI at the age of 9 was normal. Pathological confirmation of these typical MRI findings has not yet been described, but earlier reports as well as our case suggest that MRI may be helpful in making a clinical diagnosis of HSD. This case further shows that MRI may be normal in an early stage of the disease.

Abnormally increased iron concentration in basal ganglia in Shy-Drager syndrome. MR imaging and autonomic study

Report of an early case of Shy-Drager syndrome in a 67 year-old woman patient. Autonomic failure was diagnosed by functional evaluation as well as laboratory tests. MR imaging disclosed a prominent putamina hypodensity in T2-weighted images at high field strength due to iron increased depositing in this basal ganglia. MR imaging evidences confirm Shy-Drager syndrome diagnosis, and contributes for differential diagnosis of idiopathic hypotension (pure autonomic failure) in special in SDS early cases.