Bilateral striatal lesions in childhood

Neurological Disorders Associated with Striatal Lesions: Classification and Diagnostic Approach

Neostriatal abnormalities can be observed in a very large number of neurological conditions clinically dominated by the presence of movement disorders. The neuroradiological picture in some cases has been described as "bilateral striatal necrosis" (BSN). BSN represents a condition histo-pathologically defined by the involvement of the neostriata and characterized by initial swelling of putamina and caudates followed by degeneration and cellular necrosis. After the first description in 1975, numerous acquired and hereditary conditions have been associated with the presence of BSN. At the same time, a large number of disorders involving neostriata have been described as BSN, in some cases irrespective of the presence of signs of cavitation on MRI. As a consequence, the etiological spectrum and the nosographic boundaries of the syndrome have progressively become less clear. In this study, we review the clinical and radiological features of the conditions associated with MRI evidence of bilateral striatal lesions. Based on MRI findings, we have distinguished two groups of disorders: BSN and other neostriatal lesions (SL). This distinction is extremely helpful in narrowing the differential diagnosis to a small group of known conditions. The clinical picture and complementary exams will finally lead to the diagnosis. We provide an update on the etiological spectrum of BSN and propose a diagnostic flowchart for clinicians.

Biotin-responsive basal ganglia disease: neuroimaging features before and after treatment

BACKGROUND AND PURPOSE

Biotin-responsive basal ganglia disease is an autosomal recessive neurometabolic disorder presenting with subacute encephalopathy that can cause death if left untreated. The purpose of this study is to assess the neuroimaging and clinical features of the disease before and after treatment with biotin.

MATERIALS AND METHODS

We retrospectively reviewed the clinical, laboratory, and neuroimaging features of 15 genetically-proved Middle Eastern cases of biotin-responsive basal ganglia disease. Brain MR imaging was done at the onset of symptoms in all cases and within 2-8 weeks after biotin and thiamine therapy in 14 patients. The MR imaging datasets were analyzed according to lesion location, extent, and distribution.

RESULTS

Brain MR imaging showed bilateral lesions in the caudate nuclei with complete or partial involvement of the putamen and sparing of the globus pallidus in all cases. In 80%, discrete abnormal signals were observed in the mesencephalon, cerebral cortical-subcortical regions, and thalami. In 53%, when the disease was advanced, patchy deep white matter affection was found. The cerebellum was involved in 13.3%. The signal abnormality of the mesencephalon, cortex, and white matter disappeared after treatment whereas the caudate and putamen necrosis persisted in all patients, including those who became asymptomatic.

CONCLUSIONS

Biotin-responsive basal ganglia disease is a treatable underdiagnosed disease. It should be suspected in pediatric patients with unexplained encephalopathy whose brain MR imaging shows bilateral and symmetric lesions in the caudate heads and putamen, with or without involvement of mesencephalon, thalami, and cortical-subcortical regions, as the therapeutic trial of biotin and thiamine can be lifesaving.

Reversible parainfectious bilateral "striatal necrosis"

Bilateral striatal necrosis is usually associated with either endogenous or exogenous toxins, and with poor neurodevelopmental outcomes. We describe two patients with acute bilateral striatal clinical syndrome and magnetic resonance signal changes who made a complete clinical and radiologic recovery within 3 months. After an uneventful pregnancy, normal birth, and normal development, both boys presented at ages 3 and 5 years, respectively, after a viral illness with slurring of speech, bradykinesia, and an extrapyramidal movement disorder. On examination, both manifested bilateral cog wheel rigidity, with a broad-based gait and flexor plantar response. Cranial magnetic resonance imaging in both children indicated bilateral, symmetric, high signal changes in the lentiform nucleus, predominately in the putamen, with sparing of the globus pallidi bilaterally. The brain parenchyma was otherwise normal. Neurometabolic investigations produced normal results in both patients. The pathogenesis is uncertain, but could be immune-mediated. Both children, at 3-year and 1-year follow-ups, respectively, are doing well neurologically and academically. Our patients demonstrate that abnormal imaging findings during acute stages do not preclude good clinical and radiologic recovery.

Intraventricular baclofen for dystonia: techniques and outcomes. Clinical article

OBJECT

The aim of this study was to evaluate the use of intraventricular baclofen (IVB) for the treatment of severe generalized secondary and heredodegenerative dystonia.

METHODS

Nine children and 1 adult with severe dystonia unresponsive to multiple oral medications were treated with IVB. Intraventricular catheters were positioned endoscopically in the third ventricle.

RESULTS

Eight of the 10 patients responded to IVB; their mean dystonia scores on the Barry-Albright dystonia scale decreased from 23 to 8. The 2 patients who did not respond had not responded to previous high doses of intrathecal baclofen. No adverse side effects related to IVB occurred. One child developed a pump infection that required pump removal, 1 developed a CSF infection that cleared after antibiotic administration, and 1 developed ventriculomegaly that required a shunt placement.

CONCLUSIONS

Intraventricular baclofen is an effective method of infusing baclofen to treat severe, generalized secondary dystonia, and, at times, heredodegenerative dystonia. The site of baclofen's activity when treating dystonia may be at the cortical level, and intraventricular infusion may result in higher baclofen concentrations over the cortex than intrathecal infusion. Additional studies are necessary to determine whether IVB is effective at lower doses than those used with intrathecal baclofen administration.

Bilateral putaminal necrosis associated with the mitochondrial DNA A8344G myoclonus epilepsy with ragged red fibers (MERRF) mutation: an infantile case

Myoclonus epilepsy with ragged red fibers (MERRF) is one of the major mitochondrial encephalomyopathies. Its main clinical features are myoclonus epilepsy, ataxia, and myopathy with ragged red fibers. Whereas there is a close correlation between MERRF syndrome and the A8344G mutation of mitochondrial DNA, the reverse is not true. In fact, this mutation is also responsible for various other syndromes, such as Leigh syndrome, spinocerebellar degeneration, atypical Charcot-Marie-Tooth disease, and multiple truncal lipomas. We describe a child with the A8344G mutation of mitochondrial DNA and an unusual clinical, neuroradiologic, and biochemical phenotype, characterized by early-onset, nonprogressive cerebellar ataxia, and subclinical myoclonias in association with bilateral putaminal necrosis on magnetic resonance imaging and a reduction in complex V activity. Our case confirms the existence of a relationship between alteration in adenosine triphosphatase activity and basal ganglia involvement. We recommend that the possibility of a mitochondrial pathology should always be taken into consideration in the presence of bilateral symmetric lesions of the basal ganglia, even when the typical clinical picture is lacking. (J Child Neurol 2006;21:79-82).

Long-term findings on brain magnetic resonance imaging in acute encephalopathy with bilateral striatal necrosis associated with measles

The long-term findings on brain magnetic resonance imaging (MRI) in a 7 10/12-year-old boy with a history of acute encephalopathy with bilateral striatal necrosis following measles at the age of 22 months are described. At the early stage of illness, brain MRI studies revealed bilateral, symmetric basal ganglia lesions, predominant on the globi pallidi, appearing as hyperintense signals on T1- and T2-weighted images. Six years later, follow-up brain MRI studies showed that the bilateral, symmetric lesions on the globi pallidi persisted with low signal on T1- and high signal on T2 weighted images. At present, the patient has some persistent neurologic signs. These findings suggest that both clinical and neuroradiologic findings may persist in children with acute encephalopathy with bilateral striatal necrosis following measles.

Severe generalized dystonia due to primary putaminal degeneration: case report and review of the literature

Putaminal lesions of a variety of etiologies may cause secondary dystonia. We report on a case of primary putaminal degeneration as a cause of severe childhood-onset generalized dystonia and review the literature of the pathology of dystonia. A 44-year-old patient with severe generalized childhood-onset dystonia and macrocephaly underwent neurological evaluation and neuropathological examination. Neurological examination was normal apart from dystonia and signs referable to prior cryothalamotomy. Workup for metabolic and genetic causes of dystonia was negative. Neuroimaging showed severe bilateral putaminal degeneration, which subsequently correlated with the neuropathological findings of gliosis, spongiform degeneration, and cavitation. The substantia nigra pars compacta contained a normal number of neurons but decreased tyrosine hydroxylase immunoreactivity. There were no histopathological markers of other metabolic or degenerative diseases.

Infantile bilateral striatal necrosis following measles

A previously healthy 4-year-old boy presented with typical measles and demonstrated lesions confined to basal ganglia. The clinical symptoms were an abrupt onset, impaired consciousness and mutism, extrapyramidal signs and severe neurovegetative dysfunction. No modification of the cerebrospinal fluid was observed; laboratory tests were all normal with the exception of a positive serologic test for measles. Cranial magnetic resonance imaging showed abnormal signals in the striatum, affecting the putamen and the caudate nuclei bilaterally. Neurologic improvement occurred within 2 months, with regression of lesions on cranial imaging, suggesting that edema played an important role in the initial stage of the disease.

Transient seizure disappearance due to bilateral striatal necrosis in a patient with intractable epilepsy

An 8-year-old girl had suffered from intractable epilepsy due to cortical dysplasia. She developed mycoplasma pneumonia with massive pleural effusion. Fever continued for 3 weeks. Four weeks after the onset of this infection, she suddenly developed horizontal nystagmus, ataxia, choreoathetotic movements and confusion. CT disclosed swelling and low density of the heads of the caudate nuclei and putamina bilaterally. MRI revealed areas of symmetrical high intensity in the striatum on T2-weighted imaging. These lesions were thought to comprise bilateral striatal necrosis (BSN) mediated by the mycoplasma infection or Wernicke encephalopathy. Six months later, she had completely recovered clinically. During the 6 months after BSN, she did not have any epileptic seizures. Her epileptic seizures reappeared thereafter at a lower frequency. The striatum may be involved in the propagation pathway for epileptic seizure activity in this patient.

Trihexyphenidyl in posthemorrhagic dystonia: motor and language effects

Trihexyphenidyl has been found to be an effective treatment for dystonic movement disorders, improving gross motor function in patients with axial and torsional dystonia, tremors, and myoclonus. In this report, improvements in fine motor control, language, and oral motor skills are described with trihexyphenidyl in an 8-year-old female who developed dystonia after spontaneous bilateral putamenal hemorrhages. No adverse side effects occurred. The mechanism of action of trihexyphenidyl is believed to be in the basal ganglia where it inhibits muscarinic cholinergic receptors and increases the turnover of dopamine.

Fulminant Leigh syndrome and sudden unexpected death in a family with the T9176C mutation of the mitochondrial ATPase 6 gene

We report an Italian family in which the T-to-C point mutation at nucleotide 9176 of the mitochondrial adenosine triphosphate synthetase (mtATPase) 6 gene is associated with an early-onset fulminant form of Leigh syndrome and with sudden unexpected death in two siblings, respectively. Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis and direct sequencing revealed that the mutation was homoplasmic in mitochondrial DNA of the proband. The T9176C mutation changes a highly conserved leucine to a proline in subunit 6 of the mtATPase gene and is maternally inherited, but the maternal relatives are asymptomatic. This point mutation was initially described in two brothers with bilateral striatal necrosis, a milder variant of Leigh syndrome.

Acute encephalopathy with bilateral striatal necrosis: favourable response to corticosteroid therapy

A case of acute encephalopathy with selective bilateral symmetrical striatal lesions is reported. The patient was a previously healthy 4-year-old boy who became obtunded after a febrile illness and fell into a state of delirium with severe pain in the feet. He showed abnormal postures: hyperextension of the neck and upper limbs and extreme flexion of both lower limbs, and abnormal involuntary movements of the limbs: tremor, athetotic movement and right hemiballismus. Analysis of serum antibody titres suggested recent primary infection of herpes simplex type 1 (HSV-1). Cranial T2-weighted magnetic resonance imaging (MRI) demonstrated areas of high-signal intensity involving the whole basal ganglia bilaterally. He showed rapid clinical improvement after the initiation of corticosteroid therapy; complete clinical recovery was noted 3 months after the onset. Serial MRI studies demonstrated a rapid reduction of the lesions, resulting in only slight T2-hyperintense areas in both caudate nuclei. The pathogenesis of the disorder remains unknown, though an autoimmune mechanism has been speculated. The clinical and laboratory findings in this case suggested a possible role of HSV-1 in the pathomechanism of the disorder and a beneficial effect of early corticosteroid therapy.

Bilateral striatal necrosis with a novel point mutation in the mitochondrial ATPase 6 gene

A 2.5-year-old boy with bilateral striatal lesions is reported. Using polymerase chain reaction-single-strand conformation polymorphism analysis and direct DNA sequencing, a novel point mutation (T to C) at nucleotide 8851 of the mitochondrial DNA (mtDNA) was identified. This mutation changes a highly conserved tryptophan to arginine in subunit 6 of the mtATPase gene. The mutation was nearly homoplasmic and maternally inherited. This is the first published report of a mutation in the mtDNA in bilateral striatal degeneration. It is possible that other cases of bilateral striatal degeneration have been caused by mutations in the mtATPase 6 gene or genes encoding other subunits of the mtATPase; and therefore the mtATPase genes should be examined in children with this condition.

Infantile progressive striato-thalamic degeneration in two siblings: a new syndrome

The clinical features, neuroimaging, and neuropathologic findings of a new syndrome, characterized by onset in early infancy, progressive course, choreiform movements, hypotonia, and dysphagia, are described in 2 siblings originating from a consanguineous marriage. The serial neuroimaging studies indicated progressive loss of volume of both caudate nuclei and change in signal intensity in putamina. Pathologically, there was severe neuronal loss and gliosis in the striatum and thalamus. This pathologic pattern in association with clinical and radiologic correlates, to our knowledge, has not been previously described. It appears that this syndrome is an autosomal recessive disorder.