Spinal Nerve Root Enhancement on MRI Scans in Children: A Review

A New Pattern of Brain and Cord Gadolinium Enhancement in Molybdenum Cofactor Deficiency: A Case Report

Molybdenum cofactor deficiency (MoCD) is a rare and severe autosomal recessive in-born error of metabolism caused by the mutation in MOCS1, MOCS2, MOCS3 or GEPH genes, with an incidence ranging between 1 in 100,000 and 200,000 live births. The clinical presentation with seizures, lethargy and neurologic deficits reflects the neurotoxicity mediated via sulphite accumulation, and it occurs within the first hours or days after birth, often leading to severe neurodegeneration and the patient's death within days or months. The Imaging of Choice is a brain-specific MRI technique, which is usually performed without contrast and shows typical radiological findings in the early phase, such as diffuse cerebral oedema and infarction affecting the cortex and the basal ganglia and the white matter, as well as in the late phase, such as multicystic encephalomalacia. Our case report represents a novelty in the field, since the patient underwent a contrast-enhanced MRI to exclude a concomitant infectious disease. In the frame of the clinical presentation and laboratory data, we describe the MoCD Imaging findings for MRI morphological and advanced sequences, presenting a new contrast-enhanced MRI pattern characterized by the diffuse and linear leptomeningeal enhancement of brain, cord and spinal roots. The early identification of molybdenum cofactor deficiency is crucial because it may lead to the best multidisciplinary therapy for the patient, which is focused on the prompt and optimal management of the complications.

Spinal Nerve Roots Abnormalities on MRI in a Child with SURF1 Mitochondrial Disease

Variants in SURF1, encoding an assembly factor of mitochondrial respiratory chain complex IV, cause Leigh syndrome (LS) and Charcot-Marie-Tooth type 4K in children and young adolescents. Magnetic resonance imaging (MRI) appearance of enlarged nerve roots with postcontrastographic enhancement is a distinctive feature of hypertrophic neuropathy caused by onion-bulb formation and it has rarely been described in mitochondrial diseases (MDs). Spinal nerve roots abnormalities on MRI are novel findings in LS associated with variants in SURF1. Here we report detailed neuroradiological and neurophysiologic findings in a child with LS and demyelinating neuropathy SURF1-related. Our case underlines the potential contributive role of spinal neuroimaging together with neurophysiological examination to identify the full spectrum of patterns in MDs. It remains to elucidate if these observations remain peculiar of SURF1 variants or potentially detectable in other MDs with peripheral nervous system involvement.

Prognostic value of contrast-enhanced MRI in Guillain-Barré syndrome in children

BACKGROUND

The aim of this retrospective study is to explore the prognostic value of different contrast enhancement imaging patterns in childhood Guillain-Barré syndrome by comparing the clinical, laboratory, and therapeutic outcomes.

METHODS

We included a total of 37 patients who were diagnosed and followed up by a pediatric neurology team at Montpellier University Hospital between 2000 and 2016. All images were reinterpreted by the first author and a senior pediatric neuroradiology staff member in two different sessions; in the case of disagreement, the expert's reading was considered.

RESULTS

The study group comprised 22 (59.5%) boys and 15 (40.5%) girls. The age ranged from 1.5 year to 14.8 years. Muscle weakness was present in 33 (89.2%) patients. Cranial nerves involvement was observed in 22 (59.5%) patients, while 29 (78.4%) patients had albuminocytological dissociation. In 27 (73%) patients, contrast enhancement or thickening of the lumbosacral nerve roots was found. Simultaneous spinal nerve root and cranial nerve enhancement was noted in five (17.2%) patients, while isolated cranial nerve enhancement was identified in three (10.3%) patients. Clinical and radiological cranial nerve involvement was found in seven (18.9%) patients, while isolated clinical cranial nerves involvement occurred in 13 (35.1%) patients. No significant correlation between different magnetic resonance imaging (MRI) enhancement patterns and short-term or long-term outcomes was found in our cohort.

CONCLUSION

Contrast-enhanced brain and spinal MRI is a sensitive and recommended supportive test for diagnosing acute inflammatory polyradiculopathy in children. Its predictive value for clinical, and therapeutic outcomes in the short or long term has not yet been proved.

Are Repeated Cycles of Intravenous Immunoglobulin Justified in Patients With Poorly Responsive Guillain-Barré Syndrome?

Guillain-Barré syndrome (GBS) is a life-threatening form of inflammatory polyneuropathy. Immunotherapy with intravenous immunoglobulin (IVIG) has been used successfully in the treatment of GBS. In this case report, we present a severe axonal form of GBS that showed improvement after 3 cycles of IVIG. Repeated cycles of IVIG may be an option for treating severe forms of GBS not responding to the first course of such treatment. The recent work suggests that patients who are severely affected and have severe gadolinium enhancement on the magnetic resonance imaging of the spine should be considered for retreatment with IVIG. Although the cost of management was high, the outcome was excellent, which is definitely considered a reasonable approach. This case report is an urgent call for performing large multicenter trials on the use of repeated cycles of IVIG in the management of severe cases of GBS.

Acute neurotoxicity following vincristine due to Charcot-Marie-Tooth disease in a young child with medulloblastoma

Vincristine (VCR), a microtubule inhibitor that arrests the cell cycle by blocking metaphase of mitosis, is unique among the vinca alkaloids for causing polyneuropathy. Patients with increased risk of VCR neurotoxicity include the elderly and those with prior history of neuropathy-prone medical conditions. Identifying such risk factors prior to the development of neurotoxicity should be a goal prior to VCR administration. Clinicians should obtain a thorough medical and family history of neuropathies in any child scheduled to receive neurotoxic medications to avoid exacerbating an underlying disorder. We report a case of a young child with newly diagnosed medulloblastoma who started treatment on a VCR-containing chemotherapy regimen following surgery and craniospinal radiation. She subsequently developed severe peripheral polyneuropathy and new enhancement of the cranial and nerve roots following a relatively low cumulative dose of VCR and was diagnosed with previously unidentified Charcot-Marie-Tooth disease (CMTD) Type 1A. This case highlights that an evaluation of risk factors should be completed prior to initiation of neurotoxic chemotherapies and advocates for testing for inherited neuropathies such as CMTD even in asymptomatic patients when hereditary neuropathy is suspected.

Toxic-Metabolic Neurologic Disorders in Children: A Neuroimaging Review

There are multiple causes of neurotoxicity in children including medications, extrinsic toxins and insults, illicit drugs, built up of toxic metabolites due to genetic or acquired disorders, and metabolic abnormalities. The review is centered on causes of neurotoxicity affecting the pediatric brain and producing typical and easily recognized imaging manifestations. Early identification of common and less common imaging findings may point toward the correct direction, and may facilitate early diagnosis and institution of appropriate treatment to reverse or at least limit the injury to the developing brain. Two common imaging patterns of neurotoxicity in children are the posterior reversible encephalopathy syndrome and acute toxic leukoencephalopathy that are usually related to chemotherapy and immunosuppression for common pediatric malignancies. Another well-described imaging pattern of injury in children involves reversible splenial lesions with or without associated white matter abnormalities. Multiple additional extrinsic causes of neurotoxicity are presented including radiation and chemoradiation, various medications and treatment regimens, poisoning, illicit drug use or accidental exposure, and the respective characteristic neuroimaging findings are highlighted. Intrinsic neurotoxicity may occur in the setting of inborn errors of metabolism or acquired progressive organ failure leading to build up of toxic metabolites. Additional intrinsic causes of neurotoxicity include metabolic derangements and characteristic imaging findings in all instances are reviewed. The goal of the article is to enhance familiarity of neurologists and neuroradiologists with the imaging appearance of common and less common toxic insults to the pediatric brain.