Magnetic Resonance Imaging Biomarkers in Patients with Progressive Ataxia: Current Status and Future Direction

A diagnostic challenge commonly encountered in neurology is that of an adult patient presenting with ataxia. The differential is vast and clinical assessment alone may not be sufficient due to considerable overlap between different causes of ataxia. Magnetic resonance (MR)-based biomarkers such as voxel-based morphometry, MR spectroscopy, diffusion-weighted and diffusion-tensor imaging and functional MR imaging are gaining great attention for their potential as indicators of disease. A number of studies have reported correlation with clinical severity and underlying pathophysiology, and in some cases, MR imaging has been shown to allow differentiation of conditions causing ataxia. However, despite recent advances, their sensitivity and specificity vary. In addition, questions remain over their validity and reproducibility, especially when applied in routine clinical practice. This article extensively reviews the current literature regarding MR-based biomarkers for the patient with predominantly adult-onset ataxia. Imaging features characteristic of a particular ataxia are provided and features differentiating ataxia groups and subgroups are discussed. Finally, discussion will turn to the feasibility of applying these biomarkers in routine clinical practice.     

Ophthalmological injuries associated with fractures of the orbitozygomaticomaxillary complex

Our aim was to evaluate ophthalmological injuries associated with fractures of the orbitozygomaticomaxillary complex that required operative treatment, and we collected data retrospectively over a period of five years (2012-2016 inclusive). Of the 190 patients, 162 were male with a median age of 31 (IQR 25 -39) years. Assault was the most common mechanism of injury (125/190, 66%). Minor ophthalmic injuries (those unlikely to cause permanent visual disturbance) and major ophthalmic injuries (those with the potential to cause permanent visual disturbance) were recorded. The common minor ophthalmic injuries were: diplopia, enophthalmos, proptosis, subconjunctival haemorrhage, and restriction of the extraocular muscles. Commotio retinae, traumatic mydriasis, retro-orbital haemorrhage, and hyphaema were the common major ophthalmic injuries. All 13 different major ophthalmic injuries were recorded in the group who had had orbital fractures reconstructed, which suggested that more intraocular damage can be caused by this type of fracture than by others. Visual acuity was reduced in 26/190 patients with only four having persistent postoperative changes at six weeks. The odds ratio for those patients who had a major ophthalmological injury and were unable to drive was 0.07 (95% CI 0.02 to 0.21, p = 0.001), which was highly significant. Ophthalmological assessment is strongly recommended for patients with fractures of the orbitozygomaticomaxillary complex.     

Fatal metabolic stroke in a child with propionic acidemia 11 years post liver transplant

Propionic acidemia is a rare autosomal recessive inborn error of metabolism caused by a deficiency of propionyl CoA carboxylase which often manifests with frequent metabolic decompensations and risk of neurological injury. Outcomes with medical therapy remain suboptimal. Liver transplantation has been shown to be a therapeutic option for patients and results in a milder phenotype of the disease and partial correction of the enzyme defect. Liver transplantation has been increasingly reported over the last decade and experience in managing these patients is improving. Long-term outcomes are generally good; however, the risk of complications still exists despite transplantation. We report a child who presented with a fatal metabolic stroke 11 years post liver transplant without any biochemical evidence of decompensation. We highlight the need to closely monitor these patients lifelong despite liver transplantation and maintain multidisciplinary working between hepatology and metabolic clinicians.