Multiparametric MRI and T2/FLAIR mismatch complements the World Health Organization 2021 classification for the diagnosis of IDH-mutant 1p/19q non-co-deleted/ATRX-mutant astrocytoma.

AIM: To investigate whether T2-weighted imaging-fluid-attenuated inversion recovery (T2/FLAIR) mismatch, T2∗ dynamic susceptibility contrast (DSC) perfusion, and magnetic resonance spectroscopy (MRS) correlated with the histological diagnosis and grading of IDH (isocitrate dehydrogenase)-mutant, 1p/19q non-co-deleted/ATRX (alpha-thalassemia mental retardation X-linked)-mutant astrocytoma. MATERIALS: Imaging of 101 IDH-mutant diffuse glioma cases of histological grades 2-3 (2019-2021) were analysed retrospectively by two neuroradiologists blinded to the molecular diagnosis. T2/FLAIR mismatch sign is used for radio-phenotyping, and pre-biopsy multiparametric MRI images were assessed for grading purposes. Cut-off values pre-determined for radiologically high-grade lesions were relative cerebral blood volume (rCBV) ≥2, choline/creatine ratio (Cho/Cr) ≥1.5 (30 ms echo time [TE]), Cho/Cr ≥1.8 (135 ms TE). RESULTS: Sixteen of the 101 cases showed T2/FLAIR mismatch, all of which were histogenetically confirmed IDH-mutant 1p/19q non-co-deleted/ATRX mutant astrocytomas; 50% were grade 3 (8/16) and 50% grade 2 (8/16). None showed contrast enhancement. Nine of the 16 had adequate multiparametric MRI for analysis. Any positive value by combining rCBV ≥2 with Cho/Cr ≥1.5 (30 ms TE) or Cho/Cr ≥1.8 (135 ms TE) predicted grade 3 histology with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%. CONCLUSION: The T2/FLAIR mismatch sign detected diffuse astrocytomas with 100% specificity. When combined with high Cho/Cr and raised rCBV, this predicted histological grading with high accuracy. The future direction for imaging should explore a similar integrated layered approach of 2021 classification of central nervous system (CNS) tumours combining radio-phenotyping and grading from structural and multiparametric imaging.

A comparative historical and demographic study of the neuromodulation management techniques of deep brain stimulation for dystonia and cochlear implantation for sensorineural deafness in children.

Cochlear implants for sensorineural deafness in children is one of the most successful neuromodulation techniques known to relieve early chronic neurodisability, improving activity and participation. In 2012 there were 324,000 recipients of cochlear implants globally. AIM: To compare cochlear implant (CI) neuromodulation with deep brain stimulation (DBS) for dystonia in childhood and explore relations between age and duration of symptoms at implantation and outcome. METHODS: Comparison of published annual UK CI figures for 1985-2009 with a retrospective cohort of the first 9 years of DBS for dystonia in children at a single-site Functional Neurosurgery unit from 2006 to 14. RESULTS: From 2006 to 14, DBS neuromodulation of childhood dystonia increased by a factor of 3.8 to a total of 126 cases over the first 9 years, similar to the growth in cochlear implants which increased by a factor of 4.1 over a similar period in the 1980s rising to 527 children in 2009. The CI saw a dramatic shift in practice from implantation at >5 years of age at the start of the programme towards earlier implantation by the mid-1990s. Best language results were seen for implantation <5 years of age and duration of cochlear neuromodulation >4 years, hence implantation <1 year of age, indicating that severely deaf, pre-lingual children could benefit from cochlear neuromodulation if implanted early. Similar to initial CI use, the majority of children receiving DBS for dystonia in the first 9 years were 5-15 years of age, when the proportion of life lived with dystonia exceeds 90% thus limiting benefits. CONCLUSION: Early DBS neuromodulation for acquired motor disorders should be explored to maximise the benefits of dystonia reduction in a period of maximal developmental plasticity before the onset of disability. Learning from cochlear implantation, DBS can become an accepted management option in children under the age of 5 years who have a reduced proportion of life lived with dystonia, and not viewed as a last resort reserved for only the most severe cases where benefits may be at their most limited.

A single thalamic target for deep brain stimulation to treat hemi-body pain syndrome.

BACKGROUND: Patients experiencing hemi-body pain represent a difficult problem when using the thalamus as a DBS target given its anatomical topology. METHODS: A 50-year-old HIV positive male underwent a right unilateral thalamic DBS to treat his severe left hemi-body central post-stroke pain following years of unsuccessful medication therapy. RESULTS: The final active contact of the electrode corresponded to stimulation of the nucleus ventrocaudalis parvocellularis internis, which has provided prolonged pain relief. CONCLUSION: To our knowledge this was the first time this pattern of pain was treated by a single thalamic DBS electrode, suggesting stimulation in this region may be a feasible target for achieving relief from chronic severe hemi-body pain.

Excellent functional outcome following selective dorsal rhizotomy in a child with spasticity secondary to transverse myelitis.

PURPOSE: Selective dorsal rhizotomy (SDR) is a neurosurgical procedure used to treat spasticity in children with cerebral palsy (CP). The vast majority of studies to date suggest SDR is particularly effective in reducing lower limb spasticity in spastic diplegia with long-lasting effect. METHOD: We report, to the best of our knowledge for the first time, the case of a teenager who underwent SDR for the management of spasticity secondary to transverse myelitis. RESULTS: This is an unusual indication for SDR which resulted in completely loose lower limbs and an excellent functional outcome. At a follow-up 18 months following the procedure, the child had no re-occurrence of his symptoms. CONCLUSION: This report raises the possibility that the use of SDR could be expanded to include other pathologies. We discuss the case and the relevant literature. Our spasticity service at NUH has to date inserted 300 baclofen pumps and performed 60 SDRs mainly in children with cerebral palsy.

Spinal cord stimulation to abort painful spasms of atypical stiff limb syndrome.

Stiff limb syndrome (SLS) is a rare chronic condition which can result in significant debility. We report the case of a 44-year-old man suffering from severe painful spasms in his right leg with a diagnosis of SLS. He had been initially treated for his pain with a spinal cord stimulator but presented with exacerbation of pain secondary to a lead fracture for which he underwent revision of the stimulator. Postoperative programming unexpectedly resulted in not only control of his pain but also an ability to abort his spasmodic episodes related to SLS. To our knowledge, spinal cord stimulation has not been previously used for SLS and our report opens up another avenue for this rare condition. We provide a brief overview of SLS and propose an underlying mechanism for the observed phenomenon.

Never go to sleep on undrained pus: a retrospective review of surgery for intraparenchymal cerebral abscess.

Cerebral abscess is an emergency requiring urgent drainage via craniotomy or burrhole aspiration. We examine whether initial method of drainage affects outcome and important characteristics in patients with cerebral abscess. This is a retrospective analysis of 62 patients operated on in our unit with a loculated infected cerebral collection in the years 2003-2007 inclusive. Full statistical analysis was performed using data appropriate tests. Burrhole and craniotomy groups were evenly matched with no difference in any demographic factors. Surgical method made no difference to rate of re-operation (p = 0.276), antibiotic duration (p = 0.648), discharge GCS (p = 0.509), length of stay (p = 0.647) or GOS (p = 0.968). There was a trend to worsened outcome with delay to surgery (p = 0.132) with delayed patients requiring longer hospital stays (p < or = 0.005). Patients requiring a longer antibiotic duration had worse outcomes (p < or = 0.005). Surgical method did not have a significant effect on outcome, so burrhole aspiration with its advantages in terms of speed and scale of surgery should be strongly considered. Delay had an adverse affect, so operation should be as expeditious as possible whenever the differential diagnosis includes abscess, diagnosis of which may be aided by advanced magnetic resonance imaging techniques.