Rupture of a flow aneurysm secondary to spontaneous extracranial to intracranial revascularisation in the posterior fossa following radiation-induced vasculopathy for cerebellar tumour.

Paediatric patients receiving cranial irradiation therapy for brain tumours are at increased risk of cerebrovascular complications. Radiation-induced moyamoya syndrome (MMS) is a well-recognised complication of this. We present a case of an 8-year-old boy with a history of medulloblastoma, who underwent surgical excision followed by post-operative adjuvant oncological treatment. Six years later, he developed cerebellar/intraventricular haemorrhage. He underwent an emergency external ventricular drain (EVD) insertion followed by posterior fossa suboccipital craniotomy. On dural opening, an abnormal vessel was visualised on the surface of the right cerebellar hemisphere, which was not disturbed. No obvious abnormalities were identified intra-operatively. Cerebral catheter angiography confirmed the presence of a right-sided occipital artery (OA) to posterior inferior cerebellar artery (PICA) extracranial to intracranial (EC-IC) bypass with a zone of the distal PICA territory supplied by this EC-IC bypass. A presumed flow aneurysm originated from the bypass in the distal PICA, identified as cause for the haemorrhage. We highlight a rare cause for intracranial haemorrhage in this cohort of patients. Children who have undergone radiotherapy may have exquisitely sensitive cerebral vasculature and need careful vigilance and evaluation for vasculopathic complications following spontaneous haemorrhage.

Atypical teratoid rhabdoid tumours (ATRTs)-a 21-year institutional experience.

PURPOSE: Atypical teratoid/rhabdoid tumours (ATRTs) are malignant embryonal tumours of childhood that affect the central nervous system (CNS). We aim to determine which factors, including patient age, extent of resection (EOR), presence of distal metastasis and use of adjuvant therapies, affect overall survival in children with atypical teratoid/rhabdoid tumours (ATRTs) treated at this single centre. METHODS: Retrospective cohort review of patients with histological diagnosis of ATRT treated over 21 years (1999-2020) was conducted. Data on demographics, tumour location, presence of metastasis, use of adjuvant therapy, extent of resection (EOR), complications, neurological outcome post-surgery, and overall survival were collected. Kaplan-Meier survival analysis was performed. RESULTS: A total of 45 children (mean age 2 years) underwent 64 operations. 25 patients were <1 year of age. Gross-total resection (GTR) pre-adjuvant therapy was achieved in 15, near-total resection (NTR) in 15, subtotal resection (STR) in 9, and biopsy in 6 children. Most children had good neurological outcomes post-operatively (28/45 with GOS 5). Fourteen patients survived longer than 4 years. Survival analysis showed a significant difference in median survival in favour of GTR and localised disease. There was no significant difference in median survival between patients <1 year vs >1 year of age (p=0.84). CONCLUSION: We find that presence of metastasis was an important factor in poor survival in patients with ATRT. GTR, where possible, may confer significant survival benefit in ATRT. Children aged <1 year appear to have performed as well as those >1 year and therefore should still be considered for radical surgery.

Paediatric spinal cord low-grade gliomas-evaluation and management of post-surgical residual disease.

PURPOSE: To assess the evaluation and management of post-surgical residual disease for low-grade intramedullary spinal cord tumours (IMSCT) in childhood. METHODS: A single-centre retrospective review of low-grade IMSCTs treated between 2000 and 2019. All surgeries were performed with intent of safe maximal resection guided by intra-operative neurophysiological monitoring (IONM). Pre- and post-operative MRIs were reviewed to assess the extent of resection (EOR), recorded as follows: gross total resection (GTR), near total resection (NTR), sub-total resection (STR) and partial resection (PR). Outcome measures were time to recurrence, need for and modality of additional therapy and ambulatory status at last follow-up. RESULTS: Thirty patients underwent surgery for IMSCT (median age 6.9 years). EOR was GTR = 8, NTR = 4, STR = 9, PR = 9. All patients were alive at last follow-up (median follow-up 73 months [IQR 93 months]). Eighteen patients (60%) remained radiologically stable. Twelve patients (40%) developed recurrence during surveillance. Progression free survival was significantly better in cases with GTR + NTR in comparison to either STR or PR (p = 0.039). 10/30 (33%) patients were treated with additional therapy. At last follow-up, 26/30 patients were independently mobile. CONCLUSION: Survival rates for low-grade IMSCT are excellent. Radical micro-surgical resection, guided by IONM provides effective means of balancing the objectives of maximal safe resection, functional outcome and tumour control. Whilst evidence of 'residual disease' was identified in over 2/3 of immediate post-operative MRI scans, additional treatment was required in only 1/3 of cases. Critical appraisal of post-operative imaging findings is required to better define 'residual disease'. Small volume residual disease (< 5%) does not compromise progression-free survival.

Hand tapping: a simple, reproducible, objective marker of motor dysfunction in Huntington's disease.

Huntington's disease (HD) is a severe neurodegenerative condition in which the impairment in voluntary movement is related to functional disability. Clinical assessment of motor deficit currently relies largely on subjective rating scales without objective measurement. We have developed a quick and easy-to-use hand tapping device that enables measurement of (a) the number of taps in 30 seconds, (b) variability in tapping rhythm and (c) fatigue over the testing period. Initial cross-sectional testing of 178 consecutive HD clinic patients using an early model of the device showed that the total number of taps in 30 seconds correlated with the motor UHDRS (Spearmann's rho, r(s) = -0.81, p < 0.0001) and independence scores (r(s) = 0.78, p = 0.01). Longitudinal data from a small cohort followed over 10 years reveals a correlation between total number of taps in 30 seconds and motor UHDRS over time (rs = -0.49, p < 0.001), and suggests the technique may provide an objective measure of disease progression. Further tests on 15 HD patients and 9 controls were repeated three times in a single day using an updated device. The HD group made significantly fewer taps in 30 seconds (median HD = 79, control = 104, p = 0.009) and had greater variability of inter-tap interval (mean interdecile range HD = 148, control = 56, p = 0.016) compared to controls. Both the total number of taps and variability of inter-tap interval correlated with motor UHDRS. Of vital importance for any potential marker of disease progression is that these tapping parameters were reproducible with repeated measurement. Given that hand tapping parameters differ between HD and control populations, they correlate with motor UHDRS over time and are reproducible, we propose that assessment of hand tapping represents a useful objective adjunct to the clinical assessment of HD patients.