Improvement in ventriculomegaly following cervicomedullary decompressive surgery in children with achondroplasia and foramen magnum stenosis.

The role of cervicomedullary decompression (CMD) in the care of hydrocephalic achondroplastic children who present with simultaneous foramen magnum stenosis is not well understood. We sought to determine the percentage of symptomatic achondroplastic children with foramen magnum stenosis who had stabilization or improvement in ventriculomegaly following CMD. The authors retrospectively reviewed the records of pediatric patients at Cedars-Sinai Medical Center with achondroplasia and signs of progressive ventriculomegaly who underwent CMD for symptomatic foramen magnum stenosis between the years 2000 and 2018. Clinical outcomes included changes in fontanelle characteristics, head circumference (HC) percentile, and incidence of ventriculoperitoneal (VP) shunting. Radiographic outcomes measured included changes in Evans ratio. We excluded individuals who were shunted before CMD from our study. Sixteen children presented with symptomatic foramen magnum stenosis and full anterior fontanelle or jump in the HC percentiles. Two children underwent placement of a VP shunt before decompressive surgery and were excluded from further analysis. Of the remaining 14 children who underwent CMD, 13 (93%) showed softening or flattening of their fontanelles post-operatively. Ten of these 14 children had both pre- and post-operative HC percentile records available, with 8 showing increasing HC percentiles before surgery. Seven of those eight children (88%) showed a deceleration or stabilization of HC growth velocity following decompression of the foramen magnum. Among 10 children with available pre- and post-operative brain imaging, ventricular size improved in 5 (50%), stabilized in 2 (20%), and slightly increased in 3 (30%) children after decompression. Two children (14%) required a shunt despite decompression of the foramen magnum. A significant proportion of children with concomitant signs of raised intracranial pressure or findings of progressive ventriculomegaly and foramen magnum stenosis may have improvement or stabilization of these findings following CMD. CMD may decrease the need for VP shunting and its associated complications in the select group of hydrocephalic children with achondroplasia presenting with symptomatic foramen magnum stenosis.

Predictors of Primary Intracranial Hypertension in Children Using a Newly Suggested Opening Pressure Cutoff of 280 mm H2O.

OBJECTIVES: We assessed the clinical characteristics of primary intracranial hypertension (PIH) in children using a newly recommended threshold for cerebrospinal fluid opening pressure (280 mm H2O). METHOD: Cross-sectional study of patients age ≤21 years who had a lumbar puncture done for evaluation of PIH. Patients were excluded if lumbar puncture was done for a suspected infection, seizure, mental status changes, multiple sclerosis, or Guillain-Barre syndrome. Cases were identified using a text-search module followed by manual review. We performed χ2 analysis for categorical data and Mann-Whitney U test for continuous data, followed by a binary logistic regression. RESULTS: We identified 374 patients of whom 67% were female, median age was 13 years interquartile range (11 to 16 years), and admission rate was 24%. Using an opening pressure cutoff of 250 mm H2O, 127 patients (34%) were identified as having PIH, whereas using the new cutoff 105 patients (28%) met PIH criteria. Predictors for PIH included optic disc edema or sixth nerve palsy using both old, odds ratio (OR) 7.6 (4.3, 13.5), and new cutoffs, OR 9.7 (95% confidence interval 5.1, 18.5). Headache duration ≤61 days is predictive of PIH using the new cutoff OR 4.1 (95% confidence interval 1.3, 12.8). A model is presented which stratifies patients into groups with low (7%), medium (18%), and high (greater than 42%) risk of PIH. CONCLUSIONS: A higher cerebrospinal fluid opening pressure threshold in the criteria of PIH is associated with PIH patients with a different symptom profile. Children with optic disc edema, bulging fontanel or sixth nerve palsy, are at increased risk for PIH.

Estimation of elevated intracranial pressure in infants with hydroce-phalus by using transcranial Doppler velocimetry with fontanel compression.

For infants with acute progressive hydrocephalus, invasive drainage of cerebrospinal fluid (CSF) is performed until a ventriculo-peritoneal shunt can be inserted. Surrogate markers of intracranial pressure (ICP) may help optimise the timing of invasive procedures. To assess whether RI with/without fontanel compression helps distinguish between infants with normal (<5 cmH2O), mild (5-11 cmH2O), and moderate (>11 cmH2O) ICP elevation, 74 ICP measures before/after CSF removal and 148 related Doppler measures of the middle cerebral artery were assessed. Higher RI was associated with fontanel compression, elevated ICP, and their interaction (all p < 0.001). Without compression, differences in RI were observed between normal and moderate (p < 0.001) and between mild and moderate ICP elevation (p = 0.033). With compression, differences in RI were observed for all pairwise comparisons among normal, mild, and moderate ICP elevation (all p < 0.001). Without compression, areas under the receiver-operating characteristic curve for prediction of mild and moderate ICP elevation were 0.664 (95% confidence interval (CI), 0.538-0.791; p = 0.020) and 0.727 (95% CI, 0.582-0.872; p = 0.004), respectively, which improved to 0.806 (95% CI, 0.703-0.910; p < 0.001) and 0.814 (95% CI, 0.707-0.921; p < 0.001), respectively, with compression. RI with fontanel compression provides improved discrimination of infants with absent, mild, and moderate ICP elevation.

Transcranial Doppler for brain death in infants: the role of the fontanelles.

OBJECTIVE: Transcranial Doppler (TCD) is a sensitive technique for circulatory arrest diagnosis in brain death when patterns such as reverberant flow and short systolic spikes are observed. In infants, the nonossified fontanelles compensate for intracranial hypertension. We describe TCD patterns in infants with brain death, different from adults, with the hemodynamic modifications induced by anterior fontanelle compression. METHOD: TCD was performed in 2 infants with diagnosed brain death admitted to the neonatal intensive care unit. RESULTS: TCD showed a large peak 'reverberant' flow, with a high peak systolic velocity and a consistent retrograde component, away from the brain. Compression of the anterior fontanelle induced, at first, a reduction in systolic flow with the subsequent appearance of the characteristic short systolic spikes. Upon compression removal, a brief increase in the systolic flow was observed before the prompt reappearance of the reverberant flow. CONCLUSION: TCD for brain death diagnosis should be done cautiously in infants. In these cases, reverberating flow may be indicative of circulatory arrest even if with a large peak and with a high peak systolic velocity. Heavy fontanelle compression may reproduce the classical adult TCD patterns of brain death, thus supporting the diagnosis of cerebral circulatory arrest.