Adamantinomatous craniopharyngioma: evolution in the management.

BACKGROUND: In spite of the continuous progresses in pediatric neurosurgery, adamantinomatous craniopharyngioma (AC) remains a challenging tumor due to its proximity to optic pathways, pituitary gland, hypothalamus, and Willis' circle, which can result in significant endocrine, cognitive, and neurological morbidity after treatment with subsequent impact on the patient's quality of life (QoL). The relevance that QoL has today explains the changes in the management of AC observed over the time. The goal of the present article is to provide a historical background, to show the milestones in the changes of the AC treatment, and to analyze the current main options to manage such a challenging tumor. MATERIAL AND METHODS: The pertinent literature has been reviewed. Moreover, a comparison between the past and recent personal series is reported. RESULTS: Three main eras have been identified. The first (named Cushing era) was characterized by the need to realize a harmless surgery and to define the best way to approach AC; the second (microscope era) was characterized by a tremendous technical and technological development, with remarkable results in term of safe tumor resection and control but relatively poor QoL outcomes; and the third one (current period) is characterized by an increasing integration between surgery and adjuvant treatments, with relatively minor tumor control but significant improvement of QoL (comparable overall survival). The authors' experience reflects these changes. Two groups of children were compared: 52 cases (mean follow-up: 17.5 years) belong to the historical series (group 1, 1985-2003, aggressive surgical management) and 41 (mean follow-up: 8.5 years) to the current one (Group 2, 2004-2021, integrated management). No significant differences between the two groups were detected about recurrence rate, surgical mortality, and overall survival. However, Group 2 showed significant lower rates of postoperative panhypopituitarism, obesity, and visual deterioration. CONCLUSIONS: Radical surgery allows for a good AC control with a low rate of recurrence but high risk of permanent morbidity. Despite the greater number of recurrences and surgeries, the more conservative policy, based on a combination of treatments, seems to provide the same tumor control with a better QoL. The advances in trans-nasal and trans-ventricular endoscopy, in proton therapy and in the management of the AC cyst are the main factors that allowed such an improvement.

Computer tomography-based quantitative analysis of the orbital proptosis severity in infants with syndromic craniosynostosis: case-control study.

PURPOSE: Evaluation of orbital proptosis and sutural synostosis pattern along the coronal ring in craniofaciosynostosis patients with or without fibroblastic growth factor receptor 2 (FGFR2) mutation. METHODS: High-resolution computer tomography was used to assess, in children with or without FGFR2 mutation, the early synostotic involvement of the "major" and "minor" sutures/synchondroses of the coronal arch along with the following orbital parameters: interorbital angle, bone orbital cavity volume, globe volume, ventral globe volume, ventral globe index. RESULTS: Infants with FGFR2 mutation showed an increased number of closed minor sutures/synchondroses along the posterior coronal branch while both groups showed a comparable synostotic involvement of the minor sutures of the anterior coronal branch. FGFR2 infants with posterior coronal branch synostotic involvement showed a higher degree of proptosis due to both reduced bony cavity volume and increased globe volume (p<0.05). CONCLUSIONS: Our data show that FGFR2 mutation together with posterior coronal branch synostotic involvement has a synergic effect in causing a more severe degree of orbital proptosis.

Neurocutaneous melanocytosis (melanosis).

Neurocutaneous melanosis (NCM; MIM # 249400; ORPHA: 2481], first reported by the Bohemian pathologist Rokitansky in 1861, and now more precisely defined as neurocutaneous melanocytosis, is a rare, congenital syndrome characterised by the association of (1) congenital melanocytic nevi (CMN) of the skin with overlying hypertrichosis, presenting as (a) large (LCMN) or giant and/or multiple (MCMN) melanocytic lesions (or both; sometimes associated with smaller "satellite" nevi) or (b) as proliferative melanocytic nodules; and (2) melanocytosis (with infiltration) of the brain parenchyma and/or leptomeninges. CMN of the skin and leptomeningeal/nervous system infiltration are usually benign, more rarely may progress to melanoma or non-malignant melanosis of the brain. Approximately 12% of individuals with LCMN will develop NCM: wide extension and/or dorsal axial distribution of LCMN increases the risk of NCM. The CMN are recognised at birth and are distributed over the skin according to 6 or more patterns (6B patterns) in line with the archetypical patterns of distribution of mosaic skin disorders. Neurological manifestations can appear acutely in infancy, or more frequently later in childhood or adult life, and include signs/symptoms of intracranial hypertension, seizures/epilepsy, cranial nerve palsies, motor/sensory deficits, cognitive/behavioural abnormalities, sleep cycle anomalies, and eventually neurological deterioration. NMC patients may be symptomatic or asymptomatic, with or without evidence of the typical nervous system changes at MRI. Associated brain and spinal cord malformations include the Dandy-Walker malformation (DWM) complex, hemimegalencephaly, cortical dysplasia, arachnoid cysts, Chiari I and II malformations, syringomyelia, meningoceles, occult spinal dysraphism, and CNS lipoma/lipomatosis. There is no systemic involvement, or only rarely. Pathogenically, single postzygotic mutations in the NRAS (neuroblastoma RAS viral oncogene homologue; MIM # 164790; at 1p13.2) proto-oncogene explain the occurrence of single/multiple CMNs and melanocytic and non-melanocytic nervous system lesions in NCM: these disrupt the RAS/ERK/mTOR/PI3K/akt pathways. Diagnostic/surveillance work-ups require physical examination, ophthalmoscopy, brain/spinal cord magnetic resonance imaging (MRI) and angiography (MRA), positron emission tomography (PET), and video-EEG and IQ testing. Treatment strategies include laser therapy, chemical peeling, dermabrasion, and surgical removal/grafting for CMNs and shunt surgery and surgical removal/chemo/radiotherapy for CNS lesions. Biologically targeted therapies tailored (a) BRAF/MEK in NCM mice (MEK162) and GCMN (trametinib); (b) PI3K/mTOR (omipalisib/GSK2126458) in NMC cells; (c) RAS/MEK (vemurafenib and trametinib) in LCMNs cells; or created experimental NMC cells (YP-MEL).

Introduction to phacomatoses (neurocutaneous disorders) in childhood.

The Dutch ophthalmologist, Jan van der Hoeve, first introduced the terms phakoma/phakomata (from the old Greek word "ϕαχοσ" = lentil, spot, lens-shaped) to define similar retinal lesions recorded in tuberous sclerosis (1920) and in neurofibromatosis (1923). He later applied this concept: (a) to similar lesions in other organs (e.g. brain, heart and kidneys) (1932) and (b) to other disorders (i.e. von Hippel-Lindau disease and Sturge-Weber syndrome) (1933), and coined the term phakomatoses. At the same time, the American neurologist Paul Ivan Yakovlev and psychiatrist Riley H. Guthrie (1931) established the key role of nervous systems and skin manifestations in these conditions and proposed to name them neurocutaneous syndromes (or ectodermoses, to explain the pathogenesis). The Belgian pathologist, Ludo van Bogaert, came to similar conclusions (1935), but used the term neuro-ectodermal dysplasias. In the 1980s, the American paediatric neurologist Manuel R. Gomez introduced the concept of "hamartia/hamartoma" instead of phakoma/phakomata. "Genodermatoses" and "neurocristopathies" were alternative terms still used to define these conditions. Nowadays, however, the most acclaimed terms are "phacomatoses" and "neurocutaneous disorders", which are used interchangeably. Phacomatoses are a heterogeneous group of conditions (mainly) affecting the skin (with congenital pigmentary/vascular abnormalities and/or tumours), the central and peripheral nervous system (with congenital abnormalities and/or tumours) and the eye (with variable abnormalities). Manifestations may involve many other organs or systems including the heart, vessels, lungs, kidneys and bones. Pathogenically, they are explained by interplays between intra- and extra-neuronal signalling pathways encompassing receptor-to-protein and protein-to-protein cascades involving RAS, MAPK/MEK, ERK, mTOR, RHOA, PI3K/AKT, PTEN, GNAQ and GNA11 pathways, which shed light also to phenotypic variability and overlapping. We hereby review the history, classification, genomics, clinical manifestations, diagnostic criteria, surveillance protocols and therapies, in phacomatoses: (1) predisposing to development of tumours (i.e. the neurofibromatoses and allelic/similar disorders and schwannomatosis; tuberous sclerosis complex; Gorlin-Goltz and Lhermitte-Duclos-Cowden syndromes); (2) with vascular malformations (i.e. Sturge-Weber and Klippel-Trenaunay syndromes; megalencephaly/microcephaly-capillary malformation syndromes; CLOVES, Wyburn-Mason and mixed vascular nevus syndromes; blue rubber bleb nevus syndrome; hereditary haemorrhagic telangiectasia); (3) with vascular tumours (von Hippel-Lindau disease; PHACE(S)); (4) with pigmentary/connective tissue mosaicism (incontinentia pigmenti; pigmentary/Ito mosaicism; mTOR-related megalencephaly/focal cortical dysplasia/pigmentary mosaicism; RHOA-related ectodermal dysplasia; neurocutaneous melanocytosis; epidermal/papular spilus/Becker nevi syndromes; PENS and LEOPARD syndromes; encephalocraniocutaneous lipomatosis; lipoid proteinosis); (5) with dermal dysplasia (cerebellotrigeminal dermal dysplasia); and (6) with twin spotting or similar phenomena (phacomatosis pigmentovascularis and pigmentokeratotica; and cutis tricolor).

Posterior Cranial Fossa Maldevelopment in Infants with Repaired Open Myelomeningoceles: Double Trouble or a Dynamic Process of Posterior Cranial Fossa Abnormalities?

OBJECTIVE: Two degrees of posterior cranial fossa (PCF) maldevelopment can be hypothesized in children with myelomeningocele (MMC). This paper investigates the PCF deformation by quantitative magnetic resonance imaging analysis in MMC subjects with and without Chiari 2 malformation (CM2). METHODS: PCF bone volume (PCFV), PCF brain volume (PCFBV), lengths of PCF, ventriculomegaly, level, and extension of the dysraphism were analyzed by magnetic resonance image scanning of 51 newborns with MMC surgically repaired at birth (and 41 controls). The possible correlation among PCF hypoplasia, level/extension of the spinal dysraphism, and ventriculomegaly was assessed. RESULTS: In MMC and CM2, the dysraphism level was above L4 in 30 and below L4 in 10 subjects. PCFV/PCFBV ratio and supraocciput and exocciput lengths were significantly reduced; foramen magnum diameters, mammillo-pontine distance, and pons length were significantly increased (P < 0.05). In isolated MMC, the dysraphism level was below L4 in all cases. PCFV/PCFBV ratio and supraocciput length were significantly reduced; pons length was significantly increased (P < 0.05). The lower the MMC level, the lower the incidence of CM2. A positive correlation was found between PCF hypoplasia and MMC level above L4 (P < 0.001), while a negative correlation was found among PCF hypoplasia and MMC extension (P = 0.006), PCF hypoplasia, and ventriculomegaly (P = 0.02). CONCLUSIONS: PCF hypoplasia has to be considered a dynamic maldevelopment process in the 2 cohorts rather than 2 separated entities. The level of MMC is the main but not the unique cause influencing the severity of PCF maldevelopment.

Multimodal assessment of motor pathways and intracortical connections in functional hemispherectomy.

PURPOSE: For selected children with medically intractable epilepsy, hemispherectomy can be an excellent treatment option and its efficacy in achieving seizure freedom or reduction in seizure frequency has been shown in several studies, but patients' selection could not be straightforward and often it is taken on subjective basis. We described a multimodal approach to assess patient eligible for hemispherectomy and possibly predicting post-surgical outcomes. METHODS: We describe pre- and post-surgical clinical features along with neuroradiological results by magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), MR-tractography (MRT), and neurophysiological study by single and paired pulses transcranial magnetic stimulation (TMS) in a child with cerebral palsy with epileptic encephalopathy, eligible for epilepsy surgery. RESULTS: Presurgical TMS evaluation showed a lateralization of motor function on the left motor cortex for both arms, and results were confirmed by MRI studies. Interestingly, after surgery, both epilepsy and motor performances improved and TMS showed enhancement of intracortical inhibition and facilitation activity. CONCLUSION: Functional hemispherectomy is an effective treatment for drug-resistant epilepsy, and multimodal presurgical assessment may be a useful approach to guide surgeons in selecting patients. Moreover, pre- and post-surgical evaluation of these patients may enhance our understanding of brain plasticity phenomena.

Craniofacial Sutural Pattern and Surgical Management in Patients With Different Degrees of Trigonocephaly Severity.

The aim of this study was to identify quantitative tools to classify the severity of trigonocephaly to guide surgical management and predict outcome. METHODS: We reviewed high-resolution computed tomography images of 59 patients with metopic synostosis. We assessed the craniofacial sutural pattern as well as interfrontal and metopic angles, and we related the frontal angulation degree with the sutural pattern, the surgical management, and clinical outcome. RESULTS: We identified 3 groups according to the severity of trigonocephaly. No difference was found between the sutural pattern of nasion complex and severity, whereas the closure of zygomatic maxillary sutures increased with the severity degree (P < 0.05). The operative management was related to the severity degree (P < 0.001) and to the reduced age (P = 0.009). CONCLUSIONS: Interfrontal and metopic angles are complementary measurements to evaluate with high accuracy the degree of frontal angulation. In preoperative assessment, they may guide surgery decision in particular when the choice is not straightforward.

Cerebellar mutism: the predictive role of preoperative language evaluation.

BACKGROUND: The association between preoperative language impairment and development of cerebellar mutism after surgical treatment of posterior fossa tumors has gained increasing interest in recent years based on the concept that both local compression/infiltration of the infratentorial periventricular anatomical structures involved in speech and language, as well as an increased distraction of supratentorial periventricular anatomical structures, due to an associated hydrocephalus, involved in the coordination of speech circuits, might lead to the subclinical presence of language disturbances already at diagnosis, predicting the development of a cerebellar mutism syndrome after tumor removal. METHODS: A thorough review of the literature on the subject has been performed, together with a review of our institutional experience reporting the related long-term (10 years) results. RESULTS AND CONCLUSIONS: According to our institutional experience, 20/70 (28.5%) children presented preoperative language impairment and developed cerebellar mutism after surgery. A residual impairment persists in 75% of the cases at a follow-up of 2 years, and in 50% of the cases at 10 years, a finding which actually depicts cerebellar mutism no more as a transient deficit but among long-term sequelae. The appearance of complex dysarthria in the postoperative period is a negative prognostic factor for the long-term persistence of speech disturbances.

Orbito-facial dysmorphology in patients with different degrees of trigonocephaly severity: quantitative morpho-volumetric analysis in infants with non-syndromic metopic craniosynostosis.

PURPOSE: Craniofacial dysmorphology varies significantly along a wide spectrum of severity in metopic cranial synostosis (MCS). This study aimed to quantify craniofacial changes, in MCS, to investigate their relationships with the severity of trigonocephaly. METHODS: By combining the metopic ridge and interfrontal angles, we identified three groups of trigonocephaly severity (mild group n.14, moderate group n.19, severe group n.18). We perform a quantitative analysis using high-resolution CT images evaluating (1) cranial fossae dimensions; (2) vault indices and ratios: interparietal/ intercoronal (IPD/ICD), interparietal/intertemporal (IPD/ITD), cephalic index, vertico-longitudinal index; (3) orbito-facial distances (midfacial depth, maxillary height, upper facial index, orbital distances, globe protrusions), maxilla and orbital volumes; (4) supratentorial (ICV) and infratentorial (PCFV) cranial volumes and supratentorial (WBV) and infratentorial (PCFBV) brain volumes. RESULTS: In all groups, middle skull base lengths and upper midface index were increased. In moderate and severe groups: anterior hemifossa lengths were reduced, IPD/ICD and vertico-longitudinal index were changed; midfacial depth, anterior, mild, and lateral interorbital distances were reduced; globe protrusions were increased. The comparison between moderate and severe groups showed an increase of both globe protrusions and IPD/ICD. Among all groups, ICV and WBV were reduced in the severe group. CONCLUSION: This morpho-volumetric study provides new insights in understanding the craniofacial changes occurring in infants at different severity of trigonocephaly. The increase of globe protrusions and the reduction of supratentorial volumes found in the severe group reflect the severity of trigonocephaly; these findings might have a clinical and surgical relevance.

The unseen third dimension: a novel approach for assessing head shape severity in infants with isolated sagittal synostosis.

PURPOSE: This study aimed to develop a novel approach to assess the severity of skull dysmorphology in infants with isolated sagittal synostosis (ISS) and its relationship with the surgical results. METHODS: We divided 66 infants with ISS into three groups by combining the scaphocephalic (SSI-A) and platycephalic (VLI) indices as descriptors of the relation between length, width, and height. We evaluated each skull for morphology as hyperdolichocephalic (< 66%) versus dolichocephalic (66-77%) and as hyperplatycephalic (< 78%) versus platycephalic skull (78-85%). A score system was developed as follows: 2 points for values < 66% and < 78% and 1 point for values between 66 and 77% and 78 and 85% in SSI-A and VLI, respectively. The overall score was calculated and it was used to classify our patients on a 4-point ordinal scale, according to the severity of head shape (2 = mild, 3 = moderate, 4 = severe). RESULTS: Thirty-two infants resulted in mild group, 17 in moderate group, and 17 in severe group. SSI-A and VLI were reduced according to the severity of ISS. We demonstrated a positive correlation between SSA-A and VLI in mild subgroup of patients while we found a negative correlation between SSA-A and VLI in moderate and in severe subgroups. Moreover, a positive correlation was found between severe subgroup and Sloan III class of surgical results. CONCLUSION: This study describes a simple tool to better classify infants with ISS, considering the three-dimensional morphology of the skull, because it evaluates both the dolichocephalic and platycephalic component.

Chiari type I and hydrocephalus.

PURPOSE: The association between Chiari type I malformation (CIM) and hydrocephalus raises a great interest because of the still unclear pathogenesis and the management implications. The goal of this paper is to review the theories on the cause-effect mechanisms of such a relationship and to analyze the results of the management of this condition. METHODS: A review of the literature has been performed, focusing on the articles specifically addressing the problem of CIM and hydrocephalus and on the series reporting about its treatment. Also, the personal authors' experience is briefly discussed. RESULTS: As far as the pathogenesis is concerned, it seems clear that raised intracranial pressure due to hydrocephalus can cause a transient and reversible tonsillar caudal ectopia ("pressure from above" hypothesis), which is something different from CIM. A "complex" hypothesis, on the other hand, can explain the occurrence of hydrocephalus and CIM because of the venous engorgement resulting from the hypoplasia of the posterior cranial fossa (PCF) and the occlusion of the jugular foramina, leading to cerebellar edema (CIM) and CSF hypo-resorption (hydrocephalus). Nevertheless, such a mechanism can be advocated only in a minority of cases (syndromic craniosynostosis). In non-syndromic CIM subjects, the presence of hydrocephalus could be explained by an occlusion of the basal CSF pathways, which would occur completely in a minority of cases (only 7-10% of CIM patients show hydrocephalus) while it would be partial in the remaining cases (no hydrocephalus). This hypothesis still needs to be demonstrated. As far as the management is concerned, the strategy to treat the hydrocephalus first is commonly accepted. Because of the "obstructive" origin of CIM-related hydrocephalus, the use of endoscopic third ventriculostomy (ETV) is straightforward. Actually, the analysis of the literature, concerning 63 cases reported so far, reveals very high success rates of ETV in treating hydrocephalus (90.5%), CIM (78.5%), and syringomyelia symptoms (76%) as well as in giving a radiological improvement of both CIM (74%) and syringomyelia (89%). The failures of ETV were not attributable to CIM or syringomyelia. Only 11% of cases required PCF decompression after ETV. CONCLUSIONS: The association between CIM and hydrocephalus probably results from different, multifactorial, and not yet completely understood mechanisms, which place the affected patients in a peculiar subgroup among those constituting the heterogeneous CIM population. ETV is confirmed as the best first approach for this subset of patients.

Quantitative analysis of cranial-orbital changes in infants with anterior synostotic plagiocephaly.

PURPOSE: The effects of premature fusion of one coronal suture cause skull and orbital alterations in term of side-to-side asymmetry. This study aimed to quantify the cranio-orbital complex changes related to the severity of skull base dysmorphology in patients with unicoronal synostosis. METHODS: Twenty-four infants affected by unicoronal synostosis were subdivided in three subgroups according to the severity of skull base deformity and their high-resolution CT images were quantitatively analyzed (groups IIa, IIb, III). Dimensions of cranial fossae, intracranial volume (ICV), ICV synostotic and ICV non synostotic side, whole brain volume (WBV), orbital volumes (OV), ICV/WBV, ICVsynostotic/ICVnon-synostotic, and OVsynostotic/OVnon-synostotic were evaluated. RESULTS: Asymmetry and reduction in the growth of the anterior and middle fossae were found in all groups while asymmetry of the posterior cranial fossa was found only in IIb and III groups. In all groups, ICV, WBV, and ICV/WBV were not significantly different while ICVsynostotic/ICVnon-synostotic and OVsynostotic/OVnon-synostotic resulted significant difference (p < 0.05). ICVsynostotic side resulted reduction only in group III. OV on the synostotic side was not significantly reduced although a trend in progressively reducing volumes was noted according to the severity of the group. CONCLUSION: Skull and orbital changes revealed a side-to-side asymmetry but the effects of the premature synostosis were more severe in group III suggesting an earlier timing of premature unicoronal synostosis in group III with respect to the other groups. The assessment of the skull base deformity might be an indirect parameter of severity of skull orbital changes and it might be useful for surgical planning.

BBS9 gene in nonsyndromic craniosynostosis: Role of the primary cilium in the aberrant ossification of the suture osteogenic niche.

Nonsyndromic craniosynostosis (NCS) is the premature ossification of skull sutures, without associated clinical features. Mutations in several genes account for a small number of NCS patients; thus, the molecular etiopathogenesis of NCS remains largely unclear. Our study aimed at characterizing the molecular signaling implicated in the aberrant ossification of sutures in NCS patients. Comparative gene expression profiling of NCS patient sutures identified a fused suture-specific signature, including 17 genes involved in primary cilium signaling and assembly. Cells from fused sutures displayed a reduced potential to form primary cilia compared to cells from control patent sutures of the same patient. We identified specific upregulated splice variants of the Bardet Biedl syndrome-associated gene 9 (BBS9), which encodes a structural component of the ciliary BBSome complex. BBS9 expression increased during in vitro osteogenic differentiation of suture-derived mesenchymal cells of NCS patients. Also, Bbs9 expression increased during in vivo ossification of rat sutures. BBS9 functional knockdown affected the expression of primary cilia on patient suture cells and their osteogenic potential. Computational modeling of the upregulated protein isoforms (observed in patients) predicted that their binding affinity within the BBSome may be affected, providing a possible explanation for the aberrant suture ossification in NCS.

Postoperative Epileptic Seizures in Children: Is the Brain Incision a Risk Factor?

BACKGROUND: Postoperative seizures (PSs) after neurosurgical operations are common but little is known about the role of surgical brain incision on their genesis. This topic has not been addressed so far. OBJECTIVE: To verify if the corticotomy affects the risk of PSs and postoperative epilepsy (PE) in children. METHODS: One hundred forty-three consecutive pediatric cases operated on for supratentorial lesions at the same institution in the last 15 yr have been retrospectively reviewed by dividing them into group A, 68 children who required brain corticotomy mainly for hemispheric tumors, and group B, 75 children treated through extracortical approaches mainly for suprasellar and optic tumors. Patients with possible "epileptic" biases, like preoperative seizures, were excluded. RESULTS: No significant differences have been found between group A and B as far as incidence of PSs (11.7% vs 14.5%) and PE (4.5% vs 6.5%), timing, and type of seizures are concerned after a mean 6.8 yr follow-up. The size of corticotomy in group A (<3 cm2 vs >3 cm2) had no impact on epileptogenesis as well as the other variables considered in both groups (age, sex, extent of lesion resection). CONCLUSION: This study shows that the surgical cortical "trauma" would not represent a risk factor for PSs and PE. According to the present analysis and the literature, other causes seem to be involved (namely, electrolytic imbalance and brain gliosis). This information is important for preoperative surgical planning and postoperative management. A validation by both adult series and prospective studies is needed.

Surgical management of cerebellopontine angle arachnoid cysts associated with hearing deficit in pediatric patients.

OBJECTIVE Few cases of cerebellopontine angle (CPA) arachnoid cysts in pediatric patients have been described in the literature, and in only 2 of these cases were the patients described as suffering from hearing deficit. In this article, the authors report on 3 pediatric patients with CPA arachnoid cysts (2 with hearing loss and 1 with recurrent headaches) who underwent neurosurgical treatment at the authors' institution. METHODS Four pediatric patients were diagnosed with CPA arachnoid cysts at the International Neuroscience Institute during the period from October 2004 through August 2012, and 3 of these patients underwent surgical treatment. The authors describe the patients' clinical symptoms, the surgical approach, and the results on long-term follow-up. RESULTS One patient (age 14 years) who presented with headache (without hearing deficit) became asymptomatic after surgical treatment. The other 2 patients who underwent surgical treatment both had hearing loss. One of these children (age 9 years) had recent-onset hypacusia and experienced complete recovery immediately after the surgery. The other (age 6 years) had a longer history (2 years) of progressive hearing loss and showed an interruption of the deficit progression and only mild improvement at the follow-up visit. CONCLUSIONS CPA arachnoid cysts are uncommon in pediatric patients. The indication and timing of the surgical treatment are fundamental, especially when a hearing deficit is present.