Report of eight cases of occipital dermal sinus: an update, and MRI findings

Imaging of pediatric skull lytic lesions: A review

Skull lesions in pediatric population are common findings on imaging and sometimes with heterogeneous manifestations, constituting a diagnostic challenge. Some lesions can be misinterpreted for their aggressiveness, as with larger lesions eroding cortical bone, containing soft tissue components, leading to excessive and, in some cases, invasive inappropriate etiological investigation. In this review, we present multiple several conditions that may present as skull lesions or pseudolesions, organized by groups (anatomic variants, congenital and development disorders, traumatic injuries, vascular issues, infectious conditions, and tumoral processes). Anatomic variants are common imaging findings that must be recognized by the neuroradiologist. Congenital malformations are rare conditions, such as aplasia cutis congenita and sinus pericranii, usually seen at earlier ages, the majority of which are benign findings. In case of trauma, cephalohematoma, growing skull fractures, and posttraumatic lytic lesions should be considered. Osteomyelitis tends to be locally aggressive and may mimic malignancy, in which cases, the clinical history can be the key to diagnosis. Vascular (sickle cell disease) and tumoral (aneurismal bone cyst, eosinophilic granuloma, metastases) lesions are relatively rare lesions but should be considered in the differential diagnosis, in the presence of certain imaging findings. The main difficulty is the differentiation between the benign and malignant nature; therefore, the main objective of this pictorial essay is to review the main skull lytic lesions found in pediatric age, describing the main findings in different imaging modalities (CT and MRI), allowing the neuroradiologist greater confidence in establishing the differential diagnosis, through a systematic and simple characterization of the lesions.

Infected intracranial dermal sinus tract in a child

Dermal sinus tracts (DSTs) are rare congenital defects occurring along the cranial spinal axis. They may extend from the skin into the deeper structures of the central nervous system. While most DSTs remain clinically occult, they can provide a route of entry for skin pathogens to cause intracranial infection. We report a child with a recent history of fever of unknown etiology who presented to our emergency department with a subcutaneous occipital mass. She was ultimately diagnosed with an infected intracranial dermal sinus tract. In this report, we provide a review of the literature on the diagnosis and management of this unique entity.

Dermal Sinus Tract of Lumbosacral Spine in Children: Patterns on Magnetic Resonance Imaging and Scoring System

Purpose

Dermal sinus tract (DST) is a challenging clinical diagnosis in children. The purpose of our study was to analyze the added value of magnetic resonance imaging (MRI) in the diagnosis of DST involving the lumbosacral spine. We also sought to establish an MRI-based scoring system to simplify the diagnosis of DST.

Methods

MRI images of 20 patients with clinically suspected DST were retrospectively assessed by two neuroradiologists blinded to the surgical results. The MRI studies were performed from July 2003 to July 2013. Institutional Review Board (IRB) approval was obtained. All MRI studies were assessed with respect to five imaging signs: A) visualization on both sagittal and axial images, B) dural penetration, C) associated tethered cord, D) presence of tumor or inflammation, and E) attachment to conus medullaris. The frequency of each imaging sign in the study population was calculated. For the 20 patients who underwent surgery, sensitivity and specificity of each neuroradiologist’s interpretation of the MRI data were calculated using operative findings as the gold standard.

Results

Twelve of the 20 had confirmed DSTs. The incidences of the five imaging signs were as follows: A) visualization on both sagittal and axial images (12/12, 100%), B) dural penetration (10/12, 83.3%), C) associated tethered cord (7/12, 58.3%), D) presence of tumor or inflammation (4/12, 33.3%), and E) attachment to the conus medullaris (4/12, 33.3%). The best combination of findings predictive of DST was simply the appearance of DST on both axial and sagittal imaging, which resulted in a sensitivity of 100% and a specificity of 75-100%.

Conclusion

Visualization of DST on both axial and sagittal imaging is the best marker for pathology proven DST. Using a higher threshold score on the five-point scoring system that we proposed did not increase sensitivity or specificity in the diagnosis of DST; however, it may still prove clinically helpful in standardizing reporting leading to a more accurate and detailed assessment.

Mapping the functional connectome in traumatic brain injury: What can graph metrics tell us?

OBJECTIVE

Traumatic brain injury (TBI) is associated with cognitive and motor deficits, and poses a significant personal, societal, and economic burden. One mechanism by which TBI is thought to affect cognition and behavior is through changes in functional connectivity. Graph theory is a powerful framework for quantifying topological features of neuroimaging-derived functional networks. The objective of this paper is to review studies examining functional connectivity in TBI with an emphasis on graph theoretical analysis that is proving to be valuable in uncovering network abnormalities in this condition.

METHODS

We review studies that have examined TBI-related alterations in different properties of the functional brain network, including global integration, segregation, centrality and resilience. We focus on functional data using task-related fMRI or resting-state fMRI in patients with TBI of different severity and recovery phase, and consider how graph metrics may inform rehabilitation and enhance efficacy. Moreover, we outline some methodological challenges associated with the examination of functional connectivity in patients with brain injury, including the sample size, parcellation scheme used, node definition and subgroup analyses.

RESULTS

The findings suggest that TBI is associated with hyperconnectivity and a suboptimal global integration, characterized by increased connectivity degree and strength and reduced efficiency of functional networks. This altered functional connectivity, also evident in other clinical populations, is attributable to diffuse white matter pathology and reductions in gray and white matter volume. These functional alterations are implicated in post-concussional symptoms, posttraumatic stress and neurocognitive dysfunction after TBI. Finally, the effects of focal lesions have been found to depend critically on topological position and their role in the network.

CONCLUSION

Graph theory is a unique and powerful tool for exploring functional connectivity in brain-injured patients. One limitation is that its results do not provide specific measures about the biophysical mechanism underlying TBI. Continued work in this field will hopefully see graph metrics used as biomarkers to provide more accurate diagnosis and help guide treatment at the individual patient level.

Posterior fossa infected dermoid with congenital heart disease: A novel hypothesis of an unusual association

Intracranial dermoid cysts commonly present as a discharging sinus, local swelling, mass lesion, or abscess formation. These can sometimes be found in association with congenital anomalies. The author presents two original cases of infected posterior fossa dermoid associated with congenital heart diseases (CHDs) that is very rare. The embryologic basis for this unique occurrence is reviewed, and a new hypothesis proposed. Two infants with CHD presented with infected midline posterior fossa dermoid. Excision of the dermoid cyst with the sinus tract was performed. Postoperative period was uneventful. Both the infants had undergone surgery for congenial heart disease a few months prior to the present clinical presentation with uneventful recovery. Infected posterior fossa dermoid cyst without a discharging sinus should prompt a thorough examination to detect CHD. Early diagnosis and timely management results in better outcome.

[Recurrent meningitis due to anatomical defects: The bacteria indicates its origin]

INTRODUCTION

Recurrent meningitis is a rare disease. Anatomical abnormalities and immunodeficiency states are predisposing factors. Four cases, in which immunodeficiency was excluded, are presented. The causal microorganism led to the detection of the anatomical defect responsible for the recurrences.

PATIENTS AND METHODS

Retrospective review of 4 cases with clinical diagnosis of recurrent bacterial meningitis.

RESULTS

Case 1: a thirty month-old boy with unilateral hearing loss, diagnosed with Mondini abnormality by magnetic resonance imaging (MRI) after 2 episodes of Haemophilus influenzae meningitis. Surgical repair after third recurrence. Case 2: fourteen year-old girl diagnosed by MRI with cribriform plate defect after 3 episodes of meningitis due to Streptococcus pneumoniae. Ventriculoperitoneal shunt was placed. Case 3: girl with meningitis due to Staphylococcus aureus at 2 and 7 months. MRI shows occipital dermal sinus requiring excision. Complication with cerebellar abscesses because of a coexisting dermoid cyst. Case 4: child with meningitis due to Streptococcus bovis at 9 days and Enterococcus faecium, Klebsiella pneumoniae and Escherichia coli at 7 months, with positive cultures to Citrobacter freundii and E. faecium later on. Spinal MRI led to the diagnosis of Currarino syndrome with CSF fistula, which was surgically repaired. The 4 patients had undergone image studies reported as normal during the first episodes.

CONCLUSIONS

In patients with recurrent meningitis the possibility of an anatomical defect should be considered. The isolated microorganism should help to locate it. It is essential to know the normal flora of the different anatomical sites. The definitive treatment is usually surgical.

Cranial dermal sinus: presentation, complications and management

OBJECTIVE

Cranial dermal sinus is a very rare anomaly mostly found in the midline occipital area, presenting with diverse clinical features from asymptomatic dermal sinus to symptomatic situations including meningitis, dermoid tumor or abscess.

METHODS

Medical records of 18 patients with 19 cranial dermal sinuses operated at the Children's Hospital Medical Center in Tehran from 1999 to 2011 were retrospectively studied. Their presentations, accompanying anomalies, radiological and surgical findings were evaluated.

RESULTS

Patients were aged 1 month to 6 years and were followed for 2-12 years. Most sinuses were located in the midline occipital region. Infection was the most common reason for referral (50%) followed by skin dimple (33.3%). Creamy white discharge was found in 50% of patients. Posterior fossa abscess, hydrocephalus and meningitis were observed in 38.9, 38.9 and 22.2% of children, respectively. All sinus tracts with associated dermoid tumors or abscesses were removed en bloc to decrease the risk of recurrence.

CONCLUSION

The sinus tracts are a portal of entry for pathogens which result in serious complications of meningitis or abscess. In this series, 67% of children presented with serious symptoms; therefore, we recommend prophylactic surgery in all cranial dermal sinuses. The exact time of surgery is not obvious as the natural course of the disease is unknown. If any symptom is observed surgery should be done as soon as possible. For asymptomatic sinuses identified by the pediatrician during a regular visit prophylactic surgery is recommended as soon as the child can tolerate operation.

[Cerebellar abscesses secondary to infection of an occipital dermal sinus]

A dermal sinus is a congenital defect arising from a closure failure of the neural tube that results in different degrees of communication between the skin and the central nervous system. A dermal sinus can occur anywhere from the root of the nose to the conus medullaris, and the occipital location is the second most common. Dermal sinuses are often found in association with dermoid or epidermoid cysts and less frequently with teratomas. Patients with an occipital dermoid cyst associated with a dermal sinus can develop meningitis and/or abscesses as the first clinical manifestation of the disease due to the dermoid cyst itself becoming abscessed or to the formation of secondary abscesses; few cases of the formation of secondary abscesses have been reported. We present a case of a dermoid cyst associated with an infected dermal sinus and posterior development of cerebellar abscesses and hydrocephalus.

Congenital pterional dermal sinus in an 18-month-old child: case report

OBJECTIVE

Congenital dermal sinus tracts most frequently occur in the midline and are often associated with dermoid or epidermoid inclusion cysts. A lateral cranial origin is extremely rare and anatomically inconsistent with an etiology involving closure of the rostral neural tube during embryogenesis.

CLINICAL PRESENTATION

We describe the first case of a pterional cranial dermal sinus tract associated with a small epidermoid, with extension to the dura of the anterior cranial fossa.

INTERVENTION

The extra- and intracranial portions of the tract were visualized and resected with the use of an operating microscope. Pathological diagnosis confirmed dermal sinus tract.

CONCLUSION

We review the existing literature and address the developmental and clinical features pertinent to the management of cranial dermal sinus tracts, emphasizing the need for exploration of these potentially harmful lesions.

Prenatal diagnosis of occipital dermal sinus associated with hemangioma using ultrasound and MRI. Case report

OBJECTIVE

We report a case of prenatal diagnosis and postpartum management of a subcutaneous tumor without intracranial communication.

METHODS

An occipital tumor without intracranial communication was found on ultrasound scan in the 21st week of pregnancy. Using MRI, the diagnosis was confirmed. Subcutaneous localization of the tumor was verified and communication with intracranial space excluded.

RESULTS

The newborn was delivered spontaneously at term and underwent a successful surgical procedure 5 months postpartum.

CONCLUSION

The prenatal diagnosis allowed differentiation between a communicating neural tube defect with poor prognosis, and a manageable extracranial subcutaneous tumor. The precise diagnosis of uncomplicated dermal sinus was possible only after the histological evaluation of the tumor confirmed occipital dermal sinus associated with hemangioma.