|Year : 2020 | Volume
| Issue : 4 | Page : 545-548
Persistent craniopharyngeal canal: A rare cause for recurrent meningitis in pediatric population
Lokesh Lingappa1, Ramesh Konanki1, Ravi Varma2, Nikit Shah1, Subodh Raju3, Sukumar Sura3, Leenatha Reddy4, Sirisha Rani5
1 Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
2 Department of Neuroradiology, Citi Neuro Centre, Hyderabad, Telangana, India
3 Department of Neurosurgery, Rainbow Children's Hospital, Hyderabad, Telangana, India
4 Department of Endocrinology, Rainbow Children's Hospital, Hyderabad, Telangana, India
5 Department of Pediatric Hemato-Oncology, Rainbow Children's Hospital, Hyderabad, Telangana, India
|Date of Web Publication||21-Aug-2020|
Department of Pediatric Neurology, Rainbow Children's Hospital, Road No 2, Banjara Hills, Hyderabad - 500 034, Telangana
Source of Support: None, Conflict of Interest: None
| Abstract|| |
We present the case of a 5-year-old girl who had six episodes of meningitis. She also had panhypopituitarism and was found to have a persistent craniopharyngeal canal (CPC) as the cause of her recurrent meningitis. Role of neuroradiology and a high index of suspicion by the clinical team are highlighted here. Persistent CPC is a rare cause of recurrent meningitis. We discuss the approach to the child with recurrent meningitis.
Keywords: Craniopharyngeal canal, hypopituitarism, recurrent meningitis
|How to cite this article:|
Lingappa L, Konanki R, Varma R, Shah N, Raju S, Sura S, Reddy L, Rani S. Persistent craniopharyngeal canal: A rare cause for recurrent meningitis in pediatric population. Ann Indian Acad Neurol 2020;23:545-8
|How to cite this URL:|
Lingappa L, Konanki R, Varma R, Shah N, Raju S, Sura S, Reddy L, Rani S. Persistent craniopharyngeal canal: A rare cause for recurrent meningitis in pediatric population. Ann Indian Acad Neurol [serial online] 2020 [cited 2021 Mar 1];23:545-8. Available from: https://www.annalsofian.org/text.asp?2020/23/4/545/249736
| Section 1: Case Report|| |
A 5-year-old girl was diagnosed as panhypopituitarism at 4 months of age during an episode of hypoglycemic seizures. Developmental delay and short stature were noted. She was put on thyroid hormone and hydrocortisone supplements and received growth hormone injections.
She had meningitis at 2 years, confirmed by cerebrospinal fluid (CSF) analysis: showed high WBC count 1920/μL, low sugar of 28mg/dL, suggestive of bacterial meningitis. CSF culture was sterile. She had seizures on day 5 of admission; low sugar (38 mg/dL), and no cells were noted on repeat CSF analysis. There was no other neurological sign. She received ceftriaxone and vancomycin for 14 days. After 2 months, she had another episode of meningitis. CSF analysis showed 1090 cells with 70% lymphocytes, sugar – 20 mg/dL and protein – 155 mg/dL. CSF polymerase chain reaction (PCR) and culture were negative. She recovered within 3 days and received ceftriaxone for 14 days.
She continued to have repeated episodes of meningitis as detailed in [Table 1]. Maximum interval between the two episodes was 11 months (2nd and 3rd episodes).
| Section 2|| |
- How to approach a child with 2nd episode of meningitis
- Medical causes of recurrent meningitis
- Structural cause of recurrent meningitis
- Role of conventional versus protocolized magnetic resonance imaging (MRI) in investigating recurrent meningitis
- Identify craniopharyngeal canal (CPC) in images given [Figure 1].
|Figure 1: (a) Fluid-attenuated inversion recovery axial images showing leptomeningeal signal changes. (b) T2 sagittal showing hypoplastic pituitary (black arrow) and persistent craniopharyngeal canal. (c) Computed tomography head showing persistent bony canal below the pituitary fossa. (d) T2 coronal showing hypoplastic pituitary (black arrow) and persistent craniopharyngeal canal|
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How to approach a child with 2nd episode of meningitis?
Recurrent meningitis is a rare encounter in pediatrics, and establishing the diagnosis is a challenge. Of various causes, anatomical defect either congenital or acquired is an important factor, followed by infectious diseases, immunodeficiency states, and aseptic meningitis due to inflammation [Table 2].
|Table 2: Causes of recurrent meningitis (except dural connections and immunodeficiency syndromes)|
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Bacterial meningitis is recognized as an important cause of morbidity and mortality in developing countries where infections are most frequent. It may have an array of differential diagnosis ranging from tuberculous meningitis in developing countries to central nervous system (CNS) fungal infections in temperate countries, chemical meningitis, and parameningeal collections such as subdural empyema.
In the absence of obvious leading symptoms and signs (CSF otorrhea and CSF rhinorrhea), focused clinical examination to find out visible dural connections is essential. Coccygeal sinuses and nuchal areas should be actively screened as they are generally missed out in clinical examination. Laboratory investigations helping in the diagnosis are isolation of causative organism that differentiates bacterial from chemical meningitis. Culture may not be sufficient; hence, other methods (i.e., latex agglutination and PCR analysis) may have to be adopted. Anatomical defects are to be considered if the same organism is isolated, whereas various sites of infections and different organisms suggest possible immunodeficiency. Immunodeficiency workup includes immunoglobulin panel, immunoglobulin G subclass, lymphocyte subsets, and complement panel. If these measures fail to offer any clue to diagnosis, MRI brain and spine should be considered as precise localization of anatomic defect is important for surgical repair.
In addition, isolation of causative organism indicates and provides specific clues toward localization: Hemophilus and Pneumococcus species suggest possible cranial defect; Escherichia coli and Gram-negative coli indicate spinal defect; isolation of Meningococcus species suggests likely complement deficiencies or agammaglobulinemia; and extra CNS infections suggest the possibility of immunodeficiency.
Structural causes of recurrent meningitis
Several structural abnormalities may be associated with recurrent meningitis. Mass lesions such as epidermoid and craniopharyngioma are associated with aseptic meningitis.
Abnormal tracts leading to the cranial and spinal subarachnoid space may be seen in the anterior skull base (traumatic or nontraumatic CSF fistulas into the paranasal sinuses, middle ear, or mastoids), midline along the dorsal aspect of the entire spine (dorsal dermal sinuses), or along the ventral aspect of the spine (neurenteric fistulae). Conventional imaging studies can provide important clues (such as fluid collections in the paranasal sinuses or mastoid air cells and presence of spina bifida or vertebral segmentation anomalies) that can point to the presence of such abnormalities.
Concomitant occurrence of two congenital lesions is described in various combinations:
- Meningocele of the anterior skull base and a defect in the stapedial footplate
- Meningoencephalocele of the cribriform plate and a fistula at the oval foramen
- Meningocele through a cleft crista galli and a fistula at the oval foramen
- Cribriform plate and an inner-ear malformation with a fistula through the stapedial footplate
- It is important to know these associations as medial skull defects are often missed because of their rarity and difficulty in diagnosing them on routine imaging, which leads to recurrence of meningitis even after surgical correction.
We obtained a detailed history of trauma, travel and excluded any possible external dural connection by thorough clinical examination. Immunodeficiency workup (lymphocyte subset and immunoglobulin panel) was negative. Initial MRI of the brain and spine performed with routine imaging protocols failed to demonstrate any pathology. With sterile cultures and rapid resolution of symptoms within 2–3 days of onset, a possibility of chemical meningitis was considered. Her treatment history of dexamethasone- (increased doses as part of stress dosing) for panhypopituitarism further strengthened our suspicion. Moreover, complete resolution of symptoms was seen with only 3 days of antibiotic therapy in two of the six episodes. Careful review of the initial MRI and subsequent high-resolution MRI and computed tomography (CT) scan of the skull base demonstrated the presence of CPC. CSF leak through the canal could not be demonstrated.
Role of conventional versus protocolized magnetic resonance imaging in investigating recurrent meningitis
Conventional MRI techniques employ thick sections (4–5 mm thick), which are clearly suboptimal in the evaluation of dermal sinuses and CSF fistulae. High-resolution imaging with custom-built protocols employing thin section (1–2 mm thick) is required in evaluation for the skull base and spine in cases of recurrent meningitis. Often, imaging is the sole mode of diagnosis when CSF leak is not visible externally (e.g., CSF leak into the nasopharynx). Correlation with CT findings is often essential to delineate the extent of the pathology.
| Section 3|| |
Relevance of craniopharyngeal canal to hypopituitarism and recurrent meningitis
Size and site of occurrence of CPC determine the clinical presentation. CPC has been classified into three subgroups based on radiological characteristics [Table 3]. As expected, due to its developmental origin, pituitary dysfunction is a frequent manifestation and generally associated with Type 2 (size 3.5–4.4 mm) and Type 3 (size 5.9–31 mm) CPCs and was noted in 21% (n = 6/29) by Abele et al. in their series. This study also indicated the association between CPC and recurrent meningitis. Our case belongs to Type 1 canal as per the above classification system, which does not describe to have associated hypothyroidism.
|Table 3: Classification of craniopharyngeal canal as per size and other characteristics|
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Persistent CPC and hypopituitarism is a well-established association as per various reports, but association with recurrent meningitis is rare. Only three reported cases of recurrent meningitis and CPC ,, are available in literature, of which only one has been reported in a 4.5-year-old child.
| Section 4|| |
- How to treat CPC and associated symptoms
- Illustration of the surgical finding in our case
Surgical correction is the treatment option for recurrent meningitis with established persistent CPC. Debate still exists about operating incidentally picked up canals, associated pituitary dysfunction, and established visual defects. Traditional intracranial approach is being replaced by newer techniques such as neuronavigation. Defects can be corrected transnasally. Literature evidence indicates that there is no difference in the success rate of endoscopic and open-skull procedures (~90%). However, the advantages of lesser incidence of intra- and post-operative complications such as meningitis, abscess, wound infection, sepsis, and perioperative mortality rate make the former the preferred surgical method.,
In this case, the parents were informed about the available surgical options and were counseled thoroughly by a team of pediatric neurology, neurosurgery, and ENT surgery. They opted for endoscopic surgery assisted with neuronavigation over open surgery. Sphenoidotomy was performed. Under neuronavigation guidance, posterior aspect of the sphenoid bone and upper clivus was drilled. After few milimeters of drilling, the tract was delineated and was traced caudally till nasopharynx and cranially up to the posterior aspect of the pituitary fossa. Content of the canal was fibrous band, which was disconnected, and ends were coagulated. Histopathology of the dissected tissue revealed fibrous tissue. There were no postoperative complications.
She was operated in July 2015. There was no further episode of meningitis postsurgery till date. There was an episode of febrile illness in February 2016, where all investigations including CSF examination were normal. She is on levetiracetam and hormonal supplement.
- Recurrent meningitis: Neuroimaging is essential with neuroradiologist's interpretation
- Chemical meningitis versus bacterial meningitis should be differentiated for prognosis and treatment duration
- Associated hypopituitarism should raise doubt toward persistent CPC as a cause of recurrent meningitis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
We thank Dr. Srinivas Kishor, ENT surgeon of STAR Hospital, for helping us in the management of this child and help during surgery.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]