Intracranial Posterior Fossa Research Articles

Reoperation-requiring postoperative intracranial haemorrhage after posterior fossa craniotomy: Retrospective case-series

IntroductionStudies report rates of treatment-requiring postoperative intracranial haemorrhage after craniotomy around 1–2%, but do not distinguish between supratentorial and posterior fossa operations. Reports about intracranial haemorrhages’ temporal occurrence show conflicting results. Recommendations for duration of postoperative monitoring vary. Research questionTo determine the rate, temporal pattern and clinical presentation of reoperation-requiring postoperative intracranial posterior fossa haemorrhage. Material and methods: This retrospective case-series identified cases operated with posterior fossa craniotomy or craniectomy between January 1, 2007 and December 31, 2021 by an electronic search in the patient administrative database, and collected data about patient- and treatment characteristics, postoperative monitoring, and the occurrence of haemorrhagic and other serious postoperative complications. ResultsWe included 62 (n = 34, 55% women) cases with mean age 48 (interquartile range 50) years operated for tumours (n = 34, 55%), Chiari malformations (n = 18, 29%), ischemic stroke (n = 6, 10%) and other lesions (n = 3, 5%). One (2%) 66-year-old woman who was a daily smoker operated with decompressive craniectomy and infarct resection, developed a reoperation-requiring postoperative intracranial haemorrhage after 25.5 h. In four (6%) cases, other serious complications requiring reoperation or transfer from the post anaesthesia care unit or regular bed wards to the intensive care unit occurred after 0.5, 6, 9 and 54 h, respectively. Discussion and conclusionTreatment-requiring postoperative intracranial haemorrhage and other serious complications after posterior fossa craniotomies occur over a wide timespan and are difficult to capture with a standardized postoperative monitoring time. This indicates that the duration of monitoring should be individualized based on assessment of risk factors.

"Growing cerebellum" requiring operative decompression following perinatal ventriculoperitoneal shunting.

While cases of acquired Chiari I malformation following ventriculoperitoneal shunting for posthemorrhagic hydrocephalus have been reported, true disproportionate cerebellar growth is rare, with no previous cases requiring posterior fossa decompression reported. We present a premature neonate who underwent ventriculoperitoneal shunt placement for suspected posthemorrhagic hydrocephalus. He subsequently developed a symptomatic Chiari I malformation with volumetric measurements demonstrating disproportionate growth of the cerebellum. He did not demonstrate thickening of the supratentorial or posterior fossa cranium. The patient underwent an extradural posterior fossa decompression, with resolution of symptoms. We review the extant literature regarding the development of Chiari malformation type I as a manifestation of craniocerebral disproportion (CCD) following shunt placement for posthemorrhagic hydrocephalus of prematurity. Most previous reports reflect a mechanism that includes underdevelopment of the intracranial posterior fossa (or supratentorial) volume. The case presented in this report, as well as one additional case, indicates that there may exist a variant mechanism, characterized by rapid growth of the cerebellum itself, in the absence of one of the rare syndromes associated with primary macrocerebellum. While this case was effectively managed with extradural posterior fossa decompression, previous reports indicate that supratentorial cranial expansion procedures are preferable in some cases. As such, pediatric neurosurgeons should be able to distinguish the patterns of craniocerebral disproportion when considering treatment options for these patients. Further investigation regarding these uncommon patients may better describe the underlying mechanisms.

Clinicopathological spectrum of Intracranial Posterior Fossa Tumours and their Prognostic significance

Background: Intracranial Posterior fossa tumors are critical brain lesions with significant neurological morbidity and mortality due to limited space and involvement of vital brain stem nuclei and fourth ventricle. Early diagnosis of posterior fossa tumors is vital to prevent potential risks of Brain stem compression, herniation, hydrocephalus and death. Aim of the study: 1. To study the morphological spectrum of intracranial posterior fossa SOLs. 2.To determine the frequency of posterior fossa SOLs reported in the tertiary care center of Nalgonda district. 3. To correlate clinical presentation with histopathological diagnosis and assess prognosis, and compare it with national and international literature. Materials and Methods: The present study was a retrospective description study conducted at the Department of pathology, Kamineni Institute of Medical Sciences, Narketpalli over a period of 3 years starting from June 2015 to June 2018. During this period, histopathological analysis of all the intracranial posterior cranial fossa tumors was done, correlated with clinical and radiological findings and prognosis assessed. Result: In our study Posterior fossa tumors are predominantly seen in adults with peak incidence in fourth decade. In children majority of the tumors were reported below 5 years of age. Most common presenting symptom was head ache and vomiting. Most common tumor was Medulloblastoma in children and Schwannoma in adults. Most common location was Cerebello-pontine angle followed by cerebellum. Recurrence rates were higher for CP angle tumors due to difficult sub-total resection. Prognosis is good for patients with total resection of tumors. Conclusion: Posterior fossa tumours are critical brain lesions with significant neurological morbidity and mortality. With rapid advancement in radiology and advent of modern therapeutic modalities early diagnosis and treatment is possible in many cases. Histopathology remains the gold standard in diagnosing Intracranial Posterior fossa tumours and necessary for the formulation of further management after neurosurgery.

Metastatic mucinous adenocarcinoma presenting as cerebellopontine angle tumor

Intracranial posterior fossa metastasis is a common entity. Metastatic mucinous adenocarcinoma presenting as cerebellopontine angle (CPA) tumor is very rare. The authors presented a 47-year-old female patient with right CPA tumor. The magnetic resonance imaging brain showed a heterogeneous contrast-enhancing dural-based extra-axial right CPA lesion involving the right cerebellar hemisphere, internal auditory meatus, and posterior surface of the right petrous bone. The patient underwent surgery, and subtotal resection of the tumor was done. Histology of the tumor was metastasis from a mucinous adenocarcinoma. Contrast-enhanced computed tomography scan of the abdomen and pelvis, ultrasound of the thyroid, chest X-ray, and thyroid function tests were normal. Carbohydrate antigen (CA) 19-9 was 949.37 U/mL, serum carcinoembryonic antigen (CEA) was 48.17 ng/mL, and CA-125 was 8.20 U/mL. In view of the raised CA 19-9 and CEA, primary malignancy was believed to be arising from the pancreas or from the gastrointestinal tract, though the definitive diagnosis of primary malignancy was not made. Although rare, metastatic mucinous adenocarcinoma should be kept in the differential diagnosis of CPA lesions. Even though the tumor is radiologically mimicking as CPA schwannoma, the absence of hearing abnormality should raise the suspicion for other diagnoses.

Extramedullary Plasmacytoma Presenting as a Solitary Mass in the Intracranial Posterior Fossa

A patient with a 3-month history of headache refractory to pain medication was admitted. The CT scan and MRI showed evidence of a posterior fossa mass. This was pathologically confirmed as an extra medullary plasmacytoma (EMP). He had a pathologic fracture of the left humerus 7 years ago while the radiologist was unaware at the time of diagnosis. A solitary bone plasmacytoma (SBP) was the cause of the pathologic fracture. This report includes the first description of MRI findings in a patient with a rare-incidence intracranial solitary extra medullary plasmacytoma (SEP) in Iran. There is a striking similarity between the features of intracranial SEP and meningiomas. Intracranial SEP, although rare, should be included in the differential diagnosis of brain tumors in areas where meningiomas commonly arise. The MRI findings and differential diagnosis of plasmacytoma are reviewed. Before this case report, only few cases have been reported in the literature. Nonetheless, this is the first report of posterior fossa EMP from Iran.

MR Imaging of Pediatric Posterior Fossa Tumors

A wide spectrum of tumors or tumor-like masses can involve the intracranial posterior fossa in the pediatric population. The multiplanar capabilities of MR imaging and its sophisticated new pulse sequences allow improved detection and characterization of posterior fossa tumors. Determining whether a mass is intra- or extra-axial remains paramount in limiting the differential diagnosis. This article reviews the imaging characteristics of the most common pediatric posterior fossa tumors (i.e., gliomas, medulloblastoma, and ependymoma). In addition, the use and benefits of H-NMR spectral analysis, diffusion-weighted imaging (DWI), and apparent diffusion coefficient maps will be addressed. Symptoms of posterior fossa masses in children usually include early morning headaches, vomiting, cranial nerve palsies, and dysmetria (i.e., abnormalities of movement caused by cerebellar dysfunction).

Evaluation of different cerebral mass lesions by perfusion‐weighted MR imaging

To investigate the contribution of perfusion-weighted MR imaging (PWI) by using the relative cerebral blood volume (rCBV) ratio in the differential diagnosis of various intracranial space-occupying lesions. This study involved 105 patients with lesions (high-grade glioma (N=26), low-grade glioma (N=11), meningioma (N=23), metastasis (N=25), hemangioblastoma (N=6), pyogenic abscess (N=4), schwannoma (N=5), and lymphoma (N=5)). The patients were examined with a T2*-weighted (T2*W) gradient-echo single-shot EPI sequence. The rCBV ratios of the lesions were obtained by dividing the values obtained from the normal white matter. Statistical analysis was performed with the Mann-Whitney U-test. A P-value less than 0.05 was considered statistically significant. The rCBV ratio was 5.76+/-3.35 in high-grade gliomas, 1.69+/-0.51 in low-grade gliomas, 8.02+/-3.89 in meningiomas, 5.27+/-3.22 in metastases, 11.36+/-4.41 in hemangioblastomas, 0.76+/-0.12 in abscesses, 1.10+/-0.32 in lymphomas, and 3.23+/-0.81 in schwannomas. The rCBV ratios were used to discriminate between 1) high- and low-grade gliomas (P<0.001), 2) hemangioblastomas and metastases (P<0.05), 3) abscesses from high-grade gliomas and metastases (P<0.001), 4) schwannomas and meningiomas (P<0.001), 5) lymphomas from high-grade gliomas and metastases (P<0.001), and 6) typical meningiomas and atypical meningiomas (P<0.01). rCBV ratios can help discriminate intracranial space-occupying lesions by demonstrating lesion vascularity. It is possible to discriminate between 1) high- and low-grade gliomas, 2) hemangioblastomas and other intracranial posterior fossa masses, 3) abscesses from high-grade gliomas and metastases, 4) schwannomas and meningiomas, 5) lymphomas and high-grade gliomas and metastases, and 6) typical and atypical meningiomas.

Incidental finding of meningioma on bone scintigraphy

An incidental finding of an intracranial posterior fossa meningioma detected by bone scintigraphy is presented. Most of the published literature on the diagnosis of meningioma is on the use of CT and MRI. There is limited published literature on the detection of meningioma with bone scintigraphy.

Acute Intracranial Vascular Accidents

Cerebellar hemorrhage, cerebellar infarction, pontine hemorrhage, and pontine infarction are four clinical conditions representative of intracranial posterior fossa accidents, which can mimic acute vestibular disturbances. It is exceedingly important to recognize these clinical entities early and to differentiate them from peripheral vestibulopathies so that appropriate diagnostic tests and therapeutic measures can be instituted early to prevent the high mortality rate seen without appropriate treatment. It is appreciated that without computed axial tomography, rapid diagnosis of these clinical syndromes is more difficult, but it is still possible on the basis of the clinical clues mentioned if their potential significance is recognized.

“Practical suggestions on facial plastic surgery — how i do it” protic duct transfer in xerophthalmia

Xerophthalmia, or dry eye, is an old human affliction. Among the many causes are trachoma, surgical or traumatic destruction of the lacrimal gland, and paralysis of the greater superficial petrosal nerve after Bell's palsy or from the presence or removal of an intracranial posterior fossa tumor. The technique of parotid duct transfer is a well established effective means to rehabilitate the dry eye. A method of parotid duct transfer is described.