Disorders Affecting the Fourth Ventricle: Etiology and Clinical Correlates

Primary central nervous system diffuse large B-cell lymphoma in fourth ventricle: Case report and literature review

RATIONALE

Primary central nervous system lymphoma (PCNSL) is rare, especially lymphoma arising in the fourth ventricle. Only a few cases have been reported. We report a case of fourth ventricular lymphoma and review the relevant literature. Characterizing these cases can provide a basis for optimizing the diagnosis and management of fourth ventricle lymphoma.

PATIENT CONCERNS

A 48-year-old male with blurred vision, dizziness, staggering persisting for 2 months was admitted.

DIAGNOSIS

Preoperative magnetic resonance imaging revealed a space occupying lesion of the fourth ventricle. The patient presented with symptoms of hydrocephalus before surgery, such as memory loss and slurred speech. Pathological analysis following complete resection confirmed the lesion as PCNSL.

INTERVENTION

The patient underwent a midline posterior fossa craniotomy.

OUTCOMES

The patient symptoms were relieved after surgery. Postoperative chemotherapy was administered with our regular follow-up. Follow-up 9 months after operation indicated a good prognosis.

LESSONS

According to the literature, biopsy surgery and subsequent chemotherapy are generally considered as the best treatment options for PCNSL. We believe that for the special location of the fourth ventricle, lymphomas in this site are suitable for the combination of complete resection and subsequent chemotherapy. This approach facilitates tumor resection and reduces possibility of obstructive hydrocephalus.

Fourth Ventricular Epidermoid Cyst - Case Series, Systematic Review and Analysis

Background:

Epidermoid cysts are extra-axial, pearly white avascular lesions mostly found in the cerebellopontine region. They are slow-growing and mostly become symptomatic when they attain significant size. They do occur at other anatomical locations, but fourth ventricle is a rare location. Three representative cases with their outcomes are described here.

Methods:

The systematic review was done with adherence to predefined criteria. The studied variables were age, gender, duration of symptoms (DOS), clinical features, hydrocephalus (HCP), extent of resection, postoperative complications, outcome, follow–up, and recurrence. Statistical analysis was done to identify predictive factors for outcome.

Results:

Final analysis included 58 studies containing 131 patients. The most common clinical feature was cerebellar dysfunction (93%). The most common cranial nerve involved was the abducens nerve (n = 37, 28.46%). Preoperative HCP was present in nearly a third (35%) of patients. The outcomes were not different with age (P = 0.23), gender (P = 0.74), DOS (P = 0.09), and HCP (P = 0.50). Improved outcomes were associated with total resections (P = 0.001), absence of preoperative cranial nerve dysfunctions (P = 0.004), and presentation with features of raised intracranial pressure (P = 0.005). Longer DOS (mean 76.74 months) was associated with significantly increased cranial nerve nuclei involvement (P = 0.03). Aseptic meningitis was reported in 14.5% of cases. Recurrences were infrequently reported (n = 9).

Conclusions:

Although the fourth ventricular epidermoid lesions are difficult to detect in an innocuous stage, when found, they should be extirpated early and totally, as a longer DOS leads to cranial nerve dysfunctions and suboptimal outcomes.

Metal homeostasis disturbances in neurodegenerative disorders, with special emphasis on Creutzfeldt-Jakob disease - Potential pathogenetic mechanism and therapeutic implications

Creutzfeldt-Jakob disease (CJD) is characterized by a rapidly progressive dementia often accompanied by myoclonus and other signs of brain dysfunction, relying on the conversion of the normal cellular form of the prion protein (PrPC) to a misfolded form (PrPSc). The neuropathological changes include spongiform degeneration, neuronal loss, astrogliosis, and deposition of PrPSc. It is still unclear how these pathological changes correlate with the development of CJD symptoms because few patients survive beyond 2 years after diagnosis. Inasmuch as the symptoms of CJD overlap some of those observed in Alzheimer's, Parkinson's, and Huntington's diseases, there may be some underlying pathologic mechanisms associated with CJD that may contribute to the symptoms of non-prion neurodegenerative diseases as well. Data suggest that imbalance of metals, including copper, zinc, iron, and manganese, induces abnormalities in processing and degradation of prion proteins that are accompanied by self-propagation of PrPSc. These events appear to be responsible for glutamatergic synaptic dysfunctions, neuronal death, and PrPSc aggregation. Given that the prodromal symptoms of CJD such as sleep disturbances and mood disorders are associated with brain stem and limbic system dysfunction, the pathological changes may initially occur in these brain regions, then spread throughout the entire brain. Alterations in cerebrospinal fluid homeostasis, which may be linked to imbalance of these metals, seem to be more important than neuroinflammation in causing the cell death. It is proposed that metal dyshomeostasis could be responsible for the initiation and progression of the pathological changes associated with symptoms of CJD and other neurodegenerative disorders.

Anatomic Variability of the Morphometric Parameters of the Fourth Ventricle of the Brain

Objectives  The defining of the normal parameters of spacious relations and symmetry of the ventricular system of the brain depending on the gender and age is currently one of the topical research problems of clinical anatomy. The present research aims to identify the correlation between the morphometric parameters of the fourth ventricle of the brain and the shape of the skull in middle aged people. Design  This is a prospective cohort study. Setting  This study was set at the Trinity School of Medicine. Participants  A total of 118 normal computed tomography scans of the head of people aged from 21 to 86 years (mean age-48.6 years ± 17.57) were selected for the study. Main Outcome Measures  The anteroposterior, transverse diameters, and height of the fourth ventricle were measured and compared in dolichocranial, mesocranial, and brachycranial individuals. Results  The study has shown the presence of a statistically significant difference between morphometric parameters of the fourth ventricle of the brain in dolichocranial, mesocranial, and brachycranial individuals. Conclusion  The morphometric parameters of the fourth ventricle of the brain, such as height, anteroposterior, and transverse diameters, depend on the individual anatomic variability of the skull shape and gender.

Predictors of Outcomes in Fourth Ventricular Epidermoid Cysts: A Case Report and a Review of Literature

OBJECTIVE

To present an illustrative case of fourth ventricular epidermoid cyst and review the literature to identify predictors of surgical outcomes.

METHODS

A case of fourth ventricular epidermoid cyst is presented and a systematic review of 5 popular databases was performed by independent authors. Stepwise logistic regression was performed to identify clinical predictors of outcomes.

RESULTS

A 21-year-old woman presented with 3 months of headaches and visual obscurations and was diagnosed with a multilobulated mass in the fourth ventricle. The patient underwent suboccipital craniotomy. Complete removal of the mass was achieved and the final diagnosis was consistent with an epidermoid cyst. The systematic review identified 23 studies that reported 37 patients. Mean age was 42.8 years. Mean length of time between symptom onset and diagnosis was 4.43 years. Age (P = 0.049) and duration of symptoms (P < 0.001) were significantly different between patients who experienced symptom improvement and those who did not. Duration of symptom onset to diagnosis was a significant predictor of poor outcomes (odds ratio, 1.19, 95% confidence interval, 1.003-4.785).

CONCLUSIONS

Our review found that in patients with fourth ventricular epidermoid cysts, unfavorable outcomes were predicted by older age and by longer intervals from symptom onset to diagnosis. Clinicians should maintain a high index of suspicion for fourth ventricular epidermoid cysts in patients presenting with cerebellar signs and visual disturbances.

Involvement of Neuroinflammation during Brain Development in Social Cognitive Deficits in Autism Spectrum Disorder and Schizophrenia

Development of social cognition, a unique and high-order function, depends on brain maturation from childhood to adulthood in humans. Autism spectrum disorder (ASD) and schizophrenia have similar social cognitive deficits, although age of onset in each disorder is different. Pathogenesis of these disorders is complex and contains several features, including genetic risk factors, environmental risk factors, and sites of abnormalities in the brain. Although several hypotheses have been postulated, they seem to be insufficient to explain how brain alterations associated with symptoms in these disorders develop at distinct developmental stages. Development of ASD appears to be related to cerebellar dysfunction and subsequent thalamic hyperactivation in early childhood. By contrast, schizophrenia seems to be triggered by thalamic hyperactivation in late adolescence, whereas hippocampal aberration has been possibly initiated in childhood. One of the possible culprits is metal homeostasis disturbances that can induce dysfunction of blood-cerebrospinal fluid barrier. Thalamic hyperactivation is thought to be induced by microglia-mediated neuroinflammation and abnormalities of intracerebral environment. Consequently, it is likely that the thalamic hyperactivation triggers dysregulation of the dorsolateral prefrontal cortex for lower brain regions related to social cognition. In this review, we summarize the brain aberration in ASD and schizophrenia and provide a possible mechanism underlying social cognitive deficits in these disorders based on their distinct ages of onset.

Mapping affected territory of anterior/posterior inferior cerebellar artery infarction using a vestibular test battery

CONCLUSION

Although the affected territory in the posterior/anterior inferior cerebellar artery (PICA/AICA) infarction could not be meticulously demonstrated by magnetic resonance imaging (MRI), it could be picked up by the results of a vestibular test battery comprising caloric, ocular vestibular evoked myogenic potential (oVEMP), and cervical VEMP (cVEMP) tests.

OBJECTIVES

This study applied audiometry and caloric, oVEMP, and cVEMP tests to map affected territory in patients with PICA/AICA infarction.

METHODS

Fourteen patients, including 11 with PICA infarction and 3 with AICA infarction, were enrolled in this study during the last 8 years. Each patient underwent audiometry, caloric test, oVEMP test, and cVEMP test.

RESULTS

In the PICA group, 8 (36%) of 22 ears had a mean hearing level >25 dB. All six ears (100%) in the AICA group had abnormal hearing, and thus both groups revealed a significant difference. Conversely, significant differences were not observed in the vestibular test battery between the PICA and AICA groups. MRI demonstrated infarction at the brainstem for six patients, while one patient also had cerebellar involvement, indicated by loss of visual suppression on caloric nystagmus. Six patients showed infarction at the cerebellum, and four of them had brainstem affliction based on abnormal oVEMP/cVEMP test results.

Clinical significance of pathological eye movements in diagnosing posterior fossa stroke

CONCLUSION

Close observation of pathological eye movements such as disconjugate eye movements, multi-directional gaze nystagmus, and persistent unilateral gaze nystagmus may facilitate the effort of clinicians to arrange magnetic resonance imaging (MRI) study, because physical examinations may overlook the posterior fossa lesions.

OBJECTIVE

This paper reviews our experience of patients with posterior fossa stroke via observation of pathological eye movements over the past 10 years.

METHODS

Seventy patients with posterior fossa stroke manifested as acute vertiginous attack were admitted. All patients underwent examination of eye movements, MRI, and a battery of audiovestibular function tests.

RESULTS

Of the 70 patients, 22 (31%) demonstrated pathological eye movements including persistent (>24 h) unilateral gaze nystagmus in 12 patients, and multi-directional gaze nystagmus in 10 patients. Conjugate eyes movements were identified in 18 patients, and disconjugate eye movements were shown in 4 patients including medial longitudinal fasciculus syndrome in 1, paramedian pontine reticular formation syndrome in 1, and one and a half syndrome in 2. The vestibular test battery revealed abnormal responses for >85% of the patients in each test. MRI demonstrated infarction or hemorrhage involving the brainstem in 12 patients, cerebellum in 8 patients, and both in 2 patients.