Resolution of neurogenic arterial hypertension after suboccipital decompression for Chiari malformation. Case report

Chiari I malformation with neurogenic hypertension after suboccipital decompression

Patients with Chiari I malformations have a spectrum of symptoms related to craniocervical structural compression. Neurogenic hypertension has been reported in some patients with this disorder, with resolution of hypertension after suboccipital decompressions in some cases. The pathophysiology of neurogenic hypertension in these patients is thought to be related to ventrolateral medullary compression. The important role of the ventrolateral medulla in blood pressure control has been studied extensively. In this report, we present the case of a pediatric patient diagnosed with a Chiari I malformation who developed hypertension after a suboccipital decompression. We believe that this case demonstrates the important role of the ventrolateral medulla in neurogenic hypertension.

Clinical diagnosis-part II: what is attributed to Chiari I

PURPOSE

Chiari malformation type I is identified as radiological appearance of cerebellar tonsil herniation below the foramen magnum. The wide spectrum of clinical manifestations variably associated sometimes encompasses signs and symptoms whose correlation with the malformation remains debatable. However, a correct clinical framework is relevant in tailoring the strategy of management, and in particular, establishing the appropriate surgical intervention.

METHODS

An analysis of relevant articles on this issue was performed, involving both single case reports and case series. The papers were obtained from electronic databases including PubMed/MEDLINE and Google Scholar, as well as direct contact with some authors.

RESULTS

This review focuses on those unusual clinical pictures attributed to Chiari malformation type I (CMI), investigating their actual relationship with the morphological condition. Supposed physiopathogenetic mechanisms and clinical relevance are discussed along with an analysis on the surgical indications and results.

CONCLUSION

There is no clear explanation on why some patients may exhibit uncommon symptoms, often in association with the most frequent ones, but even reported as single initial clinical occurrence. Their actual incidence may have been roughly underestimated in the literature so far, because of wide heterogeneity of selection and analysis among different studies. Most of the authors appear sharing the impression that CMI surgical decompression plays a significant role in controlling the majority of these unusual symptoms, stressing their actual occurrence in relation with the malformation. A routinely multidisciplinary clinical approach has become advisable to encompass the diversity of conditions potentially associated with CMI and improve the care of CMI patients.

Normalization of systemic arterial hypertension following removal of posterior fossa hemangioblastoma: a case report

The concept of compression of the rostral ventrolateral medulla as a cause for hypertension is gaining more and more interest. This report is about a 36-year-old male with a three years history of hypertension who presented with a posterior fossa mass suggestive of a hemangioblastoma. Laboratory and imaging studies ruled out the presence of von Hippel-Lindau disease and/or concomitant pheochromocytoma. Post-surgical blood pressure monitoring revealed a 40 mmHg decline in blood pressure. It could be hypothesized that alleviation the compressive effect of the tumour on the rostral ventrolateral medulla as proposed by previous studies could be a contributing factor.

Normalization of systemic arterial hypertension following removal of posterior fossa hemangioblastoma: a case report

The concept of compression of the rostral ventrolateral medulla as a cause for hypertension is gaining more and more interest. This report is about a 36-year-old male with a three years history of hypertension who presented with a posterior fossa mass suggestive of a hemangioblastoma. Laboratory and imaging studies ruled out the presence of von Hippel-Lindau disease and/or concomitant pheochromocytoma. Post-surgical blood pressure monitoring revealed a 40 mmHg decline in blood pressure. It could be hypothesized that alleviation the compressive effect of the tumour on the rostral ventrolateral medulla as proposed by previous studies could be a contributing factor.

Acute respiratory arrest following partial suboccipital cranioplasty for cerebellar ptosis from Chiari malformation decompression

Cerebellar ptosis is a rare complication following Chiari malformation decompression, and generally is the result of a very large suboccipital craniectomy. This can lead to the descent of the cerebellum through the craniectomy defect, which in turn may result in cerebellar herniation through the surgical defect as well as the reestablishment of contact between the cerebellar tonsils and the brainstem. In addition, dorsal adherence of the herniated cerebellum to the dura mater or dural patch and an associated obstruction of cerebrospinal fluid flow at the cervicomedullary junction may ensue. Such a result is not desirable, in that it reproduces or mimics the pathoanatomical relationships that existed prior to the surgical decompression.