Primary hypertension-induced cerebellar encephalopathy causing obstructive hydrocephalus. Case report

Hypertensive posterior reversible encephalopathy causing obstructive hydrocephalus

Background:

Posterior reversible encephalopathy syndrome (PRES) can occur due to the detrimental effect of malignant hypertension on cerebral autoregulation. Most reported cases describe involvement of the supratentorial areas. Involvement of the posterior fossa structures in conjunction with supratentorial involvement has also been reported; however, PRES affecting the infratentorial structures without supratentorial involvement is a rare phenomenon. Clinical manifestations can involve severe headache, seizures, and reduced consciousness with treatment focused primarily on blood pressure control.

Case Description:

We report a case of PRES with isolated involvement of the infratentorial structures leading to obstructive hydrocephalus. The patient was managed with aggressive control of blood pressure and avoided ventriculostomy or posterior fossa decompression with a good outcome.

Conclusion:

Medical management in the absence of neurological deficit can be associated with a good outcome.

Acute obstructive hydrocephalus in posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is an uncommon, subacute neurological disorder that presents radiologically with a pattern of bilateral parieto-occipital areas of vasogenic oedema. Conditions commonly associated with PRES include autoimmune disorders, cytotoxic drugs, metabolic abnormalities and, most frequently, hypertensive emergencies. Clinically, headache, visual disturbances, seizures and an altered level of consciousness are often reported. The outcome is favourable if the underlying cause is addressed. Posterior fossa involvement resulting in obstructive hydrocephalus is a rare presentation and may be misdiagnosed as a mass lesion or infection, leading to delayed or unnecessary treatment. We describe the clinical presentation, findings on neuroimaging and conservative management of a man with PRES resulting in severe cerebellar oedema and acute obstructive hydrocephalus. This case illustrates that awareness of atypical neuroimaging in PRES is important for the management of these patients and to avoid morbidity and mortality.

Isolated cerebellar involvement in posterior reversible encephalopathy syndrome

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a serious and increasingly recognized disorder in humans. However, isolated cerebellar involvement in PRES is extremely uncommon. In this study, we sought to investigate its clinical and radiological features by describing a cohort of cases with PRES and isolated cerebellar involvement.

METHODS

We report 2 patients with PRES with only cerebellar involvement and identified additional 9 cases using the PubMed database with the MeSH terms "posterior reversible encephalopathy syndrome", "hypertensive encephalopathy", "hypertension", "cerebellum", "encephalopathy", and "magnetic resonance imaging". We then collectively analyzed the clinical and imaging characteristics of these 11 cases.

RESULTS

The average age was 28years, with 8 male and 3 female patients. All cases had severe acute hypertension and T2 hyperintensity on MRI exclusively centered within the cerebellum. Of 11 patients, 7 had hypertensive retinopathy, a favorable clinical course with only antihypertensive treatment, and resolution of the cerebellar lesions on follow-up imaging. A total of 5 of the 11 patients received external ventricular drainage due to obstructive hydrocephalus and only 2 of the 11 had a seizure.

CONCLUSIONS

Isolated cerebellar involvement in PRES may be a unique variant that affects younger, male cases with severe acute hypertension and hypertensive retinopathy, but not necessarily seizure. Most patients have full recovery after fast control of blood pressure. Awareness of atypical neuroimaging features in PRES is critical for appropriate treatment.

Reversible obstructive hydrocephalus from hypertensive encephalopathy

BACKGROUND

Diffuse edema involving the posterior fossa may be seen with hypertensive encephalopathy and has rarely been reported to cause hydrocephalus. We present three such cases and review the literature to better delineate this uniquely reversible syndrome.

METHODS

Case reports and review of literature.

RESULTS

Three patients with hypertensive encephalopathy presented to our institutions with clinical and radiographic features of obstructive hydrocephalus associated with brainstem and cerebellar edema. This required transient external drainage of cerebrospinal fluid (CSF) in two of the three patients. However, with recognition of this unusual syndrome and aggressive management of elevated blood pressure, both edema and hydrocephalus resolved. All patients made complete recoveries and did not require permanent CSF shunting. A review of the literature yielded 15 additional case reports describing reversible obstructive hydrocephalus related to hypertensive encephalopathy. All had mean arterial pressures above 130 mmHg and presented primarily with altered mental status. While half required ventriculostomy, only one required shunting. Excluding a patient who died from sepsis, all recovered neurologically once blood pressure was controlled.

CONCLUSION

It is imperative to recognize such cases where hypertension causes edema within the posterior fossa resulting in secondary hydrocephalus. Focusing management on lowering blood pressure avoids unnecessary or prolonged CSF diversion.

Posterior Reversible Encephalopathy Syndrome with Obstructive Hydrocephalus

We describe an unusual presentation of posterior reversible encephalopathy syndrome (PRES) with predominant posterior fossa edema, causing ascending transtentorial herniation, tonsillar herniation, and obstructive hydrocephalus. MR imaging with additional MR spectroscopy and MR perfusion helped discriminate PRES from infiltrative tumor, and supported the pathogenesis of hydrostatic edema. Infusion of an antihypertensive drug was promptly administered. Diversion of cerebrospinal fluid by ventriculostomy was subsequently performed. However, the patient developed thalamic hemorrhage and secondary intraventricular hemorrhage with contralateral hemiparesis. Awareness of this rare cause of obstructive hydrocephalus with aggressive treatment of high blood pressure may help obviate the need of ventriculostomy and may prevent the hemorrhagic complication.

Hypertension-induced cerebellar encephalopathy and hydrocephalus in a male

Hypertensive encephalopathy is believed to be caused by an abrupt elevation in systemic blood pressure. It rarely occurs in children and can be neurologically devastating if it is not recognized and treated immediately. This report describes an 11-year-old male who presented with edema and a cerebellar lesion, with acute obstructive hydrocephalus resulting from hypertensive encephalopathy. A shunt was inserted to relieve pressure in the acute stage. The patient's hydrocephalus and cerebellar swelling subsided when his blood pressure was controlled. The cerebellar lesion had been initially diagnosed as a glioma. In children, a cerebellar lesion occurring with acute obstructive hydrocephalus and hypertensive encephalopathy is rare but reversible. Clinicians should be aware of this condition because it might be misdiagnosed as a tumor of the posterior fossa.

Upward transtentorial herniation, hydrocephalus, and cerebellar edema in hypertensive encephalopathy

BACKGROUND

Edema of the cerebellum with secondary obstructive hydrocephalus is a rare presentation of hypertensive encephalopathy. The authors report an unusual case of isolated posterior fossa swelling with upward transtentorial herniation and hydrocephalus causing neurologic deterioration. These patients are often initially evaluated by a neurologist because of the acute neurologic symptoms. Prompt diagnosis with aggressive blood pressure control may obviate the need for emergent cerebrospinal fluid (CSF) diversion.

REVIEW SUMMARY

This is a case report of a 26-year-old man who presented to the emergency room with confusion and somnolence over a 2-day period. His initial blood pressure was 175/110 mmHg. On examination he was disoriented, with a Glasgow Coma Scale score of 12 points, opening his eyes only to loud verbal stimuli, verbalizing inappropriately, and he was only able to follow simple commands. Neuroimaging revealed edema of the cerebellar folia with noncommunicating hydrocephalus and upward transtentorial herniation. Differential diagnoses of posterior fossa tumor, rhombencephalitis, and hypertensive encephalopathy were entertained. A thorough literature review is included with the discussion of this case. The patient underwent emergent ventriculostomy for CSF drainage and prompt blood pressure control with nitroprusside. After 48 hours of CSF drainage and correction of his hypertension, his neurologic examination normalized. Repeat imaging revealed near resolution of the obstructive hydrocephalus and cerebellar edema.

CONCLUSION

Isolated edema of the cerebellum with upward transtentorial herniation and obstructive hydrocephalus is a rare presentation of hypertensive encephalopathy and should be considered in patients with an acute hypertensive crisis and mental status changes. This entity responds to prompt blood pressure control; however, emergent ventriculostomy by a neurosurgical team should be entertained for neurologic deterioration secondary to significant obstructive hydrocephalus, as illustrated in this case.

Hypertensive encephalopathy

The term hypertensive encephalopathy should be reserved for patients with diffuse cerebral effects of precipitous and sustained rises in blood pressure that reverse when blood pressure is lowered and are not due to infarction or hemorrhage. The definitive diagnosis of this syndrome depends on accurate exclusion of other causes that may be associated with elevated blood pressure and neurologic deficits. Treatment is aimed at preventing or limiting target organ (brain) damage. Therapy should be individualized but centered on reducing the mean arterial blood pressure within a period of minutes to 2 hours, by no more than 20% to 25% or to a diastolic blood pressure of 100 to 110 mm Hg (whichever is higher), using short-acting intravenous agents. Oral or sublingual agents should generally be avoided in hypertensive encephalopathy because they are more likely to cause precipitous falls in blood pressure.