Makindo Medical Notes.com

Related Subjects: |Brain Herniation syndromes |Haemorrhagic stroke |Traumatic Head/Brain Injury |Acute Hydrocephalus |Epidural Haematoma |Subdural haematoma

Introduction

• The brain is contained within a bony box but there are also rigid structures within the skull that help to maintain the position of the brain and prevent excessive brain movements in response to rapid acceleration or deceleration forces.
• The falx lies in the midline and separates the lobes but also helps prevent excessive movement. The tentorium or "tent" separates the forebrain from the brainstem. Excessive forces within the skull can distort and squeeze neural structures which can be a sign of impending death.
• Seen in the context of rising ICP in the comatose patient. These are all neurosurgical emergencies and demand rapid escalation. There are three main forms

Herniation Syndromes

Uncal herniation due to a SDH with Duret haemorrhages

Trancavarial herniation

Clinical signs of Raised ICP

• Dilation of the pupil
• Confusion and/or Headache
• Depressed state or total loss of consciousness
• Droopy eye (Ptosis) due to a partial or complete third nerve palsy
• One sided weakness of the body (hemiparesis)
• Decreased heart rate (bradycardia)
• Obtunded and Deepening coma
• Irregular breathing, Respiratory depression or cardiac arrest (no pulse) that leads to death

Investigations

• Urgent CT and/or MRI

Management

• In advanced uncal herniation recovery to functional independence with these findings is a remote possibility. Increasing age, a greater than 6-hour interval between fixed pupils and craniotomy, and compression of basal cisterns all predict death. Palliation may be the plan. For those with less severe forms management may be urgent craniectomy and decompression or other neurosurgical management when there is a neurosurgical cause.
• Other options include using diuretics such as mannitol to reduce intracranial pressure and treatment of any acute hydrocephalus with an EVD