Communicating hydrocephalus

Communicating Hydrocephalus

Communicating hydrocephalus is a type of hydrocephalus characterized by impaired cerebrospinal fluid (CSF) absorption in the absence of any obstruction to CSF flow between the ventricles and subarachnoid space. This condition is also known as non-obstructive hydrocephalus.

Pathophysiology

In communicating hydrocephalus, the flow of CSF is not blocked within the ventricles. Instead, the problem lies in the absorption of CSF into the bloodstream. This can occur due to dysfunction of the arachnoid villi, which are responsible for the reabsorption of CSF into the venous system. Conditions such as subarachnoid hemorrhage, meningitis, or traumatic brain injury can lead to scarring or inflammation of the arachnoid villi, resulting in impaired CSF absorption.

Clinical Presentation

Patients with communicating hydrocephalus may present with a variety of symptoms, depending on the age of onset and the rate of CSF accumulation. Common symptoms include:

• Headache: Often worse in the morning due to increased intracranial pressure.
• Nausea and vomiting: Resulting from increased intracranial pressure.
• Gait disturbances: Difficulty walking, often described as a "magnetic" gait.
• Cognitive impairment: Memory problems, difficulty concentrating, and other cognitive deficits.
• Urinary incontinence: Particularly in normal pressure hydrocephalus, a subtype of communicating hydrocephalus.

Diagnosis

The diagnosis of communicating hydrocephalus is typically made using neuroimaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI). These imaging modalities can reveal ventricular enlargement without evidence of obstruction. Additional tests, such as a lumbar puncture, may be performed to assess CSF pressure and composition.

Treatment

The primary treatment for communicating hydrocephalus is the surgical insertion of a ventriculoperitoneal shunt or other types of shunts to divert excess CSF from the ventricles to another part of the body where it can be absorbed. In some cases, an endoscopic third ventriculostomy (ETV) may be considered, although it is more commonly used for obstructive hydrocephalus.

Prognosis

The prognosis for patients with communicating hydrocephalus varies depending on the underlying cause, the age of the patient, and the timeliness of treatment. Early diagnosis and appropriate management can lead to significant improvement in symptoms and quality of life.

Also see

• Hydrocephalus
• Normal pressure hydrocephalus
• Ventriculoperitoneal shunt
• Endoscopic third ventriculostomy