What is Hydrocephalus?

 

 

     Our brains are not solid masses of tissue; they contain central cavities known as cerebral ventricles. Within these ventricles, a clear fluid called Cerebrospinal Fluid (CSF) is produced. CSF circulates to nourish the brain and spinal cord, existing within the ventricles and enveloping both the brain and spinal cord.

 

The Role of Cerebrospinal Fluid (CSF)

The primary functions of CSF include:

 

• Nutrient Delivery and Waste Removal: CSF transports essential nutrients to the brain and carries waste products away.
• Shock Absorption: It acts as an insulating cushion, reducing impact on the brain during head or spinal trauma.

 

     The body continuously produces CSF, typically around 500 cc per day, by filtering blood in specialized arteries within the cerebral ventricles. This fluid circulates through various brain cavities before flowing into the space beneath the meninges (brain and spinal cord coverings). It is then reabsorbed into large veins on the brain's surface. While daily production is substantial, the cranial cavity and spinal canal can only accommodate about 150-200 cc of CSF at any given time.

 

Consequences of Excess CSF Production

     Maintaining a balance between CSF production and reabsorption is crucial. Therefore, any factor leading to excessive CSF production that outpaces reabsorption, reduced reabsorption efficiency, or even impaired CSF flow from the ventricles to the subarachnoid space and brain surface, can result in CSF accumulation within the cerebral ventricles (hydrocephalus).

 

Common Conditions Causing CSF Accumulation

Various conditions can lead to CSF accumulation in the ventricles:

 

• Tumors of CSF-producing blood vessels: These can lead to an overproduction of CSF.
• Intraventricular or brain tissue tumors: These can obstruct CSF flow.
• Ventricular stenosis: Narrowing or blockage of ventricles due to congenital defects, cysts, parasites, blood clots, or tumors obstructing CSF pathways.
• In infants: If hydrocephalus occurs in infants whose fontanelles (soft spots) or cranial sutures have not yet fused, the skull may expand. Over time, this can thin brain tissue, causing the head to enlarge (e.g., "water-on-the-brain" or "watermelon head").
• In older children, adolescents, or adults: With closed fontanelles and fused cranial sutures, the skull cannot expand. This leads to symptoms such as headaches, seizures, loss of consciousness, and potentially death due to increased intracranial pressure (or CSF pressure) from fluid accumulation. Prompt medical intervention is critical in these cases.

 

Normal Pressure Hydrocephalus (NPH)

     CSF accumulation in the elderly can be a gradual, chronic process. It typically results from impaired CSF circulation that, while not a complete obstruction, is less efficient than normal. Additionally, the reabsorption filters on the brain's surface may function less effectively, possibly due to prolonged use or blockages.

 

     Even if CSF production remains relatively unchanged, fluid can accumulate slowly, perhaps less than 1 cc per day. Over months or years, this gradual accumulation can cause the ventricles to slowly enlarge and compress brain tissue. This slow progression often allows the body to tolerate the changes for longer compared to other forms of CSF accumulation.

 

Symptoms of Hydrocephalus

Eventually, noticeable symptoms will appear. Surprisingly, the most prominent symptoms of CSF accumulation are not headaches, but rather significant changes in brain function, characterized by a distinct triad of symptoms:

 

• Cognitive Impairment: Memory loss or decline.
• Gait Disturbance: Difficulty walking, unsteadiness, frequent falls, and potential limb stiffness or tremors, similar to Parkinson's disease.
• Urinary Incontinence: Inability to control urination, which helps differentiate it from conditions like an enlarged prostate or Parkinson's.

 

 

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Because its symptoms often resemble other conditions, CSF accumulation can sometimes be overlooked or misdiagnosed.

 

 

Hydrocephalus Diagnosis

Diagnosing CSF accumulation is often straightforward:

 

• MRI Brain Scan: Used to assess ventricle size and CSF flow.
• CSF Flow Measurement: Evaluates the speed of CSF circulation within the ventricles.
• Lumbar Puncture: Directly measures CSF pressure and can confirm the diagnosis. Physicians may withdraw 40-80 cc of cerebrospinal fluid (CSF) for analysis and to observe symptom improvement.

 

 

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If CSF pressure is elevated and symptoms improve (e.g., better walking, reduced unsteadiness/falls, less tremor/stiffness) after CSF drainage, then CSF accumulation in the ventricles is highly probable.

 

 

Hydrocephalus Treatment

Modern treatment for CSF accumulation is relatively simple:

 

• This involves redirecting CSF drainage from its sole reabsorption point on the brain's surface to also be absorbed by the peritoneum (lining of the abdominal cavity).
• Following appropriate treatment, patients can often return to a long and normal life.
• Many individuals previously diagnosed with Parkinson's disease can significantly reduce their medication, with some even discontinuing it entirely.

 

Summary

     It is essential to recognize that this condition is a normal part of the aging process. The focus is on enhancing the quality of life for seniors, allowing them to enjoy time with family, remain cherished, and receive the care they deserve for their immeasurable contributions. One day, as we age, we too will face this truth.

 

 

 

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With correct treatment, patients with CSF accumulation can often return to a long and normal life.

 

 

Last Updated: March 31, 2022.