What is Hydrocephalus?

Hydrocephalus is a neurological condition characterized by an abnormal accumulation of cerebrospinal fluid (CSF) within the ventricles of the brain. This buildup increases intracranial pressure, which can cause a range of symptoms including dizziness, headaches, and balance disturbances. While hydrocephalus can occur at any age, a specific form known as Normal Pressure Hydrocephalus (NPH) primarily affects older adults and is often misdiagnosed.

Normal Pressure Hydrocephalus (NPH)

Normal pressure hydrocephalus (NPH) is a chronic condition in which the ventricles enlarge even though intracranial pressure remains within the normal range when measured during a spinal tap. Despite the name, the pressure may fluctuate throughout the day. NPH is clinically defined by a classic triad of symptoms: gait disturbance (ataxia), urinary incontinence, and cognitive decline (dementia). Dizziness is also a common complaint in NPH patients, often linked to the gait instability and altered spatial perception.

The Classic Triad of NPH Symptoms

Dizziness in NPH: Why It Happens

Dizziness in normal pressure hydrocephalus is multifactorial. The apraxic gait and balance deficits create a constant sensation of unsteadiness. Additionally, the enlarged ventricles can distort the brain's vestibular pathways, which control spatial orientation. Patients may also experience "presyncopal" dizziness (feeling faint) due to autonomic dysregulation. Treating the underlying hydrocephalus with a shunt often resolves the dizziness.

Differentiating NPH from Other Conditions

IIH (Idiopathic Intracranial Hypertension) is another condition involving elevated CSF pressure, but it primarily affects younger, overweight women and presents with severe headaches, vision changes, and pulsatile tinnitus. While IIH can also cause dizziness and balance issues, it does not typically include the classic triad of ataxia, incontinence, and dementia seen in NPH. Accurate diagnosis is critical, as treatment differs — NPH requires a shunt, while IIH is managed with weight loss, medication, or sometimes a shunt as well.

Treatment: The Role of Shunting

The standard treatment for symptomatic normal pressure hydrocephalus is the surgical placement of a shunt. A shunt is a thin tube that diverts excess CSF from the brain to another part of the body (usually the abdomen) where it can be absorbed. Shunt surgery can dramatically improve gait ataxia, reduce dizziness, restore bladder control, and reverse cognitive decline. Early intervention yields the best outcomes. However, shunts can malfunction or become infected, so lifelong monitoring is necessary.

Before surgery, clinicians often perform a "tap test" — removing a large volume of CSF via lumbar puncture — to see if symptoms temporarily improve. If dizziness and gait improve, the patient is more likely to benefit from a shunt.

Living with NPH: Tips for Patients

• Report any new or worsening dizziness or balance issues to your neurologist.
• Physical therapy can help with apraxic gait and fall prevention.
• Stay hydrated and avoid sudden position changes to minimize dizziness.
• If you have a shunt, be aware of signs of malfunction: worsening gait, dementia, incontinence, or new headache.
• Join support groups for normal pressure hydrocephalus to share experiences.

Conclusion

Dizziness is a disabling symptom of hydrocephalus, especially in normal pressure hydrocephalus (NPH). Recognizing the classic triad — apraxic gait/ataxia, incontinence, and dementia — is key to early diagnosis. While IIH shares some features, a thorough neurological evaluation can distinguish these conditions. Placement of a shunt remains the most effective treatment, offering hope for significant symptom reversal and improved quality of life. If you or a loved one experiences persistent dizziness along with walking difficulties or memory problems, seek evaluation by a specialist.