1. A Sharing Sessionon Normal Pressure Hydrocephalus (NPH) Suhaila Mohamed Usuludin 17 April 2008

2. Cerebrospinal Fluid (CSF)

A clear, colourless fluid that contains small quantities of glucose and protein

Fills the ventricles of the brain and the central canal of the spinal cord

Production by choroid plexus in lateral ventricle at 20ml/hr

3. Cerebrospinal Fluid (CSF) 4. Cerebrospinal Fluid (CSF) 5.

Functions

• drainage route for waste products of brain metabolism

• bouyancy

• electrolytes and nutrient exchange

Pressure decrease from site of production -> site of absorption

• determined byvenous pressure

Cerebrospinal Fluid (CSF) 6.

Pressure is raised if

• Brain volume increases

• Venous pressure increases

• Outflow obstruction

• • At ventricles (non-communicating hydrocephalus)

• • At absorptive site (communicating hydrocephalus)

Cerebrospinal Fluid (CSF) 7. NPH

Gradual decrease CSF absorption at arachnoid granulations

• back pressure effect

• Increase pressure in ventricles

Compensatory mechanisms to maintain pressure

• Distension of ventricles

8. NPH

Slowly progressive

Onset > 40 years

Most common in elderly

9. Symptoms of NPH

Adams triad

• Impaired gait

• Urinary incontinence

• Impaired cognitive function

10. Impaired gait

Usually first and prominent symptom

• reduced step height

• stride length

• velocity

• Shuffling gait

• wide-based

• trunk sway

• magnetic gait

• gait apraxia

11.

Timed walking test

GAITRite gait analysis

Assessment: Impaired gait 12. Urinary Incontinence

Usually 2 ndsymptom to follow

• Urgency and frequency

Fecal incontinence

• Rare except in advanced cases

13. Impaired Cognitive Functions

Reversible cause of dementia

Subcortical dementia

• Inattention

• Delayed recent recall

• Delayed psychomotor functioning

• Behavioural changes

• Emotional instability

Executive functioning may be affected as disease progresses

14.

MMSE

AMT

Neuropsychological tests:

• Trail Making Test

• Digit/Letter Cancellation

• Kendrick Object Learning Test (KOLT): visual memory

Assessment of Impaired Cognitive Functions 15. NOTExpected Symptoms

Seizures

Signs and symptoms of increased ICP

• Headache

• Nausea

• Vomiting

• Altered level of consciousness

• Papilledema

16. Differential Diagnoses

Old age

Parkinsonism

Dementia AD, vascular

Depression

Cerebellar/spinal cord involvement

17. How is it Diagnosed?

MRI

• Ventricles (lateral, 3 rdand 4 th ) and Sylvian fissure dilated with normal hippocampus

MRI showing ventriculomegaly 18.

CT scan

• Rounding of horns

• Thinning of corpus callosum

How is it Diagnosed? 19. Surgical Management

Ventriculoperitoneal Shunt (VP shunt)

• Performed under general anaesthesia

• Catheter placed within a ventricle, and another end at the peritoneal cavity

20. VP Shunt

Valve (fixed or programmable) ensures one-way flow and regulates CSF flow

Permanent or temporary

May need replacement or revision if not working properly

With five pressure level settings, the programmable, adjustable Strata valve (top) can be "fine-tuned" by the physician after shunt surgery for NPH. Adjusting the valve and verifying the setting is done quickly in the physician's office using a simple set of magnetic tools (bottom), eliminating the need for additional surgery. 21. Venticuloatrial Shunt (VA Shunt)

CSF is shunted from the cerebral ventricles into the right atrium of the heart.

2 ndpreferred choice if VP shunt is not possible

• Eg. Infection of peritoneal cavity -> affects reabsorption rate of CSF

22. To Shunt or Not To Shunt?

High Volume Lumbar Tap test or External Lumbar Drainage (ELD)

• 40-50ml CSF-> beneficial from shunt

Decrease atrophy/ischemia

Prominent CSF flow void

• aqueductal stroke volume >42 Ym (Bradley, 1998)

No known history of intracranial infection

Pre-morbid functional status

23. Operation Risks

Ileus

• Slow gastric and bowel movement post operation and may feel nausea

Infection

• Most common organisms areS. epidermidis and S. aureus

Obstruction

• Most often due to the head tip is obstructed with cells, choroid plexus, or debris.

24. Operation Risks

Misplacement

• Occurs when the ventricular or peritoneal end of the shunt tubing is in a position which does not facilitate free flow of CSF

Wound breakdown/shunt tube exposure

• Occurs when the wound does not heal well or the overlying skin is thin with minimal subcutaneous tissue layer resulting in wound breakdown.

25. Prognosis

Gait shows highest improvement rates

Better gait does not correlate to better ADLs functioning

All components of triad considered to achieve higher ADL scores

Temporary improvements from 1 to 3 years

• May be substantial for improving QoL

> 1 year, co-morbidities may affect effects of shunting

26. Rehabilitation Implications

Difficulties in walking

• If given walking aid, may not know how to use it

• • Gait apraxia

• • Caregiver training on facilitation

• Changing the environment

Urinary Incontinence

• Time scheduling

Cognitive Issues

• Caregiver training on psychomotor dysfunctions, behavioural issues etc.

27. References

Presentations from various professionals from the symposium

Bradley, W.G. (1998). MR Prediction of Shunt Response in NPH: CSF Morphology versus Physiology.American Journal of Neuroradiology ,19 , 1285-1286.

Department of Neurosurgery (2007).A Patient / Family Informed Consent Guide to Ventricular Peritoneal (VP) Shunt Insertion /Revision .Singapore:National Neuroscience Institute.

Factora, R. (2006). When do common symptoms indicate normal pressure hydrocephalus?.ClevelandClinic Journal of Medicine ,73(5), 447-457.

Gallia, G.L., Rigamonti, D., & Williams, M.A. (2006). The diagnosis and treatment of idiopathic normal pressure hydrocephalus.Nature Clinical Practice Neurology ,2(7), 375-381.

28. Thank You