Normal pressure hydrocephalus (NPH)

Presentation

55 year old woman with 13 year history of bipolar affective disorder and 3 year history of urinary incontinence, falls and progressive short term memory impairment.

Patient Data

Age: 55
Gender: Female

Mental State Examination

Obese and mildly dishevelled woman with marked psychomotor slowing. 

Normal external eye movements.

Wide-based "magnetic" gait with mobility aided by 4 wheel frame. 

Speech slow and diminished in prosody.

Mood euthymic, affect blunted in quality and restricted in range.

No formal thought disorder.

Anxious conversational themes focussed on cause of falls and fear of nursing home placement.

No suicidal ideation.

No delusions or hallucinations.

Good insight into premorbid psychiatric illness and more recent cognitive deterioration.

Cognitive Examination 1

Modality: Diagram

Attention: 7/20 to 8/20

Visuoconstructional: 14.5/20 to17/20

Memory: 12/20 to 16/20

Executive: 12/20 to 15.5/20

Language: 19.5/20 to 17.5/20

Total: 65/100 improving to 74/100

Pre-operative neuroimaging

Modality: MRI

 

Features are consistent with normal pressure hydrocephalus with dilated lateral and third ventricles. The Evans index of size for the bilateral lateral ventricles is 0.48(N<0.41), with no evidence of extravasation into the ependymal tissues. A CSF flow void is noted as it runs through into the 3rd ventricle via the aqueduct with a markedly increased net stroke volume of 399 microL (normal <42)  

Pre-operative SPECT

Modality: Nuclear medicine

RADIOPHARMACEUTICAL: 99mTc ECD, 620 MBq 

CLINICAL INDICATION Clinical neurological deterioration with gait abnormality. 

RESULTS: These studies show mild to moderate reduction of perfusion to the cerebral cortex most marked in the mesial surface is at the anterior cingulate gyrus. There is also reduction of white matter perfusion which appears to be in excess of the ventriculomegaly. Perfusion of the basal ganglia is reduced disease pontine perfusion but not cerebellar perfusion. 

OVERALL IMPRESSION The studies suggest predominantly white matter and mesial grey matter perfusion reduction in a pattern suspicious of normal pressure hydrocephalus though other global cortical disease is are possible though less likely.

Post-operative neuroimaging

Modality: CT

Axial sequential acquisition through the brain without intravenous contrast. Comparison is made to pre-operative CT.


There has been interval insertion of a right parietal V-P shunt with the tip  abutting the septum pellucidum just superior to the foreman of Monroe. There has been an small reduction in degree of hydrocephalus with the lateral ventricles now measuring 29 mm at the level of the caudate heads compared with 34 mm previously. Small locules of pneumocephalus.

No evidence of acute ischaemia. No intra or extra-axial haemorrhage is seen.

The cavernous segments of the internal carotid arteries are moderately calcified.

Cognitive Examination 2

Modality: Diagram

Improved post-operative cognitive profile

Case Discussion

This case demonstrates the classical clinical presentation and neuroimaging findings of normal pressure hydrocephalus (NPH). Of special note are the clearly demonstrated CSF flow voids on T2-weighted imaging.

While VP shunting does not always improve the clinical syndrome associated with this disease, the presence of elevated CSF flow in the aqueduct is considered the best non-invasive predictor of a favourable outcome to shunting, although even this is debated.

This particular patient enjoyed a significant functional improvement in each of the key domains of mobility, continence and cognition with surgical intervention, and was able to avoid both nursing home placement and a diagnosis of young-onset dementia.

The case also demonstrates the utility of seeking potentially reversible causes of neuro-cognitive decline, and avoiding the attribution of functional decline to mental illness in an otherwise well-treated patient.

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Case Information

rID: 24415
Case created: 14th Aug 2013
Last edited: 5th Feb 2017
Inclusion in quiz mode: Included

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