2. In 1964, Colombian
neurosurgeon Salomón
Hakim and colleagues
described a syndrome of
Progressive cognitive
decline
Gait difficulties
Urinary incontinence
Ventricular dilatation
Normal cerebrospinal
fluid (CSF) pressure
during lumbar puncture
02-Dec-15 2
3. 1982, CM Fisher underscored the importance of
the gait disturbance in the description of NPH.
1986, Graff-Radford and Godersky correlated
clinical symptoms and shunt responsiveness.
The term idiopathic adult hydrocephalus
syndrome may be more accurate, because
intracranial pressure is not always normal in
NPH.
02-Dec-15 3
4. elderly individuals (age >65 y) the prevalence of
NPH was 1.4%
Incidence -1.4 per 1,00,000
No race or gender prediliction
more than 60% of patients with iNPH had
cerebrovascular disease.
In another similar study, more than 75% had
Alzheimer disease pathology at the time of shunt
surgery.
02-Dec-15 4
5. IDIOPATHIC – 50 %
SECONDARY CAUSES
subarachnoid hemorrhage (23%),
meningitis (4.5%)
and traumatic brain injury (12.5%)
Secondary NPH has higher response rate to
shunting than idiopathic NPH
02-Dec-15 5
6. 50% cases idiopathic
Leading theory is impairment of CSF outflow
Intraventricular pressure studies reveal waves
of increased pressure- B-waves
Adult hydrocephalus syndrome
Adult symptomatic hydrocephalus
02-Dec-15 6
8. Ventricle enlargement leads to periventricular
ischemia regardless of etiology
Compression and stretching of arterioles and
venules
Arterial hypertension and cerebral
arteriosclerosis increased in NPH
02-Dec-15 8
9. Increased subarachnoid space volume does not
accompany increased ventricular volume.
Symptoms result from distortion of the central
portion of the corona radiata by the distended
ventricles. Interstitial edema of the white matter
The periventricular white matter anatomically
includes the sacral motor -abnormal gait and
incontinence.
Dementia results from distortion of the
periventricular limbic system.02-Dec-15 9
10. Kiefer, M; Unterberg, A
The Differential Diagnosis and Treatment of Normal-Pressure Hydrocephalus
Dtsch Arztebl Int 2012; 109(1-2): 15-26; DOI: 10.3238/arztebl.2012.0015
02-Dec-15 10
11. CLASSIC TRIAD
GAIT DISTURBANCE -is typically the earliest feature
noted and considered to be the most responsive to treatment
No classic gait disturbance
Gait may be wide based, shuffling
More severely affected patients have “magnetic gait”- feet
stuck to ground and difficult to initiate walking
Difficulties with walking motions resolve with minimal
support of patient or lying patient down
May resemble Parkinson’s gait
Hyperreflexia
Apraxia of gait – no weakness or ataxia.
02-Dec-15 11
13. Urinary Incontinence
True incontinence found only in severely
affected patients
Urinary urgency in most patients with NPH
Due to stretching of periventricular nerve
fibers and loss of detrusor inhibition
Bladder sphincter muscle unaffected
02-Dec-15 13
14. DEMENTIA
Usually mild
Presence of dementia in NPH extremely variable
Some shunt responsive patients have little or no
dementia
Dementia usually least responsive of symptoms to
intervention
Mental status changes may resemble depression
prominent memory loss and bradyphrenia.
Frontal and subcortical deficits
forgetfulness, decreased attention,
Aphasia /agnosia – alternate diagnosis -Alzheimer
02-Dec-15 14
15. Both AD and NPH cause memory impairment
AD- “cortical” abnormalities
Aphasia, Apraxia, Agnosia
Impaired recognition and encoding deficits
NPH- “subcortical” abnormalities
Memory impairment but intact recognition
Slow information processing
Difficulty with complex tasks
02-Dec-15 15
17. AD and NPH can usually be distinguished with
formal neuropsychological testing
Primary care office testing may not be
adequate to distinguish
Mental impairment early in course of AD but
usually late in course of NPH and often
minimal impairment
AD often associated with hippocampal atrophy
on imaging studies
02-Dec-15 17
18. Both NPH and Parkinson’s Disease (PD) can
have similar gait disturbances
Hypokinesia
Freezing
Imbalance
Extrapyramidal symptoms
Trial of levadopa can help distinguish between
PD and NPH
02-Dec-15 18
20. History
Insidious onset
Age over 40
Symptom duration 3-6 months
No antecedent event known to cause
secondary NPH
Progressive over time
No other medical, psychiatric or neurological
condition that could cause symptoms
02-Dec-15 20
21. Brain imaging
Ventricular enlargement not attributable to
cerebral atrophy or congenital disorder
No macroscopic obstruction present
At least one of the following
Enlargement of lateral horns not attributable to
hippocampus atrophy
Callosal angle greater or equal to 40 degrees
Evidence of altered brain water content on
imaging not attributable ischemia or
demylination
An aqueductal or fourth ventricular flow void on
MRI 02-Dec-15 21
26. Clinical
Gait/Balance- at least two of following present
Decreased step height
Decreased step length
Decreased cadence/speed
Decreased trunk sway
Widened stance
Toes turned outward while walking
En bloc turning- turns take three or more steps
Impaired balance- two or more corrective steps
for eight steps on tandem gait testing
02-Dec-15 26
27. Cognition- two of following present
Psychomotor slowing
Decreased fine motor speed
Decreased fine motor accuracy
Difficulty dividing or maintaining attention
Impaired recall especially for recent events
Impairment of executive functions- multi-step
procedures, working memory, formulation of
abstractions, insight
Behavioral or personality changes
02-Dec-15 27
28. Urinary Symptoms- one of following
Episodic urinary incontinence not attributable
to other causes
Persistent urinary incontinence
Fecal and urinary incontinence
OR
One of following
Urinary urgency
Urinary frequency- 6 or more voids in 12 hour
period
Nocturia- more than two voids in night
02-Dec-15 28
30. History- Symptoms are
Subacute or indeterminate onset
Onset any time after childhood
<3 months or indeterminate duration
May follow trauma, hemorrhage or meningitis
Symptoms not entirely explained by co-existing
neurological conditions
Non-progressive or not clearly progressive
02-Dec-15 30
31. Brain imaging- Ventricular enlargement
associated with following
Cerebral atrophy of sufficient severity to
explain ventricular enlargement
Structural lesion that may increase
ventricular size
02-Dec-15 31
32. Clinical
Incontinence and/or cognitive impairment in
absence of gait or balance dysfunction
Gait disturbance or dementia alone
Physiological
Opening pressure unavailable or outside of
range for probable NPH
02-Dec-15 32
33. No ventriculomegaly
Signs of increased intracranial pressure
such as papilledema
No component of clinical triad
Symptoms explained by other causes (eg,
spinal stenosis)
02-Dec-15 33
34. - Vit B12 , Thyroid profile
- CSF – analysis –
opening pressure – 11 +/- 3 mm hg (150 mm H2o)
slightly higher than normal
- Transient high pressure B waves may be detected
- (CSF) protein Lipocalin-type prostaglandin D
synthase (L-PGDS) – marker of Frontal lobe
dysfunction in iNPH – decreased due to damage
of arachnoid cells
02-Dec-15 34
35. Ventriculomegaly that is out of proportion to sulcal
atrophy.
differentiates NPH from ex vacuo
ventriculomegaly,
Frontal and occipital periventricular
hypoattenuating areas, represent transependymal
CSF flow -infrequent and often may represent
periventricular leukoencephalopathy
corpus callosal thinning, -nonspecific
02-Dec-15 35
36. Rounding of frontal horns
clinical picture and ventriculosulcal
disproportion on either CT or MRI
scans, 50-70% of patients are likely to
respond to a CSF-shunting procedure.
02-Dec-15 36
38. The Evans index (EI), a linear ratio
between the maximal frontal horn width
and the cranium diameter,
signifies ventriculomegaly if it is 0.3
02-Dec-15 38
39. Temporal horns out of proportion to hippocampal
atrophy
MRI provides additional physiologic information on
NPH
T2-weighted images, regions of moving CSF
demonstrate no signal, instead of the increased
signal observed in slow-moving CSF,
CSF flow studies- jet of turbulent CSF flow may be
observed distal to the aqueduct
Cine phase-contrast MRI quantifies CSF flow in
terms of stroke volume
- significant corelation to shunt responsiveness02-Dec-15 39
41. Most prefer 45 -50 ml removal
Csf pressures may be transiently elevated
Improvement may be delayed and appear 1-2
days after
Sensitivity of test – 62 % and 33 % specificity
However it has been listed in guidelines of
prognostic evaluation of NPH
02-Dec-15 41
42. greater impact on brain volume expansion
300 ml drained for 5 days
Complications -including headache,
radiculopathy, and bacterial meningitis
More sensitive than csf tap test
sensitivity, specificity, and negative predictive
value were 95%, 64%, and 78%, respectively.
PPV 80 -100 %
Requires hospitalisation specialised care
02-Dec-15 42
44. CSF infusion testing.- One drain is used for
continuous pressure monitoring while the other drain
is used to continuously infuse solution into the CSF
space.
Ro – impedance of flow offered by csf absorption
Isotopic cisternography is no longer in frequent use
Acqueductal CSF flow – not of much diagnostic use
02-Dec-15 44
46. Neuropsychological evaluation (eg, Folstein test
or formal neuropsychological evaluation)- not
validated
Timed walking test.
Videotaping the gait evaluation before and after
the large volume lumbar puncture.- IS
PREFERABLE
Reduction in bladder hyperactivity also may be a
sign of good outcome from shunting.
02-Dec-15 46
47. No prospective, double blind, randomized, controlled
clinical triaL
Medical management – levodopa trial to rule out
idiopthic parkinson disease
No drug is known to work in NPH
Surgical Management – mainstay
Benefit expected from shunt surgery in probable case
of NPH 50 %- 61 %
02-Dec-15 47
51. Adjustable shunt valves – adjusts the opening
pressure
Gravity-controlled valves - low valve opening
pressure when the patient is lying down.
G valves lower the risk of overdrainage by 90%
02-Dec-15 51
52. Endoscopic third ventriculostomy (ETV).
Alternative to shunt placement for treatment
of hydrocephalus.
Effective in obstructive hydrocephalus.
Efficacy in NPH not known
02-Dec-15 52
53. Routine follow up 2 to 3 times per year
Earlier if shunt inection/failure
Bedside clinical examination follow up CTScan
within few weeks
D Dimer ,CRP in case of ventriculoatrial shunts
for subclinical septicemia and
thromboembolism
02-Dec-15 53
54. High CSF pressure should prompt investigation
for a secondary cause of NPH
Response to a 40-mL to 50-mL (high-volume)
lumbar tap suggests a potential benefit to shunting
An ELD may be used to evaluate those who do
not respond to a high-volume tap
There is no substantial predictive value to MRI
CSF flow studies
IF multi-infarct or Alzheimer’s disease
dementia ??
02-Dec-15 54
55. Ventricle enlargement on CT or MRI
Severity graded by ratio of maximal frontal horn
width divided by transverse inner diameter of
skull
0.32 minimal for NPH but 0.40 more typical
Lack of hippocampus or cortical atrophy
Periventricular and cortical white matter lesions
may be found in patients with NPH
Large number white matter lesions may be marker
for poor response to shunting
02-Dec-15 55
59. Most studies show fairly significant decline in
benefits over time
Initial improvement 60-75% of patients
Sustained improvement only 24-42%
Results confounded due to high mortality
from co-morbid conditions
57% patients dead within 5 years in study by
Raftopoulos et.al.
02-Dec-15 59
60. Good response to shunting
Clinical presentation
Gait disturbance preceded mental impairment
Short duration of mild mental impairment
Known cause of NPH- e.g. infection, bleed
02-Dec-15 60
61. Good response to shunting
Special studies
Lack of white matter lesions on MRI
Marked resolution of symptoms with CSF
drainage
One time removal 30-50 cc CSF
Multi-day drainage of 100-150 cc CSF
B-waves greater than 50% of time with
continuous intracranial pressure (ICP)
monitoring
Resistance to CSF outflow greater than 18
mmHg 02-Dec-15 61
62. Poor response to shunting
Severe dementia
Dementia presenting symptom
MRI abnormalities
Cerebral atrophy
Multiple white matter lesions
02-Dec-15 62
68. Monitoring of mental function
Patients should have neuropsychiatric testing
prior to shunt
Periodic testing post shunt to document
improvement
02-Dec-15 68
71. The INPH is a syndrome, characterized by gait
impairment, cognitive decline and urinary
incontinence
Associated with ventriculomegaly in the absence of
elevated CSF pressure.
Pathogenesis is not understood; intermittent
intracranial hypertension, decreased CSF
absorption and cerebral ischemia have been
blamed.
Hallmark of neuroimaging in NPH is
ventriculomegaly out of proportion with sulcal
atrophy 02-Dec-15 71
72. MRI is the choice of imaging; CSF flow in NPH is
hyperdynamic, with an increase in the amount and
velocity of CSF passing rostrally, then caudally, through
the cerebral aqueduct with each cardiac cycle.
Clinical improvement after CSF drainage implies good
response to shunting.·
The best results are found in the subjects treated with
low-pressure valves.·
Increased use of adjustable valve seems to be beneficial.
Gait is most likely to improve. Postoperative reduction
in ventriculomegaly is not always seen or proportionate
to the clinical improvement.
02-Dec-15 72