Surgically treated dementias mainly include Normal Pressure Hydrocephalus and SDH

1. - Dr. Rahul Jain
Senior Resident
Dept. of Neurology
ABVIMS & Dr. RML Hospital
Neurological workup &
Management approaches for
Dementia with emphasis on
Surgically Treatable Dementia

2. • “Dementia” replaced by Neuro-cognitive decline. (NCD)
A. Evidence of significant cognitive decline from a previous level
of performance in one or more cognitive domains (individual,
relative, clinician)
B. Interference in independence of Activities of Daily Living (ADL)
C. Cognitive decline does not occur during course of DELIRIUM
D. Cognitive deficits not explained by another mental disorder (eg.
major depression, schizophrenia).
APA, 2013
DSM V Criteria of Dementia
6 cognitive domains -
Memory
Language
Visuo-spatial (perceptual motor)
Executive function
Attention (complex attention)
Social Interaction

3. Cognitive Decline from a higher previous level of
functioning (acquired)
ADL
Preserved Affected
Mild Cognitive Impairment (MCI)
Mild Neuro-cognitive Decline (Mild NCD)
Dementia
Major Neuro-cognitive Decline (Major NCD)

4. • HISTORY
• Source
• Previous level of performance (education, occupation, ADL)
• Identify the Presenting Symptom (which cognitive domain is
involved first)
• Mode of onset - Insidious, Acute , Subacute (weeks to months)
• Duration of symptoms
• Rate of progression - slow, rapid
• Medical History - (HTN, DM, CVA, Head injury, Heart Disease, Thyroid
illness)
• Drug history - Sedatives (BZD, barbiturates) & Anticholinergics, Many
Approach to Dementia

5. Delirium -
• Acute onset/ Sudden, with a definite beginning point.
• Attention is greatly impaired.
• Level of consciousness - greatly impaired
• FLUCTUATION - with lucid intervals, worse in night (sundowning)
• Visual hallucinations common, illusions
• Sleep Wake Cycle disrupted
Differentiating Dementia from Delirium

6. • Cognitive tests - Screening by MMSE.
24-30 - No cognitive impairment
19-23 - Mild
10-18 - Moderate
9 or less - Severe cognitive impairment
• Detailed Higher Mental Function Examination
• Detailed Neurological Examination
AD - usually normal
Parkinsonism (PSP, CBS, DLB, PDD)
Focal Neurological deficits - vascular dementia
Bowel, bladder, gait - NPH
EXAMINATION

7. • Mnemonic - VITAMIN
• Vascular, SDH
• Infectious - Viral (HSV, HIV) Whipple disease, Lyme’s, Syphilis, TB, PRION
Disease
• Toxic-Metabolic - B1, B12, Alcohol, Uraemia, Liver failure, Drug toxicity -
lithium, methotrexate, Hypo hyper thyroidism, Hypo Hyper PTH,
Hypoglycemia
• Auto-immune - Hashimoto’s, Paraneoplastic Limbic Encephalitis, VGKC
limbic encephalitis, CNS vasculitis, Sarcoidosis, Connective tissue disorder
• Metastasis , CNS lymphoma
• Iatrogenic
• Neurodegenerative - CJD, Wilsons, (AD, DLB, FTD, CBS, PSP)
Rapidly Progressive Dementias (weeks to months)
+ NPH
+ Wilsons

8. • AAN recommends
CBC, KFT, LFT, HbA1C, TFT, B12
• HIV, VDRL, ANA
• CSF, EEG as necessary
• IMAGING Screen - Plain MRI Brain > CT
• FDG PET scan
INVESTIGATIONS

9. • Normal Pressure Hydrocephalus
• Sub Dural Hematoma
• Fronto-basal located meningiomas
Surgically Treatable Dementias
Source -
Cognitive Impairment in the Elderly with Chronic Subdural Hematoma, Clinical Article, J Kor Neurotraumatol Soc 2008;4:66-69
Surgical Treatment of Dementia October 2018, Nichidai Igaku Zasshi 77(5):289-293, DOI: 10.4264/numa.77.5_289

10. • First described by Salomon
Hakim (Columbian neurosurgeon
and pathologist) and Raymond
Adams (neuropathologist) in
1965.
• He found that many patients with
neurodegenerative disorders, on
autopsy had enlarged ventricles
without destruction of the cortex.
• He found the disease, on seeing
improvement in such patients
after CSF shunting procedures.
(Hakim-Adams syndrome)
Normal Pressure Hydrocephalus
Dr. Salomon Hakim
Dr. Raymond D. Adams

11. • Communicating hydrocephalus
• Chronic, progressive
• Adult onset, Usually > 60 yrs.
• Sex - Equal in males and females.
• Refers to a condition of pathologically enlarged
ventricles disproportionate to the degree of cortical
atrophy on neuroimaging with a normal/high normal
opening pressure on lumbar puncture.

12. 1. Idiopathic NPH
2. Secondary NPH - all causes lead to gradual decrease in CSF
absorption and accumulation of CSF.
IVH, SAH, Trauma, Chronic Meningitis (Fungal, Tubercular,
Syphilitic)
Paget’s disease of the skull base
Achondroplasia
Causes of NPH

13. • Decompensated congenital hydrocephalus.
(Larger head sizes commonly associated with NPH, suggests
that some patients with congenital hydrocephalus becomes
symptomatic later in life)
• Cerebrovascular Risk Factors (HTN, Periventricular ischemic
changes) - Chronic periventricular ischemia - - increased
compliance of ventricular walls & gradual ventricular
enlargement, even to mild fluctuations of ICP.
• Decreased CSF absorption - (arachnoid thickening found in
50% patients of NPH on autopsy)
Proposed Mechanisms
Pathophysiology of Idiopathic NPH

14. • During cardiac systole - influx of arterial blood takes place into
the brain, causing the intra-cranial volume to rise.
• This increase in intra-cranial volume is compensated by
outflow of CSF towards the spinal canal in Up to down
direction.
• During cardiac diastole - reverse
• This ability to compensate intracranial volume/ fluid
displacement potential depends on the INTERNAL
ELASTICITY.
In NPH patients this internal elasticity is reduced, and this
results in transmission of systolic force abnormally, towards the
centre - causing compression of lateral ventricles and
enhancing CSF movement through the cerebral aqueduct.

15. MR Elastography showing increased stiffness in NPH

16. • Unlike other hydrocephalus types, associated with persistently
enhanced CSF pressure, in NPH - exhibits enlarged ventricular
system, with normal CSF pressure, accompanied by intermittent
episodes of enhanced pulse pressure.
• Therefore, NPH is also referred to as “Intermittent or Sporadic
Pressure Hydrocephalus”
• Enlarged ventricular size compresses the paracentral corticospinal
tracts (SMA) causing GAIT disturbance. Also cause stretching of the
frontal subcortical white matter tracts responsible for frontal
subcortical type dementia.
• Ventricular dilatation begins to develop days before symptoms of
NPH appear.

17. • Classic triad (aka Hakim’s triad/ Adam’s triad) -
1. Gait disturbance 2. Cognitive Disturbance 3. Urinary
incontinence.
• Core symptom is Gait Disturbance. (Many patients may not
have other 2 of the triad) GAIT impairment is the earliest
symptom.
• Urinary incontinence is a late feature.
• As CSF pressure is normal/high normal, signs of raised ICT -
USUALLY ABSENT
Clinical Features of NPH
In early stages of illness, once the ventricles are enlarging, the patient
may suffer from drop attacks or brief loss of consciousness

18. • Apraxia of Gait
• Inability to lift feet off the
ground
• No motor weakness
• Magnetic Gait/ Glue footed
gait (not pathognomic/
typical) also seen in Frontal
ataxia/Gait Apraxia/bruns
apraxia)
• Broad based, small steps
• Difficulty in turning (piece meal)
• Postural instability, Falls
present. Pull Test positive
GAIT

19. • Subcortical dementia, Progressive
• Frontal lobe executive dysfunction (planning organisation) - (managing
finances, taking medications, driving, keeping track of appointments). Apathy,
decreased social interaction is a late feature.
• Preservation of cortical features - language, visuospatial, memory,
apraxia. (May be involved late)
• (Indicates either its not NPH, or it has advanced and may not respond well
to treatment)
Cognitive
Urinary Incontinence
• Initially urgency, later incontinence. (detrusor overactivity)
UMN signs
• DTR may be brisk, Babinski is usually absent.
• Frontal release signs like grasp reflex may be seen.

20. • All those neurodegenerative disorders which present with Prominent,
early gait dysfunction.
1. Dementia with Lewy bodies - psychotic, visual hallucinations, REM
sleep behavioural disorder, fluctuations, asymmetric parkinsonism
2. Parkinson’s Disease Dementia - Gait of IPD patients is narrow
based, additional signs ASYMMETRIC tremor/rigidity/bradykinesia.
Cognitive impairment is later stage finding (vs NPH).
3. PSP - gaze abnormality, speech involvement, dysphagia, MSA, CBD
• Alzheimer's disease - Dementia (memory impairment) starts before
gait abnormality, Cortical dementia features are early - memory,
aphasia etc. (75% patients with iNPH also have AD pathology
• FTD, Multi-infarct Dementia - early presence of cortical deficits like -
aphasia, apraxia, agnosia.
Differential Diagnosis of NPH
If any features of Parkinsonism are found, to avoid shunting unnecessarily,
a trial of levodopa may be given

21. MRI better than CT.
CT is good for screening and excluding NPH for those who cannot
undergo MRI.
1. Ventriculomegaly
Ventriculomegaly in the absence of sulcal enlargement, or much more (out
of proportion to) the sulcal enlargement, with no evidence of obstruction
at level of third or fourth ventricles. Measured by EVAN’s Index > 0.31.
Neurodegenerative/ age related cortical atrophy also produces ventricular
enlargement - Hydrocephalus ex vacuo. But Both ventricles and the
sulcal spaces are proportionately enlarged.
Imaging in NPH

22. EVANS INDEX - Maximum width of frontal horns of lateral ventricle
(at level where frontal horns are the largest) , divided by ,
Maximum Bi-parietal distance , AT THE SAME LEVEL

23. • Many studies suggested that, ventriculomegaly
with preserved sulcal (not enlarged) (preserved
cortex) is the best predictor for response to
Shunting in NPH patients.
• Hence a group in Japan coined the term DESH
• 2. Disproportionately Enlarged Sub-arachnoid
space Hydrocephalus (DESH) includes
A. Ventriculomegaly
B. Tight high convexity and medial sub
arachnoid space
C. Disproportionate enlargement of the
Sylvian fissures
D. Focally dilated or entrapped sulci (aka
transport sulci) without adjacent cortical
atrophy
• Many studies show that presence of DESH,
improves response to shunting in patients with
NPH.
CSF is
disproportionately
located between the
superior and inferior
subarachnoid spaces

25. • 3. Callosal angle - angle measured between the lateral
ventricles on coronal MRI image through the posterior
commissure, perpendicular to the anterior commissure and
posterior commissure plane.
Callosal angle measured on T1-weighted 3D images in a 73-year-old woman with iNPH.
A: Sagittal image used to identify the AC-PC plane.
B: Preoperative investigation illustrating that the CA is measured in the coronal plane
through the posterior commissure perpendicular to the AC-PC plane.
C: Postoperative MR scan with an artifact due to the shunt valve.
Source - Virhammar, J., Laurell, K., Cesarini, K. G., & Larsson, E. (2018). Increase in
callosal angle and decrease in ventricular volume after shunt surgery in patients with
idiopathic normal pressure hydrocephalus, Journal of Neurosurgery JNS, 130(1),
130-135.

26. Axial T1-weighted 3D images of preoperative (A) and postoperative (B) MR
scans in a 78-year-old man with iNPH.
Source - Virhammar, J., Laurell, K., Cesarini, K. G., & Larsson, E. (2018). Increase in
callosal angle and decrease in ventricular volume after shunt surgery in patients with
idiopathic normal pressure hydrocephalus, Journal of Neurosurgery JNS, 130(1),
130-135.

27. • The callosal angle (CA) has been reported to be of diagnostic
and prognostic value in patients with iNPH.
• Small CA is favourable to support diagnosis of iNPH vs AD
(hydrocephalus ex-vacuo), healthy people
• Small CA is favourable for predicting response to shunt surgery
in iNPH.
Normal value between 100-120°(obtuse angle)
iNPH between 50-80° (acute angle)
Source - Ishii K, Kanda T, Harada A et-al. Clinical impact of the callosal
angle in the diagnosis of idiopathic normal pressure hydrocephalus. Eur
Radiol. 2008;18 (11): 2678-83.

28. 4. Periventricular White Matter Hyper-intensities (PVWMH)
Thought to represent trans-ependymal flow of fluid.
Most studies have shown that, more the PVWMH, less is the response to shunt surgery.
5. Aqueductal flow void (JET SIGN)
NPH patients often show loss of signal in the aqueduct of sylvius. Thought to represent
higher than normal flow velocity of CSF in the aqueduct.

29. 6. Enlarged diameter of the Temporal Horns
7. Enlarged diameter of the Third Ventricle
8. Focal bulging of the roof of the lateral ventricles
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30. chronic ischemia, or plasma leakage caused by diffuse cerebrovas-
cular endothelial failure.18
FIG 4. Forest plot with sex-adjusted odds ratios for all imaging features. OR with a 95% CI of 1-SD increase for continuous variables and a 1-U
increase for dichotomous and ordinal variables. An arrow indicates that the confidence interval extends beyond the range of the plot. The
Sylvian fissure ordinal is the ordinal scale 0–2; the Sylvian fissure height is measured in millimeters. The asterisk indicates P ! .05.
Table 3: Correlations among different imaging markers at
baselinea
Source -
Research Article Brain
Preoperative Prognostic Value of MRI Findings in 108 Patients with
Idiopathic Normal Pressure Hydrocephalus
J. Virhammar, K. Laurell, K.G. Cesarini and E.-M. Larsson
American Journal of Neuroradiology December 2014,

31. AD NPH
Prominent cortical atrophy argues against the diagnosis of NPH and
predicts lesser likelihood of improvement with shunting
Identify which could be the brain of a NPH patient and which of an Alzheimer’s?

32. Excellent positive predictive
value - 90-100%,
Low negative predictive value -
30-50%
aka Miller’Fischer Test

34. 5-10ml/hour
2-7 days

35. 4. Cisternography - Isotope cisternography consists of
injection of a radio labelled isotope into the lumbar cistern and
visualising its distribution throughout the cisterns, ventricles
and brain convexities at set time periods following its
introduction. (4,24,48,72 hours). NPH is suggested by non
appearance of isotope over brain convexities at 72 hours.
Utility is doubtful.
5. CSF Aβ42, CSF tau - not good for differentiating AD vs
NPH. In AD (Low Aβ42, high tau). In NPH, pre shunting - Low
Aβ42, low tau, post shunting - both increase.

36. TABLE 95.9 Japanese Diagnostic Criteria of Idiopathic Normal Pressure Hydrocephalus (iNPH)
POSSIBLE iNPH (MEETS ALL 5 OF THE FOLLOWING)
1. Individuals who develop symptoms in their 60s or older.
2. More than 1 of the clinical triad (cognitive impairment, urinary
incontinence, gait disturbance).
3. Ventricular dilation (Evans index>0.3).
1. Above-mentioned symptoms cannot be completely explained by
other neurological or non-neurological disease.
2. Preceding diseases possibly causing ventricular dilation are not
obvious including subarachnoid hemorrhage, meningitis, head injury,
congenital hydrocephalus, and aqueductal stenosis.
POSSIBLE iNPH SUPPORTIVE FEATURES
(a) Small stride, shuffle, instability during walking and increased instability
with turning.
(b) Symptoms progress slowly; however, sometimes an undulating
course, including temporal discontinuation of development and
exacerbation, is observed.
(c) Gait disorder is the most prevalent feature followed by cognitive
impairment and urinary incontinence.
(d) Cognitive impairment is detected on cognitive tests.
(e) Sylvian fissures and basal cisterns are usually enlarged.
(f) Other neurological diseases such as Parkinson disease, Alzheimer
disease, and cerebrovascular disease may coexist; however, all such
diseases should be mild.
(g) Periventricular changes are not essential.
(h) Measurement of CBF is useful for differentiation from other
dementias.
PROBABLE iNPH (MEETS ALL OF THE
FOLLOWING 3 FEATURES) DEFINITE iNPH
1. Meets criteria for possible iNPH.
2. CSF pressure < 200 mmH2O and normal
CSF content.
3. One of the following three investigational
features:
(1) Neuroimaging of narrowing of the sulci
and subarachnoid spaces over the high
convexity/midline surface (DESH) in the
presence of a gait disturbance
(2) Improvement of symptoms after CSF
tap test
(3) Improvement of symptoms after CSF
drainage test.
Improvement of
symptoms after the
shunt procedure
iNPH, idiopathic normal pressure hydrocephalus; DESH, disproportionately enlarged subarachnoid space hydrocephalus.
(Reprinted with permission from Mori, E., Ishikawa, M., Kato, T., et al. 2012. Guidelines for management of idiopathic normal pressure
hydrocephalus: second edition. Neurol Med Chir 52, 775–809.)
pathogenesis. The clinical and radiologic presentations associ-
Clinical features of autoimmune dementia include a suba-
cute course, personal or family history of autoimmunity or
Source - Bradley’s Neurology in Clinical Practice, 7th ed.

37. Source - Bradley’s Neurology in Clinical Practice, 7th ed.
88
normal pressure hydro-
sease with white matter
l absorption of CSF. He
ve CSF, but failed to show
ced. There is evidence of
of transependymal flow of
on disease and responded
ates the overlap of normal
vascular disease, lacunar
nts may not benefit from
Fig. 88.14 An algorithm for selection of patients for VP shunt.
Those with the clinical triad undergo FLAIR MRI. If communicating
hydrocephalus is found without excessive atrophy and with trans-
ependymal absorption, then a large volume of CSF is removed and
the changes in the gait observed over several days. In those with
improvement in gait, a ventriculoperitoneal shunt is done. Patients with
white matter changes in the deep white matter probably have lacunar
state. Those with white matter changes compatible with microvascular
disease most likely have lacunar state or Parkinsonism.
Clinical suspicion of NPH
(Cognitive decline, gait apraxia, incontinence)
MRI
Enlarged ventricles
Transependymal flow
Large volume LP No change in gait
Gait improved
VP shunt WMHs
Lacunar state/
Parkinsonism

38. • VP shunting > ETV
• Maximum response in Gait, then cognition, then urinary
incontinence
• Best patients showing response would be those with gait
involvement, mild dementia and mild or nil urinary complaints.
Treatment of NPH

39. NPH Brain Atrophy
Source -
Damasceno, Benito Pereira (2015). "Neuroimaging in normal pressure hydrocephalus".
Dementia & Neuropsychologia. 9 (4): 350–355. doi:10.1590/1980-57642015DN94000350.
ISSN 1980-5764. PMC 5619317. PM

40. • Phase Contrast MRI - CSF flow imaging, helps in calculation of the aqueduct CSF flow volume
(ACFV) during cardiac systole and diastole. Studies indicate that patients who responded to surgery
had at least twice the ACFV as compared to healthy controls. Some studies refuted this. (They
recommended combination of ACFV and CSF Tap test was better)
• 18 f - FDG PET study demonstrates reduction in cerebral blood flow and metabolism in primarily
fronts-basal and anterior periventricular regions. (Caudate and putamen hypometabolism with
normal preserved cortical metabolism)
• MR Diffusion Tensor Imaging (DTI) for - volumetric measurement of the hippocampus.
Hippocampal atrophy in AD. Fornix size is reduced in both NPH and AD, but fornix length is
increased in NPH (due to stretching by the enlarged ventricles)
Advances in diagnosing NPH
tional Diagnosis and Treatment of Normal Pressure Hydrocephalus Current Drug Targets, 2019, Vol. 20, No. 6 3
ed ventricular system with normal CSF
ccompanied by intermittent episodes of
essure. The condition is therefore also re-
mittent or sporadic-pressure hydrocepha-
ubclass of communicating-hydrocephalus
mptomatic or idiopathic in nature. In the
occurs as a secondary manifestation to a
ch as cranial trauma, meningitis or hemor-
e latter case, the cause is unknown, nor-
n the later stages of life [26-28].
have proposed the mechanism of how the
enlargement, such as BEH (benign external hydrocephalus).
It was revealed that in patients with pronounced intra-cranial
volume, the initial hit took place when sutures had not even
closed, thus endorsing the idea of BEH being the original
insult [36, 37].
BEH is distinguished via reduced CSF intake through
arachnoid-granulations following the movement through the
fourth ventricle outlet-foramina. The CSF production rate
does not decrease, thus patients tend to develop a compara-
ble passage for its resorption, such as, through the brain’s
extracellular space (ECS). CSF is hence able to penetrate
mages illustrating diastolic flow-up (black) and systolic flow-down (white) [23]. Reproduced and reprinted with permis-
nc. (Copyright © 2016) through copyright clearance center.
PC-MRI images
illustrating diastolic
flow-up (black) and
systolic flow-down
(white) (Normal
Patient)
Source - Zhang L, Hussain Z, Ren Z. Recent Advances in Rational Diagnosis
and Treatment of Normal Pressure Hydrocephalus:
A Critical Appraisal on Novel Diagnostic, Therapy Monitoring and Treatment
Modalities. Curr Drug Targets. 2019;20(10):1041-1057.

41. MR Spectroscopy -
• 2004 study - significant preoperative differences in NAA/Cr and
NAA/Cho between patients who responded to shunt surgery and
those who didn’t.
• No role in differentiating iNPH from other dementias. No role in
predicting response to surgery. 2010

42. • M.C clinical feature - Cognitive
Dysfunction
• Cognitive domains involved - Attention
(M.C.), Memory, Language
• Impaired judgement, personality changes
also occur
• Hallucinations
• Memory - Retrieval of memory was
impaired more in SDH vs Alzheimer’s
where formation of new memory is
impaired.
Chronic Sub Dural Hematoma
Source -
Machulda MM, Haut MW. Clinical features of chronic subdural hematoma: neuropsychiatric and neuropsychologic
changes in pa- tients with chronic subdural hematoma. Neurosurg Clin N Am 11: 473-477, 2000

43. • Most are nonspecific and global.
• Two most common lateralising signs - Hemiparesis and
Language Dysfunction. (Dominant hemisphere)
• Aphasia - Motor Aphasia > Sensory aphasia. Suggests frontal
lobe dysfunction. Word finding difficulty.
• Gerstman syndrome - right left disorientation, finger agnosia,
agraphia, acalculia. - left frontoparietal SDH
Lateralisation and Localisation of signs and symptoms of SDH
Source -
Machulda MM, Haut MW. Clinical features of chronic subdural hematoma: neuropsychiatric and neuropsychologic
changes in pa- tients with chronic subdural hematoma. Neurosurg Clin N Am 11: 473-477, 2000

44. • SDH vs AD -
1. SDH onset - over weeks, AD onset - months to years.
2. Memory impairment is not as severe as AD.
3. New memory formation is affected in AD, where as retrieval of
newly formed memory is affected in SDH.
• SDH vs Vascular Dementia -
SDH onset is faster (weeks) than Vascular dementia (weeks to
months, in a step wise fashion). SDH has fluctuations.
D/D of SDH related Dementia
Source -
Machulda MM, Haut MW. Clinical features of chronic subdural hematoma: neuropsychiatric and neuropsychologic
changes in pa- tients with chronic subdural hematoma. Neurosurg Clin N Am 11: 473-477, 2000

45. Thank You