1. DR SANKALP MOHANSENIOR RESIDENTDEPARTMENT OF NEUROLOGYMBS HOSPITAL,KOTA

2. Hydrocephalus 3. COMMUNICATINGHYDROCEPHALUS 4. NORMAL PRESSUREHYDROCEPHALUS First described by Hakim in 1964 Normal pressure hydrocephalus (NPH) is a clinicalsymptom complex characterized by abnormal gait,urinary incontinence, and dementia. 5. EPIDEMIOLOGY elderly individuals (age >65 y) the prevalence of NPHwas 1.4% Incidence -1.4 per 1,00,000 No race or gender prediliction more than 60% of patients with iNPH hadcerebrovascular disease. In another similar study, more than 75% hadAlzheimer disease pathology at the time of shuntsurgery. 6. ETIOLOGY IDIOPATHIC 50 % SECONDARY CAUSES subarachnoid hemorrhage (23%), meningitis (4.5%) and traumatic brain injury (12.5%) 7. PATHOPHYSIOLOGY Increased subarachnoid space volume does notaccompany increased ventricular volume. Symptoms result from distortion of the central portionof the corona radiata by the distended ventricles.Interstitial edema of the white matter The periventricular white matter anatomicallyincludes the sacral motor -abnormal gait andincontinence. Dementia results from distortion of theperiventricular limbic system. 8. CLINICAL FEATURES CLASSIC TRIAD GAIT DISTURBANCE -is typically the earliest featurenoted and considered to be the most responsive totreatment Apraxia of gait no weakness or ataxia bradykinetic, broad based, magnetic, and shuffling. URINARY SYMPTOMS of NPH can present asurinary frequency, urgency, or frank incontinence. 9. DEMENTIA Usually mild prominent memory loss and bradyphrenia. Frontal and subcortical deficits forgetfulness, decreased attention, Aphasia /agnosia alternate diagnosis -Alzheimer 10. Proposed diagnostic criteriaCase of probable iNPH are Older than 40 years of age insidious (nonacute) progression of symptoms over aperiod of at least 3 months CSF opening pressures between 70 and 245 mm H2O. MRI or CT must show an Evans index of at least 0.3 as well as temporal horn enlargement , periventricular signal changes, periventricularedema, or an aqueductal/fourth ventricular flow void 11. DIFFERENTIAL DIAGNOSIS 12. Diagnosis of NPH less likely IF- Intracranial pressure above 25 cm H2O (this rules out iNPH, by definition) Age under 40 (iNPH unlikely) Asymmetrical or transient symptoms Cortical deficits, e.g., aphasia, apraxia, or paresis Progressive dementia without gait disturbance (even if the ventricles are enlarged) Lack of progression of symptoms 13. INVESTIGATIONS- 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 14. CT SCANdisproportionately enlarged temporal hornsof the lateral ventricles compared with therelatively normal sulcal size. 15. CT SCAN Ventriculomegaly that is out of proportion to sulcalatrophy. differentiates NPH from ex vacuo ventriculomegaly, Frontal and occipital periventricular hypoattenuatingareas, represent transependymal CSF flow -infrequent and often may represent periventricularleukoencephalopathy corpus callosal thinning, -nonspecific 16. Rounding of frontal horns clinical picture andventriculosulcal disproportion oneither CT or MRI scans, 50-70% ofpatients are likely to respond to aCSF-shunting procedure. 17. The Evans index (EI), a linear ratio between themaximal frontal horn width and the cranium diameter, signifies ventriculomegaly if it is 0.3 18. Magnetic Resonance Imaging Temporal horns out of proportion to hippocampal atrophy MRI provides additional physiologic information on NPH T2-weighted images, regions of moving CSF demonstrateno signal, instead of the increased signal observed in slow-movingCSF, CSF flow studies- jet of turbulent CSF flow may beobserved distal to the aqueduct Cine phase-contrast MRI quantifies CSF flow in terms ofstroke volume - significant corelation to shunt responsiveness 19. CSF TAP TEST 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 prognosticevaluation of NPH 20. EXTERNAL LUMBAR DRAINAGE 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 valuewere 95%, 64%, and 78%, respectively. PPV 80 -100 % Requires hospitalisation specialised care 21. OTHER TESTS CSF infusion testing.- One drain is used forcontinuous pressure monitoring while the other drainis used to continuously infuse solution into the CSFspace. Ro impedance of flow offered by csf absorption Isotopic cisternography is no longer in frequent use Acqueductal CSF flow not of much diagnostic use 22. PRESURGICAL EVALUATION Neuropsychological evaluation (eg, Folstein test orformal neuropsychological evaluation)- not validated Timed walking test. Videotaping the gait evaluation before and after thelarge volume lumbar puncture.- IS PREFERABLE Reduction in bladder hyperactivity also may be a signof good outcome from shunting. 23. Timed walking Test 24. MANAGEMENT No prospective, double blind, randomized, controlledclinical triaL Medical management levodopa trial to rule out idiopthicparkinson disease No drug is known to work in NPH Surgical Management mainstay Benefit expected from shunt surgery in probable case ofNPH 50 %- 61 % 25. Mean rate of complications was 38percent Additional surgery required in 22 % The decision for surgery should beindividualised 26. Newer advances adjustable shunt valves adjusts the opening pressure the introduction of gravity-controlled valves - lowvalve opening pressure when the patient is lying down. G valves lower the risk of overdrainage by 90% 27. Endoscopic third ventriculostomy (ETV). Alternative to shunt placement for treatmentof hydrocephalus. Effective in obstructive hydrocephalus. Efficacy inNPH not known 28. FOLLOW UP Routine follow up 2 to 3 times per year Earlier if shunt inection/failure Bedside clinical examination follow up CTScan withinfew weeks D Dimer ,CRP in case of ventriculoatrial shunts forsubclinical septicemia and thromboembolism 29. Whether to shunt or Not? High CSF pressure should prompt investigation for asecondary cause of NPH Response to a 40-mL to 50-mL (high-volume) lumbartap suggests a potential benefit to shunting An ELD may be used to evaluate those who do notrespond to a high-volume tap There is no substantial predictive value to MRI CSFflow studies IF multi-infarct or Alzheimers disease dementia ?? 30. THANK YOU 31. REFERNCES Curr Neurol Neurosci Rep. Sep 2008; 8(5): 371376 MDS 17th International Congress of Parkinson'sDisease and Movement Disorders, Volume 28,June 2013 Abstract Supplement Congress of neurological surgeons INPH guidelines volume 57 ,number 3 2005 Bradley s Neurology in Clinical practice