II. Pathophysiology

  1. See Cerebrospinal Fluid
  2. Defined as communicating Hydrocephalus
    1. No obstructive mass
  3. Results from decreased CSF absorption
    1. Due to scarring or fibrosis of arachnoid granulations
  4. Pressure builds within ventricles
    1. Baseline pressure higher but in normal range
  5. CSF production decreases
  6. Ventricles distend
    1. Stretch nerve fibers
    2. Compress periventricular tissue including vessels
  7. Brain parenchymal ischemia

III. Causes

  1. Idiopathic fibrosis in most cases
  2. Contributing causes in some cases
    1. Subarachnoid Hemorrhage
    2. Head Injury
    3. Meningitis

IV. Symptoms and signs

  1. Classic triad (Positive Predictive Value: 65%)
    1. Dementia (Wacky)
    2. Gait instability (Wobbly)
    3. Urinary Incontinence (Wet)
  2. Gait instability (Gait Apraxia)
    1. Most common initial symptom
    2. Short shuffling steps (feet glued to floor)
    3. Wide based, slow ambulation
  3. Urinary Incontinence
    1. Urinary urgency
    2. Urodynamics: Detrussor Muscle ineffective contraction
  4. Subcortical Dementia
    1. Late finding, and least responsive to shunting
    2. Findings
      1. Inattention
      2. Recall latency (but memory is accurate)
      3. Loss of spontaneity
    3. Cortical findings are not seen in NPH Dementia
      1. No difficulty with word formation (Aphasia)
      2. Able to interpret stimuli (Agnosia)
      3. No difficulty with sequential tasks (Apraxia)

V. Differential Diagnosis

VI. Radiology

  1. MRI Head
    1. Ventriculomegaly
    2. Cerebral parenchyma preserved
      1. Contrast with Alzheimer's Disease
    3. Medial Hippocampus and Temporal Lobe preserved
      1. Contrast with Alzheimer's Disease
  2. Cine MRI (CSF flow imaging)
    1. Turbulent posterior Third Ventricle flow
    2. Turbulent Aqueduct of Sylvius flow
  3. Radionuclide cisternography
    1. Used to evaluate for communicating Hydrocephalus

VII. Diagnostics

  1. Routine Lumbar Puncture
    1. Evaluates differential diagnosis
    2. Normal CSF Exam
      1. Normal CSF Protein
      2. Normal CSF Glucose
      3. CSF Opening Pressure <200 mm H2O
  2. High volume Lumbar Puncture
    1. Assess symptoms before/after removing 30-60 ml CSF
    2. Predictive of response to shunting
  3. Prolonged lumbar drainage
    1. CSF removed over 3-5 days via pump
    2. Predictive of response to shunting
  4. Intracranial Pressure monitoring
    1. May identify intermittent spikes in CSF Pressure
  5. CSF outflow
    1. Saline infused 0.5-5 ml/min via Lumbar Puncture
    2. Intracranial Pressure measured via ventriculostomy
    3. Observe for elevated outflow resistance
      1. May predict shunting response

VIII. Management: Ventriculoperitoneal Shunting

  1. Description
    1. Catheter in Lateral Ventricle
    2. Cap and valve placed below scalp
    3. Tubing tunneled SQ from valve to Abdomen
    4. CSF diverted from ventricle to peritoneum
  2. Efficacy
    1. Variable based on patient selection
  3. Predictors of good response to shunting
    1. Patients with known NPH etiology do best
    2. Symptoms present only for short time
    3. No Dementia or mild Dementia present
    4. Diagnostics predictive of good response
      1. High volume Lumbar Puncture
      2. Prolonged lumbar drainage

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Ontology: Hydrocephalus, Normal Pressure (C0020258)

Definition (MSH) A form of compensated hydrocephalus characterized clinically by a slowly progressive gait disorder (see GAIT DISORDERS, NEUROLOGIC), progressive intellectual decline, and URINARY INCONTINENCE. Spinal fluid pressure tends to be in the high normal range. This condition may result from processes which interfere with the absorption of CSF including SUBARACHNOID HEMORRHAGE, chronic MENINGITIS, and other conditions. (From Adams et al., Principles of Neurology, 6th ed, pp631-3)
Concepts Disease or Syndrome (T047)
MSH D006850
ICD10 G91.2
SnomedCT 69663004, 30753002
LNC LP30875-6
English Hydrocephalus, Normal Pressure, NORMAL PRESSURE HYDROCEPHALUS, Normal Pressure Hydrocephalus, NPH - Normal press hydrocephal, Normal-pressure hydrocephalus, HYDROCEPHALUS, NORMAL-PRESSURE, NORMAL PRESSURE HYDROCEPHALY, normal pressure hydrocephalus, NPH (normal pressure hydrocephalus), normal pressure hydrocephalus (diagnosis), Normal pressure hydrocephaly, Hakim Syndrome, Syndrome, Hakim, NPH (Normal Pressure Hydrocephalus), Normal pressure hydrocephalus NOS, Hydrocephalus, Normal Pressure [Disease/Finding], Nph, hakim syndrome, hydrocephalus pressure normal, normal pressure hydrocephaly, normal-pressure hydrocephalus, nph, hydrocephalus normal pressure, hydrocephalus normal nph pressure, normal pressure hydrocephalus (nph), low pressure hydrocephalus, Hakim Syndromes, NPHs (Normal Pressure Hydrocephalus), Syndromes, Hakim, Hakim's Syndrome, Hakim's Syndromes, Syndrome, Hakim's, Syndromes, Hakim's, Hakims Syndrome, Hydrocephalus, Normal-Pressure, Low pressure hydrocephalus (disorder), Low pressure hydrocephalus, Normal pressure hydrocephalus, NPH - Normal pressure hydrocephalus, Normal pressure hydrocephalus (disorder), hydrocephalus; normal-pressure, normal-pressure; hydrocephalus
Dutch normale liquordruk hydrocephalus, hydrocefalus; normale druk, normale druk; hydrocefalus, 'Normal-pressure'-hydrocefalus, normale druk hydrocephalus, Hakim-syndroom, Hydrocefalus, normotensieve, Normaledrukhydrocefalus, Normotensieve hydrocefalus
German Hydrozephalie mit normalem Druck, Hydrozephalus mit normalem Druck, Hydrozephalus ohne Hirndrucksteigerung, Hydrozephalus, Normaldruck-, Hakim-Syndrom
Portuguese Hidrocefalia normotensa, HIDROCEFALIA DE PRESSAO NORMAL, Hidrocefalia de pressão normal, Hidrocefalia de Pressão Normal, Síndrome de Hakim
Swedish Vattenskalle, normaltrycks
Japanese セイジョウアツスイトウショウ, 水頭症-正常圧, 正常圧水頭症
Czech hydrocefalus normotenzní, Normotenzní hydrocefalus
Finnish Normaalipaineinen vesipäisyys
French HYDROCEPHALIE A PRESSION NORMALE, Hydrocéphalie chronique de l'adulte, Syndrome de Hakim, Hydrocéphalie à pression normale
Italian Idrocefalo a pressione normale, Sindrome di Hakim, Idrocefalo normoteso
Korean 정상뇌압 수두증
Polish Wodogłowie normotensyjne, Wodogłowie normalnociśnieniowe
Hungarian Normális nyomású hydrocephalus, Normál-nyomású hydrocephalus
Norwegian Normaltrykkshydrocefalus, Normaltrykkshydrocephalus
Spanish hidrocefalia de presión baja (concepto no activo), hidrocefalia de presión baja, Hidrocefalia Normotensa, hidrocefalia de presión normal, hidrocefalia normotensa (trastorno), hidrocefalia normotensa, Hidrocefalia a presión normal, Hidrocéfalo de Presión Normal, Hidrocéfalo Normotenso, Síndrome de Hakim