Posttraumatic Hydrocephalus Workup

Updated: Jul 28, 2023
  • Author: John J Danko, DO, FAAPMR; Chief Editor: Elizabeth A Moberg-Wolff, MD  more...
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Laboratory Studies

Laboratory studies in the assessment of posttraumatic hydrocephalus (PTH) include the following:

  • Urine analysis and culture - Evaluate for urinary tract infections
  • Complete blood count (CBC) with differential - Evaluate for infection and anemia
  • Metabolic profile - Evaluate for electrolyte abnormalities, including syndrome of inappropriate secretion of antidiuretic hormone (SIADH), cerebral salt wasting, calcium deficiency, hypoglycemia, hyperglycemia, and encephalopathy (uremic or hepatic)
  • Thyroid-stimulating hormone (TSH), free T4 - Evaluate for hypothyroidism or hyperthyroidism
  • Arterial blood gas level - Assess oxygenation and acid/base balance
  • Serum medication levels - Measure medication levels if toxicity suspected
  • CSF analysis - Evaluate for infectious etiologies, autoimmune disease, and certain cancers

Imaging Studies

See the list below:

  • Noncontrast CT scan of the brain is one of the most commonly used diagnostic modalities.

    • The progressive enlargement of the ventricular system shown on repeat computed tomography (CT) scans is the key to the diagnosis of PTH. [7]

    • CT scans may show enlarged lateral ventricles, effaced cerebral sulci, and dilation on ventricles proximal to an obstruction. [5]

    • Periventricular edema may occur in white matter, particularly around the frontal horns. [5]

    • Sulcal enlargement with ventricular enlargement suggests atrophy and hydrocephalus ex vacuo rather than hydrocephalus. [5]

    • Large cisterns and focal regions of encephalomalacia suggest atrophy. [6, 27]

  • Magnetic resonance imaging (MRI) is another method of diagnostic evaluation. [28]

  • MRI is more useful in the evaluation of injury to structures in the posterior fossa, including cerebral aqueduct stenosis and cerebellar tonsil herniation. [29]

  • It is the neuroimaging study of choice in patients with NPH. [29]

  • MRI may be more useful than CT scanning in the identification of other neurologic disorders, especially cerebrovascular disease. [30]

Mazzini studied another imaging technique, single-photon emission CT (SPECT). [8] Mazzini found that SPECT had higher sensitivity than MRI or CT scanning in the demonstration of temporal lobe abnormality secondary to PTH.


Other Tests

See the list below:

  • Radionuclide cisternography: [5]

    • Radioiodinated serum albumin (RISA) injected into the subarachnoid space by way of lumbar puncture (LP) can normally be detected in the cisterna magna, basal cisterns, and subtentorial subarachnoid space within 6 hours, with little accumulation in the ventricular system. In NPH, RISA accumulates in the ventricular system with delayed pericerebral diffusion.

    • Cisternography is usually normal in hydrocephalus ex vacuo.

  • Although debate exists, cisternography may be a useful adjunct to CT scanning of the brain.



See the list below:

  • CSF tap test

    • This test is an LP with manometry and CSF removal.

    • Imaging of the brain should be performed before initiating the LP. The risk of cerebral herniation associated with the LP is increased in patients with greatly elevated ICP.

    • The CSF tap test may be a useful predictor of the potential benefits of shunting. Kim (2005) found that symptomatic improvement after lumbar drainage has a significant role in predicting the result of shunting.

    • CSF pressure is normally 110 mm water. Shunting may help if the pressure is 135-275 mm water, and it does help if the pressure is greater than 275 mm water.

    • Cognitive and physical functions are assessed before and after the removal of 50 mL of CSF. Improvement suggests that shunting may be beneficial.