Radiology Teaching Files > Case 48174467

Last visited 11-09-2010 SUBEPENDYMAL NODULES
Contributed by: Jonathan Wood, Resident, Brooke Army Medical Center, Texas, USA.
Patient: 32 year old male
History: male: with worsening migraine headaches and gait changes. Remote history of collapse with shaking of right arm.

Fig. 1
Findings: Axial T2 weight MR image through the lateral ventricles which demonstrates an irregular, nodular contour along the posterolateral surface of the left ventricle.
Diagnosis: Unknown

Heterotopia: disorganized brain tissue, usually gray matter, located in the wrong place.

Due to premature arrest of neuronal migration from the periventricular germinal matrix to the cortex.

  • Occurs during 7th to 16th week of gestation
  • Possibly due to damage of radial glial fibers which orient the migrating neurons

Symptoms may include: seizures, weakness, spasticity, and developmental delay.

Two main types: Nodular and band


  • Subependymal
    • Same signal intensity as gray matter
    • Most commonly trigone or occipital horns of lateral ventricles
    • Right ventricle more common than the left
  • Subcortical
    • Abnormal sulcation superficial to heterotopia
    • Nodular or curvilinear
    • Ipsilateral hemisphere may be smaller


  • Severe developmental delay and earlier seizure onset than nodular
  • Associated with x-linked doublecortin gene
  • Isointense to gray matter with smooth margins
  • Double cortex sign: smooth white matter in between band and cortex


 Tuberous Sclerosis: Neurocutaneous disorder that is usually spontaneous (60%), although may be autosomal dominant.

Classic triad: adenoma secaceum, seizures, and mental retardation found in only 33%.

Associated with angiomyolipomas, multiple bone islands, pulmonary lymphangioleiomyomatosis

Intracranial findings

  • Periventricular subependymal nodules (usually calcified)
  • Subcortical and cortical tubers
  • White matter hamartomas (usually bands radiating to the ventricles)
  • Subependymal giant cell astrocytoma


Subependymoma: Ependymal cell neoplasm, variant of ependymoma.

Most commonly in the fourth ventricle, elderly males.

May also arise in the lateral ventricles and septum pellucidum although less likely.

Frequently multiple.

Tend to not seed the CSF, unlike ependymomas.

Benign course and noninvasive. Excission is curative.


 Cytomegalovirus: A herpes virus causing disease usually in the fetus, neonate, and immunocompromised.

Most common TORCH infection.

Maternal transmission from reactivation (3.4% risk) or primary infection (up to 50% risk).

Clinical symptoms range from asymptomatic to microcephaly, ocular abnormalities, and hearing loss.

May have periventricular calcifications, but limited to subependymal region.


Toxoplasmosis: Ubiquitous protozoan parasite

Second most common TORCH infection.

Maternal transmission usually from primary maternal infection.

Clinical symptoms include hydrocephalus and chorioretinitis.

TORCH infection that most commonly calcifies.

Treatment can reduce or eliminate intracerebral calcifications.

Calcifications frequently periventricular, however may be elsewhere in parenchyma including curvilinear calcifications within the basal ganglia.


Yousem DM, Grossman RI; Neuroradiology: the requisites (3rd edition). Mosby Elsevier 2010.

Weissleder, Wittenberg, Harisinghani, Chen; Primer of Diagnostic Imaging (4th edition). Mosby Elsevier 2007.

Genetics Reference, U.S. National Library of Medicine.

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Additional Details:

Case Number: 48174467Last Updated: 11-09-2010
Anatomy: Cranium and Contents   Pathology: Other
Modality: MRAccess Level: Readable by all users

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