Mayo Flashcards
7F with mild developmental delay and multiple hypopigmented skin lesions
Tuberous Sclerosis
Subependymal giant cell astrocytoma in the left lateral ventricle in a girl with tuberous sclerosis.
*Note also the FLAIR image showing multiple cortical and subcortical hamartomas.
29M with history of developmental delay and seizures presents to ED in status epilepticus
Polymicrogyria
Coronal views of this T1 weighted MRI head demonstrated multiple congenital anomalies including polymicrogyria of inferior left temporal lobe, absence of septum pellucidum, hemimegalencephaly and tortuous torcular Herophili.
38F with spells of left arm posturing
Sturge-Weber
MRI head demonstrates changes typical of Sturge-Weber syndrome with cortical calcification and atrophy involving the right posterior temporal and occipital lobes.
Video EEG revealed several behaviorally identical complex partial seizures with prominent right temporal ictal discharge.
A 16 month old girl s/p myelomeningocele repair has progressive loss of motor milestones, scoliosis, and dysphagia.
Chiari II malformation
She has partial agenesis of the corpus callosum, a beaked tectum, tonsillar ectopia, fused thalami (large massa intermedia), interdigitation of the gyri at the interhemispheric fissure, and low insertion of the straight sinus. She also had syringomyelia.
A seven-year-old boy has frequent seizures, developmental delay, and autism.
Tuberous sclerosis
On MRI imaging we see several typical features of tuberous sclerosis, including multiple cortical and subcortical tubers, which are collections of abnormally sized neurons and glial cells. Also seen are subependymal nodules, which are found along the walls of the lateral ventricles. The appearance of multiple nodules is sometimes referred to as “candle guttering” to convey the similarity to drippings of wax from a candle. In 5-10% of cases, these benign lesions can degenerate into subependymal giant cell astrocytomas (SEGA), which are dangerous because they can cause hydrocephalus as they grow near the foramen of Munro.
Name this MRI finding.
Cavum septum pellucidum
This is considered a normal variant. The two laminae making up the septum pellucidum are separated in utero and fuse as the fetus approaches term (1). When the cavity formed by this separation persists, it is called a cavum septum pellucidum. While sometimes called “the 5th ventricle,” it does not actually contain CSF. Although cavum septi pellucidi are often seen in newborn infants, especially preemies, 80% disappear by age 3 to 6 months (2). In some the space persists, however, and can be seen in up to 10% of adults (2).
The significance of a persistent cavum septum pellucidum is uncertain, though studies have shown an increased prevalence in patients with schizophrenia, alcohol abuse, mental retardation, or a history of head trauma (1, 3). Cavum septi pellucidi are also larger in such patients. Thus, it is speculated that cavum septi pellucidi may reflect developmental abnormalities of other midline brain structures such as the limbic system.
4-month-old girl with normal development until 6 weeks of age when she presented with seizures. This was followed by developmental regression, decreased head circumference (from the 30th percentile to <3rd percentile), progressively declining mental status, and respiratory difficulties. Of note, her older brother had similar symptoms at the same age.
Leigh’s disease
(mitochondrial disorder characterized by subacute necrotizing encephalomyelopathy).
MRI imaging characteristically shows symmetric T2 hyperintensities in the highly metabolic regions of the brain (i.e. basal ganglia).
52 yo male with a life-long history of seizures. In childhood, noted to have mild right hemiparesis and moderate mental retardation.
Sturge Weber Syndrome
Exam was notable for left port-wine stain along V1/V2/V3 and blindness in left eye. He has right hemiatrophy with mild hemiparesis, and a wide based ataxic gait. (Shown: MRI T1 w/ gad, axial CT, coronal FLAIR, coronal FLAIR)
MRI shows findings consistent with Sturge Weber syndrome. There is left hemisphere atrophy with asymmetric thickening of left calverium and overgrowth in left frontal sinus.
Note the extensive left pial and subarachnoid enhancement compatible with pial angiomatosis. (Image 1)
The hippocampal formations are small bilaterally, compatible with mesial temporal sclerosis, to a greater extent on the left. (Image 2)
There is an enlarged enhancing left choroid plexus with adjacent T2 signal abnormality in the periventricular white . (Image 3)
CT shows laminar cortically based calcification in the left hemisphere, most prominent posteriorly (Image 4).
What incidental abnormality is shown above?
Hypoplasia of corpus callosum
There are three types of congenital abnormalities of the corpus callosum.
These include: Callosal agenesis (completely absent) Callosal hypogenesis (variably formed, partially absent) Callosal hypoplasia (completely formed but small in size)
A 20-year-old college student presents with a 4 year history of seizures. Her typical spells involves a prodrome of feeling nauseous, unwell, and “trapped in her body.” Witnesses have observed her turning her head to the left and then developing generalized tonic-clonic seizure activity. On one occasion, the patient recalled seeing “little colored swirls in the upper left that were making me look at them.” The above MRI is obtained.
Bilateral periventricular nodular heterotopias
Periventricular nodular heterotopias are caused by an early defect of migration during brain development and can be hereditary.
Recurrent seizures are common, often with temporo-parieto-occipital auras.
An 80 year-old woman presents with a slowly progressive cognitive decline beginning many years prior to evaluation. On examination, her STMS is 7/38. Other than some dysnomia, the remainder of her examination was normal. Her imaging (MRI T2 weighted images) is below.
Arachnoid cysts
Her imaging demonstrates multiple cystic areas with T2 characteristics of CSF. These areas are associated with adjacent bony remodeling. Overall, these look like multiple arachnoid cysts.
The best approach in most cases is observation over pursuing surgical intervention.
A 54M with history of generalized seizures. Initial evaluation demonstrated a reportedly 5cm frontal cystic mass. He was placed on antiepileptic medication and had infrequent seizures thereafter. Twenty-five years later, he began having progressive cognitive dysfunction consisting initially of forgetfulness, but then developing into frank disinhibition, compulsivity, and abulia.
First image from 2006, remaining are recent within last year
neuroglial cyst or a porencephalic cyst
sequential enlargement (presumably over many years) of a large right frontal cystic structure whose contents possess CSF-like characteristics. These features, along with the history dating back decades, suggest a congenital or longstanding cyst with subsequent expansion.
There was likely a subradiographic ventricular or subarachnoid communication which resulted in a ball-valve effect and gradual enlargement of the cyst over time.
