Thursday 28 November 2013

Calcification of trochlear apparatus of orbit

A 50 yo female with left side weakness advised Non contrast CT for Brain to rule out any intra cranial bleed or infarction.


Finding:

No bleed or infarct on CT study of Brain.

A dense nodular calcification noted in the superior-nasal quadrant of the right orbit. Clinically right eye vision and movement normal.  No history of trauma to right eye.

Final diagnosis:

Unilateral calcification of trochlear apparatus of right orbit_ noted an incidental finding.

Calcification of trochlear apparatus of Obit.

Syn: Calcified Trochlea of the Superior Oblique Muscle.

The trochlear apparatus of the eye is a cartilaginous structure with a synovium lined sheath that permits unimpeded movement of the superior oblique muscle.

It is not clear yet the accurate location of calcification whether its cartilage, the synovial sheath, or the tendon.

Hart et al. in his study reported an association between calcification of the trochlear apparatus and DM, reviewed some 159 CT scans of patients and observed trochlear calcifications in 12% of patients with a significant correlation between diabetic patients under 40 years of age and the presence of calcification in the trochlear apparatus. The trochlear calcification on CT is a benign condition may serve as a marker for diabetes in young patients. Trochlear calcifications are observed frequently in persons more than 50 years old. When it is present in patients younger than 40 years, it is strongly associated with diabetes.
Another thing which is observed in these studies is trochlear calcifications were more prevalent in male patients and none of the patients in these studies had symptoms related to their trochlear calcification.

Studies conducted later, results were In contrast to the findings of Hart et al, did not find a significant correlation between patients under 40 years of age with DM and the presence of trochlear apparatus calcifications. Even there was no increase in trochlear calcifications with advancing age or the presence of systemic disease indicating that trochlear calcifications is not suggestive of a degenerative process and occur regardless of chronic medical disease.

Left parietal cyst MRI

MRI findings:

A left temporo parietal cystic lesion.
Lesion is multi locular, its difficult to mention whether the lesion is intra axial or extra axial as it is insinuating in brain parenchyma.
Content of cyst is clear fluid, iso intense to Csf.
No restricted diffusion on Dw images.
Lesion has thin imperceptible wall.
No solid component.
No peri lesional odema.
Significant mass effect_ mid line shift with sub falcine as well as uncal herniation. Mid brain compression.

Imaging wise possible DDs : Arachnoid cyst >  Neuroglial Cyst.

Pt operated, left parietal craniotomy with complete excision of lesion.

Histopathology Report

Specimen : Excisional biospy.
Gross appearance : The specimen consist of soft wrinkled pieces of dull grey white tissue _ cyst wall.
Microscopy : Sections shows a benign cystic lesion comprising delicate membranous fibrous connective tissue cyst wall lined by meningothelial cells, at places seen to form focal aggregates. There is no evidence of cytological atypia.

Final Diagnosis : Arachnoid cyst. 

Sunday 10 November 2013

Congenital Bilateral Perisylvian Syndrome MRI

This MRI brain axial T2w image shows bilateral deep wide vertically running clefts in the region of Sylvian fissures lined by thick gyri.

Imaging diagnosis : Congenital Bilateral Perisylvian Syndrome.

Syn :
Opercular syndrome,
Foix-Chavany-Marie syndrome,
Worster-Drought syndrome,
Bilateral symmetrical polymicrogyria

The term “perisylvian” refers to the area (“peri” = about or around) of the sylvian fissure (lateral sulcus), which acts as the brain’s language and speech center. It is basically an organization anomaly in which the neurons reach their final destination in the cortex but are distributed abnormally.

The syndrome is one of a group of congenital neurological diseases characterized by slack muscles of the face and tongue, chewing and swallowing difficulties, delayed or abnormal speech and language development, epilepsy, and in certain cases, impairment of cognitive function and impaired mobility. Similar disorders were described first by the French neurologists Charles Foix, Jan Alfred Chavany and Julien Marie in 1926, and later by the English physician Cecil Charles Worster-Drought in 1956.

Causes:
Genetic factors are very important, and there are families in which more than one person has the syndrome, although the symptoms may vary from person to person. Linked with a mutation on the long arm of the X chromosome (Xq27.2-q27.3 and Xq28). Disorders caused by mutations in genes on the X chromosome primarily affect boys.
Acquired, the Perisylvian syndrome may also be acquired, for example from a local malfunction in the blood circulation of the brain, or an infection in the relevant area of the temporal lobe during the foetal stage like congenital cytomegalovirus infection. In these cases the condition is not hereditary.

Clinical presentation:
The most common symptoms are impairments of the mobility of the tongue and throat (pseudobulbar palsy), epilepsy and mild cognitive impairment.
In serious forms of the disease, neonates may have problems sucking and swallowing.
May not become apparent till the child starts eating solids. It can be difficult to chew, move food around in the mouth, and swallow. Drooling is common.
Child is slow to start talking or has speech difficulties. The most common symptoms are paralysis or impaired motor capacity of the organs necessary for speech (dysarthria) and difficulties coordinating movements (dyspraxia) of the mouth.
Unclear and slurred speech, as well as problems forming certain sounds, are signs of dysarthia whith as associated drooling and swallowing difficulties. Problems in moving the tongue and the mouth mean that children with the syndrome cannot purse their lips or whistle. Oral motor problems, which commonly cause difficulties eating, drinking and speaking, remain throughout life.
Oral motor problems may affect the growth of the lower jaw, which may be smaller than normal (micrognathia). Misalignment of the teeth (malocclusion) may mean that it is difficult to close the mouth completely and that the lower jaw protrudes.
Dyspraxia may be oral or verbal. Oral dyspraxia means that it is difficult to exert voluntary control over movements of the tongue and lips. Verbal dyspraxia means that it is difficult to form words, despite the relevant organs having normal functionality. The symptoms are the result of abnormalities in areas of the brain controlling the motor skills necessary for speech. In verbal dyspraxia it is difficult to make a connection between sounds and syllables, which is necessary to form words. The degree of severity varies. Less severe disabilities give rise to problems with multi-syllable and longer sentences, which become more difficult to formulate the longer they get. Severe dyspraxia may mean that the child cannot form syllables or words.
Other language and communication problems may also occur, including difficulties with grammar and phonology (speech sounds). Children with the syndrome may have specific reading and writing problems (dyslexia). Speech comprehension, however, does not appear to be affected.
Most individuals with this syndrome have epilepsy. Seizures may present as infantile spasms during the child’s first two years of life and develop into other, difficult to treat, forms of epilepsy as the child gets older. In infantile spasms the child experiences a series of short, sudden, cramp-like jerks of the arms, or wider, uncontrolled movements of the arms.
Physical disability characterized by stiffness in the arms, legs and neck. Stiff, malformed joints make it difficult to walk, and to move in general. Require special aids or a wheelchair.
Mild cognitive impairment and hyperactivity may also present. Individuals with intellectual disability require more time to understand and learn new skills.

Diagnosis: 
The diagnosis is based on observation of the symptoms, as well as finding structural abnormalities on CT and MRI.

Treatment and Rehabilitation: 
There is no cure for Perisylvian syndrome.
Training in oral motor skills and swallowing at an early stage.
Exercises to the muscles of the tongue.
Training in closing the mouth will help prevent deformities of the lower jaw.
Child may need to be fed with the help of a PEG (percutaneous endoscopic gastrostomy), a procedure where a feeding tube is inserted into the stomach directly through the abdominal wall.
Their epilepsy is often difficult to control as the nature of the attacks varies greatly. Medication is prescribed on the basis of type of seizure, EEG results and the effects of the medication.
Surgery may sometimes be used to control epileptic attacks. A vagus nerve stimulator can be an alternative if other measures fail. The vagus nerve is one of the twelve cranial nerves originating in the brain. In an operation the stimulator is placed under the left collar bone and it sends electric impulses to the brain with the help of an electrode placed around the vagus nerve in the neck. These impulses can reduce epileptic activity and attacks.
Speech therapist to assesses and treats chewing and swallowing problems, drooling and communication difficulties.
Treatment usually requires mutli-disciplinary teamwork. The major hospitals in Sweden have specialist teams (dysphagia and nutrition teams) for assessing and treating speech, eating and swallowing difficulties.
Dental treatment for chewing and oral hygiene in the form of dental braces.

Spinal Drop Metastasis from Choroid Plexus Papilloma MRI

A 16 y o female patient, known case of posterior fossa mass _ Operated 2 years back.
Here are few snaps of Pre operative MRI Brain images showing lesion at the floor of posterior cranial fossa with caudal protrusion through foramen magnum.
Previous histo pathology report noted mentioning it to be Choroid Plexus Papilloma.

Now patient presented with backache and bilateral lower limb weakness, MRI Brain with spine screening done with contrast.
The Post Opeative MRI Brain shows:
E/o mid line sub occipital craniotomy, complete excision of lesion.
No obvious recurrent or residual lesion on post contrast T1.
Complete regression of hydrocephalus.

The Post Operative MRI Spine shows spinal drop metastasis.


Description of findings:

MRI Sagittal T2w images shows an intra medullary lesions in cervical cord, mild expansion of cord, non enhancing on post contrast fat sat T1.
Similar lesions on surface of spinal cord through out its length and completely filling thecal sac in lumbar region, an abnormal enhancement along surface of cord and nerve roots of cauda equina on post contrast fat sat T1 consistent with Spinal Drop Metastasis from Posterior fossa Choroid Plexus Papilloma.

Discussion: 

Choroid plexus papillomas (CPPs) are typically considered as benign tumors, with a favorable long-term prognosis. The standard treatment for a CPP is complete surgical resection and is thought to be curative.
Drop metastasis of CPP into the spinal subarachnoid space is rare.
In our case 16 year-old female who presented with back pain and lower limb weakness 2  years after removal of a posterior fossa CPP due to its spinal drop metastasis.
CPP can spread via cerebrospinal fluid pathways and cause spinal drop metastasis. Therefore, it is necessary to evaluate the whole spine in addition to brain, pre operatively as well as with post operative periodic follow-up MRIs in patients with CPP.

Monday 4 November 2013

Choroid Plexus Papilloma MRI

A 1 y o male with headache, signs of raised ICT. 
On Admission CT followed by MRI Brain with Contrast.

This CT and MRI study of Brain shows an intra ventricular ovoid solid frond like well defined lesion in right lateral ventricle.
Lesion is isodense on CT with faint specks of calcifications.
Restricted diffusion on Dw MRI Images.
Avid homogeneous enhancement on post contrast T1w MRI.
No adjacent parenchymal invasion.

Imaging diagnosis given was Choroid Plexus Papilloma, moderate communicating hydrocephalus due to over production of Csf.

HISTOPATHOLOGY REPORT

Specimen : Excisional biopsy, right lateral ventricle mass.

Gross appearance : Multiple irregular soft to friable soft pieces of dull gray tan tissue, together measuring ~ 44x4x29mm. The cut section thru the larger piece appears papillary.

Microscopy : Benign neoplasm of probable choroid plexus epithelia comprising predominantly complex and branching neoplastic papillae lined by single layer of low cuboidal epithelia - devoid of significant cellular pleomorphism nor increased mitosis. In few foci the epithelia show focal stratification and crowding. The sub epithelial cord substance of the papillae appears focally odematous with congested blood vessels and sparse lymphocytic infiltrates. There is no evidence of cytological anaplasia.

Histopathological diagnosis : Choroid Plexus Papilloma.


Choroid Plexus Papilloma (CPP)

Imaging findings:
Location wise most common i.e ~ 50% in  atrium of lateral ventricle, left> right, ~ 40%  fourth ventricle.
~ 10%  third ventricle (roof) and ~ 5%  multiple sites.
• Morphology: Well delineated, lobulated intra ventricular cauliflower like mass, frond like surface projection.
Benign, slowly growing tumor often larger at the time of presentation.
Solid density on CT and signal intensity on MRI.
Foci of calcification best seen on CT.
Intense homogenous enhancement on post contrast T1.
CSF seeding of lesions is known.

Clinical Presentation: 
Age: Lateral ventricular CPPs common in infants and children where as fourth ventricular CPPs common in adults.
Most common signs/symptoms are of raised ICT, Macrocrania, bulging fontanelle, vomiting, headache, ataxia.

DD: 
Imaging wise difficult to differentiate from Choroid plexus carcinoma (CPCA)
Heterogeneous enhancement, invasion of adjacent brain parenchyma goes in favor of CPCA.

Reference : DI Osborn.

Saturday 2 November 2013

CV Junction Meningioma MRI

A 40 y o female with progressive lower limb weakness. 
On admission MRI Brain and Cervical spine screening done.
This MRI sagittal T2w images and Post contrast fat sat T1w images shows an extra axial solid signal intensity lesion, iso intense on T2w images at foramen magnum causing foramen magnum stenosis and significant cord compression. Intense homogeneous enhancement of lesion on post contrast with dural tailing.

Imaging diagnosis : CV Junction / Foramen Magnum Meningioma.