Spinal Epidural Lymphoma- Review Article

Primary spinal epidural lymphoma (PSEL) is a subset of lymphomas, where there are no other recognizable sites

of lymphomas at the time of diagnosis.  The incidence of this subset of lymphomas is much less. It, however, is increasingly diagnosed, due to the increased use of more sensitive imaging modalities. 

Review article is now published with me as one of the contributors: Cugati G, Singh M, Pande A, Ramamurthi R, Balasubramanyam M, Sethi SK, et al. Primary spinal epidural lymphomas. J Craniovert Jun Spine 2011;2:3-11. Full free text is available.

Acute Cerebellitis-is it infectious or post infectious?

12 yr old boy had febrile episode of 5 days before developing seizures, and ataxia with altered sensorium and shows  on MRI,  an ill defined possibly” C “shaped , subtly enhancing  fluid signal intensity on all pulse sequences , of predominantly white matter regions  of posterior fossa, with more of vasogenic  rather than cytotoxic oedema ,  mass effect on 4^th ventricle, leading to  proximal hydrocephalus  and no bleed- picture suggestive of post infectious BRPINDs (Benign  Regressive  Post   Infectious Neurological  Disorders)

Teaching points by Dr MGK Murthy.  Contributors- Mr Hamid and  Mr Gupta

1.      Infectious edema  can be diagnosed by (a) short duration ,(b) gray matter as site of involvement,(c) decreased mental status  and (d) abnormal CSF, with post infectious exhibiting  opposites of these characteristics

2.      “C” shape is apparently on account of myelinating axons separating the areas of edema

3.      Post infectious demyelinating oedema is possible

4.      BRPINDs  usually exhibit good prognosis with no residual  disabilities

5.      These can be of ADEM variety where brain and cord are involved, or neuromyelitis optica where only optic nerves and cord are involved or only cerebellar variety (as in this case)

6.      MRI  is usually diagnostic  with CSF playing complementary role

7.      BRPINDs could be caused by bacterial/viral/vaccination (MMR)/drugs(arsenic, gold and sulfas etc)/Miscellaneous(herbal extracts etc)

Opercular Syndrome-MRI

10 year old male child comes with history of seizures with no significant birth history. MRI shows bilateral symmetrical FLAIR hyperintensities which are heterogeneous involving opercular regions with no restriced diffusion or blooming on SWI suggesting bilateral opercular syndrome.

Teaching points by Dr MGK Murthy :

Also called facio-labio-pharyngo-glosso-laryngeal and brachial paralysis or cortical variety of pseudo-bulbar-palsy or Foix – Chavany – Marie syndrome.

Five clinical types:
(a) the classical and most common form associated with cerebrovascular disease.
(b) a subacute form caused by CNS infections.
(c) a developmental form most often related to neuronal migration disorders.
(d) a reversible form in children with epilepsy.
(e) a rare type associated with neurodegenerative disorders.

Can be congenital or acquired, intermitant or persistent.

Characterised by a loss of voluntary control of facial, lingual, pharyngeal and masticatory muscles in the presence of preserved reflexive and automatic functions of the same muscles.

Dengue Hemorrhagic Fever-MRI

32 yr adult with clinical and serology positive Dengue fever with acute encephalopathy with low platelet  counts   shows on CEMRI, multiple hemorrhagic   focal lesions in supra and infratentorial locations with relative sparing of basal ganglia and brainstem and varying degrees of  restriction and enhancement ,   possibly explained by different ages of bleed and  therefore varying  degrees  of breakdown of blood brain barrier

Questions in the case

1. Thalami spared?---   variations are reported

2. Enhancement is varied  in different lesions? possibly  related to  different ages of  bleed

3. Meninges normal--  Imaging  is not good  enough for meningitis

4. Cord is normal?--- encephalomyelitis is only  known to occur in some

5. Is comorbidity possible with some other infections?—certainly possible, but since serology and CSF are negative, less likely

Teaching points  for Radiologist  by Dr MGK Murthy. Images by Mr Hariom and Mr Venkat.

·         Dengue fever occurs in about 100 countries ,and is caused by RNA virus of Flavivirdae family

·          Non-neurotropic nature of the virus is now questioned with some  growing from CSF

·         Neurology involvement can be encephalitis (direct virus effects) or more common encephalopathy (usually metabolic, hypotension or haemorrhage  related findings)

·         CSF serology an virus culture are considered as gold standard

·         MRI plays crucial role in altered sensorium patients to  exclude  other causes  as well  show focal lesions apart from  severity and nature

·         Viral encephalitides have predilection for certain sites as below :

HSV: Frontal, Temporal lobes

Japanese Encephalaitis: Thalamus, basal ganglia, cerebellum, brainstem

West Nile fever: Deep grey matter, mesial temporal lobe, cerebellum, brainstem. Difficult to differentiate from JE on imaging alone

Rabies: Hippocampi, basal ganglia, brainstem , temporal lobes.

Chikungunya: cingulated gyrus, Limbic system

Nipah: multiple white matter lesions.

Trigeminal Neuralgia-MRA

An adult with left trigeminal neuralgia on MRA shows a tortuous enlarged vascular loop of anterior inferior cerebellar artery pressing upon ipsilateral trigeminal nerve. This MRA was done by 3 Tesla MR scanner. Case submitted by Dr MGK Murthy, Mr Hariom, Mr Sahadev

 

Teaching Points :

• Trigeminal neuralgia (Tic Douloureux) is by definition intermitant shooting pain lasting from few seconds to less than 2 minutes, along the distribution of the trigeminal nerve.

• Commonest cause is an enlarged looping artery / vein pressing upon the nerve, others being multiple sclerosis / neoplasms / other space occupying lesions in  the vicinity.

• MRI along with MRA is considered as an ideal modality for delineation of the vessels.

• Anterior inferior cerebellar artery, a branch of the same, vertebral artery, superior cerebellar arteries are usually responsible for this syndrome.

• Commonest area of the contact is root entry zone of preganglionic segment  of the trigeminal nerve.

• Slow flow / Thrombous could occasionally be demonstrated.

• Coronal projection shows AICA vessels leading to the nerve with superior  cerebellar vessel in the cranial aspect.

Cauda Equina Tumour-Differentials

29 yr old lady comes with gradually increasing pain and weakness of both lower limbs  including buttocks region. Routine MRI shows solitary, enhancing, well defined ,glomus shaped , nodule intramedullary region possibly  from filum  terminale internum with separation of nerve fibers of cauda at L3 level with no clumping of nerve roots or bony anomaly or disc disease  or conus  disease. Case by Dr MGK Murthy and Mr Hariom.

What is the diagnosis ?

It is of  intramedullary  neoplastic etiology and probably represents    ependymoma (commonest in this region, enhancement, and age group)

Differentials include extruded discs (not likely as no significant disc prolapse is identified otherwise and  the enhancement  ) spinal haemangioblastoma (no mural nodule), neurofibroma and schwannoma(not homogenous and intense in enhancement  as  well as no extension along the intervertebral foramina),Lipoma, dermoid and epidermoids (though relatively bright on T1, enhancement  goes against these),meningioma(though T2 low , enhancement is not typical and location is unusual), paraganglioma(intense enhancing nodule is the rule )and lastly the ever mimicker of neoplasm in our country tuberculoma (no other evidence of TB otherwise )

Teaching points:

-Spinal cord ends at lower border of L1 as conus in adults

-filum continues as strand of connective tissue for 15 cms appx with first 5-6 cms having central canal as well

-filum terminale internum continues as externum to coccyx after piercing the dura caudally

Intramedullary Metastases-MRI

An elderly person with known small cell cancer of lung comes with neurological deficits and has demonstrated solitary ,expansile,  intramedullary SOL consistent with intramedullary  metastases . In addition brain metastases are appreciated. Case by Dr MGK Murthy and Mr A.Hamid

Teaching points

4 possible routes are suggested for occurrence

(a)  Arterial haematogenous-supported by the fact that 61% of all intramedullary metastases patients have multiple sites of cerebral and spinal lesions

(b)  Venous route from pelvis by vertebral batson’s venous plexus is suggested

(c)     Leptomeningeal dissemination by CSF

(d)   Direct contiguous spread from the neighboring organs by penetrating the normally protective dura

CEMR is the gold standard with typical lesion described as small, oval, small, with little or no spinal cord defect , with heterogeneous nodular enhancement and pencil thin,  non enhancing , edema more in the cranial aspect. 

Striatocapsular haemorrhage-MRI

13 yr old with movement disorders with history of hypoxia. MR shows bilateral, symmetrical linear altered  signal intensity with no restricted diffusion or blooming on susceptibility images. Possibly represents striatal haemorrhage sequelae in the external capsular area between lateral putamen and insular cortex. By Dr MGK Murthy, Mr Hamid and Dr Mukarab.

Teaching points

Striatocapsular haemorrhage is classfied by chung etal

type1-Anterior                                  in the region of artery of heubner

type2-Middle-                                   in the  region of medial lenticulostriatal  artery

type3-Posteromedial-                       in the region of Postero medial branches of  lateral lenticulostriatal artery

type4-Posterolateral-                        in the region of postero lateralbranches of lateral lentiuclostriate artery

type5-lateral-                                   Most lateral branches of lateral lenticulostriatal artery

type6-Massive 

Leber's Optic Atrophy-DTI

18 yr old student has developed sudden visual loss in one eye with history of maternal uncles having been blind in youth. Clinical exam and eye evaluation suggested hereditary optic atrophy . MRI showed symmetrical thinning of the optic nerves in introorbital regions consistent with lebers variety of hereditary optic atrophy. Case by Dr MGK Murthy and Mr Hari Om.

Teaching points

• It is mitochondrial neurodegenerative disease acquired through the mutated genes. Females pass it on and affected males do not
• It is bilateral with simultaneous(25%) or sequential (75%)involvement of both eyes
• Starts in young age with males(24 years mean) affected earlier than females(31years)
• Sometimes coexists with Multiple sclerosis when it is called Hardings syndrome
• LHON plus is referred to the Lebers Atophy with other diseases like movement disorders and cardiac arrhythmias
• Pathology is limited to retinal ganglion cell layer with reduced glutamate transportation

Optic nerve has various components and MRI can delineate them all

1. Intraocular component 1mm
2. Intraorbital 25 mm
3. Intracanalicular 5mm
4.  Intracranial 10 mm

Visual pathway
Optic nerves- optic chiasma- optic tracts- lateral geniculate bodies in the pulvinar –superior colliculi of brainstem-visual cortex of occipital lobes . This could be effectively depicted on Diffusion Tractography

Post Spinal Anesthesia Intramedullary Injury

A young lady  2months after undergoing Caesarean section  complaints of both lower limbs weakness with non-specific distribution . In he history, during the  epidural anesthesia for caesarean, she experienced severe shooting pain in to the Right lower limb, which resolved with medication. MRI shows longitudinal  ill defined  cord signal abnormality possibly hydrosyrinx from D11 to conus with no bleed, expansion or arachnoiditis  or epidural collections. Submitted by Dr MGK Murthy and Mr Hari Om.

Epidural anaesthesia  is one of the safest procedures, but occasional complications are known. This case represents possibly

(i) inadvertent injection of local anesthetic  in to low lying   variant radiculomeduallry artery  branch, feeding the anterior spinal artery , leading to vascular injury

The other possibilities include

(ii) direct intradural administration of LA leading to chemical injury

(iii) direct long needle injury to the cord in high injection

(iv)hypotension injury to the cord during the procedure

(v) post infective sequelae (myelomalacia)

(vi)unusual epidural venous plexus injection leading to venous hypertension and infarction

(vii) unrelated to the procedure and incidental finding due to other  causes including trauma, Chiari malformation etc

Tuberous Sclerosis with SGCA

14 yr old male child has seizures and mental retardation. MRI shows non enhancing cortical  hyperintensities on T2 and FLAIR.  In addition, a large intensely and heterogenously enhancing intraventricular, foramen of Monroe Space occupying lesion with obstructive hydrocephalus  with calcification. Features possibly  represent  cortical tubers with subependymal giant cell astrocytoma. Case submitted by-Dr MGK Murthy.

Tuberous sclerosis for the Radiologist

Synonym:  Bournveilles disease. Genetic disease – mutation of TSC1and TSC2, which encode for proteins hamartin and Tuberin (act as tumour growth suppressive factors )

Dignostic  criteria=   11 Major criteria and 9 minor criteria

Brain lesions

Tubers- triangular in shape with apex towards ventricles  and look hyperintense on T2. It may subside with age , but histopathology will still reveal it. Represents neuronal migration disorder. Other MR findings –Radial white matter tracts hyperintense on  T2. Heterotopic grey matter-Subependymal  nodules—abnormal  swollen glial cells and bizarre multinucleated cells . These could turn in to subependymal giant cell astrocytoma (SGCA). Ventricular enlargement

Peritrigonal T2 White Matter Hyperintensity

Myelination is a dynamic process that occurs during fetal life and goes on after birth in a well-defined, predetermined manner. On T1-weighted images, the pattern of myelination reaches the adult aspect at 1 year of age; on T2-weighted images, at about 2 years of age.  On MR images, the last associative area to mature is considered to be the peritrigonal zone—a triangular region posterior and superior to the trigones of the lateral ventricles characterized by a persistent high signal intensity on T2-weighted images . Our MRI image of 5 year old child shows peritrigonal linear areas of hyperintensity that can be referred to perivascular spaces. According to Paper entitled "Terminal Zones of Myelination: MR Evaluation of Children Aged 20–40 Months" -- American Journal of Neuroradiology 23:1669-1673, November-December 2002, the so-called terminal zones are most likely subcortical areas rather than the peritrigonal area.

Chronic Tubercular Arachnoidtis of Foramen Magnum- Rare Case Report

Syringomyelia is often linked to pathological lesions of the foramen magnum. Note in this case who was on treatment for TBM and suddenly developed cervical cord symptoms. Spinomedullary junction shows altered contour, with posteriorly displaced spinal cord. Cisterna magna is obliterated and prominent anterior CSF space. Thick leptomeningeal enhancement is seen in the prepontine and retrocerebellar cisterns. Note is also made of syringobulbia & syringomyelia.  Diagnosis of chronic arachnoiditis at foramen magnum was made. There is some tonsillar descent as well, which may indicate co-existent chiari malformation.  Further reading-- Syringomyelia due to chronic arachnoiditis at the foramen magnum.  Journal of the Neurological Sciences. Volume 8, Issue 3, May-June 1969, Pages 451-464 

Anterior Arch of Atlas Fissure-CT

This 8 yr old child had minor injury and then was unable to rotate his neck. Anterior arch of the atlas appears congenitally split and shows 5mm gap in the anterior arch possibly indicating fissure in the anterior arch. Although, altantodental distance is maitained, there is some altered articulation in the atltanto-axial articulation.  Torticollis has been reported after minor trauma in patients with split atlas.  Reference- Torticollis of a Specific C1 Dislocation With Split Atlas. Spine: 15 June 2010 - Volume 35 - Issue 14 - pp E672-E675.

Hot Cross Bun Appearance-MRI

The hot cross bun sign is seen on transverse T2-weighted magnetic resonance images of the brain as a cruciform hyperintensity in the pons This appearance is seen in patients with MSA-c. The sign is due to a selective loss of myelinated transverse pontocerebellar fibers and neurons in the pontine raphe with preservation of the pontine tegmentum and corticospinal tracts.  Note in our case of 47 year old female, cruciform hyperintensity in pons, cerebellar atrophy and high signal in the middle cerebellar peduncles, possibly MSA-c.

Early Cavernous Sinus Thrombosis-Gd MRI

The cavernous sinuses receive venous blood from the facial veins (via the superior and inferior ophthalmic veins) as well as the sphenoid and middle cerebral veins. They, in turn, empty into the inferior petrosal sinuses, then into the internal jugular veins and the sigmoid sinuses via the superior petrosal sinuses. This complex web of veins contains no valves; blood can flow in any direction depending on the prevailing pressure gradients. This is diabetic female with clinical history of multiple cranial nerve palsies. Case submitted by Dr MGK Murthy.

Teaching points

• Multiple cranial nerve palsies in diabetic lady should always suggest infection base of the skull and venous thrombosis unless other wise proved
• Superior opthalmic vein is sensitive indicator of things hapening in cavernous sinus 
• Base of the  skull in this case shows diffuse enhancing oedema -producing literally sheet of gadolinium possibly encasing all the foramina at base including foramen ovale
•  Widened cavernous sinus with some asymetry is suggestive of stasis and thrombus along with asymmetry of flow void of ICA within
• No proptosis is no guarantee against venous thrombosis 
• Sphenoid sinus is is notorious for producing base of the skull and meningeal inflammation
• All muslces and soft tissues including temporalis are inflammed