2nd Aug 2021

ICRI CASE OF THE WEEK

Contributed By : Dr. Vardhan Joshi
Senior Consultant & HOD
Department of Radiology
Sahyadri Specialty hospitals, Pune

Copyright of the Case belongs to : Dr Vardhan Joshi

Clinical Details

• 10 year old girl
• Progressive paraparesis with bladder involvement

over a period of 3-4 days
• Gave history of ? blurring of vision about 1 month

back.
• No h/o prior vaccination or fever.
• MRI brain / orbits with MRI spine was performed.

Brain parenchyma was
normal.

T2 FAT SAT

POST CONTRAST T1 FAT SAT

What is the finding?

• There is mild abnormal signal within the right optic
nerve. It also shows abnormal contrast enhancement.

• The right ocular muscles show normal size and signal
pattern.

• No retro-ocular fat stranding.
• Left optic nerve and ocular muscles appear normal.

Above findings are suggestive of Right Optic Neuritis.

• MRI Spine was also performed.

T2
CORONAL

POST CONTRAST T1 FAT SAT

What is the finding?

• There is long segment cord abnormality with cord
swelling and T2 hyperintensity. It shows
heterogeneous abnormal contrast enhancement.

• The cord abnormality is more than 3 segments on
sagittal images.

• It is involving entire cross section of the cord on axial
images.

Considering the History and MRI findings
what is the most probable diagnosis?

A) Cord Astrocytoma
B) Multiple Sclerosis
C) Devic’s Syndrome
D) Acute Disseminated Encephalo-Myelitis

Discussion

A) Cord Astrocytoma – will not have such a short history.
Also, optic nerve involvement is difficult to explain.

B) Multiple Sclerosis – Optic nerve involvement is very
characteristic, but spinal cord involvement is too extensive
for MS. MS lesions are generally less than 2 cord segments
on sagittal sections, and focal eccentric on axial sections.

C) Devic’s Syndrome – most likely.

D) Acute Disseminated Encephalo-Myelitis – No history of prior
precipitating factor. Also, optic nerve involvement is not
likely to occur.

Devic’s Disease / Syndrome / NMO

(Neuromyelitis Optica)

• Severe form of acute demyelinating disease that
preferentially involves the spinal cord and optic nerves,
with relative sparing of cerebral white matter.

• Initially thought to be special form of MS. Now
considered to be separate entity.

• Characterised by antibodies to aquaporin-4 (AQP4),
which is the most abundant water channel in CNS,
located in foot processes of astrocytes surrounding
the blood-brain barrier.

• NMO-IgG – 90% specific and 70-75 % sensitive for
NMO (always negative in MS / SLE / Sjogren’s)

Overall spectrum of NMO

• Optic neuritis + Acute myelitis
+ Peri-ventricular ill defined lesions

REVISED NMO DIAGNOSTIC CRITERIA

• REQUIRED-

– Optic neuritis
– Acute myelitis

• PLUS 2 or MORE SUPPORTIVE CRITERIA

– Disease onset MR imaging non-diagnostic for MS
– Contiguous spinal cord lesions on MR > 3

segments
– NMO-IgG sero-positivity

• Absence of brain lesions should not deter us
from suspecting NMO

• NMO spectrum-

– Relapsing myelitis in absence of optic nerve or
brain involvement

– Relapsing optic neuritis in absence of cord or brain
involvement.