A case of Internuclear Ophthalmoparesis as the first manifestation of multiple sclerosis

Sanjai Kumar1, Ravikumar2

1Duty Medical Officer, Department of Emergency, Kauvery Hospital, Tennur, Trichy

2Consultant Neurologist, Kauvery Hospital, Tennur, Trichy

Objective

Internuclear Ophthalmoparesis (INO) is the second most common ocular finding in Multiple Sclerosis next to Optic Neuritis.

Background

Multiple Sclerosis (MS) is a relatively common acquired chronic demyelinating disease involving the central nervous system.

Characteristically multiple sclerosis is disseminated in space and in time. The presentation is usually between adolescence and the sixth decade, most commonly between 20 and 40, with strong, well-recognized female predilection and a F:M ratio of approximately 2:1.

Internuclear Ophthalmoparesis is characterized by a deficit in ipsilateral abduction with contralateral abducting nystagmus which mainly occurs due to lesion in the medial longitudinal fasciculus (MLF)

Case Presentation

A healthy 35-years-aged, medium built female presented to the emergency department with H/O fever for one day followed by double vision for one month which aggravated on left-sided gaze. The patient was on Omnacortil 10 mg for past 10 days. Patient was not known to have any systemic illness. There was no ocular trauma, head injury or chronic drug intake prior to the episode. There was no significant past history or family history.

Her menstrual history was regular and she had a normal labor at the age of 25.

On examination, patient was conscious and oriented and vitals were stable. Pupils were 3mm, reacting to both direct and consensual light reflex. Vision and Fundus Examination were within normal limits. Ocular movements were restricted with bilateral abduction nystagmus and restricted  adduction suggestive of bilateral Internuclear Opthalmoparesis.

Neurological examination revealed Right side facial lag more than left.

As a Demyelinating disease was suspected, magnetic resonance imaging (MRI) with whole spine screening was done and it showed T2/Flair hyperintensities involving the pons, left thalamus, right medial cerebellum, bilateral periventricular cortex and subcortical white matter of left temporo-parietal region suggestive of demyelinating disorder likely MS.

Internuclear-Ophthalmoparesis1

Lumbar puncture was done and CSF analysis showed elevated IgG index (1.16) and oligoclonal bands were seen. Total wbc counts were also elevated (19800). Other routine investigations were within normal limits. ECHO cardiogram showed Mild concentric LVH and Trivial mitral regurgitation.

Internuclear-Ophthalmoparesis2
Internuclear-Ophthalmoparesis3

Important Values

(1) CSF IgG Index: 1.16 (0.3-0.7) [1].

(2) CSF for Oligoclonal Bands

Type 3 Pattern: Oligoclonal bands were seen in both serum and CSF. Additional bands were seen in CSF, indicating intrathecal synthesis of IgG.

(3) Number of unique bands in CSF: 12 [2].

(More than 3 indicates intrathecal synthesis of IgG)

Treatment

Patient was given a dose of Immunomodulator ( Inj. REBIF 44 mcg) which is an Interferon beta-1a, and was advised for a weekly follow up dose (weekly once prescribed) and oral corticosteroids (Tab. OMNACORTIL-10) and multivitamins on discharge. Follow-up examination of the patient after 2 weeks showed improvement in terms of ocular movements and did not have symptoms of diplopia.

Discussion

Even though Optic Neuritis is the most common presentation of Multiple sclerosis, features of Internuclear opthalmoplegia (bilateral > unilateral) and nystagmus should also be considered on a strong basis.

The diagnostic Criteria for MS are based on a combination of clinical, imaging and laboratory evidence for disease in the central nervous system.

According to 2017 revised McDonald’s diagnostic criteria presence of more than or equal to 2 CSF specific oligoclonal IgG bands can be used in demonstrating DIT (Dissemination in Time) possibly leading to an early diagnosis. However Oligoclonal CSF testing is time consuming and prediction of CSF IgG index is much easier and less time consuming and if value of CSF IgG index > 0.7 then 99 per of the time it probably signifies the presence of OCB’s in CSF.

Differential Diagnosis of INO

  1. Multiple sclerosis ( especially if bilateral)
  2. Infarct
  3. Tumor of brainstem or fourth ventricle
  4. Infection
  5. Toxicity ( amitryptilline, benzodiazepines and ethanol)
  6. Chiari malformation
  7. Trauma

Conclusion

Multiple sclerosis can be a severely disabling disease. Hence starting Immunomodulator therapies ( Interferon Beta and Glatiramer acetate) with oral corticosteroids should be considered for the treatment in early stage of the disease mainly if they have a relapsing remitting course.

References

  1.  Burtis CA, Ashwood ER, Bruns DE, (eds): Tietz Textbook of Clinical Chemistry and Molecular Diagnosis (5th edition). Elsevier, St. Louis, USA, 2012, 2238 pp, 909.
  2. Hegen H, et al. The clinical significance of single or double bands in cerebrospinal fluid isoelectric focusing. A retrospective study and systematic review.PLoS One 2019;14(4):e0215410.
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Dr. V. Ravikumar

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