Curious Case of a Medullary Lesion following Pontine Cavernoma Resection

Perikal J Parichay; Kiran Khanapure; T J Aniruddha; J V Mahendra; Krishna C Joshi; Sunil V Furtado; A S Hegde

doi:10.46347/jmsh.2017.v03i02.007

Journal of Medical Sciences and Health

DOI: 10.46347/jmsh.2017.v03i02.007

Year: 2017, Volume: 3, Issue: 2, Pages: 27-28

Review Article

Curious Case of a Medullary Lesion following Pontine Cavernoma Resection

Perikal J Parichay¹, Kiran Khanapure², T J Aniruddha³, J V Mahendra⁴, Krishna C Joshi⁵, Sunil V Furtado³, A S Hegde²

¹Senior Resident, Department of Neurosurgery, Ramaiah Institute of Neurosciences, Ramaiah Medical College, Bengaluru, Karnataka, India,
²Professor, Department of Neurosurgery, Ramaiah Institute of Neurosciences, Ramaiah Medical College, Bengaluru, Karnataka, India,
³Associate Professor, Department of Neurosurgery, Ramaiah Institute of Neurosciences, Ramaiah Medical College, Bengaluru, Karnataka, India,
⁴Associate Professor, Department of Neurology, Ramaiah Institute of Neurosciences, Ramaiah Medical College, Bengaluru, Karnataka, India,
⁵Assistant Professor, Department of Neurology, Ramaiah Institute of Neurosciences, Ramaiah Medical College, Bengaluru, Karnataka, India

Address for correspondence:

Dr. Perikal J Parichay, Department of Neurosurgery, Ramaiah Institute of Neurosciences, Ramaiah Medical College, Bengaluru, Karnataka, India. Phone: +91-9886778242. E-mail: [email protected]

This work is licensed under a Creative Commons Attribution 4.0 International License.

Abstract

Question

A 36-year-old gentleman, presented with right hemiparesis and internuclear ophthalmoplegia, was operated for left pontine cavernoma [Figure 1]. He followed up in outpatient department with gradual onset of palatal myoclonus 13 months post-surgery post-surgery [Figure 2 and 3]. Patient was evaluated with magnetic resonance imaging (MRI) brain which showed the above findings. Can you the guess the sequelae of pontine surgery in this patient? For answer turn to next page.

Answer

Left sided hypertrophic olivary degeneration (HOD).

Explanation

The patient was evaluated with MRI brain which showed a hyperintensity in the left inferior olivary nucleus (ION). With a precedent history of brainstem surgery, a rare manifestation of pathology in the Guillain-Mollaret triangle causing HOD was ascertained. Figure 4 depicts the Guillain-Mollaret triangle and its connections.[1,2] With unilateral hypertrophy of ION, pathology is either in the red nucleus or the central tegmental tract (CTT). In this case, it is more likely the CTT on the left side is affected following the surgery Figure 4: Illustrative diagram of Guillain-Mollaret triangle of the left pontine lesion.[3] There is transsynaptic transneuronal degeneration of the left ION. This degeneration is unique as it causes hypertrophy of the ION rather than atrophy. Focal signal changes seen in the inferior medulla are not pathognomonic for HOD. Non-enhancement on contrast MRI differentiates it from other likely causes such as infarction, demyelinating disease, malignancy, infections, and inflammatory processes could also produce similar signal changes.[3,4] Symptomatic patients are difficult to treat and rarely resolve, but successful management of symptoms with benzodiazepines and carbamazepine has been reported.

References

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