Rare neurological case raises alerts for clinicians

When a man in his late fifties was referred to neurologist Professor Owen White in August 2016 with double vision, facial weakness and an unsteady gait, it appeared he had suffered something akin to a stroke. The reality was even more sinister. A concerted effort by medical teams to pinpoint the mysterious condition as the man’s health progressively failed eventually led to the diagnosis of an exceptionally rare disease – and some lessons for those involved and clinicians beyond. A paper documenting this unusual case appeared recently in the Journal of Clinical Neuroscience.

However, the man didn’t follow the normal history of stroke. Multiple investigations failed to find an answer to fluctuating, persistent and evolving symptoms.

“Clinically he looked like patients with myasthenia gravis, an immune condition where an antibody is created which blocks conduction from the nerve to muscle. He had changed cranial nerve signs which is always unusual except in myasthenia gravis,” Professor White said.

Muscles in parts of the patient’s face were fatigued; he was unable to maintain a gaze in one direction and his eyelids drooped. These muscles progressively weakened over a minute or so.

The man responded well to steroids and intravenous immunoglobulin – classic treatments for myasthenia gravis – and Professor While felt confident this diagnosis was correct.

In the following months however, the man relapsed a number of times and was admitted to two further hospitals, often with weakness around the face, difficulty in swallowing and severe headaches. Each time he responded well to more immune therapy.

But the aggressive immunotherapy failed to halt his deterioration and the weakness he experienced became more generalised.

Professor White was still concerned by the lesion in the pons (back part of the brain) which had remained the same. He pushed the teams of neurosurgeons from three different hospitals for a biopsy; they refused saying that the location of the tumour made this too dangerous.

The man’s health progressively deteriorated throughout 2017 as he rapidly lost weight and wasted physically. An abnormal MRI scan suggested changes consistent with demyelination – damage to the protective covering (myelin sheath) surrounding nerve fibres. This was consistent with multiple sclerosis (MS) in the cerebral hemisphere.

The man and his family became increasingly distressed as it became apparent that there was nothing the medical teams could do to help him recover. Eventually he became too weak to swallow or eat. He passed away in July 2017 suffering pancreatitis, exhaustion due to lack of nourishment and respiratory failure.

A post-mortem, agreed to by the family, revealed that a glioneuronal tumour in the pons had infiltrated very subtly throughout much of his brain. The small white spots that had looked like MS were in fact the extension of the original tumour.

“This is an unusual case of an infiltrative brainstem lesion,” Professor White said.

The rare tumour, usually reported in children, has only been documented in 26 such cases in scientific literature, he said. The only successful treatments had occurred in young children when the child was diagnosed very early, biopsied and treated radically with excision of the original tumour followed by chemotherapy.

The fact that the symptoms could be confused with those of many other diseases made diagnosis difficult and suggested the tumours hadn’t been reported as often as they occur.

“There was probably not much we could have done for the man but we would have prepared him and his family better – and that’s an important part of what we do. It’s not just about finding a cure, it’s managing the patient and the patient and family’s expectations over a period of time,” Professor White said.

“We published the paper to point out firstly that there’s an unusual tumour that we’re not looking for that we probably should be,” he said. “And also to generally review the reluctance of medical teams to biopsy in the presence of an appropriate lesion and no diagnosis. The saying 'tissue is the issue' remains as relevant today as it was 50 years ago.”

First author on the paper was Dr Emma Foster from the Monash University Department of Neuroscience, a registrar at the time who had much contact with the patient; Professor Catriona McLean, Head of the Department of Anatomical Pathology at the Alfred Hospital conducted the autopsy. Professor White works in The Alfred’s Department of Neurology and with the Monash University Department of Neuroscience.

Foster E, McLean C, White O. Glioneuronal brainstem tumor - It's all in the eyes. J Clin Neurosci. 2019 Feb;60:151-153. doi: 10.1016/j.jocn.2018.10.084. Epub 2018 Oct 23.