A Young Woman With Acute Onset of Clumsiness and Ophthalmoplegia

A 23-year-old woman came with a 2-day history of increased clumsiness and blurred vision; she had flu-like symptoms with diarrhea 2 weeks prior to her presentation. Past medical history and social history were unremarkable.

During examination, she was alert and had normal mentation. She had limitation of gaze in all directions with relative preservation of the right lateral rectus function ( Fig. 41-1 ) and had bilateral ptosis with normal pupils, and mild bilateral facial weakness. She developed complete ophthalmoplegia after 2 days.

The patient had very mild proximal leg and foot dorsiflexor weakness but severe limb and truncal ataxia and difficulty walking. She was areflexic and had mildly decreased vibratory and position senses in the toes; pain and temperature sensations were normal. There were no Babinski signs, and the rest of the examination was normal.

What is the Most Likely Diagnosis?

This young woman had an acute onset of ataxia and ophthalmoplegia and was areflexic but had normal mental function. Ophthalmoplegia and ptosis could suggest myasthenia gravis; however, in myasthenia, reflexes are present and patients are not ataxic. When in doubt, an edrophonium test could be important to rule out myasthenia. Another neuromuscular transmission defect that needs to be considered in these patients is botulism, which presents with ophthalmoplegia and areflexia, but such patients are usually severely weak, are not ataxic, and have dilated pupils. Ataxia and ophthalmoplegia occur in mitochondrial disease, but these are chronic conditions. The lack of long tract signs and normal mental status makes a brainstem disorder unlikely. Ataxia, ophthalmoplegia, and areflexia suggest the Miller Fisher syndrome (MFS), a variant of Guillain–Barré syndrome (GBS). Brainstem encephalitis has a similar presentation, and some believe that MFS is caused by an inflammation of the brainstem. Wernicke’s encephalopathy presents acutely in alcoholics with ataxia, areflexia, and ophthalmoplegia, but these patients have altered mental status. Multiple sclerosis presents with ophthalmoplegia, although it is usually intermittent; patients can be ataxic but are not areflexic and usually have long tract signs. Rarely, patients with classic GBS might also develop ophthalmoplegia, but this patient had only very mild weakness.

What Tests Should Be Done?

Although there was no clinical evidence to suggest a disease of the brainstem, the pupils were spared, and there was no nystagmus, an MRI was done to rule out a central nervous system (CNS) disease in this patient. Her MRI was normal.