Facial Myokymia Due to a Pontine Inflammatory Demyelinating Disorder Associated with Mixed Connective Tissue Disorder [MCTD]

A 49-year-old lady, presented with unsteadiness in walking, dysphagia, and proximal weakness of upper and lower limbs of 3 months duration. She was referred to us with abnormal facial movements of 2 months duration. In 2012 she was diagnosed with mixed connective tissue disorder after developing polyarthralgia. She was currently on hydroxychloroquine 200 mg BD. On examination, she had tight skin over her face and neck, dysarthria, proximal weakness of limbs, and ataxic gait. Bifacial myokimia was observed. CT brain showed hypodensity of the middle cerebellar peduncles and cerebellar white matter, along with a hypodensity in central pons. MRI brain showed bilateral symmetric confluent T2 and FLAIR hyperintensity along both middle cerebellar peducles [MCPs] and central pons with patchy contrast enhancement [Video 1 and Figure 1]. Routine CSF analysis, malignant cytology, oligoclonal bands, and CSF JC/BK virus were negative. The initial differential diagnosis included an inflammatory demyelinating disorder (IDD), multiple sclerosis, pontine glioma, progressive multifocal leukoencephalopathy, multiple system atrophy, paraneoplastic encephalitis, and central pontine myelinolysis. She was treated with 5 days of IV methylprednisolone. 3 months later on follow-up her facial myokymia had disappeared and MRI showed mild pontocerebellar atrophy. Facial myokymia is classically associated with a pontine glioma, multiple sclerosis, and other intrinsic brainstem pathologies. Our final diagnosis was an IDD associated with MCTD.

Figure 1.

Axial FLAIR MRI images; Panel A and B; The left MCP is larger than the right. Central pontine hyperintensity is seen to involve the transverse pontine fibres without any pontine enlargement. Panel C; There is feathery edge contrast enhancement along the MCP signal abnormalities and patchy enhancement within the deep cerebellar white matter bilaterally. Panel D and E; Repeat axial FLAIR MRI after 3 months; shows a dimnuition of in hyperintensities in the pons, cerebellum and MCP with mild atrophy of the pons and MCP

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