Effects of Tafamidis Meglumine on Transient Focal Neurological Episodes and Meningeal Contrast Enhancement in Hereditary Transthyretin-Related Meningeal Amyloidosis: Report of Two Patients Carrying the c.265T>C (p.Y89H) Variant.

BACKGROUND

Y69H (p.Y89H) variant hereditary transthyretin (ATTRv) amyloidosis causes meningeal amyloidosis, with mutant TTR deposits localized to the leptomeninges and vitreous body.

METHODS

The effect of tafamidis meglumine on neurological disorders, such as the frequency of transient focal neurological episodes (TFNEs), magnetic resonance imaging (MRI) findings, and TTR levels in cerebrospinal fluid, was investigated in two patients diagnosed with Y69H ATTRv mutation.

RESULTS

The initial symptoms in both patients were TFNEs, such as aphasia, sensory disturbance, motor paralysis, ataxia, and drop attacks. Neither epileptic drugs nor antiplatelet therapy decreased the frequency of attacks. The patients exhibited diffuse leptomeningeal enhancement on brain and spinal MRI. Tafamidis meglumine was initiated at a dose of 20 mg/day and was found to be partially effective. The TFNEs nearly resolved, and meningeal enhancement on brain MRI improved; however, the neurological deficits progressed over the following 2 years.

CONCLUSIONS

Tafamidis had a partial effect on TFNEs and meningeal contrast enhancement on MRI; however, cerebellar ataxia and cognitive decline continued to progress.